I guess what I am questioning is the relatively smaller diameter of the side pipes creating restriction. It seems that freeing it up through the larger rear pipes would provide the maximum gain

 

Installed Roush axel backs tonight on my Boss 302. Also I am running a 5/8 hole in the discs. the sound is what I was looking for. The car now has Great sound from the rear along with the side. Two things I noticed. After the axel backs were in, it stoped the minor popping that you get from the side exhaust and the car seemed to breath better. I also noticed a small gain in how the car response. I also went from 16.3 MPG to 16.5MPG. The whole job took about 70 minutes with 1 jack, and 2 wrenches. Plus you shave about 25 pounds off the rear of your car. Stock mufflers are heavy.
IMO the Roush Axel backs are the best bang for the buck.

 

+ 1! Awesome you are enjoying the Roush's

 

Could
You get size and weight of the stock mufflers!

 

Sound clips man. Sound clips!!!!!!!!!!

 

That's great news. I was wondering if the popping/cackling would go away with a freer flowing axle back. Hopefully I'll get the same result with the Corsas. That's pretty cool that you cut 25 lbs. I need to remember to weigh mine before putting them on.

 

Great info, thanks

 

Two things.

The popping/crackling is the best part of driving this car daily.

Want the side exist to free up HP? Put turn down immediately where the "plate" flang is. Loud, very. Illegal, absolutely. But big flow increase.

S.

 

this!

 

The Roush Axle Backs pop/crackle all the time. Trust me, if it went away from the side pipes..the mufflers make up for it. I love the way mine decels.

 

Hum, I hope they sound better in person than they do in this Video.

http://www.youtube.com/watch?feature...&v=2nQ25LvX9lQ

 

A 3-5hp gain will not lower your 0-60 or 1/4 mile times.

 

I heard them on a friend's 5.0 at the track. It's a much deeper sound and he swears there is no drone at all at highway speeds. I've never really been able to get a good feel for exhaust sound from videos. It almost always sounds different in person A lot of other friends have Corsas on their Vettes and they sound awesome. I know it's a different car, but still really great sounding exhaust. Exhaust is one of those personal preference deals and there will be a huge range of opinions based on what each individual wants from it. Heck look at how many different sized side pipe discs people are running. For me, it's just far too quiet from the back of the car after having driven it for 3 months. I really like the sound from the sides, and like I said earlier the pop/crackle is kind of raw...in a good way, so I'm good either way on that.

 

I know what you mean. You can watch 5 different videos of the same exhaust and they all sound different. I've watched other videos with the Corsa Extremes and off road X pipes and they sound great.

 

I'm wondering if you have to retune the car with a exhaust change. Seems like I read somewhere if you changed the air filter with a cold air system and K&N filter you should retune the car.

 

No.

 

You've asked a question to which the answer is no, and made a statement to which the answer is yes whether it's a K&N filter, FRPP filter or other open filter used in an after-market CAI system.

 

Thanks for the responses, I think I will consider changing mine out too.

 

I have MRT Interceptor axle back and they sound GREAT.You can hear them on a video Laguna Seca MRT.

LS014

 

Yep curious about this as well. Looks like my package weight is 35.5 lbs according to FedEx. Oh well I should have them tomorrow or Wednesday so can weigh the stock ones after I get them off the car.