Umm .... how about the Stage 3 tune is a hell of a lot better than the Stage 2 tune. Runs leaner/smoother. Has an adjustable rev limiter, high octane mode, and is already set up to run a 50 shot of nitrous. It also includes a dual pass endplate which helps lower IAT2 temps.

If the OP is worried about warrenty Stage 3 isn't for him, but don't knock it like it isn't a good upgrade. So many people on this site know nothing more than Stage 3 will void your warrenty, and the tune is locked.

There are soo many options out there for the Cobalt SS/SC now in terms of tunes/power adders that it really just comes down to personal preference/goals.

 

The ECU tune is a downfall because it is locked and can not be modified. It may or may not be a better tune ( I would imagine a bit better, but idk if anyone has ever seen it..not sure) but if he is going to void warranty he might as well just get a custom tune since anyone that knows what they are doing with HPT should be able to give a better tune than gm. See what Im getting at? If the stage 3 didint void warranty and wasnt locked I would say go for it until your warranty is up, but thats not the case unfortunately

 

correct! just hpt the damn thing. gm tunes ftl. to me the tunes are too weak and thus creating a bad name for the cobalt in the import/sport compact car scene.

 

Well the somewhat weak tunes are underatandable beacause If gm releases it they obviously want the cars to last if some kid installs it and just beats the **** out of it day in and day out it wont blow up right away. But my point was if he is going to void his warranty he might as well go custom tune with 60's and whatever pulley he chooses. As long as he doesnt beat on the car like a step child and has a reputable tuner tune his car he should be making more power than a gm tune and be sitting about as reliable

 

if ppl would not slam there car into 2nd at 90mph we could get a better gm tune. i tell you this! i have a modified ottp stage 2 tune and i run my car pretty hard at times and its been a yr. and not a damn thing is wrong with my car. maybe luck,tune, or i kno have to drive the thing correctly. what ever it may be i just dont see why ppl have so much problems with there cars...

 

I know a guy that basically unlocked the stage 3 tune.

It is my understanding that he can now read/modify the tune and the A/C still works too.

Stage 3 isn't warrantied though, just FYI. Because of the nitrous option and laxed emissions goals with the tune, it is "for off road use only", which is why they disabled the A/C... to discourage road use of the tune/abilities.

Let me know if you're interested in learning more and I'll get you in contact with him. I think he didn't post it up because he didn't want to get e-bashed.

 

Thats cool if he unlocked it. I know a lot of people shy away from buying it just cause its locked

 

you're always reading my mind. haha

intake, header, dp, catback, 2.8/60, methanol.

 

I got the details from him just now on what he's able to do as of now:

He can now tune the Stage 3 tune without the A/C, but you'd keep HOM and nitrous.

He can also now tune the Stage 3 tune with the A/C, but then you give up HOM and nitrous.

I'll ask him for more details and see how far out he is from a full solution.

 

all they did with the stage 3 computer is remove the pin for the AC. if you add a pin you can still use it. there is a how to here on the site

 

Most people don't make enough power with the M62 to warrant a 3" exhaust.

If you got it cheap though, throw it on.

 

Well that sounds like a winning option there then.

He tunes the Stage 3 + Somebody installs the pin = Win... no compromise.

 

They didnt remove a pin. This is the post you're thinking of:

https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/gmpp-stage-3-c-76479/

The stage 3 calibration can be flashed to ANY Atlas P12 PCM, and the A/C will still be disabled. If you flash back to stock/stage 2/whatever, you will have your A/C back. No missing pins.

McWarren found a workaround, but the fact remains its all in the calibration.

Trifecta Performance can tune your Stage 3 PCM for a nominal fee.

 

haha... and he shows!

Yeah, I'm pretty clueless when it comes to the LSJ stuff. Hopefully you'd be able to answer their LSJ-specific questions much better than I would.

 

Don't get a stage 3.... no HPT = effin useless PCM.

And don't get any catback yet.... put the money toward a mid-length, or long tube header /DP combo. It will do far more for the car.
Some people will argue this fact.... but the stock catback can sustain a decent amount of power without major adverse affects. The stock header /dp... not so much... it's a piece of ****.

 

Does a 3inch downpipe hurt performance? Over a 2.5

 

nope!

 

Weird, ive heard it does.

 

Should match your header collector which is usually 2.5".

 

y would it? i have the 3" cti d/p and all it got was pure gain.

 

the change in piping diameter will shift powerband but 3 inch downpipes on LSJ's rock

 

just get the full 3" now. jeez. so you'll have a wee bit less power till you're fully modded. but it'll save you money

 

You're both right. In theory, if you're in boost, then you'd want a larger diameter to get the exhaust out easier, but when in vacuum it's better to have a smaller diameter pipe to an extent for fully utilizing the scavenging effect.

Since you're in vacuum a majority of the time when you're cruising on the highway, having too big of a pipe could cause loss of fuel economy because the engine isn't using the scavenging effect to naturally get more air into the engine "for free", and therefore you'd find yourself needing to add more pedal. This is also why it's good to have a healthy amount of cam overlap when in vacuum.

When you put it under boost though, less restriction is the name of the game and you'll end up with more top end power.

I'm not familiar enough with the LSJ to know 2.5 vs 3 inch as far as functionality, but that's the theory behind it at least.

 

Match your DP to your header.

If your not planning to mod the car past 300.... just go with the over axle bend. It's the best bang for the buck.



The bottom line is that 75% of the exhaust is in the header. A good long tube, will promote the torque band, and aid in top end power.
Don't even bother with shorty headers, as they are just as junky as the stocker.

 

When i had my SS/SC i swapped catbacks with the GMPP exhaust . When i was measuring the stock exhaust I found that the stock resonator had a 2 and 1/16th inch inside diameter right behind the flange that connects it to the downpipe . It was 2- 1/16th'' for a short run of maybe 2 to 3 inches and then opened up into the resonator. I'm wondering if since the restriction is only for a short run in the pipe does it kill flow the same as if the whole catback was 2 and 1/16th........or if by opening up again it helps with velocity or some other aspect O'm not aware of?

I'm guessing that restriction in the stock res is why people saw gains with the "smaller" than stock....2.25" GMPP exhaust's . I'm no expert when it comes to exhaust's so this is just me thinking out loud. Please feel free to correct me if i;m wrong.