I had my 2006 Cobalt SS Supercharged dynoed when it was bone stock and it made 211.4 HP. I installed an AEM dryflow filter, did the airbox mod, and installed the GM Performance Stage 1 upgrade (fuel injectors and tune). After the installs, the dyno run showed only 213.6 HP (a gain of only 2.4 HP).

Has anyone else dynoed their Cobalt before and after the GM Stage 1 upgrade? I was expecting much more from an upgrade that promised 30 HP over stock, and I didn't even get 1/10th as much horsepower as GM advertises.

Here is the video of the GM Stage 1 dyno pulls. Let me know what you think.

I think it shows how under-rated the Cobalt really is stock. It is deceptive though that GM advertises so much more horsepower than you actually get with Stage 1.

http://videos.streetfire.net/video/G...ock_634271.htm
Enjoy
Eric

 

why did you only get stage 1???

It was only a fuel injector upgrade, considering that they should of given you a tune up to 7,000 rpms if im not mistaken.... I forgot if thats just stage 2 or not but that would be the difference maker right there

 

wHY WOULD U GET STAGE 1??
That was the first mistake
Stage 2 is the way to go
This coversation is over bro

 

man that sucks...stage 1 FTL

 

you spent like 300-400 beans on stage 1 when you can get stage 2 for 550 bucks and installs for 150-200 bucks....

the pulley is going to make the biggest difference not the fuel injectors.... Also i have never seen any ss/sc gain only 2 hp from a mod like that... Ive always seen good numbers from the upgrade, what probably happened is that the guy running dynoying your car didnt no you can run it up to 7 grand, considering that redline on the tach is 6500....tell him to go up to 7 grand if you hit redline then they didnt tune your car and you need to take it back to chevy!!!!!!

 

ott. that sucks was it installed correctly???

 

I will answer a couple questions, I got stage 1 instead of stage 2 so I can still run in my class during autocross events. They don't allow you to change the pulley size on superchargers, or increase boost pressure on turbo cars and stay in the stock division.

I figured that the value of 30 hp over stock for about $400 was a good value, so I chose Stage 1. Plus, I didn't want my car to run lean on the factory fuel injectors when I am pushing it to the limit at high rpms on the track.

My redline did increase to 7,000 rpm, but I don't really see any increase in power. It just holds the stock HP levels all the way to 7,000 rpm instead of only 6,500 rpm.

If you look at the DYNO graph that GM publishes for the Stage 1 upgrade, they used a very thick line to mask how similar stage 1 is to stock.

 

When i had only stage 1 i felt a nice bump in power from 5500rpm - 7000rpm .... You should have at least made it into the 220's whp range with stage 1. True that all it does is extend the stock power range to 7000 rpm, but these cars keep making power after 6500 rpm so you should have gained more than 2 or so hp.

 

hmmm my 06 ss/sc is "bone stock" right now and i dynoed it @ 216whp on a dyno jet dyno!! ???

 

Did you rev to 7,000rpms? The only place it makes teh additional HP is above the stock 6,500 rpm limiter.

 

What were the conditions like when you dynoed the first time as compared to the second time?
Also was it the same dyno?

 

My 06 G85 bone stock made 238.8 WHP and 189 WTQ on the heartbreaker at SMG in mass, you know what I mean by heart breaker! It really all depends? I assume the break in is the absolute most vital thing!!!!

 

i just watched your video .... it doesnt sound like they brought it to your 7000 rpm rev limiter. Everytime, they cut the dyno short .... prob at 6500 rpm. Look at your dyno sheets and make sure they ran it to 7000 rpm. that could be the solution to your problem. on a good note, your car is very consistant with hp numbers between pulls.

 

Although your results are common they are not unexpected.

The stock 34# injectors have no problem providing enough fuel for the stock 3.35" pulley.

The GMS 42# injectors will allow you to build for my hp in the future. Don't let anyone tell you that you made a bad purchase. You actually saved yourself some money because now you can buy a Modular Pulley System (MPS) much cheaper then GM charges.

http://smoothflowpulleys.com/Stage2.html

And you can order a 2.9" pulley right off the bat. Instead of getting GMS2 which includes a 3.1" pulley and then going out and buying a 2.9" pulley.

You probably saved yourself at least $150 once it is all said and done.

Now go and order your MPS and get back on the dyno!


^^^^This statement is false.

Everyone knows that the LSJ does NOT make more hp past 6500 rpms. Unless you are running aftermarket cams or a different power adder. After 6500rpms the hp always drops off.

 

Here are the stock dyno graphs.
http://videos.streetfire.net/photo/S...no_1013558.htm

Here are the stage 1 graphs plus the stock all on one graph. You can clearly see that the rpm cutoff is higher with stage 1 than stock (6,500 rpm vs 7,000 rpm)
http://videos.streetfire.net/photo/A...pg_1598160.htm

Here is just stage 1 dyno graphs.
http://videos.streetfire.net/photo/G...pg_1598161.htm

Yes, all of the dyno pulls were done on the same dyno with the same conditions. Yes, the operator did bring it to 7,000 rpm because I told him the rev limiter was changed with the Stage 1 tune.

 

haha are you serious ?!?!? have you ever seen a stock dyno graph, the cars whp climbs to 6500 rpm without falling off. that is why gm with the stage kits increased your rev limit to 7000 rpm. the car makes horsepower after 6500 rpm get your facts straight. Infact, GM rates GM Stage 1 at 236 crank hp at 6800 rpm. half the members on here make their peak horspower above 6500 rpm WITHOUT cams !!!!!!

 

HuH?!? Every SS/SC cobalt I have seen with either Stage 1 or Stage 2 always makes HP all the way to 7K. If your HP drops off at 6.5K then there is something wrong with the car.

 

Yes. They still make hp but they make PEAK hp around 6500.

Sorry. If you think a Stage 2 car makes more hp at 7000 rpms then at 6500 rpms there is something wrong with you...

Just like the guy in this thread.

Peak hp about 6600. NOT 7k!

 

sorry dude, but i made peak power at 7200

 

They wouldnt increase the rev limit if the power dropped off...

from what i understood the power held, just didnt really go up or anything...

 

That is because you have a turbo. I said with the stock cams and stock power adder the peak hp is right around 6500.

I would like to see your dyno graph though!

 

peak whp power at 7000 rpms ?



Anyways, isnt the gm stage 1 upgrade in bhp on gm's site?

 

Nope.

What happened to all my dyno graphs I posted? I have like 6-7 of them where the peak power is around 6500 and they all drop off by 7k.

I'll try this again.





[img]https://i123.photobucket.com/albums/o291/1bojan/P7180038.jpg[img]

 

your statement about how you need cams to make power at 7 thousand rpms is ridiculous....Idk how long youve been around bud, but my stage 2 car made power up to 6900 rpms....

 

first run was 6500rpm and second was 6500rpm according to the dyno graph


first run was 67.78F second run was 67.86F 30% Humidity