what do you guys think? [Archive] - SaabCentral Forums

: what do you guys think?


M4Gunner
28th April 2004, 06:43 PM
as we know, neapleaze tried a "T" valve with an open end and ended up throwing a CEL. what if we were to try this? www.boostvalve.com/moreinfo.html because its a regulated amount of pressure, do you think we would still throw a CEL as long as you were conservative?

sjhudon
28th April 2004, 06:53 PM
I think any aftermarket product like this that is not made for our T8 system will throw a CEL. I think we are well beyond simple modifications like the saab's of ole.

RED
28th April 2004, 10:05 PM
The T8 system has huge tuning potential, as the serious tuners out there are only just starting to show us with products that produce really impressive power gains, and more to come. If you can match that level of expertise as a DIY, you can get great results!

However, you will get nothing but trouble without the right diagnostic tools and the expertise to interpret the data those tools provide. I always keep Clint's advice in mind - Know Your Limitations.

M4Gunner
29th April 2004, 02:09 AM
yeah, i hear that. a new dyno place is opening up in town, so im going to get down there when i can, and kind of give myself a starting point so i can judge any future mods. IF i do try this valve thing, all im trying to achieve is maybe 2-3 psi increase and less turbo lag. the theory of the whole thing makes perfect sence, im just nervous about the T8 system. in all reality, with this valve, if its all the way open, its like its not even there. and if i was to dial it in a half turn at a time, i may not have any trouble... but then again, i may! i dont know, what do ya think?

ctrlz
29th April 2004, 09:48 AM
yeah, i hear that. a new dyno place is opening up in town, so im going to get down there when i can, and kind of give myself a starting point so i can judge any future mods. IF i do try this valve thing, all im trying to achieve is maybe 2-3 psi increase and less turbo lag. the theory of the whole thing makes perfect sence, im just nervous about the T8 system. in all reality, with this valve, if its all the way open, its like its not even there. and if i was to dial it in a half turn at a time, i may not have any trouble... but then again, i may! i dont know, what do ya think?

You could try tweaking it gradually. The boostvalve product will only delay the "signal" seen by the factory boost control solenoid. The "T" works differently. It reduces pressure by bleeding it off, at a pretty significant rate.
The best way to do this is to record stock boost and A/F ratios. This site has plenty of tips:
http://www.xmission.com/~dempsey/perform/
He offers an electronic alternative to the pressure relief valve approach:
http://www.xmission.com/~dempsey/perform/nospike.htm
He also uses intake manifold pressure for signal, rather than turbo outlet.

Getting any of these systems to work without throwing a code may require additional modifications. The ECM with stock setpoints will only tolerate so much boost. That's where the gauges come in.

Basically, this low-budget approach takes A LOT more effort to save several hundred bucks. If you want to get a different perspective on this, check out some of the Scoobie WRX forums. The concept of manual boost control (MBC) has gained much wider acceptance in that crowd. The bleed "T" tube mod is known as the 3/16 mod in the wrx forums. Very common. Some run it with no problems, some get ECU codes. The 5/64 variation of this is safer, with less boost. As far as manual boost controllers, this pretty much somes up the approach:
Or do what I did , buy a $70 turboxs MBC, basic one , install a boost gauge( maybe a greddy 60mm like mine, ($140). 210 dollars you can run 1 bar(14.4lb) pretty safely UNTIL YOU CAN SAVE UP THE $1000 for the UTEC. The boost gauge is always a good buy, sell the MBC to a noobie for 40, call it a day. Go out with the 40 bucks and get drunk.:>)
In short, you can increase boost over stock only to a certain point. To go higher, you need to blow some dough.

As some of us play around with the 9-3, we will eventually find out how much boost can safely be run, what valves are good for that, etc. Right now there are more Saabers throwing their disposable income at ECM upgrades, than there are cheapskates like myself. My hat goes off to them, that's the best way to do it. Someday, I'll be there. But, right now, I tell you, I prefer the intellectual challenge, and I LOVE being cheap!

M4Gunner
29th April 2004, 11:29 AM
my friend, i couldnt have said it better myself! im in the cheapskate boat too. :wink: i have a friend that makes valves like the boostvalve.com ones, and hes going to be giving me one. so, it wont cost me anything and i plan on trying it VERY gradually. even if i dont gain boost, i can still cut turbo lag w/out thowing a code. in one of my first posts on this forum, i had asked a question that nobody knew, and saba had told me to "do some trailblazing"... so, here i go!

HI-HO SILVER..AWAY!!!

Saba
29th April 2004, 11:48 AM
in one of my first posts on this forum, i had asked a question that nobody knew, and saba had told me to "do some trailblazing"... so, here i go!

HI-HO SILVER..AWAY!!!

:o

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ctrlz
29th April 2004, 11:52 AM
Here's some more info. I think neapleaze got a code to "check boost control solenoid" because the ECM detected an overboost condition. Saab used to use an "overboost switch" which cut power to the fuel pump over a certain pressure. That changed in 1987. There is still an overboost sensor, but now it reports to the ECM. Not sure of the specific levels the ECM can tolerate in our cars, but this is interesting, although it pertains to the 9000:
http://www.saabperformanceparts.com/item139.htm
Now, I wonder if these guys can give any specifics about the new 9-3?

If our big "T" turbo is 0.85 bar, that's 12.3 psi. From what I can find, the 9000 turbo ran 0.75 bar (11 psi). So, Saab allowed for 4 psi headroom in the 9000, if these numbers are accurate.

BTW, reprogramming the ECM can change the level considered "overboost."

M4Gunner
29th April 2004, 11:53 AM
lol.. well put man!

but seriously.. if this works out and people around here start doing it.. i want royalties.. nothing in monitary value, just props! we'll call it the "gunner-mod"!

Saba
29th April 2004, 11:58 AM
lol.. well put man!

but seriously.. if this works out and people around here start doing it.. i want royalties.. nothing in monitary value, just props! we'll call it the "gunner-mod"!Jet Spoiler, Ep Cable, Alex_Aux, Mav Merlot, Gunner-Mod. Legends! :nono;

ctrlz
29th April 2004, 12:32 PM
Check this out. Click on "Manual Boost Control." This is a simple spring valve with no bleed, installed on 1999 Saab. Again, he quotes 15 psi as the overboost point. Hmmm.
http://www.people.cornell.edu/pages/pmm12/Performance.html

"an MBC is the poor man's equivalent to a $500-$1000 aftermarket ECU"

M4, sounds like he's singin' our song :cheesy:

ctrlz
29th April 2004, 01:40 PM
Some good info here, including how drivability might change.

Pressure relief valves, and how the ECM handles them:
http://minimopar.knizefamily.net/perf/wcv.html

Bleed valves, with similar description:
http://minimopar.knizefamily.net/perf/wcb.html

ctrlz
29th April 2004, 02:47 PM
i have a friend that makes valves like the boostvalve.com ones, and hes going to be giving me one. so, it wont cost me anything and i plan on trying it VERY gradually. even if i dont gain boost, i can still cut turbo lag w/out thowing a code.

Find out how your friend's valve allows bleed for the wastgate to close. Personally, I lean toward the valves which have the adjustable bleed. I think the non-adjustable ones just have a pinhole drilled somewhere. You want the wastegate to able to close quickly.

Also, could you ask his advice on solenoid valves? Like if he recommends any ones in particular? I suppose I could always hit the junkyard. I ask because I have a plan in mind that incoporates two solenoids and one in-car switch. The switch would function as a his/her type thing, allowing one to toggle between the stock boost control setup, and the manual boost control. I think that might be helpful in wet conditions, and when I let my wife drive :cry:

And, personally, I like the sound of "Gunner valve" as opposed to "Gunner mod"-- provided it all works, of course :wink:

M4Gunner
30th April 2004, 01:51 AM
the valve would be the same exact thing as on boostvalve. all that guy is doing is making it in one piece. you could construct the same thing from parts at the home depot, or maybe a place a little more valve specific, but its VERY do-able, for a fraction of the price. and gunner valve is just fine! :cheesy:

ctrlz
30th April 2004, 12:30 PM
FYI, for a little more than the price of good A/F and pressure gauges, this tool will allow simultaneous monitoring of two vehicle sensors, and let you generate a GRAPH of their output. You need a Palm unit. I have another thread going on this topic.

I think this would be a superior method to follow the O2 sensor voltage and MAP sensor output to see if things are getting too lean. (I would still probably verify by checking the plugs.) Also, this gadget will clear any codes and come in handy for future troubleshooting.
http://www.auterraweb.com/scantoolsoftware.html

AND THE BEST PART-- it comes with its own A-pillar mounting bracket AND disables all airbags immediately upon plug-in :suprised; :lol:

M4Gunner
30th April 2004, 12:52 PM
hey, thats pretty crafty! and it works on our cars? it would TOTALLY rock if it did HP,1/4 mi times & 0-60 times like that g-tech pro or whatever its called. oh well, i guess you cant have it all!

ctrlz
30th April 2004, 01:13 PM
hey, thats pretty crafty! and it works on our cars? it would TOTALLY rock if it did HP,1/4 mi times & 0-60 times like that g-tech pro or whatever its called. oh well, i guess you cant have it all!
Those include an accelerometer. This won't do that. The G-tech devices are surprisingly accurate, according to my friend who supercharged his pickup. They're not that expensive either.
This guys got 74 of 'em:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2476408141&category=46100

9.3 Joe
30th April 2004, 01:41 PM
According to the Auterra web site they do compute 1/8mi, 1/4 mi, 0-60 times and HP in addition to the obII info

ctrlz
30th April 2004, 02:01 PM
According to the Auterra web site they do compute 1/8mi, 1/4 mi, 0-60 times and HP in addition to the obd-II info

Saw that. I suppose it calculates from the odometer and vehicle speed sensor.

Here's how the G-tech operates:
http://www.mustangworld.com/ourpics/hitech/gtech1.htm

And some negative opinions:
http://www.nsxprime.com/FAQ/Miscellaneous/GTechPro.htm

ctrlz
30th April 2004, 03:01 PM
SportCompactCar did a comparison of various boost controllers:
http://www.sportcompactcarweb.com/tech/0207scc_boostcontrol/

The part on ball valves gives some dimensions, including bleed hole diameter.

M4Gunner
30th April 2004, 04:43 PM
this is turning ver productive, isnt it!? that g-tech is cheap as hell.. last i knew they were up well over a $100. looks like ill be getting one of those in a few weeks.

M4Gunner
30th April 2004, 07:40 PM
i got a reply from Ric at boostvalve.com, and he says as long as we only try to run 3-4 pounds of boost, we shouldnt trow a code. however, he is going to lok into it more this weekend, and i will post the results.

ctrlz
30th April 2004, 09:42 PM
i got a reply from Ric at boostvalve.com, and he says as long as we only try to run 3-4 pounds of boost, we shouldnt trow a code. however, he is going to lok into it more this weekend, and i will post the results.

That's consistent with what Saab allowed in the 9000, 4 psi over stock. In the big "T" that's 16 psi boost (up from 12). So the theoretical overboost point from the MAP is 31 psi (16 psi boost pressure + 15 psi atmospheric pressure).

M4Gunner, keep in mind you may get boost spiking as you tweak the valve setting. That will likely throw a code. That's why I'm more in favor of getting a Palm-based OBD II tool, as opposed to traditional gauges plus the G-tech. I already have the Palm, though.

M4Gunner
1st May 2004, 01:54 AM
yeah, i have a palm as well, but did i miss something? can the OBD adjust boost? or do you just mean for reading spikes and so on?

ctrlz
3rd May 2004, 09:21 AM
yeah, i have a palm as well, but did i miss something? can the OBD adjust boost? or do you just mean for reading spikes and so on?

The basic scanner will only clear codes. If you get boost spiking, which seems likely since none of us know specific pressure threshholds, etc., you will end up with a check engine light (CEL). The basic code reading/clearing tools are very cheap ($20-30) on ebay.

The more sophisticated scanners (see the other thread) allow tracking of engine sensors in real time. If you interface to a laptop, the only limit is hard drive space. The Palm would be limited by memory. Since you can track four sensors simultaneously (plus read/clear codes), you really don't have to keep your eye on gauges. For example, If you track the trottle position sensor, MAP sensor, and oxygen sensor you will know what the boost is, when you are at wide-open throttle, and if you are running lean. The tool allows you to keep your eyes on the road while dialing things in. Not to mention you don't have to run wires and hoses to gauges.

And some of the software packages give you 0-60 times, 1/4 mile times, HP, etc.

ctrlz
3rd May 2004, 10:59 AM
REAL NICE diagrams explaining ball check valves.
Very professional looking document!
http://www.imoc.co.uk/users/upload/GV-Instructions.pdf

M4Gunner
3rd May 2004, 11:22 AM
good find man!

ctrlz
3rd May 2004, 11:26 AM
Nice explanation of boost creep vs spiking:
http://www.allpar.com/mopar/boost-creep.html

Note: Boost creep is different from wastegate creep!

Wastegate creep is early, gradual opening of the wastegate which decreases the boost pressure.

Boost creep occurs once the wastegate is opened. If the wastgate isn't opened at the proper rate (e.g. because the manual valve bleed rate is too high), the boost pressure continues to build slowly at high rpm's.