i hear I have an LSJ header stock, would you recommend upgrading the header and DP to something like zzp or vibrant if I were to do the 2.4 intake manifold swap? or would an LSJ DP be enough flow without being restrictive? (I have a DC sports 2.5" exhaust which is 2.5" OD and 2.25 ID. thanks for the help.

also i read ppl get 42 mpg having CAI, EXH, H/DP, 2.4 man, + tune on their 2.2's, is that true? 42mpg sounds really high. I would do that just for the extra ummff and fuel economy, but i do realize i'd have to run 93 oct.

WHAT ARE THE DEMENSIONS OF THE LSJ DP????

 

1. LE5 is the 2.4L found in the Sport/ 2.4L SS

2. its kinda of up to you. aftermarket is better.

 

thats what i thought, but having a 2.5"/2.25" ID exhaust, arent the LSJ header the same diameters? so going any larger would my exhaust just restrict it?

 

I am not sure what the stock LSJ header diameter is.

But i know after market wise you want to stay below 3 inches unless you have plans for 300 + whp. Most exhausts for cobalts are 2.5", the gmpp/borla are the only ones i know about that are 2.25"

 

suscribed for answering when i get home

 

yea my exhaust is a "so called" 2.5" but that's measuring the OD, the IS is really 2.25".... so i have to reasearch and find if the LSJ PD is 2.25" ID because if it is i think that's the way to go because i'm building an economy car for now until my warranty is up

sweetness

 

2.25" dp is fine, i have the vibrant mine is 2.5" my exhaust is 2.5" od, 2.25" id

 

do you have pics? I believe the 07-08s have the LSJ header, but not the cat backs. The LSJ's have different cat backs I believe. pics would be helpful.

Sounds like you have the 2.2L one though.

 

he has a aftermarket exhaust, intake, wants to know if he should get a aftermarket dp or just the lsj dp i think, i ddint read it all as im too lazy and he made it quite long

 

OK i TOTALLY got the incorrect drift of that.

My bad OP. I would suggest aftermarket myself.

 

my exhaus tis 2.5" OD, 2.25 ID, i'm curious to know the demensions of the LSJ DP becaus ei cant find it by searching, i'll keep looking but I'm guessing its 2.5" with about an inch at the end with 2.25" which sounds like it would work perfect for my exhaust

a 2.5" ID DP seems like it wouldn't help much because i belive the exhaust would restrict it being 2.25 ID.

that's exactly what i'm asking

 

I went from 36 to 38 on the highway just from an intake and exhaust. If I also got a tune and header / downpipe, I would fully expect to get 40 mpg highway. The biggest trick is to drive the speed limit.

It it was a manual, I would believe 42 mpg, after all, I have an auto.

 

ok thanks, yea i'm seeing 32-34 cty/hwy avg. w/CAI + Exh which is higher then i was seeing, 30-31 stock

 

Just get this combo,





ZZP header and downpipe.

You'll never look back.

 

thats the one I was thinking about because it's $550 shipped or alittle less bepending on how you want it, plus they give you $50 coupon for sending in your stock DP w/ cat,

when you were buying the dp did you buy it new? did you select the 2.5" flange?

 

Dont waste your money on the ZZP shorty header. Youll still need a DP, it doesnt have equal length runners, its got a big tapered step in the runners for 1 and 4, ans 2/3 just dump into the large collector tubes, the O2 sensor reads almost entirely off of the #4 runner, and its only $20 cheaper than their midlength which is MUCH nicer.( Idont mean to bash your combo Red, I just think for $20 the midlength is absolutely the way to go as far as ZZP is concerned)

I wish that someone made a nice mid-long tube header in 304 stainless with 1 5/8" primaries.


Red, is it just the picture, or are the primaries not welded to the flange on the outside?

 

thanks for all the help guys, i went with an LSJ DP for now.