ive been lookin on the net some and cant seem to get a good answer on this topic. i have a full stock exhaust and had the mufflers replaced with well no mufflers. what is the expected hp gain or loss with this.

 

I had a 3in xpipe welded in place that resulted in sans mufflers.

I really dissnt notice any gains or losses.

The shop who did them makes thier own xpipes, they said that normally they see about a 2-3hp gain in the higher end, and a loss of 1-2ftlbs of torque on the lower end.

 

Since the main restriction is before the mufflers, you probably won't gain much (or loose much in that case). Generally though, you will loose power since the engine is set-up w/ that back pressure in mind. However, tune the engine for open exhaust and you will see a gain.

 

any way to tune it for open exhaust with the diablo tuner?

 

you would most likely have to take it to a tuner for that. Do you still have the cats on the setup?

 

yea i still have cats with this setup, and they are stock.

 

if you still have the cats you shouldnt need a retune. If you removed the cats then you would definately need a new tune.

 

On an otherwise stock car, hardly.

My a/f was dead on with an offroad pipe and catback. The only thing a tune would do is turn off the SES light with some MIL's can do for $50

 

Or see if someone on here has some tuner knowledge and can walk you through on how to turn it off and save $50...

 

The GT that I just got doesn't have mufflers either, weird. I didn't think about there being any horsepower loss.

 

Jack nailed it. If the pipes are still full length and exit the rear then you're almost certainly not noise-legal in most states. It's illegal in about half the states to run a registered passenger car without a muffler unless it came from the manufacturer that way (STR4's don't have any mufflers in stock trim... the turbo quiets down their farty-fart noise.)

 

yea it is pretty loud, lucky for me tho the police really dont care about the noise restriction on exhaust, or smog testing for that matter. funny thing is my buddy has a 95 gt w/ the slp loud mouth,long tube headers, and off road xpipe it is quite a bit louder then mine, when cops pull him over they dont say anything about his exhaust and it is loud enough to make your ears bleed(not really, but close).

 

i don't have mufflers on mine either, i don't think there is a gain or a loss of power, and if there is its not enough to tell, just louder thats all

 

only way to know whether or not you have a hp gain or loss on your car is to dyno before and after. Every car will be differant though.

 

i don't know if i would waste the money dynoing it just to find that you maybe gained or loss a couple of hp at the most, but everybody is different,