Found this interesting (Vortech Cobra's)

[akatherazor4]

I was calculating the impeller speed of my S-Trim on Vortech's website. Surprisingly it's already running near max efficiancy! I believe the stock crank pulley on our cars is 6.625 and I used that for calculations. My blower is currently spinning at 46,503.82 (Impeller speed) shifting at 7000rpms. Now the efficiant max is 45,000 and the absolute max is 50,000. It's darn near time to upgrade!

I compiled impeller speeds below for Vortech cobra users.;-)

*Crank pulley 6.625*
*Shift point 7000rpms*

Vortech S-Trim, Efficiant max 45,000 Absolute max 50,000

3.6 pulley - 46503.82
3.4 pulley - 49239.34
3.3 pulley - 50731.44 (Over Max)
3.1 pulley - 54004.44 (Over Max)

Vortech SC-Trim, Efficiant max 50,000 Absolute max 53,000

3.6 pulley - 46503.82
3.4 pulley - 49239.34
3.3 pulley - 50731.44
3.1 pulley - 54004.44 (Over Max)

Vortech E-Trim, Efficiant max 62,000 Absolute max 65,000

3.6 pulley - 46503.82
3.4 pulley - 49239.34
3.3 pulley - 50731.44
3.1 pulley - 54004.44
2.93 pulley - 57137.8
2.73 pulley - 61323.72

Razor.:beer:

 

[99SVTcobraVERT]

hmm never payed much attention to the strim and sc trim. just assumed they were the same and person was just calling it different. well well...learn something new every day. what is pulley size on stock 9psi pulley that comes with the vortech kit? and what pulleys are used to make 10psi,11psi,12 and 13? i am most likely getting kit soon and do not with to spin more than 12psi for better life of the motor... a stock 01 cobra with not even exhaust here (with stock chip with the vortech) @ 9-9.5psi (stock blower pulley) put down 425rwhp,this is also with no aftercooler. and how much are the upgraded pulleys??

 

[akatherazor4]

Originally posted by NOScobra2001
hmm never payed much attention to the strim and sc trim. just assumed they were the same and person was just calling it different. well well...learn something new every day. what is pulley size on stock 9psi pulley that comes with the vortech kit? and what pulleys are used to make 10psi,11psi,12 and 13? i am most likely getting kit soon and do not with to spin more than 12psi for better life of the motor... a stock 01 cobra with not even exhaust here (with stock chip with the vortech) @ 9-9.5psi (stock blower pulley) put down 425rwhp,this is also with no aftercooler. and how much are the upgraded pulleys??

Deciding which pulley will make 9psi depends on what trim blower you want. I'm guessing that with the standard Cobra kit (The SC-Trim) you will run a 3.6 pulley standard and create around 9-10psi. I am running an S-Trim with the GT impeller in my car and with a 3.6 pulley I make over 14psi. The S-Trim and SC-Trim are very different blowers. The cost to buy new pulleys are pretty cheap. I think they are under $100 from Vortech directly.

Razor.

 

[99SVTcobraVERT]

well i will have the strim, which is more expensive? i thought the strim was standard? so if the sc trim then it is the cheaper model? i will have strim and i DEF dont want to make 14psi...

 

[akatherazor4]

Originally posted by NOScobra2001
well i will have the strim, which is more expensive? i thought the strim was standard? so if the sc trim then it is the cheaper model? i will have strim and i DEF dont want to make 14psi...

The SC-Trim is standard for the cobra's. You don't want the S-Trim on your cobra if you don't want to make 14psi.:lol: I'm doing that with a stock 3.6 pulley. The SC-Trim is an S-Trim with a different impeller designed for the higher rpm levels a cobra pulls. Same blower just different impellers in each.

Razor.:beer:

 

[LSs1Power]

Originally posted by akatherazor4
I believe the stock crank pulley on our cars is 6.625 and I used that for calculations. My blower is currently spinning at 46,503.82 (Impeller speed) shifting at 7000rpms. Now the efficiant max is 45,000 and the absolute max is 50,000. It's darn near time to upgrade!

If u pass the efficiant max for a SC by only 1500 u are alright. If u passed the Absolute max by 1000 then u should really look for an upgrade. Good luck.