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

1FAST SS · 02-07-2022, 09:05 PM

Need advice on pulley size. I am located in Northern Colorado (5,000 feet above sea level) which makes the pulley size more tricky. To make matters worse is there isn't any good LS shops in Colorado to get advice from. I have ID 1050 injectors and DSX Tuning low side aux fuel system. Other mods are in signature.

1JEWLDSSRS · 02-08-2022, 11:33 AM

Give Ted at Jannetty a call and see what he says. They do a lot of FI work.

Batmanntexas · 02-09-2022, 07:23 AM

Rule of thumb is that for every 1/8" pulley diameter decrease, it equates to roughly 1psi of boost pressure increase.

I put the Whipple on my car when I was in Albuquerque, NM, which is similar elevation. With a stock damper and the 4" pulley supplied by Whipple, the car made about 600rwhp @7-8psi. On the 3.75" pulley, the car made 630rwhp @9psi. At that time I had LT headers, full 3" exhaust, ZL1 pump, ADM FPCM, LS9 cam, custom tune, and stock everything else. Those results were on 91 octane pump gas.

I have several 6-rib Whipple pulleys if you are looking for a certain size. Feel free to shoot me a PM.

1FAST SS · 02-10-2022, 09:31 PM

Quote:

Originally Posted by Batmanntexas

Rule of thumb is that for every 1/8" pulley diameter increase, it equates to roughly 1psi of boost pressure increase.

I put the Whipple on my car when I was in Albuquerque, NM, which is similar elevation. With a stock damper and the 4" pulley supplied by Whipple, the car made about 600rwhp @7-8psi. On the 3.75" pulley, the car made 630rwhp @9psi. At that time I had LT headers, full 3" exhaust, ZL1 pump, ADM FPCM, LS9 cam, custom tune, and stock everything else. Those results were on 91 octane pump gas.

I have several 6-rib Whipple pulleys if you are looking for a certain size. Feel free to shoot me a PM.

Thanks for the information. I spoke to JDP and the recommendation from them was a 3.5" or 3.625. Based upon your numbers with 3.75" at a high elevation I'm wondering where it will fall power wise?

Batmanntexas · 02-13-2022, 04:01 PM

With a cam and fuel supply, you could be in the 650-700whp range I'd think. As I mentioned previously, with the 3.75" pulley, my car made 630whp.

My current combo is using a 3.625" pulley, custom cam, ported stock heads, and fuel system. On 93, it made 746whp @ ~10psi, and 806whp on E85.

fz4k98 · 02-14-2022, 07:58 AM

Does the car need to be retuned if the pulley size is changed on a whipple? I am currently running a 4 inch pulley and use 93 octane.

Batmanntexas · 02-15-2022, 03:48 PM

Quote:

Originally Posted by fz4k98

Does the car need to be retuned if the pulley size is changed on a whipple? I am currently running a 4 inch pulley and use 93 octane.

Ideally, yes. For a small change (1/8") you can get away without it, but any significant change will dramatically change the airflow. The MAF curve will be off as well as the speed density portion (VE/VVE table).

eLeSthree · 02-17-2022, 05:34 AM

Quote:

Originally Posted by Batmanntexas

Rule of thumb is that for every 1/8" pulley diameter increase, it equates to roughly 1psi of boost pressure increase.

I put the Whipple on my car when I was in Albuquerque, NM, which is similar elevation. With a stock damper and the 4" pulley supplied by Whipple, the car made about 600rwhp @7-8psi. On the 3.75" pulley, the car made 630rwhp @9psi. At that time I had LT headers, full 3" exhaust, ZL1 pump, ADM FPCM, LS9 cam, custom tune, and stock everything else. Those results were on 91 octane pump gas.

I have several 6-rib Whipple pulleys if you are looking for a certain size. Feel free to shoot me a PM.

Hey Batmanntexas, did you mean to say decrease instead of increase?

Batmanntexas · 02-17-2022, 01:52 PM

Quote:

Originally Posted by eLeSthree

Hey Batmanntexas, did you mean to say decrease instead of increase?

Yep, good catch. Thanks!!

I'll edit the original post.

02-07-2022, 09:05 PM	#1
1FAST SS Drives: 2011 Camaro SS Join Date: Nov 2010 Location: Greeley, CO Posts: 769	Whipple Pulley Size Need advice on pulley size. I am located in Northern Colorado (5,000 feet above sea level) which makes the pulley size more tricky. To make matters worse is there isn't any good LS shops in Colorado to get advice from. I have ID 1050 injectors and DSX Tuning low side aux fuel system. Other mods are in signature. __________________ 2011 Camaro SS Synergy Green CAI Cold Air Induction, ADM Race Scoop, Apex Washer Bottle Kit, Vengeance Racing Kaotic Cam, DOD/VVT delete and LS3 conversion, American Racing LT Headers, American Racing Headers Off Road pipes, Borla S-Type Catback, FTI Billet Triple Disk 3600 rpm Torque Converter, DSS Aluminium Drive Shaft, AAC Plasma DRL's, Showstopper LED Sidemarkers,Carbon FIber Bow Ties, 35% Window Tint, Llyod's Floor Mats, JBL MS-8 Sound Processor, 2 Alpine PDX-1.600, Alpine PDX-4.100, JL Audio C5-650, JL Audio C5-650x, Alpine T10 Type R Shallow Mount, Stinger Dry Cell Battery Last edited by 1FAST SS; 02-10-2022 at 09:32 PM. Reason: Deleted information

02-08-2022, 11:33 AM	#2
1JEWLDSSRS Drives: 2011 SS-RS Join Date: May 2011 Location: FLORIDA Posts: 11,442	Give Ted at Jannetty a call and see what he says. They do a lot of FI work. __________________ TSP STAGE 3 CAM,231/246 @112 LSA 614/641 LIFT, CIRCLE D 5C-4200-4500 CONVERTER,LOD INTAKE.CORSA EXHAUST. DSS 1 PC DS. PEGASUS SOLID CRADLE MOUNTS. 486RWHP/475RWTQ.LOTS MORE.

02-09-2022, 07:23 AM	#3
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	Rule of thumb is that for every 1/8" pulley diameter decrease, it equates to roughly 1psi of boost pressure increase. I put the Whipple on my car when I was in Albuquerque, NM, which is similar elevation. With a stock damper and the 4" pulley supplied by Whipple, the car made about 600rwhp @7-8psi. On the 3.75" pulley, the car made 630rwhp @9psi. At that time I had LT headers, full 3" exhaust, ZL1 pump, ADM FPCM, LS9 cam, custom tune, and stock everything else. Those results were on 91 octane pump gas. I have several 6-rib Whipple pulleys if you are looking for a certain size. Feel free to shoot me a PM. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14 Last edited by Batmanntexas; 02-17-2022 at 01:53 PM.

02-13-2022, 04:01 PM	#5
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	With a cam and fuel supply, you could be in the 650-700whp range I'd think. As I mentioned previously, with the 3.75" pulley, my car made 630whp. My current combo is using a 3.625" pulley, custom cam, ported stock heads, and fuel system. On 93, it made 746whp @ ~10psi, and 806whp on E85. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

02-14-2022, 07:58 AM	#6
fz4k98 Drives: 2013 1ss Join Date: Jul 2012 Location: WI. Posts: 520	Does the car need to be retuned if the pulley size is changed on a whipple? I am currently running a 4 inch pulley and use 93 octane.