I don't know what size your stock pulley is, but if it is 7-1/2" and you go to 8-1/2", to keep the same ratio the blower pulley would only increase to 2.83. (Or all the way to 2.83, depending on your perspective.)
I knew that was your next question.

 

Wrong!!!! My next question was going to be, "why aren't you watching batman?"

 

Sorry I don't. I did have one layin around. If I still had it I woulda gave it to you.

 

I am out of ideas....I am calling Jeff and Mike @ Whipple tomorrow. They need to tell me what the limit of this blower is so I know if its something wrong with my setup, a defective part, or a defective truck owner..

 

Is that sliding idler pulley what keeps that belt tensioned? I haven't seen an 8.1 kit in person but it looks like there's some re-routing of the belt involved with the kit and it sort of even looks like the alternator is running from the water pump?

If the pulley isn't keeping tension, I might have an idea for re-routing the sepentine belt for optimal wrap.
I meant to ask before, but are you running a Dayco Poly-Cog belt already?

 

Truck is using the stock tensioner. The tensioner on the whipple blower bracket is adjustable, but not spring loaded......you set it and tighten it down. That pulley is a 76mm Dayco and I was considering upgrading to a 90mm to get a little more wrap. The alternator runs off of a secondary belt driven from the water pump pulley. The 8.1L kit replaces the single belt pulley with a double belt one.

 

You need to check if the I/C is a restriction first. Whipple already told you that their wonderful blower should make 7-8 lbs. on your engine. I don't think that they will ever tell you that it is inadequate, even if it is, which it probably isn't. Are you the only person with a Whipplecharged 8.1? Won't Whipple help you get in touch with somebody else with your setup? Sorry if you've covered this before.

 

Okay, cool. Being adjustable might make this possible.

In this first diagram, you could consider routing the belt from the current path (dotted line) to the new path. My only concern with this is the angle that the stock belt tensioner is pulling on the belt at and if the reduction of angle would be too much for it to adequately absorb the slack.


In this other diagram, if the Whipple idler pulley can be reduced to the smallest size available and slid to the passenger side, the belt might clear. I'm looking at a stock 8100 photo and your pictures to draw this, all of them were at weird angles so I can't tell if this would work or not in real life. You could probably use a piece of string between the pullies to find out.


I thought about routing the water pump as the last driven accessory but doing that would put it after the tensioner which could cause the belt to go slack if the clutch fan locks or the alternator is drawing current since it appears to be running from the water pump pulley on a seperate belt. That option was ruled out.

As far as total belt length for this... I have no idea.

 

Thats pretty cool James.....I actually like the second option better as it continues to utilize the stock idler where the first option does not. I would definately have to find a smaller whipple idler for the whipple bracket though. I will take a look at these options tomorrow and see which one would actually work out better and exactly how things lay out.

 

I plan on testing the IC as soon as i can. I was going off of what Tbyrne posted a while back when he did his tests. He said he saw a 1.5lb pressure loss and he had the same setup i have except he was running the electronics. The same thing was posted by "Gandolphlox" or something like that on the avalanche forum. I dont know anyone that is currently running an 8.1L intercooled whipple setup right now that has the means or ability to accurately measure MAP via software. There are a few guys running the non intercooled setup but i dont know if any of them are using tuning software. Perhaps its time to start searching the net for my 8.1L brothers.