Also seeing some talk about the stock ford mapping for the supercharged cobra in the low 10 range AFR .

As far as the Vette engine , obviously they are shooting for safety. And supposedly the stock blower causes some high IAT readings.

I'm sure there's some power on the table by pulling a bit of fuel out, but I don't see a ZR1 blowing gobs of black smoke and washing the rings out of it .

Now remember that is in a rolling vehicle, the load on a marine motor would justify this even more. IMO

And its a modern EFI engine with knock sensors, iat temp sensors, port injection, etc. A far cry from a carbed marine engine with poor fuel distribution, no iat sensors, no knock sensors, etc.

Late to the game, but my guess was going to be in the 10's... Our 07 Whippled Shelby (5.4) is set up between 10.2 and 10.8. I run the boat in the 10's also.

i think people would be suprised at how little the power loss is going from 11.8 to 10.5.i don,t know the afr on a merc 1075 but il bet it,s not 12.1.

Oh come on had to be "beginners luck" LMAO!!

Don't bet
The 2 I've put widebands on would run in the 13 at cruise and only drop to 12.7/9.real scary,tried adjusting regulator for more fuel up top and it did nothing but richen the bottom a little.ended up having Marc boos add some fuel.
And the timing they run,wow.I'd never tune like that.

So the 1075 merc is 12.7 Wot?

Heck my gas GM dually is 12.6 at wot.

12.6 hp ?
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Lol.

Remember these are 7.9-1 compression,,but yes they were lean and they had like 36degrees of timing to 2lbs of boost.then backed down to 32 degree.
But 13lbs of boost was 12.7ish to 13.3 depending on load.the motor has a fuel pressure compensation table and we brought it up to it's limit.tried to cheat it a little.
Boats were 42 and 46 outerlimits.