47 lightning gear ratio
 

hello i need some information about 47 lightning 98 mod 3x525 hp what kind of gear ratio and propeller will work on that boat and what are fountain normally deliver for seawater use. anyone there who can help .Thanks.

Re: 47 lightning gear ratio
 

My friend has a 42 with trip 525SC's. Drives are 1.50:1, spinning 26" Hydromotive QIV's

Re: 47 lightning gear ratio
 

Tanks do you know the speed of that boat as far as i know 525 have max 5200 rpm fountain said 90+++? with those numbers and my calculations the speed is a way down but maybe fountains number is under special condition i am happy for all information

Re: 47 lightning gear ratio
 

93mph on his 42. Don't know what a 47 would run though.

Re: 47 lightning gear ratio
 

Thank you . Do you now the rpm on those engines.

Re: 47 lightning gear ratio
 

also 5200. He's gone through 2 drives, Bravo's. But runs hard too.

Re: 47 lightning gear ratio
 

My 2000 47 lightning running IMCO SC's 1.50 and 27P Hyromotive P5X Right on the limiters at 82mph 2003 500EFI's I think 5150 limiter.

Re: 47 lightning gear ratio
 

Interesting it seems that you have 7-8% slip anyone who can tell me x dimension for that boat.Haven't received any answer from fountain

Re: 47 lightning gear ratio
 

Seems like it should be higher than 7-8% how did you figure it out. It is a tripple engine boat too. The IMCO's have a pointy nose cone too. Also 82 is ringing it out, I can hit 79 - 80 easy with 4-5 people on board.

I have no x demension details. I know the 2000 had a diffeent hull than in past years I think they changed in 99. The newer 47's say 95 tops with 525's I would say it would be closer to 90.

Re: 47 lightning gear ratio
 

I am back from my job . 5150rpm-1.5 ratio=3433 prop rpm x27" x60 will give you theoretical speed 88mph-6.5%=82Mph.I hope that you understand my explanation .Its approximate numbers i have seen a link to a slip calculator some where but i couldn't find it.That will be allot of questions in the future so i hope i get some help her. by the way nice forum