Yah call them, and then inform the rest of us what was suggested!

All tuned port/ multi port e.f.i engines stop breathing in the 5200-5400 rpm range, due to the nature of the plenum's they use. As far as a 540, no problem. Just remember to enhance all phases of the engine. You'll need more fuel, bigger pump, regulator, injector's (45lb disc type by Lucas work well) throttle body, e.c.u, knock sensor, etc,,,,,. These engines will make some good power 600 + with out killing them, just don't turn them too high. Believe it or not Lingenfelter has a host of info on t.p.i/m.p.i engines. And after all these h.p's 500/525 are giant tune port vette and z28 engines just 10 year's behind.

Thanks for the reply.

I pretty well guessed 65HP was BS. I never had that kind of increase on a Carb engine by adding the same conditions. I figured 25HP was right.

I did talk to ASM for a good while. They tell me the EFI manifold is good for way more than 700HP if you open up the ports at the heads. Apparently they are real small there & Merc does not spend the time to open them up.

Jeff, I will work with you on the offer if you wait just a little.

Open, Didn't you do the 540 EFI upggrade? I talked about 6 months ago from someone in LA about this who was getting ready to dyno the setup. Thanks, I will call Precision today

I like the ASM throttle body.

Thanks for help, I have two motors coming out in the next week or so.

Linster,
If you look on the boards here or over at Hotboat.net there is a guy who recently converted a pair of 500's to 540's. I believe he goes by Infomaniac, if I remember right he even has the build up on his website. Good luck,
Rick

I will look up the other guy. I know how to get power out of motors, I have not experimented with the EFI ECU. To me thats like have your arms tied on the timing and jetting of a carb motor.

I did talk to Performance Marine. He was very informative and willing to help. That may be what I was looking for.

http://www.pfaffengines.com/ they do a 540, the challenger. 600 hp.

http://www.pfaffengines.com/challenger600na.shtml

Ray, it looks like the Challenger is a 502 not a 540 or am i looking at it wrong?

Here is link to Info's site- http://marineassault.net/
Has been a while since I looked at his site but think on main page there is a link for projects and the 540 deal was under that.

performance or PRECISION??

I'll second Precision Marine. When you see the number of computers that show up from all over the country, Mark must be doing something right. Tell him Mooner sent you.