Can you buy pulleys for these from whipple or is this the only pulley they offer (the one that comes on it)?

 

yeah, you can buy smaller pulleys. every 1/8th" should add ~1lb. a boost

 

btw, measure the pulley thats on it now, should be 4 3/8" for a 5.3L, if the kit was for a 4.8L and had the bigger pulley that would explain the low boost.

 

The instructions say its for a 4.8-6.0, but now that you mention that it makes a lot of sense. I did not see anything on whipples web site. Can you buy them aftermarket or do I need to try to get them on the phone now so I can get one for christmas???

 

How many pounds of boost is the 4 3/8'' pulley suppose to make? What size would be on there for a 4.8?

 

4 3/8" would make 5-6psi on a 5.3 which is the one whipple supplies. the kit for a 6.0 comes with a 4" pulley which makes about 8-9psi on a 5.3, and a kit for a 4.8 has a 4 5/8" or a 4 3/4" pulley, can't remember exactly which one but it would make 2-4psi on a 5.3.

 

You might try and talk to George about it, i would think he might know. Hopefully you get everything sorted out, and she's a beast.

 

i struggled with my whipple for a year before finally deciding to get larger injectors, fuel pump, methanol and most importantly, a tune. When it first went on it was a mess. Actually had less power. something was severely wrong. In the end it took my 6000lb truck to 13.066@102 in the quarter mile. Non-intercooled. stock i made 222rwhp. 12lbs boost made 416rwhp

 

I dyno'd 440hp and 660 @ wheels on a '99 7.4L sub. Water/meth is needed over 6 lbs boost. I run 11 lbs. Truck runs great with injectors and custom tune. Being replaced with a 2007 Escaladed 427" with a 3.3L Whipple.