I just got back from a local exhaust shop. Would a 2.5 inch exhaust from the downpipe back into a flow pro muffler. Only thing is its not mandrel bent...I figured this is going to be better than stock, but will it still suffocate the 2.7, meth, and nitrous in the summer?

 

do not get anything that isnt mandrel bent, its just a waste of money and yes it will suffocate your mods.

mandrelexhaustsystems.com
go to the cobalt section
get the 120 dollar MANDREL BENT tubing
bring it to the muffler shop and get the flow pro muffler installed

oh yeah and you want 3 inch exhaust not 2.5 because of your forced induction.

 

thanks I figured that. I already have their website up and I'm probably just going to order the tubing. Ill do a search and figure out if 3 inch is the way to go.

Does anyone know how well aluminized tubing will hold up in the northern weather?

 

what is your hp goal? you should not run a 3 inch unless your looking to push over 300.

 

Im running 2.7 and meth, but I have a nitrous kit at home in the basement thats going to go in over the winter. Gonna start with the 35 and go to 50 shot. May pulley up to a 2.9 or so, not sure yet.

I was at 243 whp before meth and was on a 2.9, so maybe 260whp +- a few???



So mandrel and stainless are a must....just need to do a bit more research on the piping diameter. thanks recklessactn

Also I have the CIA 1 3/4 primaries, 3inch dp with a cat.....Should I go catless because of the nitrous

 

np, my friend is runnin 2.8 sand 60's with nitrous and hes hovering around 300. Definitely go with the mandrel bent and I would recommend stainless as well, the piping diameter is like you say in question... but im running 2.9 and making 264whp with a gmpp exhaust and thats 2.25 diameter ;-)

 

I have a crush bent exhaust, i don't know what the big deal is about them being crap. Works fine for me...

 

Happy dyno! Just kidding. Im probably going to go mandrel 2.5. Whose your friends running the nitrous? I am looking into window switches and either a wot switch or tps unit....if he wouldnt mind I'd like to know what he would suggest or his experiences.

 

stay away from the aluminum. i had 3in mandrel bent and it busted to peices. First place it busted was right after the dp(which was stainless) then got tat fixed and replaced with stainless. Then it busted right over the axle. all in all i threw away a 800$ exhaust system done by fabworx(a local performance shop that claimed i hit something) and they did nothing to fix it. I now have 3in mild steel and it has a few crush spots on it but it runs just as good as the 3in mandrel bent aluminum exhaust

 

thanks for the replies. /thread going 2.5 inch mandrel bent SS with flow pro muffler and resonator yet to be determined and before I spray the nitrous I am going to replace the catted dp with a catless one.

 

3" is not necesary unless you are pushing some impressive flow bench numbers. You will not utilize it. Bigger is not always better.

Works fine, yes. Efficient for performance? No. Crush bent gets pretty tight around corners. If you have 1 area thats equal to a 1.75", whats it really matter if the rest of the piping is 2.5"? The piping is only as big as the smallest restriction in it.

 

3" Custom catback on my IRL and it's not mandrel and it's sure not choking anything off

 

my piping is 3", I don't think I have anything to worry about. It's not that tight around corners at all.

 

let me lay down some facts here. crush bending or non mandrel bent is only slightly less efficient. you can buy pre-mandrel bent elbows and such at your local speed shop. mandrel is always a better choice because there is less bottle necking in the bends.
Your stock catback is 2.5 from the resonator back, so it wouldn't make sense to replace the whole thing if only going 2.5. resonator isn't restrictive at all.
the best idea for your setup is 3" exhaust especially with n2o, there's a lot of gases going through that pipe. also, methanol will destroy your cat so you might want to consider a test pipe. hope I was helpful. good luck with your decision!

 

HAHN 3" catback...end of story...been through many exhaust selling a coulple complete setups<---this sound the best and easy to adjust

 

thanks i appreciate the info

 

Custom > Hahn

Why? My custom setup ran me 120 bucks. How much is the hahn again?