If i plan on going to 60's and 2.8, what is a better sized downpipe that i will see more gains from. I wanna keep my GMPP exhaust so should i stay with a header and a 2.5 dowpipe or go with a header and 3in downpipe?

 

3inch downpipe with a 2.5" Connector and a 2.5inch exhaust to keep up with the flow.

 

How much are you planning on doing past that? If you're going to run a 2.7" or smaller or ever think about TVS, turbo, nitrous, etc, go full 3".

I really don't see you being happy with the 2.8" pulley when a 2.7" or 2.6" is so different.

 

Hey coop, Im going to do the 2.8 inch setup like in your signiture. I sold tvs already so I can put money in new car I have. How does that setup run/pull like? We have to meet up one day so you can show me before i put it all on my car

 

For the full satge 3 kit it was less than 500 bucks. That's with the larger s3 heat exchanger and larger idler pulley. If you want to do it I would be more than happy to assist you in this and I do have the pulley puller so you wouldnt have to worry about that we could get it taken care of. It you want to meet up we can do so, just me know and we can work out a date and time. Where is it that you are located again I apologize my memory is not the greatest.

Also, If you dont mind me asking why did you ditch the TVS?

I will tell you it definately better than stock and does pull but its no where close to the TVS.

 

Im around 42nd and center area. I can drive where ever though and I used to live on 200th and maple area and thanks. Where did you buy kit at? And thanks also

 

pm sent

 

2.5. No debate.

 

Sorry for the thread jack OP

 

i think 3" is unnecessary.

 

most aftermarket downpipes are 3 inches with a 2.5 inch flange on them. I wouldnt even know where to find a 2.5 inch downpipe lol

 

Well for the people that think 3" is unnecessary, you are blatantly wrong. This is a forced induction application so the more exhaust flow the better.

If you are trying to be prudent for your build or don't want a 'loud' exhaust do a 3" downpipe with a 2.5" catback (even stock batback). If you know anything about exhaust you know that as it cools it's velocity slows down, meaning you need the extra flow straight out of the engine, but it won't hurt you as bad towards the rear of the car.

3" all the way, or 3" to 2.5"

/endthreadfornubs

 

Do not put a 2.5" downpipe on the LSJ. The production downpipe is 2.785" (for the most part). If you are going to get an aftermarket downpipe, make sure it's at least a 3" /thread.

Perfect setup for 90% of the LSJ's on this site

 

We win lol.

 

if u go with a 3 " catless u will get a raspy sound on wot but will sound rumbly and throaty on idle and cruising, im currently having zzp custom make me one that is 3 " catless with a vibrant resonator on it yaaaay so it will sound deep still with no raspiness on wot

i have a CA-V2 Header With a GMPP Touring Exhaust it sounds so nice when u let off the gas its soo rumbly and throaty i love it but i need the 3 " coz i got ottp stage 2 with 60's and a 2.8 pulley

 

not in all cases, usually a catless dp is only raspy with a straight piped exhaust with no resonators and other cheap exhausts

 

true that...but i'm running a gm touring exhaust :'( thats not cheap lol but yeah try running a catless on a fart can muffler then all the raspiness will come out haha

 

I got a 2.5" downpipe. I like it.

 

I got pretty good results from ZZP's catted 3 inch DP with a 2.5" flange. I'm still running the stock cat-back. See sig for full list of mods, etc.

 

i just got zzp catless dp with gmpp catback will that sound good

 

So whats the verdict? 2.5 downpipe or 3in?

 

I'll say this again .... Do not put a dinky 2.5" downpipe on the LSJ !!!! If you are going to touch the downpipe, make sure it's 2.75" - 3.00".

 

Please listen to people who know WTF they're talking about. Not people with next to no mods... Modding cars and then being disappointed is a rather costly mistake. Do it right the first time.

 

Ya fer sure

 

Ok thats what i was thinking, so ill be good with a aftermarket with a 3in collector, 3in downpipe into a 2.5 catback