stock class autocross muffler delete worth it?

[AutoXSS]

I've been setting up a msp for stock class autocross. Been looking at exhausts. The rules say anything is open after catalytic converters. Those have to remain unaltered. Since this car plays double duty and is my wife car, I've been thinking about having a muffler delete pipe made so i can unbolt the factory muffler and replace with the straight pipe when i autocross. This way, my wife doesn't hate on the exhaust note, its cheap, and hopefully makes a very few ponies while cutting some weight.

My questions are Will a muffler delete pipe, keeping the resonator, be extremely, annoyingly loud even with the pipe ending in a turndown towards the ground? I know there is some weight savings to be had, anyone know what the stock msp exhaust weighs? Will there be ANY performance gain, probably not?

 

[Brian_K]

the cats and turbo do a good job of quieting down the exhaust on these cars. try taking the muffler off and starting the car, it gives a very grumbly almost subaru sound. it's a little louder but not unbearable. just replacing the stock muffler with a straight pipe isnt going to do much if anything. you might just want to get a larger diameter straight pipe exhaust put together from the cat back if you're looking for a bit more power add a resonator for a little deeper tone. should be pretty cheap if you tell the exhaust shop to make the exhaust an underaxle instead of adding all those bends to replicate the stock routing.

 

[AutoXSS]

Underaxle sounds like a good idea. I was being hopeful about power gains. I would love to get a catback made but its quiet now and this would allow me to make it that way after Im done driving it. The weight savings might be worth it as a track only weekend mod. Im sure the sound is worth it.....that's probably worth a half second on course alone

 

[KrayzieFox]

If your only aim is to improve your AutoX time, I wouldn't bother. Replacing the catback all by itself yields such minimal gains that you're unlikely to see any difference. Just go out and have a good time and don't push it too hard or you'll risk ripping some of the suspension bushings and your wife will most definitely NOT like the sound of that (ask me how I know...)