Question for the exhaust experts....

[fe155]

Just finished installing Belanger headers , r/t high flo cats , (supposed to be the quieter ones) and 3" Corsa on my 02' GTS . Only moved the car a few feet last night but noticed a few things i was not happy with . First i now have a vibration in my steering wheel at idle , and seems to be too loud and throttle response does not seem as good .I installed everything properly and nothing is hitting the frame . Anyone keep the headers and put a reducer and a 2 1/2 inch system or put a muffler in place of the cat ? Any observations appreciated .

 

[GTS Bruce]

Probably lost a little low end torque.Too loud?Vibrates at idle?Punch it after the computer gets used to the new set up and see how you like it.I thought I lost a little bit of very low end torque too.Maybe its time for a minivan. Bruce

 

[Vipermed 97.01]

Fe155......Your pcm will have to relearn its new addition.as far as the vibration it is usually indicative of a bad or loose motor mount,more than likely loose.Did you install the system yourself if not they may have loosened the motor mount to slightly lift or lower the right side to get a better fit through the frame side sill opening and that will cause your vibration.Addition of your mods with everything installed properly and tight should not cause this symptom.Good luck and give your new mods a little time before you undo as i believe you will be pleased

 

[TorQ Junkie]

I bought my ACR with the Belanger headers and catback installed. It had the stock cats originally (droned, loud). Last yr I installed the Roe 3 inch cats and added the Borla XR1 behind them - drone down, could hear stereo, but throttle response down as well (405 rwhp). This yr I learned how to weld and put in flanges to make swapping exhaust parts easier. I am running only the Borlas in place of the cats and have found a happy medium. Throttle response restored, sound acceptable, drone way down (not eliminated) 435 rwhp. Not bad with 3.55's.

The difference in hp could be more miles (4000 vs 7000), VEC-1, and different dynojets, but squirrely factor went up after getting rid of the cats. I did add O2 sims to the highflow cats and improved the low speed driveability, but it added no effect to the rest.