I have a 2001 Fountain Fever 29' with an HP 575 sci and Bravo XR. Engine has been overhaul recently with overbore (507 cu in), 8.9:1 compression and a Roller cam and lifters fitted. The cam is .606 lift on both and 236" duration on both @ .050 lift. Stock Weiand supercharger with twin TBI (All stock stuff).


The question is:

I would like to be able to run on 87 (Max 89) octane fuel if possible. I was looking at the Whipple low profile Intercooler Kit to help achieve this. Maybe leave the stock pulley in place as I am not necessarily looking for lots of horsepower just no detonation on lower octane fuel. I do understand the MEFI 3 PCM will need changes. Any knowledgeable input appreciated. Also any recommendations on a shop that would be worth talking to?

Your static comp ratio is already 8.9:1. Even without being SC'd, you are pretty close to maxed out for 87 Octane.
Add in the stock 4# of boost and your Dynamic Comp ratio is 11.4 ish which will need at least 91 octane.
https://documents.holley.com/techlib..._tech_info.pdf

No. I had a kid at a marina accidentally fill up my 575 sci boat with 87. it took about 30 minutes of running to destroy the exhaust valves. Mefi will pull timing to keep it from detonating, but EGT's go through the roof. I would run 93