With all the talk about the new stage kits coming with only a 3" pulley due to over-revving it; it made me wonder what size the pulley was in the Build Book. So I pulled it out and checked, "The new GMPP 73 mm (2.874") pulley increases the RPM of the blower vanes...." My question is, where did people get the information that the blower redlines at 14k RPM (probably Eaton)? The redline of the Build Book is 7800 RPM versus the stage kits 7K RPM. So the supercharger is definitely over-revving (not sure of the exact RPM). Are they sacrificing performance for a potentially blown supercharger, I realize it is GM and they probably aren't worried about blowing the supercharger?

 

Well actually the last gen M62 had a max spin rate of 14000 rpm the current gen which is in our cars have a max spin rate of 16000 rpm

 

how did you find this out?

 

wouldn't 2.874 by 7800rpm be over 16000 also.

 

noo on the one in the book it says m62 hybrid. take a look thats what the difference is.

 

do a search on the model of M62 that the cobalt ss/sc has....

 

also you will not be spinning at 7800 rpm the stg2 kit only puts you at 7000 rpm

 

also you can overspin as long as you have water injection or something too cool the heat of the air down and the sc......

 

No, it says, "The stock supercharger can make the 300HP....The pulley will need to be replaces with a smaller unit." I don't see where it says anything about the supercharger being a hybrid.

 

I am not talking about Stage 2, I am talking about the build book which has a redline of 7750 or 7800 RPM, the dyno chart isn't that easy to read.

 

I would imagine at that high of rpm you would need at least water injection.... the heat created in the air with that small of a pulley and that high of a redline would actually take away hp as opposed to increasing it.... i would also imagine pistons and cams would be needed.....

 

It doesn't seem like you know what the build book is:

https://www.cobaltss.net/forums/show...ght=build+book

Check it out, there is a lot of good information in there.

 

i know what is it , i just havent read it ....

 

you can get a buildbook for free, i did...i just emailed some guy and he sent me one, free shipping and everything.

 

people have been overspinning the crap out of their sc's on cobras for a long time, and nobody really has much trouble with the blower seizing up. Even if it did happen, it's not very expensive to fix. Don't worry about it, just pulley it.

 

screw it just put a 1.5 inch pulley on there and boost to 35 psi !

 

Hells yeah, or better, a 1 inch pulley. Anything smaller and you might need to fix the belt slip. However, there shouldn't be too much so you could probably use the stock supercharger belt.


JK!!!

I just want a company to come out with a bigger supercharger for our cars like the m90....or m112 . Sell it for around $500 and that would be sweet.

 

m90 swap, or the whipple twinscrew setup somehow. now that would be sweet.