Cheap Guy

iTrader: (3)

When I had my LT1, instead of going catback, I just used a Magnaflow muffler (part no. 12267) and installed my own Magnaflow tips (35167). I was told that since the stock intermediate pipe is 2.75 in., I really wasn't going to get much more performance by going with a total catback, plus I didn't like the truck cannons that come with the typical Magnaflow catback.

Well, the LT1 was replaced by my new LS1 and I plan on doing the same thing but I noticed the LS1 is noticeably quieter than the LT1. Is is safe to assume that:
a. the LS1 intermediate is the same as the LT1 = 2.75 in and
b. there is no significant performance gain by going catback v. muffler on a LS1
c. the Magnaflow is going to pretty much sound the same as on a LT1.

(I'm also looking for a good deal on these parts from a sponsor - send PM)

brian_rs/ss

a. yes
b. yes there is, if you go to a 3.5" or 4" merge/intermediate pipe/cat back(i would reccomend this if you plan on h/c/i)
c. no it will not sound the same, ls1's and lt1's fire in a different order, have different ports, and different chambers. ls1's tend to be more raspy.

Cheap Guy

iTrader: (3)

I should have added that I don't plan on any major mods for this car - not even headers - I'm still trying to recover from my LT1 nightmare $$$$.

I hate raspy - I don't want to turn this into a "what sounds best" thread, but is there a non/less raspy muffler which has a nice, mellow, not-to-loud tone?

Guess I'll have to go to the exhaust sound thread, but sound clips sometimes aren't accurate.

Blackhawk777

Since you don't plan on headers or an ORY, you honestly have the best non raspy catback/muffler out there for ls1 cars. Magnaflow stays real civil and mellow as long as you have cats and stock manifolds.

pewter2002

iTrader: (4)

Try Magnaflow p/n 16723 - quad exhaust tips instead of the cannon tips, which personally I don't care for. All stainless, even the band clamps, and the cheapest I was quoted was $530 US, way cheaper than "suggested" pricing. Mellow, deep sounding with no rasp. Louder than stock, def not abnoxious. Quality seems to be there, fitment was good, excellent warranty. You probably could make a similar system for cheaper yourself, though.

Cheap Guy

iTrader: (3)

That's kind of what I'm trying to do. I like that catback a lot better than the cannon catback, but I figured why spend the extra money if it's not necessary. The Magnaflow muffler runs $100, tips run $160 and any decent muffler shop should be able to do the rest to the after-intermediate piping for less than $100 installed.

Funny, the one thing the LT1 has over the LS1 is that it just sound meaner. That's about the only thing I miss about my LT1 (that and the low-end torque),