GETU1

New to OSO, first performance boat. 01 35 Lightning w 500 EFI's, Bravo 1's, -2" Sportmaster lowers, 32 Bravo's. Data Tach numbers show 86 mph @ 5450 rpm w 24% slip. My prop slip numbers seem high but a bigger concern is trying to achieve plane in LOZ weekend traffic. On calm water there is no problem but when it is rough I have not done that many burnouts since I was a kid. Spacer plates or do I need driving lessons. Thanks.

compedgemarine

we need to know what height the drives are at. x dimension is where the crank center is located in relation to the bottom of the boat. drive height is where the prop shaft is in relation to the bottom. trim the drive so the prop shaft is level to the bottom of the boat and put a straight edge on the bottom of the boat going back to the drive and measure where the shaft center is. i.e. is it 1" above the bottom or 3" below, etc.

GETU1

Thanks for the reply, I, m a week away from getting back to my boat but I think I can have my buddy at the lake get this measurement and forward. By the way it was originally equipped with standard length Bravo lowers and the shorties were installed before I purchased it.

dereknkathy

so, it has 2 inch shorties on original drive location? at least to best of your knowledge? I wouldn't think 2 inches above stock would be that extreme. try to bum a pair of 30's and see how that behaves. probly put rpms up about 350-400 higher at wot.

Expensive Date

Dumb question, you are tabs down, drives in and taking her up easy? Are you sure you don't have 1.65 drives? Because thats a lot of slip for that speed.

GETU1

I need to say that the numbers mentioned are not the boats max, that's as fast as I want to go until I get more seat time in it. It will still pull the 32's higher but if my prop slip numbers were lower may not be the case. As for getting on plane tabs down, drives tucked, around 3500 rpm. Calm water, no problem but at LOZ weekends when it is rough it wants to blowout and takes a lot of fhrottle work and a lot longer to plane.

compedgemarine

alot of fountains came from the factory with the drives some what high. they were looking for speed remember. if that is the case and it then had 2" shorties put on it then you could very well be too high for anything but top end speed. if you know someone with a set of stock drives that you can sucker them into loaning you for a day then try that and see if it is more user friendly. personally I am willing to give up a little top end speed to have a more usable boat that you can stop and get back on plane with.

GETU1

My thoughts exactly as to the loss of top speed. Just want make sure I was headed in the right direction with a cure. I should have the drive height measurement tomorrow. Thanks again.

Screamineagle

Prop centerline to pad on getu1's Lightning is 6.5 inches.

ALL_IN!

iTrader: (1)

If you don't have it, call Fountain and get the Performance Report. It will show stock drive height, then you can compare to what you have now vs where you want/need to go.

My X is 18 1/4" on a 2002 Lightning with stock lowers + Hydromotive nose cones. I was lucky a few times, but I was very disappointed trying to get it on plane the first few times on the boat (Bravo 34's). I purchased a used set of Bravo 32's and the boat would get out of the hole around 2800 RPM, and rather quickly. I lost some cruise speed which I desired. Bblades was a wealth of knowledge on the 34's and he worked them over the winter, and now I can get on plane pretty good. However, when the water is sloppy or I expect it to be sloppy, I still put the 32's on.