hoping to fine tune boat this spring...if want to call it that..M3 procharger on a 500HP, what AFR's would be ideal @ cruise & WOT ? Running 6psi ,@ 5600 thanks Rob

you could go 305's but we did the 335cnc's first then used the heads when we upgraded to 540's.so far we got a 38 formula w/ arnesons to 110mph in alittle under a mile from a 30mph start.1 of my videos is on Arneson's web site.

I think he meant AFR's not AFR's, lol

Thinking he meant air fuel ratio
Mid 12's to 13 cruise, if you plan on running wot for extended periods of time high 10's, if short bursts 11.2-11.6

i think with the m3 and 6 lbs boost you can get away with a leaner afr than with a roots deal.it also depends on the type of boat and how long the stick will be pinned.

It would be nice to compare egts and see what it likes

yes air fuel ratio...just hoping can get the 02 to live in these lightnings, killed 3 in the last couple of years, put a bung in a tube this time, know it's not ideal, but normal location will not work...

sorry about the confusion(something to ponder later on ),,cruise I wouldn't go more than 12.8,,wot shoot for 11-11.3.does your procharger have an oil feed and return?friends set up gets the air pretty warm before the biggest intercooler they have,although 6lbs isn't to much.we run 8-9lbs.

No, its a SC(self contained unit), also don't do any real long WOT runs, 25' checkmate, things get interesting !

I recently learned of a M3 procharged intercooled setup that runs 7psi, and has the same air intake temps at wot, as a roots blown 10-71 WITHOUT an intercooler running similar boost . (130-140*)

I think we've all been led to believe roots blowers make tremendous heat and centrifugals simply blow icy cold air out of them.

If its a blow thru carb setup, I'd be very careful with leaning the afrs too much. The fuel distribution sucks on those setups. While you maybe will see 11.8 Afr average from the bank of the 4 cylinders, you very well can have a cylinder in the 12's ....port injection with a good intercooler, high 11's no problem at wot. .