Thread: Exhaust Modifications.

A) without a cat and resonator it will sound raspy and junky. these cars make a foul exhaust note, no matter what you do to the exhaust.

B) backpressure doesnt matter on a roots blower car, so dont worry about it.

C) you need more than that stuff to get that pulley on. you need some exhaust mods (the catback does absolutely nothing for performance, so that doesnt count) to help with the flow you just created with a smaller pulley. i suggest getting headers as they are pretty cheap nowadays.

D) get a DHP or an overkill. ZZP is known to have crappy PCMs around here

Originally Posted by 98SilvermistGTP

You do not need headers to run a 3.4.

how do you know? have you scanned his car lately?

Originally Posted by 98SilvermistGTP

You do not need headers to run a 3.4.

Really. I wish I was as smart as you...

Get the headers now that way you won't have to worry about it in the future.

If you don't have the money for the headers then get a PowerLog, 3" Downpipe/U-Bend Delete. Save the pulley for last and get that PCM on before it...IMO.

Are you trying to steal my name?

catback does nothing. a 3" is a waste of money.

because the catback does not do anything for performance. there are plenty of guys making 350+ whp on a stock catback.

a 3" catback just makes it loud and wastes money. now a 3" downpipe, that is needed. anything past that is just fine at 2.5".

Originally Posted by SilverGT

In any boosted car (turbo or supercharged) you want the exhaust as free flowing as possible! Im sure the stock mufflers wont flow well. And yes the grand prix will sound really "raspy" without resonators. Maybe look into a full 3" exhaust (more flow the better! And will support more with future mods) a high flow cat and big resonator(s) to some straight through mufflers.

No point wasting money on 2.5" exhaust and wishing you went 3" down the road (then spend more $$$)

Just my 2cents.

Ha. Like Bio says the stock catback flows very well. Hell some dyno runs even show a LOSS of power with a aftermarket catback system. Only time you would need anything like that is if you are running some huge trim turbo setup where 3" is a necessity.

Originally Posted by Bio248

catback does nothing. a 3" is a waste of money.

It just looks good and sounds like poop

Originally Posted by SilverGT

How exactly is 3" a waste of money? Care to elaborate?

See my post above

Originally Posted by Bio248

because the catback does not do anything for performance. there are plenty of guys making 350+ whp on a stock catback.

a 3" catback just makes it loud and wastes money. now a 3" downpipe, that is needed. anything past that is just fine at 2.5".

X2.

Originally Posted by SilverGT

The bigger the exhaust, the better it flows... The better it flows, the more power you make. Simple.

on a turbo car maybe...bigger isnt always better..

TOO big will lose you power. obviously the RSX benefits more from a big exhaust.

these cars do not.

what is the point of spending 500+ $$ on a catback that MAY pick up a few horses??? you could buy headers with that and pick up way more power.

the stock cat back flows fine.

Originally Posted by SilverGT

My last comment was about boosted cars.

Even though Ive seen RSX's make more HP with a 3" exhaust vs a 2.5" exhaust. It was N/A and he still made a bit more power (10-12whp and torque).

Dyno sheets on a 12 WHEEL HORSEPOWER GAIN on a 4 n/a 4 banger...maybe to the crank LOL

Stick with the stock catback. When I installed my 3" System (First big mod after CAI, T-Stat, and plugs) I straightpiped the entire thing and it was just A LOT louder and nope...no faster. Put in a 3" Downpipe/U-Bend Delete...WOW!! Seat in the pants difference.

Originally Posted by SilverGT

The bigger the exhaust, the better it flows... The better it flows, the more power you make. Simple.

And sorry, I was meaning a full 3" exhaust (including downpipe). Yes a 3" catback would be a waste.

Um, no, it is about velocity, if bigger was better, we would have 3" primary headers, and 5" cat backs, the stock cat back flows fine, on our local 600+HP whippled 3800, it ran with a stock catback for a little while, now a 3" is on there, unless you are making more than 350WHP, you might as well just burn the money.......


and the Dyno gain on the RSX, peak horsepower isn't what it is all about, sure the car could have gained 12hp at the top, but what about the losses in the middle and the bottom, I'd bet the average HP was lower......