what next?

[vishus]

1994 RapidCraft Riot
1993 Mercury 200XRi, no exhaust liner, holes drilled for relief, fiberglass reeds, heads cut to 150psi compression (everything else stock, flywheel, laser injection, etc.)

26 Ron Hill Drag prop @ 7000rpm = 84.1 mph on GPS.

I ran a 28 drag prop to 7000rpm didn't have the GPS with me at the time.

The boat is running great!!! Great holeshot, gets to topend quick and the boat is flying well with no issues.

It revs quick but seems to hit a brick wall at 7000rpm. I trim it up a bit, no change in rpm (not willing to trim it any harder in fear of blowover!)

WHAT NEXT? How do I get more revs!!!

ps the RON HILL DRAG PROP is the BOMB!!! I had the hardest time driving this hull with big ear choppers and RE4s, the boat would porpoise and chinewalk hard at 70+, now its smooth in the mid 80s....

[vector mike]

But I'll give my .02. The stock 200 port height is probably limiting you to your 7000 peak power limit. I think you need to reprop to keep your power under 7000 to get the most of your setup.

[WATERWINGS]

It does have alot to do with the prop,

26 Trophy @ 7000= 88.6

32 cleaver @ 6700= 89.4

28 inline chopper @ 7000= 94.1

All GPS!

[vishus]

Damn John,

that Trophy was running VERY efficient, about 6.5% slip and almost the same speed as your 32!

I am picking up a 30 to see what she will do!

thx.sid

[WATERWINGS]

I really think the 32 cleaver was just not working for me,

The 28 chopper is the same as the 26 trophy at most all RPM's (speed wise vs RPM wise) but when the chopper gets to turning over 6000-6500 is where it starts to shine!

Also, if your not to high already with propshaft height, raising the jack plate will give you more RPM and speed!

[vishus]

I was having some handling issues with Choppers and such, so I am currently set directly on the transom (1 hole down from max) the propshaft is 1" above pad. I think I will put the jackplate back on and see how that runs.

I do think a stock ported, stock tuner 2.5 steel sleeve laser injected motor just runs out of power at 7000rpm or so...

thx.sid

[WATERWINGS]

When I took my 6" jack plate off, I lost 5 MPH,

now I am running an 8" jack plate (when I ran the 94.1)

[STVBOY]

Unless you have a rev limiter most likely you are just at the motors limit. On my 2.4 it was the same thing it would just stop at 7000 rpms with a 28 or 26p prop. With a 28p prop at 7000 I was running around 94mph on GPS so with a 28p you should be close to 90mph and thats about the limit for 200hp.

[us1]

Originally posted by vector mike
But I'll give my .02. The stock 200 port height is probably limiting you to your 7000 peak power limit. I think you need to reprop to keep your power under 7000 to get the most of your setup.


You said it.

[vishus]

Great people, Great advice.

thanks again.

I will run a larger prop to get more speed for now....

later ($$$) I'll get US1 to port for POWER!!!


thx.sid

[us1]

I am ready when you are, the shop is acualy done now. Sorry I couldn't do it last time.:)