Pulley Poll - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

1st Gen Forever · 07-20-2012, 11:30 AM

So for those of you that are modifying your ZL1 engine. What pulleys are you running? Share a little something about the results, how many miles you've driven it this way, and why you chose this combination.

I've rounded sizes to the most common.

RoketRdr · 07-20-2012, 11:39 AM

On my CTS-V I ran the 10" lower and 2.55" upper because I was needing the high boost (18-19psi) with the mods that were done to the car. Pulley selection should be based on how much boost is needed given the expected mods to be done (end power level). You need to get with your tuner on this to decide the best course of action. Most of you will never need to change the crank pulley for a daily driven car that isn't making monster power. Here's a list of what each pulley size will generate on an LSA.

Crank ______SC Pulley____Ratio_______Boost
8.0------------2.95--------2.71--------8.6 psi (stock)
8.0------------2.55--------3.14--------13 psi (change only SC pulley)

8.6------------2.95--------2.92--------10.5 psi (change crank pulley)
8.6------------2.55--------3.37--------14 psi (change both pulleys)

9.1------------2.95--------3.09--------11.5 psi (change crank pulley)
9.1------------2.55--------3.57--------15.5 psi (change both pulleys)

9.6------------2.95--------3.25--------13 psi (change crank pulley)
9.6------------2.55--------3.77--------17 psi (change both pulleys)

10.0-----------2.95--------3.39--------14 psi (change crank pulley)
10.0-----------2.55--------3.92--------18 psi (change both pulleys)

1st Gen Forever · 07-20-2012, 11:55 AM

One concern I have is the life of the supercharger once over driven. Right now I'm planning to start with a conservative 8.6/2.5 and see what my power looks like with my other mods. How many miles did you get on your CTS-V with 10/2.5?

RoketRdr · 07-20-2012, 12:10 PM

It definitely wont live as long but if you don't beat on it on a constant basis you can expect long life. If you hammer it everyday and race every weekend then the bearings definitely won't last 100K. I usually only keep my cars for 2 years then get rid of them so I can't really talk about longevity. But I've had over 80K on a highly boosted daily driven engine with some regular track use and didn't experience any failures or problems. If built properly and well maintained without being abused I don't see any reason you can't get 100K+.

2012ZL1 · 10-28-2012, 12:18 PM

Are there better bearings available to support the higher blower speeds?

OldScoolCamaro · 10-28-2012, 09:39 PM

...I want a factory stage two upgrade...supported by the warranty. I will run stock for now.

69NMYSS · 10-28-2012, 09:49 PM

For those of you who haven't read the thread yet, Jannety Racing put a 9.1 crank pulley on and got a 50hp/50tq increase with NO tune. About ~11lbs boost.

http://www.camaro5.com/forums/showthread.php?t=257750

View Poll Results: What pulley sizes have you changed your LSA to?
8.6 lower / stock upper	2	5.71%
9.1 lower / stock upper	0	0%
9.5 lower / stock upper	7	20.00%
10 lower / stock upper	2	5.71%
Stock lower / 2.5 upper	9	25.71%
8.6 lower / 2.5 upper	5	14.29%
9.1 lower / 2.5 upper	6	17.14%
10 lower 2.5 upper	4	11.43%
Voters: 35. You may not vote on this poll

07-20-2012, 11:30 AM	#1
1st Gen Forever ZL1 #140 Drives: Camaros: 68 SS, 10 2SS/RS, 12 ZL1 Join Date: Mar 2008 Location: Arizona Posts: 594	Pulley Poll So for those of you that are modifying your ZL1 engine. What pulleys are you running? Share a little something about the results, how many miles you've driven it this way, and why you chose this combination. I've rounded sizes to the most common.

10-28-2012, 12:18 PM	#5
2012ZL1 CaRaHoLiC Drives: '12 ZL1,67 Cam,68 Biscayne 427 4 sp Join Date: Aug 2011 Location: B.C. Canada Posts: 1,701	Are there better bearings available to support the higher blower speeds? __________________ 2012 ZL1 2.55 upper, 10" lower pullies, Innovators west billet hub and sfi balancer, solid blower drive isolator, 50 mm idler kit, full length S/S headers no cats, comp cams custom grind cam, comp roller rocker trunion kit, comp push rods,dual valve springs retainers and locks, Injector dynamics ID850 inectors, Rotofab ZL1 cold air kit, Lingenfelter 160 thermostat, Rotofab intercooler reservoir, stock plugs, LS7 90mm throttle body, GTO clutch reservoir mod, my own custom catch can, Tuning by Jannetty, install by me.

10-28-2012, 09:39 PM	#6
OldScoolCamaro Drives: Camaro's, always have, always will. Join Date: Oct 2010 Location: Home of the brave Posts: 4,851	...I want a factory stage two upgrade...supported by the warranty. I will run stock for now. __________________ In Scott We Trust...all others must show proof.

10-28-2012, 09:49 PM	#7
69NMYSS Drives: '69 Camaro SS and '12 ZL1 Join Date: Sep 2011 Location: CA Posts: 1,274 View My Garage	For those of you who haven't read the thread yet, Jannety Racing put a 9.1 crank pulley on and got a 50hp/50tq increase with NO tune. About ~11lbs boost. http://www.camaro5.com/forums/showthread.php?t=257750 __________________

07-20-2012, 11:39 AM	#2
RoketRdr Drives: 2010 Duramax; 2012 CTS-V Coupe Join Date: Apr 2012 Location: Houston, Tx Posts: 387	On my CTS-V I ran the 10" lower and 2.55" upper because I was needing the high boost (18-19psi) with the mods that were done to the car. Pulley selection should be based on how much boost is needed given the expected mods to be done (end power level). You need to get with your tuner on this to decide the best course of action. Most of you will never need to change the crank pulley for a daily driven car that isn't making monster power. Here's a list of what each pulley size will generate on an LSA. Crank ______SC Pulley____Ratio_______Boost 8.0------------2.95--------2.71--------8.6 psi (stock) 8.0------------2.55--------3.14--------13 psi (change only SC pulley) 8.6------------2.95--------2.92--------10.5 psi (change crank pulley) 8.6------------2.55--------3.37--------14 psi (change both pulleys) 9.1------------2.95--------3.09--------11.5 psi (change crank pulley) 9.1------------2.55--------3.57--------15.5 psi (change both pulleys) 9.6------------2.95--------3.25--------13 psi (change crank pulley) 9.6------------2.55--------3.77--------17 psi (change both pulleys) 10.0-----------2.95--------3.39--------14 psi (change crank pulley) 10.0-----------2.55--------3.92--------18 psi (change both pulleys)

07-20-2012, 11:55 AM	#3
1st Gen Forever ZL1 #140 Drives: Camaros: 68 SS, 10 2SS/RS, 12 ZL1 Join Date: Mar 2008 Location: Arizona Posts: 594	One concern I have is the life of the supercharger once over driven. Right now I'm planning to start with a conservative 8.6/2.5 and see what my power looks like with my other mods. How many miles did you get on your CTS-V with 10/2.5?

07-20-2012, 12:10 PM	#4
RoketRdr Drives: 2010 Duramax; 2012 CTS-V Coupe Join Date: Apr 2012 Location: Houston, Tx Posts: 387	It definitely wont live as long but if you don't beat on it on a constant basis you can expect long life. If you hammer it everyday and race every weekend then the bearings definitely won't last 100K. I usually only keep my cars for 2 years then get rid of them so I can't really talk about longevity. But I've had over 80K on a highly boosted daily driven engine with some regular track use and didn't experience any failures or problems. If built properly and well maintained without being abused I don't see any reason you can't get 100K+.