is it legal to remove the rear section on an Si,, and run STS?? just want to clarify something

 

I suggest against it..

The HOT gasses point DIRECTLY towards the lower control arm/Sway bar/shock mount bushings, and WILL MELT THEM

Trust me.. I know.

 

its not me thats doing it.. a guy in my region runs this way and he always is in STS. i thought he should be in street prepared, not that i care hes runnin STS, i run FSP anyway.. so is it legal.plus he runs and doesnt work not that im gonna taddle or anything.

 

i think it would be legal but not sure.

But another question would be would a straight pipe replacing the axleback make any more power. Since its just for auto-x i've considered trying to make my own just to put on for race days if it would help.

 

doubtful. sts doesn't allow enough engine mods to make a straight pipe necessary. in fact, i feel that you want the longest exhaust possible to enhance low end torque. i run a stock b-pipe (agian, for low end torque) with a generic 2" diameter axle back that is just a straight through. this setup feels stronger then just the stock b-pipe and no muffler, and way stronger then a straight pipe terminating 30" behind the cat. (not to mention a LOT quieter) of course, i have no actual dyno numbers so this is pure conjecture on my part.

and to keep this on topic, yes it is legal to remove the rear muffler section. HOWEVER, if the safety steward feels the car is too loud he can boot it, or if the exhaust terminates before the end of the passenger compartment it could be deemed illegal. if its that short, its hurting him anyway, so who cares. not to mention he's quite the *** for not working in a volunteer sport. in short, you won't see him at nats and if he doesn't work he probably isn't very serious about this sport anyhow and as such won't be the best driver on sunday.

nate-who loaths anyone who doesn't do their fair share

 

nate's right... exhaust is free from the cat back, even in stock class.

 

thanks for clearing that up guys.

 

New to the STS rules this year is:

"All STS vehicles must comply with the Federal 49-state safety and tailpipe emissions test requirements as a minimum."

I'n not sure what the 49-state rule includes but I would bet it requires the exhaust to quietly terminate behind the driver or something like that.

 

i'm pretty sure that was in the rules from the start. there have been many discussions on the st list concerning emissions requirements. the concensus is that the rule is intended to prevent removal or modification of emissions equipment, not restrict any exhaust type.

due to the variations in emissions inspections, enforcement of a specific location of termination or a certain volume level is nearly impossible. realistically, the only proof one has that their car is 49-state legal is an inspection sticker. changing your exhaust just to get a sticker is very easy.

nate

 

So what do you do if you come from a state that doesn't require inspections?

 

You make sure your STS/STX car is 49-state legal.

 

not having a muffler does not exclude one from passing emissions. However the guy at the gas station will probably hate you bringing an un-muffled piece to echo through his garage area and make his ears bleed.

 

I wasn't thinking that you would fail smog but rather the safety inspection. Having hot exhaust gas exit while still under the car must be some sort of safety violation.

 

what about vipers and superformance/factory five cobras?