25 foot Eliminator eagle XP. MPI 502, exhaust, fuel system and intercooled M3 procharger. Bravo 1 with racing lower unit. Right now has a 28P 4 blade prop that the last owner sent to Denver twice to get tuned to the boat. On average runs close to 80 mph at just under 5,000 rpm. Has run 89 at best up here. Do you think the prop is a bit big? With 650 horse it seems it should pull to 5500/5800 rpm pretty easily and run a bit faster.

Water temp about 100°
Water pressure 30
Fuel pressure, 80 psi wot.

Fordtrucks,
What rpm do you want to turn the engine with the M3 system?
That determines where you need to go with propeller pitch. In addition or even more important is where the max HP is generated.
Going to a 26 may be the better decision.

Brett

Thanks for the reply, and I don't know! Lol. I'm new at this and its my first boat. Now I'm almost wondering if the prop is kind of small.. My buddy has a 28' eagle like mine, same motor but with a Whipple and He'es running a lapped 33p. Right now I'm working on getting the engine temp up because I found out below 105 degree water temp and its running in cold enrichment mode all day. If I can get it warmed up, it should run a lot better. As for the pro charger, it maxes out the boost almost as soon as I mash the throttle but ide say there's no reason to spin it more than 5500 rpm ish during a wide open run ...

Ft,

Take you time. Enjoy what you are learning. Boating is supposed to be fun. It is a hobby!

Call us anytime and we will do the best we can to help you.

Brett

Thanks Brett! Not sure I need to call and bother you at work just yet but if I end up needing a prop, I certainly will. .. So do you think this boat needs something bigger than a lapped 28p for its setup and power? I think if going bigger would allow me to run in the 60/80mph area at less rpm than I do now but not loose me any low and mid range then it seems it would be a good idea!

Running lower rpms with too much prop loads the engine harder and increases the risk of detonation.

With a stock 502mpi, that is a 72-74mph boat. Guy here used to have one.
How much boost are you running???? Who recalibrated the ECM and what was the rev limiter set to. Stock is 5150rpms.
If the engine is basically stock except for the M3, then keep the rpms around 5100.

Tomorrow night I can post the name of the company that tuned it. The paperwork didn't say what the limiter is set at but previous owner told me He'es seen 5400 ish out of it.. Turns out the boat made 25 psi ish water pressure at wot before I bought it. I must have sucked sand and ruined my sea pump. I'm going to replace that but it also means I won't be able to run the restrictor because the pressure will be to high. I think I'm just going to send the ECM back and have the cold enrichment mode set at like 75° or something so even at the 100 I get now it will run correctly..

Good point on the prop and load. Makes sense.

Pushing close to or just at 7psi on the inter cooled M3SC
Internals are stock. Bolt ons are the exhaust, M3, intercooler, fuel system, racing lower out drive with dual hyd steering and a few gauges. One other thing another eliminator guy down here liked was my idea to put a brass ball valve in the inlet hose to my sea pump so if need be I could close it some to slow the water flow through the motor which should increase the temp but wouldn't raise water pressure...might try that. If it doesn't work, I can simply open the valve all the way. No harm done there in don't think.