2.0 s/c Pulley's
 

Jonel, yes we have our DUB Interchangeable Supercharger Pulley Unit for the
new Cobalt units, from sizes 3.4" down to 2.60" . Hope this helps, as you
will need to remove the 4 bolts securing the supercharger to remove the
stock pulley and install our new unit. This is about an hour job to make
this change. Hope this helps.

http://www.southfloridapulleyhq.com/

well, as soon as someone can get one we'll see if this just creates heat like everyone says or if it actually wakes the car up a bit.....thanks for posting this!

What size pulley comes stock on the 2L S/C?

I'm wondering how Psi-fi got 20PSI of boost from the 2.0L. Did they put a smaller pulley on the SC?

puttting a pulley on a sc is just going to hurt your car....dont even think about the mod

why would putting a smaller pulley on the supercharger hurt the car?? That's how to make more boost with a s/c motor the safe way. It's like getting a boost controller for a turboed vehicle and turning up the boost a little. It's not gonna hurt anything as long as you're not pushing 20 psi through that motor continuously. The 270 hp cobalt they had at the sema show was pushing 16 lbs of boost with not problem and I believe stock is 12, so this ^^^ is an unfounded response.

It will just cause damage and yield no performance improvement, if you don't take care if the fact that the car is boost limited at 12psi first, your SC will be making more boost but no more will get to the engine it will be wasted by the bipass valve. Second it would be a good idea to remove some heat from the system before adding it, or you will get reliability issues.

Or maybe he is refering to this article that guy on the redline forum wrote about the m62 already being at max efficiency.

http://www.******************/showthread.php?t=81&highlight=smaller+pulley

i'm sure a lower thermostat will help things, but i'd like to see the results on a redline before going out to buy a pulley upgrade it. they can make it, but have they tried it, i'd be wary of that, as there has already been a smaller pully tried out (hearsay) and it apparantly fried the blower.

after 3 pulls on the dyno, the coolant on our test car was coming out the overflow (intercooler), so increasing heat will NOT be a good thing

after actually looking at the link, it's for the m90/m112, nothing for the cobalt/redline...

Pulley's for the M90/M112 will work on the M62 and M45

that doesn't mean that they should be used on the redline/cobalt...

A Pulley is a Pulley. It not going to break anything. They're all press on pulley's

you're missing my point, the fact is that this is advertised in the forum as a pulley for the 2.0s/c, but it's not, i don't want anyone going out to do this, messing up their blower (from heat) and voiding their warranty stuck with an expensive fix, this shouldn't be messed with unless you know what you're doing. there have been rumors of someone frying their blower by swapping in a smaller pulley, and it shouldn't be done unless you address cooling issues first, not to mention freeing up the exhaust and intake as well

I agree, you greatly risk your blower more from not knowing what your settings on the pulley will be. Cooling and more air into the engine would be the first steps before messing with boost in general. Otherwise you won't have a motor :-D

yeah what vita and star said....but do it so you can fuckup your shit

the psi-fi guys are very satisfied with the results from the supercharger so far...

theyve said the cooler is doing a great job at keeping the charge temps down...

isnt that what a supercharger does?









lol, i know what you mean just messing with you

lol didnt notice that..well yes it feeds it more air like nothing!

sup
 

i have herd from a local dealer that gm has a pulley for it and if gm instals it its still under warranty that just what a loccaL dealership it might just be a dealer thing to get more buisness too

I think you are right. GM is trying to do what Dodge is doing for the SRT4, have a dealer-made aftermarket.

the guy from at the auto show said was talkin about that.

sup
 

how much more power/boost does going from 3.4" down to 2.60" make???

If the measurement is the diameter than then.

3.4 x 3.14 = 10.68"
2.6 x 3.14 = 8.17"

8.17 / 10.68 = 0.76

So for every 3 revs of the stock pulley it's 4 revs of the new pulley. How much more boast? I dunno cause I am not an expert on that stuff but I would think about 20-25% increase in boost. Everyone keeps talking about the roots type blower not having a linear increase in power with RPMs so who knows. Probably won't know until someone does it and puts it on the dyno. Until them all we can do is argue about it :-d

sup
 

thanks! good stuff

for every 1/4 inch smaller on the pully it gets you about 2 psi.

stock lets say 3.50 pulley is 7 psi
3.25 pulley is 9 psi
3.00 pulley is 11 psi
2.75 pulley is 13 psi
2.50 pulley is 15 psi

so if stock is 3.4 and you go to a 2.6 thats .8 difference which will bring up your boost about 6.5 psi from stock


im thinking stock is about 7 psi right?? going to 10 is most i would go before tuning, injectors etc. even 12 psi you can prob get away with. 3.0 pully prob would do the trick if the stock one was 3.5 inches.

anyone know the stock psi for a cobalt ss and puleysize