fixx
 

also if your running 93 octane that can account for some soot also..

Running 93

Talked to Justin a few minutes ago, glad to hear its running well, and just minor tuning issues. I'll be out next weekend if you want to get together

weather permitting i'll be out

You guys running blowers, what are you targeting for cruise AFR??? Say around 0" of vacuum/boost??

My buddy's procharged engines are 11.2 at wot, but like 13.5 cruising at 4000RPM. Seems a little lean cruising to me, even not in boost.

That's way to lean to be safe at 4000rpm under load. There really is no such thing as a crusing load in a marine engine, it's going uphill all the time and I think those air fuels there should be no higher than 12.2 to 12.5 to be safe, especially with todays rot gut fuels and hot summer temps!

Best Regards,
Ray @ raylar

Makes sense to me Ray. He was going off the chart in his F.A.S.T wideband.

While that may be acceptable in a car, cruising down the road at 50mph, I can see what you're saying about the boat/load while cruising. It probably takes 25hp to keep the car moving at 50mph on flat ground. It probably takes 400HP per side to keep a 40+ft offshore boat cruising at 55mph.

He was seeing 11.2 under wot conditions. This is a high boost procharger setup. He was thinkin leaning it out to around 11.8 or so at wot. I don't think thats a good idea, especially on a high boost 1200+hp engine...

Any thoughts on that situation??? Its a blow thru carb setup. Since he's lean cruising, my thoughts were to add some more jet in the primary to get cruise afr down, and if it goes below 11.0 at wot, pull a little secondary jet if needed.

Guessing your are running carbs. If so I would richen up the secondarys a step or 2. You might be getting your soot from your acceleator pumps. I agree with trying to get 11.8 at wot

No way he is leaning those secondaries !!!!

I just found out he has the clearance for extended tip plugs.

That should help with the fouling at idle .

Id like to throw a jet or two back in the primaries for added security midrange, to close to the edge for my taste.

be careful with extended tip plugs and high boost. If you need them to clean up the idle go at least one heat range cooler.