LNF Exhaust Questions: downpipe, exhaust flange, catback?
 

i was wondering a few things.....

1. are all catbacks the same? Like will a cat-back from a SS SC, or a 2.4, or even a 2.2L fit on a SS turbo and visa versa? I know obviously the downpipe is way different. but it appears to me that all cobalts seem to share a similar looking cat/DP flange... and it seems to be in the same or similar location on all the various models. So do i NEED to buy a catback designed for the turbo? or would a 3" exhaust for a SS SC work? like the GM performance sport exhaust?

2. if i am installing a new DP. Say the hahn 3" catless DP... Do i need to buy new gaskets or anything? Are they copper? or steel? can you find these at an autoparts store? or is this a dealer only item? or can you re-use original? or are these dry flanges? or what?

3. The 3-bolt flange between the "cat" and the "cat back" is this the same on all cobalts? is this a standard flange for all cars? If i wanted to fabricate some exhaust components, is this flange something i could pick up easily? I would like to save my stock exhaust just in case. so would rather not have to hack it off and use the original one if i dont have to.

I'll take care of one and three.

The bend pattern is the same. The 3 bolt flange on the SS/TC is the difference. 2.2, 2.4, and SS/SC all share a 2 bolt flange.

sweet.....

so basically if i had a 3-bolt SS turbo flange.... i could weld it on to any other cobalt exhaust and it should slap right up in place?

do we know if the hangers or anything little changed?

so i assume all exhausts from all other cobalts are interchangable.... up too the LNF and it just changed the flange... If i understand you correctly

Correct. :cool:

And no you don't need a new gasket,you reuse the ones on the car.If you have any questions feel free to ask I can swap out my downpipe in about 20 minutes now

of course... we are talking coupe-coupe or sedan-sedan.... It is a given that a sedan would not swap with a coupe... right?

(just want to throw that in there to avoid someone asking later)

done it a few times already i assume? might i ask what would make you need to do it more than once or twice, let alone enough where you have timed yourself? :)

The sedan's and coupe's use the same catback's .

1. most of the bend patterns are entirely the same. the biggest difference is the muffler/resonator combination along with the tc having a 3 bolt flange where as the sc has a 2 bolt.

2. when i installed mine i was able to use all of the stock gaskets. the gasket for the o2 sensor housing to dp is embedded into the o2 housing and you will only get it out if you pry it out.

3. again not th same on all cobalts. the turbocharged model i believe is the only 3 bolt flange. custom making an exhaust would probablly require using a universal flange.

::cussing:I forgot to put the gaskets back on the first time,the second time te gasket on the manfold slipped out of place and caused a little exhaust leak,so that is three times,do i win a cookie:twothumbs

just for you!!! http://2.bp.blogspot.com/_53oMB4-fxX...0-R/cookie.gif

the exhaust diameter for the T/C should be 2.5" or greater. 2.5" is stock although most have measured 2.75" where Chevy claims 2.5"!!!

The exhausts that GM sells are 2.25" I believe, they would not be a good match for a T/C.

3" is desired on the turbo cobalt. with a 3" downpipe.

Thanks, i was actually going to ask that next... what size is the stock SS turbo exhaust piping....

I know 2.5" or smaller would be restrictive. I was asking about interchange more for upgraded stuff, not so i could put a oem exhaust from a base 2.2 onto my turbo...

I was thinking about trying to put together my own "cat-back" from components. like mix and match... this resonator, that muffler, these pipes... but was wondering if i could find a cheap oem catback from a junk yard or something to use for mock up, and getting the bends and such right. that way i can still drive on my SS with stock exhaust while i make my new one, and then keep my oem SS intact in case i ever want to go back to stock.

Stock CB is 2.5" mostly. It is 2.75" coming out of the muffler IIRC. It is 3" right at the front flange and necks down to 2.5" right at the factory resonator (so appox 2 inches of it is 3" LOL). 3" CB will add 6-7 whp if you are tuned. Factory DP is 3" but has restrictive cats and a crush point where the O2 sensor is. Aftermarket DP (I suggest catless) is worth 15-20 whp when tuned.