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Discussion Starter #1
has anyone ever heard/tried/or thought about doing an electric exhaust cut out before the cat on thier saab..-is it even possible..is there enough room...help me out..thanks
Tyler
 

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Discussion Starter #3
because thats probably the easiest way to get the most horsepower..instead of doing a full exhaust with downpipe..
 

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Our cars specifically have the Cat directly behind the turbo to increase Cat temp. to reduce emissions. Therefore there is no way fabricate a "dump" into the exhaust, also the post-cat O2 sensor would throw a fit causing driveability issues, and on top of that it would be illegal due to emmissions standards, and without proper engine tuning you wouldn't gain any horsepower or torque, just possibly a shorter spool up time and a lean condition. Why not look into a PPC from BSR, or whoever?
 

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yea i understand..just trying to get some info about it...i'm not sure really how i wan't to go about doing my exhaust..i really just trying to get ideas..i already have the PPC stg 1..i'm eventually going to to the stg3 and downpipe i'm just not sure what i want to do after the cat..i don't kno if i should get a BSr exhaust or do a custom exhaust elmiting the resignator and buying an muffler from borla, magnaflow..etc..
 

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i don't kno if i should get a BSr exhaust or do a custom exhaust elmiting the resignator and buying an muffler from borla, magnaflow..etc..
i just got my resonator cut off and a straight pipe put in its place. i would definately recommend this mod. the "burble" or crackling during throttle let off sounds awesome.
 

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9-3 2.0T said:
yea i understand..just trying to get some info about it...i'm not sure really how i wan't to go about doing my exhaust..i really just trying to get ideas..i already have the PPC stg 1..i'm eventually going to to the stg3 and downpipe i'm just not sure what i want to do after the cat..i don't kno if i should get a BSr exhaust or do a custom exhaust elmiting the resignator and buying an muffler from borla, magnaflow..etc..

The answer to that question is yes, you can do the electronic exhuast thing. you can get it activated at a certain speed or rpm or pressure..etc

On a stock car, you'll probably get max 10hp? torque isn't going to improve.
Its going to be hell noisy. (experimented before). You might want to work on the air box and inflow as well, if you're going to be pushing out so much air, you need an equivalent coming in.

Since I am reading that you're from the States, you're probably going to have stricter controls and your car might just throw a fit. No harm trying though and report the results. Best is if you can dyno it before and after.
 

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if you dump the exhast too soon, you will loose too much backpressure, and you will take a performance hit...just get a real exhast, we arent driving a db9 here after all
 

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Dach said:
You might want to work on the air box and inflow as well, if you're going to be pushing out so much air, you need an equivalent coming in.
you neglected to take into acount that you need adequate fueling and timing advance to take advantage of the added air. you have to remember that your combustion chamber is a system that needs to stay balanced. Power is made by having air, gas, proper ignition, and a compression ratio that suits the mix, and having it all balanced. adding one isnt going to make much difference at all, if not throwing off the sensitive ecu's in 9-3s. also an aircone isnt going to make a difference. we are working with forced induction, and if you are playing in the ballpark of stock power, the airbox is more than suitable due to the vacuume pre-compressor side that is being made
 

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yfs87 said:
if you dump the exhast too soon, you will loose too much backpressure, and you will take a performance hit...just get a real exhast, we arent driving a db9 here after all
Agreed.... thats why there is a lot of talk of the bigger the exhaust the better, doesn't make much sense to me. it only moves up the torque to limited rpm range... esp in the higher rpm.

In this case, I am supposing his electric exhuast cut out is one where exhaust flows through the normal channels until a certain pressure/rpm is achieved. when that occurs, the cut out portion will divert the exhause out from a shorter exit point somewhere after the downpipe. this will increase the hp, not torque. therefore getting better high end performance.

With stock software, it could be minimal gains. with tuned software, you could get a decent percentage point higher... but then again, I have to hazard a guess as to which ECU type as in US, Euro, Asia, which might make it more or less sensitive to these changes.
 

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yfs87 said:
you neglected to take into acount that you need adequate fueling and timing advance to take advantage of the added air. you have to remember that your combustion chamber is a system that needs to stay balanced. Power is made by having air, gas, proper ignition, and a compression ratio that suits the mix, and having it all balanced. adding one isnt going to make much difference at all, if not throwing off the sensitive ecu's in 9-3s. also an aircone isnt going to make a difference. we are working with forced induction, and if you are playing in the ballpark of stock power, the airbox is more than suitable due to the vacuume pre-compressor side that is being made
Again, I agree with you. This is with relevance to optimising the software and hardware.

At the same time, not all ECUs are as sensitive as the US ones. needless to say, there are a quite a few experimental 93SS around the world who have yet to post their findings and test to see how far the T8 can go. US ECUs throw a fit once a BOV or CAI is fitted. In other parts of the world, there ar T8s with CAI, BOV, non-recommended sparkies, very near freeflow exhausts, alternative FPR and injecters and what have you are running on tuned software thats available to almost everyone easily, and these cars run beautifully, smoothly, of course with the added maintenance required of such performance mods.

Since this is performance mod section, there are bound to be mods that have not been tried out before, or effectively sorted out, and requires R&D and tweaking on the part of the owner.

There will come a time, and I see it already, that a stage 1 may not even be considered a mod at all.

As for the threadstarter, esp with the US ECU, we all wont know until someone treads where no one has gone before. Over here, the Asian ECUs are more friendly and can accomodate that exhuast mod, just that on a stock car, the gains weren't as fantastic as was expected.
With a tuned car, we dont know, but there are signs here that it could be promising.
 
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