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: GS 3in DP


vinnnocc
27-01-11, 01:59 PM
i have a 1996 900se..i am looking to buy a 3in dp from gs..if i get it without a CAT will my car go into limp mode...i heard the t7 will do so but idk about the t5..dose any one here have a dp with no cat and still use the two o2 sensors?

lowbudgethero
27-01-11, 02:34 PM
you can but you will need your programmer to change your ecu to not use the rear sensor

mike saunders
27-01-11, 02:38 PM
i have a 1996 900se..i am looking to buy a 3in dp from gs..if i get it without a CAT will my car go into limp mode...i heard the t7 will do so but idk about the t5..dose any one here have a dp with no cat and still use the two o2 sensors?

Just get a Catco cat and have it welded on.

Messinian900S
27-01-11, 02:41 PM
you can but you will need your programmer to change your ecu to not use the rear sensor

I did this awhile ago with no cat and it still threw a code for it. Maybe T5 suite got updated for this issue since then, but I had to keep the sensor plugged in still just ziptied somewhere in the bay so that the code would stop coming up.

vinnnocc
27-01-11, 02:44 PM
thanx but the point of not getting the cat version is to not run a cat lol...is anyone running a dp without a cat?

Kei
27-01-11, 05:31 PM
I've got a 2.5" stainless decat on mine, but i only had one lambda sensor as standard. This is a UK car so i'm not certain that the same would apply to you.

I'll be replacing it in the summer anyway as the car is unlikely to pass the emissions tests without a catalyst. I only fitted it as it was a super cheap way to stage 3.

comtrang
27-01-11, 05:39 PM
I'm running a downpipe without a cat. There's not much to be done about turning off the CEL. Within T5suite, yes, you can turn off the second O2 sensor but it will eventually go bad from doing so. I have not done this to my car because I've probably got a check engine light for other things anyway so it doesn't bother me a whole lot.

2002BlackViggen
27-01-11, 09:38 PM
I'm running a downpipe without a cat. There's not much to be done about turning off the CEL. Within T5suite, yes, you can turn off the second O2 sensor but it will eventually go bad from doing so. I have not done this to my car because I've probably got a check engine light for other things anyway so it doesn't bother me a whole lot.


Can you elaborate, what goes bad once you turn off the rear sensor? My cousin has had a catless JT turbo-back (disabled rear O2 sensor) for a while and has no codes but we just can't seem to get her totally dialed in. It's a '97 SE, JZW stage 5 tune.

Jeremy R.
27-01-11, 09:58 PM
You can use a couple of spark plug non-foulers to raise the rear O2 sensor up out of the exhaust stream. I did that trick on my '97 900 when I ran it without a cat for around a year. It never once turned on the check engine light.

saabkid37
27-01-11, 10:31 PM
Can you elaborate, what goes bad once you turn off the rear sensor? My cousin has had a catless JT turbo-back (disabled rear O2 sensor) for a while and has no codes but we just can't seem to get her totally dialed in. It's a '97 SE, JZW stage 5 tune.

it has to do with the heater not turning on, the sensor just gets ruined.

vinnnocc
28-01-11, 05:08 PM
so looks like ill buy the no cat one and wait to see if i get any codes..if not ill keep it without a cat...but ill probly end up putting my own cat in

saabkid37
28-01-11, 05:31 PM
you have an obd2 car, you will get a code.

vinnnocc
28-01-11, 05:56 PM
you have an obd2 car, you will get a code.


im hopeing i wont get one..but if i do will my car run diff?

saabkid37
29-01-11, 12:02 PM
its not a hope. you WILL get one period. you will just have to deal with the cel.

Jeremy R.
29-01-11, 12:05 PM
its not a hope. you WILL get one period. you will just have to deal with the cel.
You won't get one if you use non-foulers.

vinnnocc
29-01-11, 02:03 PM
You won't get one if you use non-foulers.
i just looked up about the non fouler but dont realy seem to get it...do you have pics or a wright up??

hyprspec
29-01-11, 02:08 PM
i just looked up about the non fouler but dont realy seem to get it...do you have pics or a wright up??

It's very simple. It backs the head of the o2 sensor out of the direct path of the exhaust. It simply tricks the o2 into thinking the air is cleaner than it really is. And therefore it does not do its job of sending a "somethings wrong" signal to the ECU.

vinnnocc
29-01-11, 02:12 PM
It's very simple. It backs the head of the o2 sensor out of the direct path of the exhaust. It simply tricks the o2 into thinking the air is cleaner than it really is. And therefore it does not do its job of sending a "somethings wrong" signal to the ECU.


o i see thanx for the help..ill do that once i get my dp from GS

Trollhättan Bil
29-01-11, 02:40 PM
It's very simple. It backs the head of the o2 sensor out of the direct path of the exhaust. It simply tricks the o2 into thinking the air is cleaner than it really is. And therefore it does not do its job of sending a "somethings wrong" signal to the ECU.

That's great that you're able to trick the O2 sensor, but I'm wondering if the lack of feedback on the backside will cause mismanagement of the engines' functions, you know, since they depend on reliable input from the rear sensor to modulate fuel flow and air mixture, idle and timing -?-

fiveiron9688
29-01-11, 02:56 PM
That's great that you're able to trick the O2 sensor, but I'm wondering if the lack of feedback on the backside will cause mismanagement of the engines' functions, you know, since they depend on reliable input from the rear sensor to modulate fuel flow and air mixture, idle and timing -?-

I believe the 2nd sensor is only to analyze how well the cat is working. The front one is the one you need to have working correctly...

Trollhättan Bil
29-01-11, 03:06 PM
I believe the 2nd sensor is only to analyze how well the cat is working. The front one is the one you need to have working correctly...

If it's there to analyze the results of the CAT as they compare to the readings from the first sensor, then it could be potentially sending incorrect information back the the ECU as you're tricking it into thinking that the first sensor is doing a great job, though it may not be.

This would consequentially serve to throw everything off and your car could be fouling for a good while before you'll ever know anything is wrong, possibly compounding what would have been an easy fix into an insurmountable one, because you've circumvented it's ability to tell you.

Just saying....

saabkid37
29-01-11, 03:09 PM
That's great that you're able to trick the O2 sensor, but I'm wondering if the lack of feedback on the backside will cause mismanagement of the engines' functions, you know, since they depend on reliable input from the rear sensor to modulate fuel flow and air mixture, idle and timing -?-

The rear 02 has no say in the mixture

Trollhättan Bil
29-01-11, 03:40 PM
The rear 02 has no say in the mixture

The purpose of the secondary O2 sensor is to gauge the results of the first/primary sensor, there simply is no other purpose for it otherwise.

So, if it is prevented from obtaining an accurate reading of the results of the first sensors' efforts, then it is sending incorrect information back to the ECU which, in turn, sends incorrect information to the other components of the engines' management system prior to those results reaching the primary sensor, throwing the entire failsafe circuit off.

Consider it a closed looped system with built in redundancy in the form of regulators and check valves to insure that all of the components are operating correctly.

Now, if one of the components are failing and a regulator in the system makes adjustments to correct/compensate for it, how is the check valve to know if the adjustments remedied/compensated for the fault if you've prevented it from doing it's job? And, now with it unable to do it's job, who's to say that it's not sending faulty information back to the ECU for it to know that there is anything wrong/faulty/broken or not?

ALL of the components in the system are interdependent on one another for their proper function and maintenance, if you remove one, you're infringing on the ability of the others.

You handicap a systems' ability to manage itself and a domino effect ensues, ultimately resulting in failure...Think about it.

vinnnocc
29-01-11, 04:06 PM
all this cat talk to making me hungry chineese anyone?...
i think i am just gonna go with the non cat one and then try the non-fouler...then later install a cat if it doesnt work

mike saunders
29-01-11, 04:16 PM
.... stuff ...

Not really.

Just back the sensor out of the exhaust stream with a spark-plug antifouler and you're golden.

The second sensor is an emissions sensor designed to monitor the health of the catalytic converter, and by extension, the efficiency of the car's anti-pollution mechanisms. Fuel trim and other factors are monitored by the FRONT sensor.

Trollhättan Bil
29-01-11, 04:18 PM
all this cat talk to making me hungry chineese anyone?...

Oh, now that's just wrong, lol.

i think i am just gonna go with the non cat one and then try the non-fouler...then later install a cat if it doesnt work

No harm in a little trial and error, afterall, you'll never know if you don't try.

mike saunders
29-01-11, 04:21 PM
all this cat talk to making me hungry chineese anyone?...
i think i am just gonna go with the non cat one and then try the non-fouler...then later install a cat if it doesnt work

Where are you goinng to put the second bung? The second 02 sensor needs to be heated to 800 degrees or so (both with car current and with exhaust gas heat).

You'll need to have a second bung put into the downpipe, so you might as well just get a pre-bunged cat and put that in.

Without a cat, if your state uses visual inspections (a simple mirror on a stick passed uinder the car) you're seriously screwed.

EDIT: This is from the Connecticut RMV (http://www.ctemissions.com/expect-rejected.html). Pay particular attention to the last line.

Trollhättan Bil
29-01-11, 04:47 PM
The second sensor is an emissions sensor designed to monitor the health of the catalytic converter, and by extension, the efficiency of the car's anti-pollution mechanisms. Fuel trim and other factors are monitored by the FRONT sensor.

Yeah, that's what I was saying.

saabkid37
29-01-11, 04:49 PM
ALL of the components in the system are interdependent on one another for their proper function and maintenance, if you remove one, you're infringing on the ability of the others.

You handicap a systems' ability to manage itself and a domino effect ensues, ultimately resulting in failure...Think about it.

in this case, they are not. they are two independent sensors with two independent functions. see below.

Not really.

The second sensor is an emissions sensor designed to monitor the health of the catalytic converter, and by extension, the efficiency of the car's anti-pollution mechanisms. Fuel trim and other factors are monitored by the FRONT sensor.

Trollhättan Bil
29-01-11, 05:25 PM
in this case, they are not. they are two independent sensors with two independent functions. see below.

You may have misunderstood mike, or perhaps I did?

Either way, the first oxygen sensor is there to detect rich and lean mixtures and then send this information to the engine's computer to look at which does so by reading the voltage of the sensor (modulated by indirect electrochemical interactions of the composite materials that the O2 sensor consists of) to determine if the mixture is rich or lean, and then adjusts the amount of fuel entering the engine to alter it accordingly

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to...Performance + Emissions = Economy + Performance.

An O2 sensor is essentially a very high temperature thermometer. Most O2 sensors use zirconium dioxide (also known as cubic zirconium) or titanium dioxide to detect temperature via an indirect electrochemical process. When heated, electrochemical substances such as these actually produce their own voltage, which the computer interprets as an indication of temperature. Rich (excess) fuel mixtures carry more vaporized and (possibly) still burning fuel than lean (fuel poor) mixtures, which makes them measurably hotter. The engine causes the first O2 sensor to determine the air/fuel relationship by extrapolating from temperature.

Then there's the CAT...As exhaust passes through the matrix (essentially an expanding mesh composed of other electrochemical materials) of the CAT, it traps a certain amount of the heat and stores it. When impurities like carbon monoxide, nitrogen oxide and unburnt hydrocarbons land on the converter's matrix, the stored energy super heats the molecules to break them apart. In order to break down impurities, the converter's matrix must maintain a steady temperature of at least 500 degrees (known as the converter's "light-off" temperature).

Now this is where the second O2 sensor comes into play as it is used solely to ensure that the CAT maintains its light-off temperature at all times. If the O2 sensor voltage drops too low (indicating cold temperatures/fuel poor mixture), the computer will usually inject more fuel to raise the temperature. If the computer's efforts to regain proper light-off temperature are in vain, it will trigger a check engine light to notify you of converter malfunction.

So, while the sensors function independently they are, inevitably, interdependent (rely) upon one another for proper functioning of the fuel, combustion and emissions systems of the engine and, without any real time feedback from the secondary sensor, there will be no way for the ECU to determine if the engine is running rich or lean, either of which modes bode their own set of issues for the livelihood of your engine.

mike saunders
29-01-11, 06:00 PM
You may have misunderstood mike, or perhaps I did?

Either way, the first oxygen sensor is there to detect rich and lean mixtures and then send this information to the engine's computer to look at which does so by reading the voltage of the sensor (modulated by indirect electrochemical interactions of the composite materials that the O2 sensor consists of) to determine if the mixture is rich or lean, and then adjusts the amount of fuel entering the engine to alter it accordingly

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to...Performance + Emissions = Economy + Performance.

An O2 sensor is essentially a very high temperature thermometer. Most O2 sensors use zirconium dioxide (also known as cubic zirconium) or titanium dioxide to detect temperature via an indirect electrochemical process. When heated, electrochemical substances such as these actually produce their own voltage, which the computer interprets as an indication of temperature. Rich (excess) fuel mixtures carry more vaporized and (possibly) still burning fuel than lean (fuel poor) mixtures, which makes them measurably hotter. The engine causes the first O2 sensor to determine the air/fuel relationship by extrapolating from temperature.

Then there's the CAT...As exhaust passes through the matrix (essentially an expanding mesh composed of other electrochemical materials) of the CAT, it traps a certain amount of the heat and stores it. When impurities like carbon monoxide, nitrogen oxide and unburnt hydrocarbons land on the converter's matrix, the stored energy super heats the molecules to break them apart. In order to break down impurities, the converter's matrix must maintain a steady temperature of at least 500 degrees (known as the converter's "light-off" temperature).

Now this is where the second O2 sensor comes into play as it is used solely to ensure that the CAT maintains its light-off temperature at all times. If the O2 sensor voltage drops too low (indicating cold temperatures/fuel poor mixture), the computer will usually inject more fuel to raise the temperature. If the computer's efforts to regain proper light-off temperature are in vain, it will trigger a check engine light to notify you of converter malfunction.

So, while the sensors function independently they are, inevitably, interdependent (rely) upon one another for proper functioning of the fuel, combustion and emissions systems of the engine and, without any real time feedback from the secondary sensor, there will be no way for the ECU to determine if the engine is running rich or lean, either of which modes bode their own set of issues for the livelihood of your engine.

Not quite accurate.

Bil, most if not all of the trim adjustments are made from inputs from the first 02 sensor. The rear sensor is more of a yes/no signal that the catalytic converter is functioning. A clogged or burned out cat could very well be caused by long-term operation with an overly rich mixture...but that condition would be initially caught by the first sensor.

Look, here's the most common code (http://www.obd-codes.com/p0140) for a bad rear sensor. And here's the pertinent part:
Your check engine light(CEL), or malfuction indicator lamp (MIL) will be illuminated. There will not likely be any noticeable drivability problems other than the MIL. The reason is this: The rear or post catalytic converter Oxygen sensor does not affect fuel deliver(this is an exception on Chryslers (http://www.obd-codes.com/p0140#)). It only MONITORS the efficiency of the catalytic converter. For this reason, you will likely not notice any engine trouble.
Here are the most common codes for a bad front sensor (http://www.obd-codes.com/p0031).
A P0031 DTC (diagnostic trouble code) refers to the O2 sensorhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://www.obd-codes.com/p0031#) (oxygen sensor) located on Bank 1 (http://www.obd-codes.com/faq/what-is-bank-1-and-bank-2.php) in front of the catalytic converterhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://www.obd-codes.com/p0031#). There is also an oxygen sensor behind the converter which is Sensor #2.
This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles (http://www.obd-codes.com/p0031#) it is. It detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle's (http://www.obd-codes.com/p0031#) computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the A/F O2 sensor. Essentially this P0031 code means that the resistance of the heater circuit is lower than normal. In most cases, that resistance level must fall below 0.8 A to trigger the DTC code.
Note, this code is very similar in nature to P0032 (http://www.obd-codes.com/p0032), P0051 (http://www.obd-codes.com/p0051), and P0052 (http://www.obd-codes.com/p0052)

And then there's this (http://www.aa1car.com/library/o2sensor.htm):
A downstream oxygen sensor in or behind the catalytic converter works exactly the same as an upstream O2 sensor in the exhaust manifold. The sensor produces a voltage that changes when the amount of unburned oxygen in the exhaust changes. If the O2 sensor is a traditional zirconia type sensor, the voltage output drops to about 0.2 volts when the fuel mixture is lean (more oxygen in the exhaust). When the fuel mixture is rich (less oxygen in the exhaust), the sensor's output jumps up to a high of about 0.9 volts. The high or low voltage signal tells the PCM the fuel mixture is rich or lean.On some newer vehicles, a new type of Wide Ratio Air Fuel (WRAF) Sensor (http://www.aa1car.com/library/wraf.htm) is used. Instead of producing a high or low voltage signal, the signal changes in direct proportion to the amount of oxygen in the exhaust. This provides a more precise measurement for better fuel control. These sensors are also called wideband oxygen sensors because they can read very lean air/fuel mixtures.
The OBD II system monitors converter efficiency by comparing the upstream and downstream oxygen sensor signals. If the converter is doing its job and is reducing the pollutants in the exhaust, the downstream oxygen sensor should show little activity (few lean-to-rich transitions, which are also called "crosscounts"). The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0.45 volts or higher.
If the signal from the downstream oxygen sensor starts to mirror that from the upstream oxygen sensor(s), it means converter efficiency has dropped off and the converter isn't cleaning up the pollutants in the exhaust. The threshold for setting a diagnostic trouble code (DTC) and turning on the Malfunction Indicator Lamp (MIL) is when emissions are estimated to exceed federal limits by 1.5 times. See Troubleshooting a P0420 Catalyst Code (http://www.aa1car.com/library/p0420_dtc.htm) for more info about converter problems.
If converter efficiency had declined to the point where the vehicle may be exceeding the pollution limit, the PCM will turn on the Malfunction Indicator Lamp (MIL) and set a diagnostic trouble code. At that point, additional diagnosis may be needed to confirm the failing converter. If the upstream and downstream O2 sensors are functioning properly and show a drop off in converter efficiency, the converter must be replaced to restore emissions compliance. The vehicle will not pass an OBD II emissions test if there are any converter codes in the PCM.
So, to sum up:

Our rear 02 sensor monitors the health of the catalytic converter, isn't extensively involved with fuel trim, and can be bypassed with a simple "anti-fouler." The second sensor will heat up as expected and won't show an evil "not ready" code.

Trollhättan Bil
29-01-11, 06:35 PM
Not quite accurate.

Bil, most if not all of the trim adjustments are made from inputs from the first 02 sensor. The rear sensor is more of a yes/no signal that the catalytic converter is functioning. A clogged or burned out cat could very well be caused by long-term operation with an overly rich mixture...but that condition would be initially caught by the first sensor.

Look, here's the most common code (http://www.obd-codes.com/p0140) for a bad rear sensor. And here's the pertinent part:Your check engine light(CEL), or malfuction indicator lamp (MIL) will be illuminated. There will not likely be any noticeable drivability problems other than the MIL. The reason is this: The rear or post catalytic converter Oxygen sensor does not affect fuel deliver(this is an exception on Chryslers (http://www.obd-codes.com/p0140#)). It only MONITORS the efficiency of the catalytic converter. For this reason, you will likely not notice any engine trouble.
Here are the most common codes for a bad front sensor (http://www.obd-codes.com/p0031).A P0031 DTC (diagnostic trouble code) refers to the O2 sensorhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://www.obd-codes.com/p0031#) (oxygen sensor) located on Bank 1 (http://www.obd-codes.com/faq/what-is-bank-1-and-bank-2.php) in front of the catalytic converterhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://www.obd-codes.com/p0031#). There is also an oxygen sensor behind the converter which is Sensor #2.
This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles (http://www.obd-codes.com/p0031#) it is. It detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle's (http://www.obd-codes.com/p0031#) computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the A/F O2 sensor. Essentially this P0031 code means that the resistance of the heater circuit is lower than normal. In most cases, that resistance level must fall below 0.8 A to trigger the DTC code.
Note, this code is very similar in nature to P0032 (http://www.obd-codes.com/p0032), P0051 (http://www.obd-codes.com/p0051), and P0052 (http://www.obd-codes.com/p0052)

And then there's this (http://www.aa1car.com/library/o2sensor.htm):A downstream oxygen sensor in or behind the catalytic converter works exactly the same as an upstream O2 sensor in the exhaust manifold. The sensor produces a voltage that changes when the amount of unburned oxygen in the exhaust changes. If the O2 sensor is a traditional zirconia type sensor, the voltage output drops to about 0.2 volts when the fuel mixture is lean (more oxygen in the exhaust). When the fuel mixture is rich (less oxygen in the exhaust), the sensor's output jumps up to a high of about 0.9 volts. The high or low voltage signal tells the PCM the fuel mixture is rich or lean.On some newer vehicles, a new type of Wide Ratio Air Fuel (WRAF) Sensor (http://www.aa1car.com/library/wraf.htm) is used. Instead of producing a high or low voltage signal, the signal changes in direct proportion to the amount of oxygen in the exhaust. This provides a more precise measurement for better fuel control. These sensors are also called wideband oxygen sensors because they can read very lean air/fuel mixtures.
The OBD II system monitors converter efficiency by comparing the upstream and downstream oxygen sensor signals. If the converter is doing its job and is reducing the pollutants in the exhaust, the downstream oxygen sensor should show little activity (few lean-to-rich transitions, which are also called "crosscounts"). The sensor's voltage reading should also be fairly steady (not changing up or down), and average 0.45 volts or higher.
If the signal from the downstream oxygen sensor starts to mirror that from the upstream oxygen sensor(s), it means converter efficiency has dropped off and the converter isn't cleaning up the pollutants in the exhaust. The threshold for setting a diagnostic trouble code (DTC) and turning on the Malfunction Indicator Lamp (MIL) is when emissions are estimated to exceed federal limits by 1.5 times. See Troubleshooting a P0420 Catalyst Code (http://www.aa1car.com/library/p0420_dtc.htm) for more info about converter problems.
If converter efficiency had declined to the point where the vehicle may be exceeding the pollution limit, the PCM will turn on the Malfunction Indicator Lamp (MIL) and set a diagnostic trouble code. At that point, additional diagnosis may be needed to confirm the failing converter. If the upstream and downstream O2 sensors are functioning properly and show a drop off in converter efficiency, the converter must be replaced to restore emissions compliance. The vehicle will not pass an OBD II emissions test if there are any converter codes in the PCM.
So, to sum up:

Our rear 02 sensor monitors the health of the catalytic converter, isn't extensively involved with fuel trim, and can be bypassed with a simple "anti-fouler." The second sensor will heat up as expected and won't show an evil "not ready" code.

And now we're back to the differences between conduction (the transfer of heat from one material to another) and convection (the transfer of heat through gaseous states) heat transfer (as was touched on in the OEM intake mod thread).

As it is, it occurs to me that, if you remove the rear sensor from the primary flow/the oncoming path of the exhaust gases (it's typical location), you circumvent it's ability to render an accurate reading as it will then only be subjected to the conduction heating of the surrounding material (the exhaust piping) and not the convection heating of the exhaust gases as it was originally intended/designed to do so, if anything, it will only be able to supply an insufficient reading of the actual status of the exhaust gases/CAT.

These machines of ours are finely mechanically engineered and regimentally regulated electronically, much like an exquisitely crafted watch, if you will, all specifically tuned to coordinate their efforts to work with one another towards the ultimate goal of motoring us down the roadways with the minimalist of efforts and ease.

Granted, there may well always be room for improvement, but generally not at the expense of one of the integrated components, particularly one in which a great deal many others are dependent upon.

p.s. Or perhaps it is that I am just a stickler for detail?

vinnnocc
29-01-11, 07:38 PM
wait a min the GS version 2 doesn't come with two o2 sensors spots?? with or without cat?

im so lost on what to do. spend the ex $100 for the cat or save a lil money and deal with it later...a lil help guys thanx

mike saunders
29-01-11, 07:54 PM
wait a min the GS version 2 doesn't come with two o2 sensors spots?? with or without cat?

im so lost on what to do. spend the ex $100 for the cat or save a lil money and deal with it later...a lil help guys thanx

I don't think the non-race catted one comes with two bungs -- mine didn't -- but confirm that with GenuineSaab.

I bought a GenuineSaab downpipe, and had a Cat and bung installed. That was maybe 5-6 years ago. IIRC, the price then for the race-catted model was higher than it is now, so the $100 extra about covers what a aftermarket cat would cost installed.

mike saunders
29-01-11, 07:59 PM
And now we're back to the differences between conduction (the transfer of heat from one material to another) and convection (the transfer of heat through gaseous states) heat transfer (as was touched on in the OEM intake mod thread).

As it is, it occurs to me that, if you remove the rear sensor from the primary flow/the oncoming path of the exhaust gases (it's typical location), you circumvent it's ability to render an accurate reading as it will then only be subjected to the conduction heating of the surrounding material (the exhaust piping) and not the convection heating of the exhaust gases as it was originally intended/designed to do so, if anything, it will only be able to supply an insufficient reading of the actual status of the exhaust gases/CAT.

No, all the second sensor cares about is whether the readings are within an expected range to indicate a functioning cat. That's it.

These machines of ours are finely mechanically engineered and regimentally regulated electronically, much like an exquisitely crafted watch, if you will, all specifically tuned to coordinate their efforts to work with one another towards the ultimate goal of motoring us down the roadways with the minimalist of efforts and ease.

Granted, there may well always be room for improvement, but generally not at the expense of one of the integrated components, particularly one in which a great deal many others are dependent upon.

p.s. Or perhaps it is that I am just a stickler for detail?

Yes, you're a stickler for details. The car will operate fine with the second sensor partially removed from the exhaust stream.

saabkid37
29-01-11, 08:02 PM
mike and i are on the same page bil, have been for years.

your totally over thinking this.

ask yourself this. if the rear o2 is involved in mixture, then why do no european models have the need for a secondary sensor?

the answer is that it is only for US emissions. it has a voltage threshold programmed into the ecu (which can be changed by a tuner to allow for varying brands of cats and their varying flow). when the sensor reads outside this range it triggers a cel for the cat, it sends no info to the front sensor, and does not alter mixture. period.

using an anti fouler allows the sensor to see less gas therefore less of the higher level of gas coming by due to lack of cat. but it will still be heated.

when you turn off the rear o2 in the ecu, the exhaust cannot heat the sensor enough alone and it will eventually crap out, albeit you will most likely never know.

vinnnocc - if you have questions about the dp call GS, im not too sure many people even buy it without a cat

Trollhättan Bil
29-01-11, 08:22 PM
No, all the second sensor cares about is whether the readings are within an expected range to indicate a functioning cat. That's it.

Yes, I am aware of that.

The point that I am making is that repositioning the second sensor will, obvious I believe to all, result in an incorrect reading as it will no longer be in the appropriate position to determine if the CAT is functioning at it's optimal operating temperature as raising it out of it's recessed position in the exhaust stream will essentially equate to wrapping a protective fence around it to block it from the current.

Yes, you're a stickler for details. The car will operate fine with the second sensor partially removed from the exhaust stream.

Perhaps it will...Does anyone have any real numbers available from the sensor in place, removed, then repositioned?

These specifics are of some import for me due to a number of modifications I intend to make, each of which will serve to either effect or influence the overall operational ability of the engine.

mike saunders
29-01-11, 08:33 PM
Yes, I am aware of that.

The point that I am making is that repositioning the second sensor will, obvious I believe to all, result in an incorrect reading as it will no longer be in the appropriate position to determine if the CAT is functioning at it's optimal operating temperature as raising it out of it's recessed position in the exhaust stream will essentially equate to wrapping a protective fence around it to block it from the current.

Actual real-life experience with this exact setup tends to throw cold water on your theory. I've used it. It works. ;)



Perhaps it will...Does anyone have any real numbers available from the sensor in place, removed, then repositioned?

These specifics are of some import for me due to a number of modifications I intend to make, each of which will serve to either effect or influence the overall operational ability of the engine.Bil, all you -- and the sensor -- care about is whether you get a CEL. The car's other control systems will handle air metering (whether via manifold pressure or airflow) and fuel delivery.

There are hundreds of other variables worth devoting energy to. The second O2 sensor falls under the category of a necessary annoyance.

Trollhättan Bil
29-01-11, 08:43 PM
mike and i are on the same page bil, have been for years.

your totally over thinking this.

I may well be, but then, someone has to and I seem to be predisposed to being the sort that does...Lucky me, huh?

ask yourself this. if the rear o2 is involved in mixture, then why do no european models have the need for a secondary sensor?

Marginalized emission standards as compared to domestic models...?!

the answer is that it is only for US emissions. it has a voltage threshold programmed into the ecu (which can be changed by a tuner to allow for varying brands of cats and their varying flow). when the sensor reads outside this range it triggers a cel for the cat, it sends no info to the front sensor, and does not alter mixture. period.

You say this, yet all of the literature, manuals, specs. and what have you (including the info mike provided), I've read all serve to reiterate exactly that which I have expressed here, that is, while the second/rear sensor may not send any data to the primary/first sensor, i.e., no dedicated intercommunication, the first sensor is still effected by the readings of the second sensor in that it is it's data that the CU relies on to determine that the CAT is operating to spec.

If you can so me literature that stipulates otherwise, I would appreciate it.

using an anti fouler allows the sensor to see less gas therefore less of the higher level of gas coming by due to lack of cat. but it will still be heated.

I am aware of that just as I am aware that the sensor also reads the temperature of the heated gasses, a function which you prevent it from doing when you extract it from the exhaust stream, forcing it to rely solely on the temperature readings derived solely from conduction alone.

when you turn off the rear o2 in the ecu, the exhaust cannot heat the sensor enough alone and it will eventually crap out, albeit you will most likely never know.

The CE light will tell me, will it not?

Trollhättan Bil
29-01-11, 08:55 PM
Actual real-life experience with this exact setup tends to throw cold water on your theory. I've used it. It works. ;)

That's what I was looking for, real world results, thanks!

Bil, all you -- and the sensor -- care about is whether you get a CEL. The car's other control systems will handle air metering (whether via manifold pressure or airflow) and fuel delivery.

There are hundreds of other variables worth devoting energy to. The second O2 sensor falls under the category of a necessary annoyance.

The jury is still out on this assertion in that every technical spec sheet on every secondary O2 sensor emission system ever produced clearly stipulates that the ECU determines whether or not additional fuel needs, or needs not, be added to compensate for a rich/lean reading from the first sensor dependent solely on the reading from the second sensor...Solely.

However, if you could provide me with a link to literature to the contrary, I would appreciate it. ;ol;

mike saunders
30-01-11, 12:36 AM
The jury is still out on this assertion in that every technical spec sheet on every secondary O2 sensor emission system ever produced clearly stipulates that the ECU determines whether or not additional fuel needs, or needs not, be added to compensate for a rich/lean reading from the first sensor dependent solely on the reading from the second sensor...Solely.

However, if you could provide me with a link to literature to the contrary, I would appreciate it. ;ol;

Bil, there is no jury. It is not out. ;)

Again, the second O2 sensor doesn't help modify fuel trim because that's not its function. The first O2 sensor is able to determine, albeit roughly, whether the engine is running too rich or too lean. That's why, as pointed out earlier, European versions of our cars are able to toodle down the road just fine.

OBD II is an EPA-mandated standard to control car emissions. That's the function of the second sensor, to indicate that there's a working emissions control device, i.e. the catalytic converter. Here are the EPA docs. (http://www.epa.gov/obd/regtech/inspection.htm)

Trollhättan Bil
30-01-11, 04:21 PM
Bil, there is no jury. It is not out. ;)

Again, the second O2 sensor doesn't help modify fuel trim because that's not its function. The first O2 sensor is able to determine, albeit roughly, whether the engine is running too rich or too lean. That's why, as pointed out earlier, European versions of our cars are able to toodle down the road just fine.

OBD II is an EPA-mandated standard to control car emissions. That's the function of the second sensor, to indicate that there's a working emissions control device, i.e. the catalytic converter. Here are the EPA docs. (http://www.epa.gov/obd/regtech/inspection.htm)

And for which aspect of the engine management system does it (the second O2) make this determination/communicate these findings with?

mike saunders
30-01-11, 04:53 PM
And for which aspect of the engine management system does it (the second O2) make this determination/communicate these findings with?

Which aspect? The "we're-doing-this-to-comply-with-US-government-regs" aspect. ;) That's really the main point of it, as part of an enhanced emissions-control mandate. The fuel trim adjustments and related programmatic tweaks are made with inputs from the first sensor. The second sensor is tied into Trionic as a yes/no function.

If I'm wrong, then please enlighten me....I'm sure there are folks far, far more knowledgable than I am about the exact workings of Trionic, but I've explained what I know at some length and with a fair degree of specificity.

Trollhättan Bil
30-01-11, 05:08 PM
Which aspect? The "we're-doing-this-to-comply-with-US-government-regs" aspect. ;) That's really the main point of it, as part of an enhanced emissions-control mandate. The fuel trim adjustments and related programmatic tweaks are made with inputs from the first sensor. The second sensor is tied into Trionic as a yes/no function.

If I'm wrong, then please enlighten me....I'm sure there are folks far, far more knowledgable than I am about the exact workings of Trionic, but I've explained what I know at some length and with a fair degree of specificity.

So, if I understand you correctly, all that the second sensor does is tell the Trionic (the Engine Management System) whether or not the first sensor is working, yes?

A.Breton
30-01-11, 06:09 PM
So, if I understand you correctly, all that the second sensor does is tell the Trionic (the Engine Management System) whether or not the first sensor is working, yes?No, 2nd o2 is for checking that the cat is working correctly. The sensor should be sending 0.6v to trionic.

Trollhättan Bil
30-01-11, 06:38 PM
No, 2nd o2 is for checking that the cat is working correctly. The sensor should be sending 0.6v to trionic.

So, if the 2nd O2 tells the Trionic that the CAT isn't working properly, what happens? That is, what does the Trionic do?

localized
30-01-11, 06:41 PM
So, if the 2nd O2 tells the Trionic that the CAT isn't working properly, what happens? That is, what does the Trionic do?

Your CEL comes on.

vinnnocc
30-01-11, 06:44 PM
Your CEL comes on.


and then what does the CEL do??

Trollhättan Bil
30-01-11, 06:49 PM
and then what does the CEL do??

...Lol!

http://www.youtube.com/watch?v=K7luMp6lb9M&feature=related

And thennnnn.........?

localized
30-01-11, 06:52 PM
and then what does the CEL do??

It goes away after a while if you drive it for a couple of weeks. Or faster if you have a scanner. I have been having issues with my rear 02 sensor since I bought the car over a year ago, and it literally does nothing except to turn the light on. It finally died last night and now has zero voltage running to it. Good riddance, I say.

vinnnocc
30-01-11, 06:53 PM
lol sounds good to me

Trollhättan Bil
30-01-11, 06:55 PM
Your CEL comes on.

So, you're saying that the only thing triggered by a 'bad' signal from the 2nd O2 is a CEL? Am I right? That is what you're saying?

It also doesn't, for instance, cause the Trionic to reconfigure the air/fuel ratios to compensate for the 'bad' signal in an effort to remedy it?

localized
30-01-11, 06:57 PM
So, you're saying that the only thing triggered by a 'bad' signal from the 2nd O2 is a CEL? Am I right? That is what you're saying?

It also doesn't, for instance, cause the Trionic to reconfigure the air/fuel ratios to compensate for the 'bad' signal in an effort to remedy it?


Precisely. The front O2 sensor is what contributes to the control of the a/f ratio, and when that starts to go it can actually cause the car to stutter and misfire.

Trollhättan Bil
30-01-11, 07:12 PM
Precisely. The front O2 sensor is what contributes to the control of the a/f ratio, and when that starts to go it can actually cause the car to stutter and misfire.

Well, you see, that's where my understanding of the systems' operation comes into conflict with (apparently) everyone else because every piece of literature I have ever read on the O2 sensor/engines' emissions regulation system stipulates that, if the 2nd O2 sensors' voltage drops too low (indicating cold temperatures/fuel poor mixture), the computer/Trionic will usually inject more fuel to raise the temperature.

Then, and only then, if the computer's efforts to regain proper voltage/temperature by enriching the fuel are in vain, it will trigger the CEL to notify you of a potential (as it could actually be due to a fault elsewhere in the system) CAT malfunction.

Now, I don't know about you guys, but that seems to be telling me that the 2nd O2 plays a somewhat larger role than merely turning the CEL on, or keeping it off, as the case may be.

Trollhättan Bil
30-01-11, 07:19 PM
BTW people, the only reason why I'm being such a stickler about the details is that a large part of what I'm working on (maintaining idyllic Stoich throughout the power band) is dependent on acquiring accurate readings from all onboard monitoring systems involved with the engines air/fuel management so that they can be properly modulated.

So, not trying to be a dick or anything, just trying to work things out for the better.

mike saunders
30-01-11, 08:07 PM
Well, you see, that's where my understanding of the systems' operation comes into conflict with (apparently) everyone else because every piece of literature I have ever read on the O2 sensor/engines' emissions regulation system stipulates that, if the 2nd O2 sensors' voltage drops too low (indicating cold temperatures/fuel poor mixture), the computer/Trionic will usually inject more fuel to raise the temperature.

Then, and only then, if the computer's efforts to regain proper voltage/temperature by enriching the fuel are in vain, it will trigger the CEL to notify you of a potential (as it could actually be due to a fault elsewhere in the system) CAT malfunction.

Now, I don't know about you guys, but that seems to be telling me that the 2nd O2 plays a somewhat larger role than merely turning the CEL on, or keeping it off, as the case may be.

Bil, I've cited several sources. I've relayed direct personal experience. I've tried to explain the operation to you as best as I understand it, and understanding that is apparently corroborated by the observations of others.

Not sure what else you need....

Maybe some testimony from European drivers whose cars didn't need the second sensor because they weren't bound by OBD II?

Maybe even more links (http://www.google.com/url?sa=t&source=web&cd=5&ved=0CEsQFjAE&url=http%3A%2F%2Fwww.mintoff.co.uk%2FT5%2FEngine%2 520management%2520system%2520SAAB%2520TRIONIC%2520 T5.5%2C%2520rev%2520102.pdf&rct=j&q=trionic%20second%2002%20sensor&ei=ywlGTePWLMzAgQe19syNAg&usg=AFQjCNF54g4HGHZQq43SqXUrRbbBKprX9A&sig2=J5vZ9oKYcqOunu3N5vQsRw&cad=rja) to the T5 (http://www.saabcentral.com/forums/trionic.mobixs.eu/t5suite2/T5Suite2%20User%20Manual.pd) and T7 Suite (http://www.google.com/url?sa=t&source=web&cd=10&ved=0CHYQFjAJ&url=http%3A%2F%2Fwww.trionicsuites.com%2FData%2Fma nuals%2FTrionic%25207.pdf&rct=j&q=trionic%20second%2002%20sensor&ei=ywlGTePWLMzAgQe19syNAg&usg=AFQjCNFSY8f1k8RR_hRZtf0lL46mf-7Rwg&sig2=Ke8MTrS8PawCSXb0a1FL_A&cad=rja) documentation?


Your aims may be lofty -- essentially attempting to re-engineer something that was developed nearly 20 years ago -- but that's time spent on minutiae that is likely better spent driving. :cool:

A.Breton
31-01-11, 07:39 AM
http://i859.photobucket.com/albums/ab151/a_breton/WIS.jpg

mike saunders
31-01-11, 10:08 AM
This seems to validate Bil's viewpoint, at least for T7, so I stand corrected. There are some minor inputs made by the second sensor.

http://i859.photobucket.com/albums/ab151/a_breton/WIS.jpg

Trollhättan Bil
31-01-11, 11:38 AM
http://i859.photobucket.com/albums/ab151/a_breton/WIS.jpg

Damn, I didn't know that someone was going to pull out the WIS on us, but yeah, like even the WIS says:

"In addition to the catalytic converter diagnosis, the oxygen sensor value is also used to correct the closed loop for minor faults in oxygen sensor 1."

Thank you A.Breton.

Say, you wouldn't happen to have a downloadable link for the WIS, would you? I've been trying to get ahold of it.

Trollhättan Bil
31-01-11, 12:00 PM
This seems to validate Bil's viewpoint, at least for T7, so I stand corrected. There are some minor inputs made by the second sensor.

Now, with this understanding, perhaps you are able to recognize that more adjustments than merely retracting the 2nd O2 from the exhaust flow are required for overall engine management stability, recognize that even something as seemingly minute as disabling or circumventing something as seemingly inconsequential as the 2nd O2 sensors' ability to do it's job would trigger a domino effect that could result in considerable mismanagement of the engines' Trionic system?

This is not to say that you still couldn't do just that (use an anti-fouler to withdraw the 2nd O2), you can, but you'll also need to recalibrate the entire mapping for the engine management system to compensate for the adjustment so that it doesn't throw off your fuels' mapping parameters and cause your car to run rich, develop excessive carbon buildup, foul the plugs, and burn out the 1st O2 sensor and the CAT as well.

An ounce of prevention and what have you.

And thennnnnn....

Trollhättan Bil
31-01-11, 01:04 PM
Your aims may be lofty -- essentially attempting to re-engineer something that was developed nearly 20 years ago

You say it like no ones' ever done exactly that before.... ;)

-- but that's time spent on minutiae that is likely better spent driving. :cool:

It is from the love of driving my car that I draw the passion/desire to improve it/its' performance.

mike saunders
31-01-11, 01:42 PM
Now, with this understanding, perhaps you are able to recognize that more adjustments than merely retracting the 2nd O2 from the exhaust flow are required for overall engine management stability, recognize that even something as seemingly minute as disabling or circumventing something as seemingly inconsequential as the 2nd O2 sensors' ability to do it's job would trigger a domino effect that could result in considerable mismanagement of the engines' Trionic system?

Bil, now you're just over-reaching. :) The "seemingly minute" adjustments are just that and are only to counteract possible problems with the first sensor.

This is not to say that you still couldn't do just that (use an anti-fouler to withdraw the 2nd O2), you can, but you'll also need to recalibrate the entire mapping for the engine management system to compensate for the adjustment so that it doesn't throw off your fuels' mapping parameters and cause your car to run rich, develop excessive carbon buildup, foul the plugs, and burn out the 1st O2 sensor and the CAT as well.

An ounce of prevention and what have you.

And thennnnnn....

Bil, I actively WANT the car to run slightly rich at WOT. At my desired power levels, I'm perfectly willing to trade some efficiency for increased fueling.

Plugs are cheap, and are critical to proper DIC operation so most higher output cars change them every other oil change. Re: reliability of O2 sensors: I've changed three of them, all in separate cars with more than 140K miles on the clock ;)

Trollhättan Bil
31-01-11, 11:42 PM
Bil, now you're just over-reaching. :) The "seemingly minute" adjustments are just that and are only to counteract possible problems with the first sensor.



Bil, I actively WANT the car to run slightly rich at WOT. At my desired power levels, I'm perfectly willing to trade some efficiency for increased fueling.

Plugs are cheap, and are critical to proper DIC operation so most higher output cars change them every other oil change. Re: reliability of O2 sensors: I've changed three of them, all in separate cars with more than 140K miles on the clock ;)

Lol! I like the way you say I'm 'over-reaching' in one paragraph, then go on to outline the steps you take to compensate for the very faults I listed that would result from an improperly seated/calibrated secondary O2 sensor in your next paragraph...Priceless!

Mike, everyone running a tuned, or even just boosted, engine wants a slightly richer WOT fuel mixture to retard detonation/insure higher combustion, that's just common sense/rule of thumb for a tuned/boosted engine, but we both know that that's not what I'm talking about.

Anyway, what I'm up to is developing a means of circumventing this necessity in such a fashion that would enable us to not only achieve a cleaner, more robust burn of the available fuel molecules, but also do it more so economically with less wear on the engine than is typically experienced with combusting fuel.

saabkid37
31-01-11, 11:56 PM
Anyway, what I'm up to is developing a means of circumventing this necessity in such a fashion that would enable us to not only achieve a cleaner, more robust burn of the available fuel molecules, but also do it more so economically with less wear on the engine than is typically experienced with combusting fuel.

sounds like your just gonna leave the car turned off :roll:

Trollhättan Bil
01-02-11, 12:16 AM
sounds like your just gonna leave the car turned off :roll:

Yeah, for the most part, Lol!

Seriously though, the majority of the cause for the excessive carbon build up we experience in our engines is because of fuel deposits resulting from unburnt fuel charges/combustion cycles so, metering the amount of fuel required and insuring complete combustion of the available fuel charge will serve to eliminate a number of the encumbrances associated with ICE's, freeing up just that much more power proportionately while doing so economically.

mike saunders
01-02-11, 01:28 AM
Lol! I like the way you say I'm 'over-reaching' in one paragraph, then go on to outline the steps you take to compensate for the very faults I listed that would result from an improperly seated/calibrated secondary O2 sensor in your next paragraph...Priceless!

Bil, the changing of the plugs has ZERO to do with carbon deposits and everything to do with proper DIC operation when your performance tolerances are narrowed by considerably higher outputs. The DIC is finicky on the best days, so the last thing you want is a plug-induced misfire when you're running at 6K+ rpm. Plugs are changed more frequently on higher-output vehicles regardless of second O2 sensor status. If anything, plugs in healthy FI engines tend to show evidence of heat, not carbon.

Mike, everyone running a tuned, or even just boosted, engine wants a slightly richer WOT fuel mixture to retard detonation/insure higher combustion, that's just common sense/rule of thumb for a tuned/boosted engine, but we both know that that's not what I'm talking about.

Anyway, what I'm up to is developing a means of circumventing this necessity in such a fashion that would enable us to not only achieve a cleaner, more robust burn of the available fuel molecules, but also do it more so economically with less wear on the engine than is typically experienced with combusting fuel.Um. OK. I'll bite. My grandfather swore by Marvel Mystery Oil...:lol:

Bil, what exactly are you talking about? If you're going to revolutionize internal combustion with a new additive or some new way of calculating proper stoich ratios, please enlighten us. Please show us what you've done. Please show us what engines you've worked on, or what vehicles have benefitted from this new way of producing power.

I'd honestly like to know.

Trollhättan Bil
01-02-11, 10:15 AM
Bil, the changing of the plugs has ZERO to do with carbon deposits and everything to do with proper DIC operation when your performance tolerances are narrowed by considerably higher outputs. The DIC is finicky on the best days, so the last thing you want is a plug-induced misfire when you're running at 6K+ rpm. Plugs are changed more frequently on higher-output vehicles regardless of second O2 sensor status. If anything, plugs in healthy FI engines tend to show evidence of heat, not carbon.

Alright already, mike, I've no interest in beating a dead horse with you (it makes my arm tired and I need it for other things).

Um. OK. I'll bite. My grandfather swore by Marvel Mystery Oil...:lol:

:o You guessed my secret! How did you do it?! Damn, now everyone knows....

Bil, what exactly are you talking about? If you're going to revolutionize internal combustion with a new additive or some new way of calculating proper stoich ratios, please enlighten us. Please show us what you've done. Please show us what engines you've worked on, or what vehicles have benefitted from this new way of producing power.

As I've said, it is a work in progress so, besides whatever proprietary concerns typically associated with the development of an innovative technology/process/methodology, etc., there is also the responsibility of properly vetting said technology prior to releasing it to the public to insure safety and stability of results.

I'd honestly like to know.

Wouldn't everyone? And one day you, and they, all will.

It's really quite simple, afterall, we all know what the idyllic Stoich is, just as we all know compression ratios, cylinder capacities, plenum cubics, runner lengths, etc., etc., and all of the other systems and associated componentry and the like involved in the combustion that occurs in our engines.

Now, knowing these basics, how would you go about configuring/modulating/etc., them to attain the idyllic Stoich all across the power band...?

See...simple.

fiveiron9688
01-02-11, 10:56 AM
Bil, what exactly are you talking about? If you're going to revolutionize internal combustion with a new additive or some new way of calculating proper stoich ratios, please enlighten us. Please show us what you've done. Please show us what engines you've worked on, or what vehicles have benefitted from this new way of producing power.

I'd honestly like to know.

Me too.

I think if you're wanting to basically change most of decades-upon-decades of experience in internal combustion engines, you're going to need some entirely different engine, not an old B204 or whatever it is you are currently using. Someone correct if I'm wrong, but no gasoline engine attempts to use stoichiometric ratios, and I think there is a reason or two for that...

Pichers or it didn't happen!;)

Trollhättan Bil
01-02-11, 11:45 AM
Me too.

I think if you're wanting to basically change most of decades-upon-decades of experience in internal combustion engines, you're going to need some entirely different engine, not an old B204 or whatever it is you are currently using. Someone correct if I'm wrong, but no gasoline engine attempts to use stoichiometric ratios, and I think there is a reason or two for that...

Pichers or it didn't happen!;)

That is far too impractical of an approach to a potential remedy for all of the handicaps associated with an ICE. Just think about all of the engines that would need be scrapped/recycled/removed and replaced with this newly designed engine of yours when the most readily available resolution would be the manufacture and distribution of an off-the-shelf application that is configured in such a way as to have cross-platform adaptability and integration.

The only reason I've determined why no one has made use of Stoich is because they've been unable to devise a means of doing so.

But, hey! All of this is a topic for a different thread...We're discussing the proper configuration of a down pipe in this thread.

fiveiron9688
01-02-11, 01:41 PM
Maybe I didn't get my point across correctly. What I'm really wondering is...how do you plan to accomplish this?

mike saunders
01-02-11, 02:18 PM
Seriously though, the majority of the cause for the excessive carbon build up we experience in our engines is because of fuel deposits resulting from unburnt fuel charges/combustion cycles so, metering the amount of fuel required and insuring complete combustion of the available fuel charge will serve to eliminate a number of the encumbrances associated with ICE's, freeing up just that much more power proportionately while doing so economically.


Oy.....:o Bil, if the "we" you're referring to is directed at the Saab-driving folks on this forum, then this shows you've never cracked open a B204/B234 or B205/B235.

I've never seen "excessive carbon buildup" in any of the above examples, some stock, some modded. As stated above, just a minor coating on the top of the head dome and on the valves faces. Little if any on the valve stems. However, I am old enough to remember changing the head gasket on a carbed '64 Chevy straight 6, and I've replaced carbs on my old Jeep Grand Wagoneners. Those had carbon buildup.

With later model Saabs, the DIC helps a lot to limit carbon buildup by self-cleaning the plugs when the ignition is turned off.

But I'm still eager to see your invention. Sounds facinating.

saabkid37
01-02-11, 04:24 PM
having compared honda guts to saab guts. the saab is leaps and bounds cleaner.

Trollhättan Bil
01-02-11, 04:35 PM
Maybe I didn't get my point across correctly. What I'm really wondering is...how do you plan to accomplish this?

Well, that's where the 'proprietary' (don't you know what proprietary means?) aspect of the whole process comes into play and, as I've said a number of times already, it's still in development, so I've nothing to disclose at this time.:cool:

Trollhättan Bil
01-02-11, 04:41 PM
Oy.....:o Bil, if the "we" you're referring to is directed at the Saab-driving folks on this forum, then this shows you've never cracked open a B204/B234 or B205/B235.

I've never seen "excessive carbon buildup" in any of the above examples, some stock, some modded. As stated above, just a minor coating on the top of the head dome and on the valves faces. Little if any on the valve stems. However, I am old enough to remember changing the head gasket on a carbed '64 Chevy straight 6, and I've replaced carbs on my old Jeep Grand Wagoneners. Those had carbon buildup.

With later model Saabs, the DIC helps a lot to limit carbon buildup by self-cleaning the plugs when the ignition is turned off.

But I'm still eager to see your invention. Sounds facinating.

Which is what makes Saabs such a great platform base for the development of the technology as adjusting it to compensate for the increased deposits one typically finds in domestic applications would be but a little tweak here or there once it's been dialed in as I'll then have the base parameters by which to gauge the necessary adjustments.