So, I went to day and updated my L61 Header and Downpipe to an LSJ. I've seen alot of posts about this being "a cheap upgrade mod". And it is. I got my Header and DP for $125, and with a little machining work to the studs, and all new Gaskets, I have $200 in a better exhaust.

There are some major differences between the L61 and LSJ Header.

DownPipe: Flange to Cat:
L61: 2-1/4"
LSJ: 2-3/4"

Downpipe: Cat to o2 Sensor:
L61: 1-7/8"
LSJ: 2-3/4"

Downpipe: After O2 Sensor:
L61: 2"
LSJ: 2-3/4"

Header to Downpipe Port opening
L61: 1.9" x 1.6" D shaped
LSJ: 2 1/4" Round

L61 Header:



LSJ Header:



Comparison:



LSJ to L61 Downpipe:



It sounds louder and lower exhaust note. This is hooked to a GMPP Cat back.

I will be dyno'ing the car Saturday, at which time I will be able to list whats gained, as my car was last ddyno'd in April, and this is the only performance mod since then.

 

I actually have an LSJ header sitting in my trunk right now, and have been wondering if it was even worth it to go ahead and get a DP and hook it up.

 

i have an lsj mani for sale... 60 shipped

 

pm'd!

 

Would it be better to go to the ljs Or would it be better going to an aftermarket one? and where did u get the parts for only 200. I think it would be more expensive then that

 

for the l61 header, the d-shaped portion, is that part able to be ported out, or is it one solid piece?....if that made sense. i dont got my stock header anymore and i never bothered to look

 

I aswell have an LSJ Mani, no use for it so I will consider offers.

 

i aswell have one for sale b/o
https://www.cobaltss.net/forums/parts-66/lsj-cams-pullys-gauge-pod-etc-226158/

 

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No, the D-collector on the L61 manifold can not be ported out. The primaries neck down to that shape, there isnt any extra material that can be removed.

 

ooh. aight, thanks.

 

well saturday has come and gone... what did the dyno show?

 

I lost 3 on the total power, but the car has definite better acceleration and mid range. Im sure its because of their being less backpressure. Once I can afford the 2.4 Mani, and hte adapter plate and harness (got an LSJ TB) I will get retuned and then we will see a bigger gain

 

im just wondering, cuz i have the 2.4 intake mani, and tb... i will be getting an ljs mani and then im gonna find a 2.5" catted dp... then ofcoarse... a tune... i just want to make sure im not going to go backwards with the lsj manifold

 

Can you post the before and after graph?

 

Interesting...I was going to go this route, but there was so much talk about whether the LSJ mani and DP bolt up correctly on an L61 with an auto that I just said forget it and went aftermarket...I got a Pacesetter header and Exhaust Depot DP (catless) that were second hand (but they were never installed on the first owners car so in essence they were brand new) for $200 shipped to me...I picked up a stock LSJ cat-back to go with it for $45 locally.

I was very happy with the gains in both fuel economy and power. Mainly in the mid and upper range. I'm also glad that it's not very loud and obnoxious. I was going for quiet which is why I originally wanted the LSJ mani and DP as well. I would say it is definitely worth the money to go aftermarket if you can find good deals. If not, I think the LSJ mani and DP are worth the money (as long as you aren't spending more than $150-200 for both pieces). The LSJ cat-back is pretty well worth it too. Being the stock exhaust for the LSJ, it has a decent resonator and muffler. The DP I have, even though catless, does have a resonator in it so it helps keep it a little more quiet.

OP, nice job on the thread. It all comes down to: 1) What you want to spend. 2) What you're looking for as far as gains (performance, economy, sound, etc.).

 

i got my lsj mani for 45 shipped so pretty good there. im looking at a zzp catted dp... though i am still looking around

 

I have the L61 in my car would i ultimately be better getting a DC header or do you guys think i should get some LSJ stuff?

 

lsj is cheaper... but if you want real strong gains for alot of money go full after market... nice thing is, the lsj wont void your warrenty as its a gm part lol

 

right now I'm running no muffler, just cat and resonator, and I love how it sounds but I'd like to start replacing things and to have parts for if I wanted to return to (Kinda) stock, I'm pretty sure I read this but will the entire stock LSJ exhaust fit? sorry for asking stupid questions but I'm really new and I'd just like to make totally sure

Edit: My warranty is gone by about 20k miles so I'm not worried about that

 

then mod away my friend! gm cant say ****! lol... they still can laugh at me... but my warenty will be gone in like 6 months anyways... lol Daily Driver FTW! lol

 

yeah well my cobalt is my daily driver so until another daily comes along i'm not gonna do anything crazy like supercharge or turbocharge and right now I'm throwing the PO496 code so i've got to figure that out before i really mod anything, but my car is all show and no go. My 240 is my no show all tire smoke soon to be drift monster hahaha but one day i'd like to get something like DC headers or something and have a LSJ header as a back up if i were to ever sell my car

 

2007 Chevy Cobalt PO496 Stored and Pending DTC's - JustAnswer

this is your DTC issue and fix

 

Yeah see I've looked at all of this but the cobalt is my daily driver and i know a local guy i can trust to fix it right, i just dont trust me self enough to fix my daily, i'm a lot better with nissans

 

fair enough. just thought id help ya out. mine kept throwing a lean code... now that i have my cat back it doesnt... im not sure why lol

 

I will post the dyno's this weekend when I have time.