Anyone know how much the hp gain is on a t/c

From what I understand the peak gain is nothing with out a tune. The computer will detune your engine to make up for any peak gain the exhaust might give you. You may however have a small gain that you can see through the RPM range. Just remember that you will need a tune if you make over 260hp or the computer will detune you.

Not true, there will be some gain. A tune will be better with it though. The PCM might pull the TQ down but there will be more power gain.

see that is what I thought, I thought this whole electronic nightmare was based around that magical torque number not hp.

It is true, HP is just a calculation of torque at a given RPM. Other things i've heard about the PCM controlling power is mostly to keep the car from underpowering, not over. This is why some see 20psi and others see 16-17. The torque coming down at the top of the RPM band might be just the nature of this motor at stock levels. However Torque Managment has been in the tunes on all of these Drive By Wire cars since it's been out. The GTO and Vette benifit greatly from getting rid of engine TQ management. I've even felt the presence of TQ management in my truck. It varies the TB blade to keep you from losing control of the car and what not. It may be different somehow in the new T/C's and what not.

But I don't buy the whole you can throw a CAI, DP and Catback and stuff on the car and see 0 gain in HP or torque. I bet there will be gain in both, and the TQ curve still might come down toward the top. But power gain across the band will be more and the car WILL be faster. Granted now, tuning and getting rid of that TM crap will help alot more. If I had the $$$, I'd try this theory myself.

Tuning is a lot in these cars, as was in my Camaro and even my ancient technology Buick, which actually has a pretty advanced PCM for it's time.

Sorry for my rant, just my opinion. If I'm wrong on all this, let me know POLITELY. No need to bash me or call me retarded or something, I'll admit being wrong. Most of this is conjecture on this car anyway.

It is true, HP is just a calculation of torque at a given RPM. Other things i've heard about the PCM controlling power is mostly to keep the car from underpowering, not over. This is why some see 20psi and others see 16-17. The torque coming down at the top of the RPM band might be just the nature of this motor at stock levels. However Torque Managment has been in the tunes on all of these Drive By Wire cars since it's been out. The GTO and Vette benifit greatly from getting rid of engine TQ management. I've even felt the presence of TQ management in my truck. It varies the TB blade to keep you from losing control of the car and what not. It may be different somehow in the new T/C's and what not.

But I don't buy the whole you can throw a CAI, DP and Catback and stuff on the car and see 0 gain in HP or torque. I bet there will be gain in both, and the TQ curve still might come down toward the top. But power gain across the band will be more and the car WILL be faster. Granted now, tuning and getting rid of that TM crap will help alot more. If I had the $$$, I'd try this theory myself.

Tuning is a lot in these cars, as was in my Camaro and even my ancient technology Buick, which actually has a pretty advanced PCM for it's time.

Sorry for my rant, just my opinion. If I'm wrong on all this, let me know POLITELY. No need to bash me or call me retarded or something, I'll admit being wrong. Most of this is conjecture on this car anyway.

Very well said.

This is how I understand it.

Very well said.

This is how I understand it.

2x to that, very useful info

Very well said. You will breathe better so your response might quicken a bit. Especially I/E but your not gonna feel any power. Your not going to make more then 260ft/lbs of torque until after the tune. The thing is you'll prob. hit that 260 quicker then stock. Won't make you any faster when it comes down to 0-60 or 1/4 mile times. But you might notice a diff. in response say when cruising and just downshifting a bit for a burst.

And tuning is cheap for these cars. That PPC costs twice as much for a Saab so feel blessed since your making more power for much cheaper.

15whp was added with a 3" DP, no cat. No tune.. Go figure.

15whp was added with a 3" DP, no cat. No tune.. Go figure.

i ordered the synapse 3 '' catless DP yesterday :)

You better post a SOTP dyno!

15whp was added with a 3" DP, no cat. No tune.. Go figure.


I'm retracting this statement. It appears the TQ numbers go up briefly but once the PCM relearns - it remaps and the TQ drops down to near stock levels. Thanks GM! :twothumbs

I've seen a few videos of the Hahn exhaust and it sounds very nice...and loud...

From a noise standpoint, it is completely legal? I believe that Hahn's goal is to make most of their bolt on performance parts street legal, but I've been worried about getting an exhaust that too loud for street use (or at least too loud for cops to ignore!)...

cant wait to get mine should be here any friggin day