i did a search and didnt see anything so if this is a repost sorry but any way i was wondering what is the smallest pulley that you can put on the ss with out having to tune the computer i dont mind changing the plugs or anything like that but i just dont have the means for retune at this time

 

i heard u can run a 3.0" pulley wit out changin anything meaning injectors and tune but u may have to change the spark plugs but idk thats wat im hearing

 

Guys run 3" pulleys without changing anything. Its not recommended to run a smaller pulley without smaller injectors but it can be done with stock injectors. GM Stage 2 runs a 3" pulley and you don't have to retune it because the dealership does.

 

bumped

 

What else do you want to know?

 

I'm sure its just a typo but you want bigger injectors not smaller ones. And everyone also probably knows this but the stage II gets bigger injectors along with a tune to run the 3" pulley. However, you can probably get away with stock injectors since the stage II kit runs pretty rich. As for no tuning, I can't say for sure.

 

Now that I think about it many people run as low as 2.8" or 2.7" on the stage II tune. So perhaps going from 3.15" to 3" on the stock setup is possible.

 

this may be a stupid question but can you ad a smaller pulley and bigger injectors like 40 pounders or so without retuning the computer

 

You can add a smaller pulley without at tune, but adding larger injectors without a tune would thoroughly eff up your fuel trims. Most people don't recomend driving or even starting the car with larger injectors without a tune.

 

^x2 big time, especially if you go from stock to 60lbs/hr

 

Yeah really! When I put my 60s in it took my car like 15 minutes to learn how to idle right, EVEN WITH A TUNE! Car is trying to demand a .9 pulse width and minimum pulse with on the 60s is 1.1!

 

you can add a smaller pulley and larger injectors without a tune. GM stage 2 (3" pulley with 42lb injectors) can be installed without the tune from the dealership and still run a safe and descent Air/Fuel ratio, However without the tune performance gain is less than with the tune. It is not a good idea to run pulley by itself without injectors or tune.

 

I don't know if you have any first hand experience with this or not, but from what I have heard that is not recommended at all and the car will run like ****. I don't know of anyone who runs this setup untuned. Also, everyone that I have known who has done the stage 2 install themselves has babied the hell out of the car to get it to the dealer for the reflash. Personally, I would not want to take that kind of chance.

 

Bah, it's easy as hel to get to the dealership. Just drive the car there with the stock injectors and while they get the flash numbers verified and crap swap the injectors in the lot.

 

I have a 06 with a 3" pulley and hacked up air box and no tune and was seeing 10.1afr 11 at the leanest. Was thinking about going smaller.

 

Yeah, like I said I have heard that there isn't much of a problem running the 3" with stock injectors and no tune, but I don't think you can change the injectors and run it without a tune.

 

Your Cobalt is so dumb it forgot how to idle...it's like the star quarterback of the football team that's in special ed.

 

It may have forgotten how to how to idle but it certainly knows how to run at WOT and thats all that matters.

 

I know...I'm just poking fun because I've got mod envy. The wife is really holding me and the balt back. You would not believe how hard I had to fight to get the CAI, and right now I am working on the exhaust. At this rate I'll have Stage II in a couple years. Also, do you know how much power is getting to the wheels with your setup? any track times? just curious.

 

If I had to estimate on power, in good weather on 101 octane I wouldn't put 280 whp out of the equation, and track times, I've run 14.59 @ 98 with intake and exhaust only, haven't been to the track since then.

 

thanx for the info

 

I did run a 3" with stock injectors and was doing some scanning and noticed the injector pulse with is way to high for my liking. I was seeing about 100 at 5,000 rpm hell when you really pushed it to rev limiter I was seeing 144 way over the 80 which is ideal.

 

I see. I guess it's one of those setups where people tell you "oh yeah no problems" when in fact they are setting themselves up for failure and don't know it. That's why I asked for an interceptor for Christmas. I have a buddy who was running the 2.8" on the stage II kit and was seeing the same problem with overworking the injectors so he went back to the 3". Thanks for the heads-up.

 

Yeah for 100 posts Sorry, I couldn't resist.