ken728

Hey guys i have a 2000 25 daytona with a 540 built to 650 hp dynod. It has a xr drive with a.1.36 drive and a 24 pitch stock bravo prop. All i could get out of it was 5200 rpm 83 mph on a good day. Well i broke the crank in half no idea how and now i rebuilt it and its 720 hp 680 foot pounds. U guys think.ill see a big improvement in top speed going to a 1.50 ratio and a taller pitch? Also do u guys recommend going shorter on the lower drive on this boat? And does anyone have pics of any diffrent exhaust on that boat besides cmi e tops?

lake speed

cant help with the exhaust pics but I can tell you than mine has a 3" imco sc shorty and It works excellent. I have a 1.36 gear set and a labbed 30" prop. my motor is a 640 bbc and I spin it to 5600 rpm.

DirtyJohnson

I am running 800hp with 1.36 gears and 30". As for lower I have was talking with Eliminator and Imco 2 weeks ago about this and they said to go up to 1" below sponsons. My x-dim is 2.5" below so for me I need to shorten 1.5". I am also considering the Imco SCX next year. I cant attach an image or else I would show you my exhause. I have imco powerflow. I can email if you like.

ken728

[email protected] wow 1 inch above. I think im around 4 inchs below. Think i have a really low x dimension.i know the oil pan almost hits the floor. That's probably slowing me down

J.P.

No he said 1" below sponsons not 1" above.

DirtyJohnson

sent you some pics. Like J.P. said, 1" below the lowest point. My transom housing is touching the rub rail at the top if that helps. My oil pan is about level with the upper part of the tunnels, so the highest part of the floor

Airpacker

Where is your transom assembly in relation to your rub rail?
A 3"shorty on mine would have put the prop shaft well above the bottom of the boat.

any issues with cavitation burns on the bottom of your drive directly infront of the water pick up opening?

what speed are you seeing from this setup?

Airpacker

What rpm does that turn? What speed?

PS, you cannot use the SCX lower. Too fat and high speed handling was the concern voiced to me by IMCO.

I went SCX upper, -1 SC lower. Probably could have gone -2 but heard planing could be tough.

psi

Hey Guys...When I built my 25 Daytona I was also back and forth with Eliminator regarding the height of my drive...I also felt it was also mounted to low and it had a -2 shorty lower....the problem was, with the -2 lower and where it was mounted to the transom I was stuck on going up....I went with the 12in setback and 3in rise extension box from IMCO. Cant really relate how it performs cause my engine combo is 1 of a kind....I posted a pic so u guys can see it with the box...

DirtyJohnson

I am not sure of rpm at WOT since I just bought the boat a few months ago and I'm getting use to it and don't want to blow the drive up. This past weekend I was running 4500 rpm at 80.5 gps. I probably could have trimmed a little more out of it.

As for the SCX I meant lower dimensions not SCX lower even though we did discuss that. They did say to run the SC lower but I will blow those up too. I am willing to lose a few mph to keep from blowing these up but what is the high speed handling concern?

SCX upper for sure is the plan.

Imco did recommened I go with the 12in setback as well because I have the twin step hull with an open bow. They said it would help with bow lift.

So is that 3in rise and a -2 shorty?

I like your power choice. I was just showing your boat and setup last week to a co-worker that has a supra. I am a fan of the 2jz and am surprised there are not more of them in boats. nice setup you got.