28 replies to this topic

[thumper]

yuji

did you ever find out about the rooster tail thing????

[Yuji]

Not a thing..I think a person could rig one up with some work, but I've been busy finishing my Cold Air Intake and Freeflow Exhaust mods. I would luv to have an adjustable rooster tail where you could open a solenoid or something and it would allow water thru the passage way...and ROOOOOOOOST at will I'll probably tackle that after I'm done all this other stuff.

[thumper]

do you expect a significant change in performance with those two mods?

[Yuji]

So far...improved low to mid power with no gain in top end. I'm cavitating out of the hole now and I gained some rpm's on top which points to increased hp. I plan on repitching my stock impeller to gain some much needed low end and acceleration...if I get a a mph or two on top I'll be happy. A larger intercooler and the Vortech Supercharger impeller also make a big difference in hp on these motors..so I may add those at a later date. The main thing is to dial in the impeller so I have zero cavitation and arm stretching accelleration

[D Lo]

Yuji, do you have any update on that repitched impeller? I guess my main question is are you finding an aftermarket impeller or having someone repitch it for you? Thx.

[Yuji]

No impeller yet...was going to get my stock impeller repitched but II can't afford the downtime with holidays and all...so I'm ordering a Solas repitched impeller once we can figure out the stock pitch BRP has no info for me except that the sportster scic has the same one...which explains the great performance for the 14.5 footer and the poor performance for the challenger. No way a boat that weighs upwards of 600 lbs more should be running the same pitch

[D Lo]

I just read a boating magazine that shows how to run measurements on a prop and determine pitch. I'll have to go look for that...

[thumper]

I GUESS that means you will be going up in pitch - which means you will have to ensure that the engine does not over rev - but i guess if these are fitted with rev limiters you will be ok.........???????

i am assuming that incresing pitch on these has roughly the same effect as a prop boat does in the same instance

[thumper]

yuji - boat looks v cool with tower - is it new (the tower that is)