Is it safe?

Saabohème said:

Sheesh, gave me flashbacks to The Marathon Man. A DP without a tune will not hurt you in way shape or form. Hardware mods do not up your HP and torque by themselves, at least not in any appreciable way. Hardware mods ARE necessary to support certain levels of tune, and putting on say a stage 3 tune with fully stock hardware would be a disaster.

T-8 will compensate for the reduction in pumping losses on the exhaust side that the DP has given you in this case. The ECU reads the pedal position sensor (how far you have pressed the pedal down) and consults its stored data on how you drive (its stored adaptation data). It takes the MAF signal (telling it the mass of the air being ingested), the knock sensing data from the spark plugs (the quality of the combustion in each cylinder), the manifold absolute pressure, the bank 1 (front) O2 sensor readings, your axial temperature and pulse rate, and measures how much you are perspiring. Using this critical data, it determines the appropriate torque request. Because your engine will be breathing easier due to the 3" DP, the amount of ignition advance and boost needed to propel your car forward within its optimum performance, efficiency and economy envelope will be a tad less than it was before, because your car with the 3" DP has achieved slightly better volumetric efficiency. And T-8 will figure this out nearly instantaneously and adjust accordingly.

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Saabohème said:

Enjoy your tune when you get it. Ha, like that even has to be said. You are going to be soooooo happy. You think that car is pretty powerful now, you are in for an awakening. As satori. The epiphany of epiphanies.

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Saabohème said:

Sheesh, gave me flashbacks to The Marathon Man. It takes the MAF signal (telling it the mass of the air being ingested), the knock sensing data from the spark plugs (the quality of the combustion in each cylinder), the manifold absolute pressure, the bank 1 (front) O2 sensor readings, your axial temperature and pulse rate, and measures how much you are perspiring. Using this critical data, it determines the appropriate torque request. And T-8 will figure this out nearly instantaneously and adjust accordingly.

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Saabohème said:

Sheesh, gave me flashbacks to The Marathon Man. A DP without a tune will not hurt you in way shape or form. Hardware mods do not up your HP and torque by themselves, at least not in any appreciable way. Hardware mods ARE necessary to support certain levels of tune, and putting on say a stage 3 tune with fully stock hardware would be a disaster.

T-8 will compensate for the reduction in pumping losses on the exhaust side that the DP has given you in this case. The ECU reads the pedal position sensor (how far you have pressed the pedal down) and consults its stored data on how you drive (its stored adaptation data). It takes the MAF signal (telling it the mass of the air being ingested), the knock sensing data from the spark plugs (the quality of the combustion in each cylinder), the manifold absolute pressure, the bank 1 (front) O2 sensor readings, your axial temperature and pulse rate, and measures how much you are perspiring. Using this critical data, it determines the appropriate torque request. Because your engine will be breathing easier due to the 3" DP, the amount of ignition advance and boost needed to propel your car forward within its optimum performance, efficiency and economy envelope will be a tad less than it was before, because your car with the 3" DP has achieved slightly better volumetric efficiency. And T-8 will figure this out nearly instantaneously and adjust accordingly.

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Tmarter said:

Subarus are a lot more simple than t8, but t8 works by constantly correcting boost, injector pulse width and ignition timing to achieve a torque request (in the tune) at a specific air mass (MAF) and all the calculations are done in the ECU...this is a really reliable way to keep the power levels the same, but when it comes to tuning for performance it becomes kind of a bottleneck at some points...

Unless you start messing with the mechanical adjustments of things, for example the wastegate actuator rod, the ECU adjusts ignition fuel and boost to keep everything in check, so that if something is out of balance, it will adjust the other areas that put it back in the "green". If something is way out of wack to where the ECU can not compensate any further, it goes into limp home mode.

Not sure how Subaru's engine management works for stuff like the wrx and sti, but i've heard of guys all the time that remove and install aftermarket sensors, add a manual boost controller, remove boost restrictor pills in vacuum lines, bypassing what the car was designed to do and have no issues... but to get it to run perfect, it's adjusting and testing it til it's right, but it can go south if something isn't done right and if the atmosphere or hardware changes the fueling or air volume, you have to adjust it again so it runs right... T8 takes care of those adjustments automatically...so people can just get in and drive their car every day with no guesswork or knowledge of what is going on.

T8 wants the engine making a certain amount of power, and if it sees too much it pulls back...it's safer, and tries to keep the engine performing the same all the time, but also is very particular of all of the input from the sensors, which makes it hard to work around without reprogramming, and that being said it's still not easy to do what you want the engine to do the same way 100% of the time

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Tmarter said:

There's a 3 way solenoid that controls the boost, sandwiched in between the turbo's boost signal line and the port on the wastegate that pushes the actuator out and opens the flap to limit boost...which is the same place you would put a manual boost controller so you can adjust something on the fly on a wrx. If the sensor is unplugged the car won't even make boost and it'll throw a code for "wastegate solenoid circuit range/performance"

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Saabohème said:

No, you have T7 engine management. The easy way to tell the difference for you is that you have a black DIC (direct ignition cassette) or IDM (ignition discharge module) that house four coil packs within the module, whereas T8 uses individual separate coil packs. The DIC looks like this,

while the T8 individual ignition coils look like this:

The two systems are substantially similar in most respects. Both utilize ion current sensing via the spark plugs to detect knock and misfire by applying an 80 volt DC bias current through the spark plug immediately following combustion. If no ion current or a severely attenuated ion current is generated by the electric field created by the bias current in the plug gap, a misfire occurred in that cylinder (as uncombusted air/fuel charges contain no or insufficient ions) and if the ion current detected shows a sharp spike in amplitude, autoignition occurred in the cylinder. Both Trionic 7 and 8 react to these phenomena in similar ways.
You can get a ton of useful information about T7 here.
There are many, many technical papers discussing ion current sensing technology available on the web. A sampling:
http://am.delphi.com/pdf/techpapers/2003-01-1119.pdf
http://www.vehicular.isy.liu.se/en/Publications/PhD/99_PhD_580_LE.pdf
http://www.ieeecss.org/CSM/library/1998/oct1998/02-EngineFineTuner.pdf
http://s3.amazonaws.com/zanran_storage/www.fs.isy.liu.se/ContentPages/12609742.pdf
Here are two I like, since they pretty well confirm what I have thought to be the case for a long time - that all along GM wanted the Saab/Mecel ion current sensing intellectual property for their very own when they first purchased 50% of Saab in 1989 (Mecel first patented ion current sensing in 1984):
http://delphi.com/shared/pdf/ppd/pwrtrn/ionization-current-sensing-ignition-susbystem.pdf
http://delphi.com/pdf/techpapers/2013-01-0354.pdf

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Saabohème said:

Not to make excuses (he said making an excuse) but I can't see for diddly squat out of my right eye since I got my retina reattached. And then had the post-reattachment cataract dealt with (apparently development of a cataract is a rather expected sequela of retinal reattachment surgery). Now I have an artificial lens in my right eye from the cataract correction. I am myopic. The surgeon said we should not put a 20/20 lens in when he did the cataract. He said my left eye would still require the full external lens correction it has always needed and the right eye would require none. He said this great disparity in visual acuity between the two eyes would prevent the them from playing together nicely. So we compromised and he put in a lens that is roughly twice as good as the natural one that remains in my left eye. And I have to take off my glasses to read and to sit at the computer. As God is my witness, I thought your upper right hand car description stated you had a 2005 9-5 Aero, which IS a T7 car.

So, the answer is you still do not have T8. All GM 9440 platform 4 cylinder 9-3 SS models have T8 (2003 >, except convertibles in which case it is 2004 >). The V-6 9440 cars have Bosch engine management.

As to your last question, yes. You can put on the supporting hardware and then add the tune later. The performance increase will come from the tune, but you cannot tune aggressively without having the required supporting hardware in place.

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Saabohème said:

So, the answer is you still do not have T8. All GM 9440 platform 4 cylinder 9-3 SS models have T8 (2003 >, except convertibles in which case it is 2004 >). The V-6 9440 cars have Bosch engine management.

As to your last question, yes. You can put on the supporting hardware and then add the tune later. The performance increase will come from the tune, but you cannot tune aggressively without having the required supporting hardware in place.

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Diggs said:

He does in fact have a 2.0T and it is T8.

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lowoffset said:

Thank you. So your saying 2003 and below, and 2004 and below cabrio have t8, but that confuses me. Is T7 newer than t8? I assume from your post that 2003 > SS have t8.

Sorry, very new to saabs. Not trying to annoy anyone.

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