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Discussion Starter #1
Hello!

I'm trying to gather some information on a TB exhaust upgrade. I could have swore I read about people have some problems with the computer when they upgrade the exhaust only. This comes in the form of boost creep, etc. Can anyone with the exhaust only let me know their impressions. If you have exhaust only at once and had to do something else to fix it or make it better, that's what I want to hear too. I really want an APS turbo-back back I don't want to do it if it's going to compromise something.

Thanks!
 

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evoklr said:
Hello!

I'm trying to gather some information on a TB exhaust upgrade. I could have swore I read about people have some problems with the computer when they upgrade the exhaust only. This comes in the form of boost creep, etc. Can anyone with the exhaust only let me know their impressions. If you have exhaust only at once and had to do something else to fix it or make it better, that's what I want to hear too. I really want an APS turbo-back back I don't want to do it if it's going to compromise something.

Thanks!
Boost creep is caused by the inefficient wastegate design, not a computer problem. The exhaust flow is too much for the wastegate to handle with a catback exhaust (which is included in a TBE upgrade). So the turbo just keeps boosting until you overboost.. im sure theres a more complicated / indepth version, but thats it in a nutshell.

The only way to fix it is to either get a new turbo (NOT IHI) or port the wastegate. EBCs and such help , but arent a cure.

Robert~
 

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Discussion Starter #3
That is a great explanation thanks. APS said exactly the same thing.

So, porting the wastegate sounds easy, not :)
 

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ya... I got my mechanic to do it, but i dont know who i'd trust to do it. My guy does professional racing in NASCAR (first celica in the goody dash series), SCCA, and all sorts of racing and is sponsored by TRD to race his Supra and Celica and work on them to optimize their stock performance (fixing valve seats, etc... all very tedious complicated stuff to gain maybe 3-4hp). So I figured he'd be smart enough to port the wastegate ;). I believe he used a dremel and a carbon bit.

Robert~
 
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