Whipple 3.25 or 3.00 pulley upgrade - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Brad7294 · 03-12-2021, 09:24 AM

Read a few forums about this but was not covered completely. I am going to get a 10-rib setup from Whipple. I want to max the 2.9L out, but do not want to overspin it. If I get the 6% crank pulley what blower pulley do you guys use (3.25, 3.125, 3.00)? What boost you guys seeing?
I am going with 416ci, PRC 255 heads, fore pump, Id1300's, E-85, meth, and blower cam approx. 247,263, .624 lift
I read that around 17 psi might be the max??
I did see that COPO 2.9L came with a 3.50 pulley that hits around 15.0-15.5 psi.

Any thoughts? Thanks

Batmanntexas · 03-15-2021, 07:51 PM

I'd focus more on the blower RPM versus boost number, as boost is just a measure of air resistance. For the 2.9L Whipple, max advertised RPM is 18,000.

To calculate blower RPM: (Balancer diameter/blower pulley diameter) x engine RPM = blower rpm

EX: (8/3.625) x 6500 = 14,345 RPM

Should be a stout combo, though!!

RedRyder · 03-15-2021, 08:42 PM

Quote:

Originally Posted by Batmanntexas

I'd focus more on the blower RPM versus boost number, as boost is just a measure of air resistance. For the 2.9L Whipple, max advertised RPM is 18,000.

To calculate blower RPM: (Balancer diameter/blower pulley diameter) x engine RPM = blower rpm

EX: (8/3.625) x 6500 = 14,345 RPM

Should be a stout combo, though!!

This.

The usual maxed combo is 8" balancer and 2.75" whipple pulley which usually translates to around 17psi. It's a touch higher than the recommended rpm but some people spin it even higher.

Brad7294 · 03-16-2021, 10:57 AM

The 2.9L is maxed out at 18,000. Interesting. Did not know that.

So by the numbers pushing the RPM's to 6,800 is this:
(8/3.250) X 6800 = 16,592
(8/3.125) x 6800 = 17.300
(8/3.000) x 6800 = 18,020

I also read that ATI 10- rib set up for the COPO 2.9L, the crank pulley 6% is 7.95. The ATI web site for the 10-rib set up said the 6% crank pulley is 8.19.
Regardless it only changes the numbers above by a little.
So the way it looks going lower than a 3.00 is useless and could hurt the performance.

RedRyder · 03-16-2021, 11:53 AM

Quote:

Originally Posted by Brad7294

The 2.9L is maxed out at 18,000. Interesting. Did not know that.

So by the numbers pushing the RPM's to 6,800 is this:
(8/3.250) X 6800 = 16,592
(8/3.125) x 6800 = 17.300
(8/3.000) x 6800 = 18,020

I also read that ATI 10- rib set up for the COPO 2.9L, the crank pulley 6% is 7.95. The ATI web site for the 10-rib set up said the 6% crank pulley is 8.19.
Regardless it only changes the numbers above by a little.
So the way it looks going lower than a 3.00 is useless and could hurt the performance.

Not exactly useless to go under 3". You still make more power, but it will be out of the whipple's efficiency range.

As with most things, you should go with whatever you're comfortable with. 3" pulley will still make loads of power.

Brad7294 · 03-16-2021, 10:37 PM

Thanks for the input. I probably am going with the 3.00

Maybe ted jannetty will see this thread and give his opinion.

03-12-2021, 09:24 AM	#1
Brad7294 Drives: 2010 2SS/RS LS3 Join Date: Apr 2011 Location: Greensburg,PA. Posts: 151	Whipple 3.25 or 3.00 pulley upgrade Read a few forums about this but was not covered completely. I am going to get a 10-rib setup from Whipple. I want to max the 2.9L out, but do not want to overspin it. If I get the 6% crank pulley what blower pulley do you guys use (3.25, 3.125, 3.00)? What boost you guys seeing? I am going with 416ci, PRC 255 heads, fore pump, Id1300's, E-85, meth, and blower cam approx. 247,263, .624 lift I read that around 17 psi might be the max?? I did see that COPO 2.9L came with a 3.50 pulley that hits around 15.0-15.5 psi. Any thoughts? Thanks

03-15-2021, 07:51 PM	#2
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	I'd focus more on the blower RPM versus boost number, as boost is just a measure of air resistance. For the 2.9L Whipple, max advertised RPM is 18,000. To calculate blower RPM: (Balancer diameter/blower pulley diameter) x engine RPM = blower rpm EX: (8/3.625) x 6500 = 14,345 RPM Should be a stout combo, though!! __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

03-16-2021, 10:57 AM	#4
Brad7294 Drives: 2010 2SS/RS LS3 Join Date: Apr 2011 Location: Greensburg,PA. Posts: 151	The 2.9L is maxed out at 18,000. Interesting. Did not know that. So by the numbers pushing the RPM's to 6,800 is this: (8/3.250) X 6800 = 16,592 (8/3.125) x 6800 = 17.300 (8/3.000) x 6800 = 18,020 I also read that ATI 10- rib set up for the COPO 2.9L, the crank pulley 6% is 7.95. The ATI web site for the 10-rib set up said the 6% crank pulley is 8.19. Regardless it only changes the numbers above by a little. So the way it looks going lower than a 3.00 is useless and could hurt the performance.

03-16-2021, 10:37 PM	#6
Brad7294 Drives: 2010 2SS/RS LS3 Join Date: Apr 2011 Location: Greensburg,PA. Posts: 151	Thanks for the input. I probably am going with the 3.00 Maybe ted jannetty will see this thread and give his opinion.