NeverEndn

My buddy has a 1999 38 Top Gun straight bottom, he re did his motors this year and supposedly is pushing roughly 1000HP maybe 1050HP or so. Hes running SSM #3's not sure of his prop pitch, hes hoping to break 100MPH. Whatta you guys think? Will he do it , the fastest ive ever been in the boat was 88mph last year when he said he was making 910HP and the boat ran 94mph supposedly but no one ever seen it go that fast. Eitherway the boats a sick boat, im just curious as to what im up against this year. I just re did my 1996 35 ft single step Fountain the motors now making 700HP with bravo XR's , i havent hit the water yet , so prop pitch not sure of yet most likely a 32P 5 blade maybe 34P or might even go to a 6 blade, im hoping for 95ish or more who knows!

cigrocket

iTrader: (3)

Alot of factors as I am sure many will Chime in with. X dimension has alot to do with speed, and proper prop setup. The X dimension was raised on my straight bottom gun 3 times with my #3a's at TNT marine before they were satisfied with the setup. I would say if it is actually making 1000hp to 1050 hp and correctly setup, I would say yes. 1999 boats were also vaccum bagged and a little lighter (cover girl cabin?)

NeverEndn

I do remember him saying he thinks his X dimension is to low and needs to be raised more so i dont know if hes doing that as well or not! So lets say at best whats his boat gonna run?

4195

I hate to give up one of best secrets but here, play around here for some info. http://go-fast.com/boat_speed_predictions.htm

thisistank

a 42 straight bottom Tiger will just about be right at 100 with 1000 hp each side and 6's, so I don't see why a gun would not be able to.

dnebo

Should be close to 100 John's biggest problem will be that he has a full cabin.

NeverEndn

Well either way i hope he does thad be sick!! , i hope i come close as well!, as for full cabin, meaning with *****es or seats and bed and head etc lol!!

bigfarmer

Yes my full cabin is going to be a factor with slowing me down. The fastest Ive ever seen on my gps was 94.7mph which cant be done every single time out (conditions have to be right) on average im 91mph on the hottest day of the year with a full tank and lots of girls of coarse. I was running a 4bl prop which came with the boat when it originally had 750hp, never re-propped after my new power, which im thinking would drastically increase my speed (and handling due to the new technology with props). My prop shaft being 7" below the running bottom of the boat and spinning a 17.5" dia prop to me doesnt seem to be the best setup for speed. No more 3a's, as im switching to #5's on boxes and am going to shoot for my prop shaft 1.5" below the running surface, thinking of trying a 21* rake 5 blade, being such a high rake it might act like a 4blade!?.. I was told with the higher prop shaft and new prop i MIGHT see up to 10-12mph gain....but i guess there is only 1 way to find out......just give-er

thisistank

This has been discussed a few times and I'm sure someone with more experience actually installing drives could/will chime in but putting boxes on #5's will defeat the purpose of switching from 3's to 5's all together.

The 3's and 5's are virtually the same drive except the lower on the 5 is shorter (bringing the X up). The boxes will push the drives out and down (bringing the X back down).

I know boxes look cool and all but you're going to do all that work and have pretty much the ame affect from the drives. And I'll tell you what's going to look cooler is the rooster you're going to get from the shorter 5's with out boxes! I think with out the boxes you're going to get what you're looking for.

Unless of course you're blocking the transom and re-cutting for the boxes/5's. Then never mind everything I just said. But that also seems to be a lot of work just to have boxes.

bigfarmer

I thought because of the #5 being so short you have to run a box to get the drive back further so it wont cavitate and to get on plane easier?? Running the box in the bottom hole i wouldn't think would drop the drive 6"... maybe 2, which is needed to get the prop shaft where id like it to be. With a #5 you can always space down..not so with a 3a. I have talked with Gary who has done this on his flat deck and he thinks 10mph wouldn't be too far off.

"Unless of course you're blocking the transom and re-cutting for the boxes/5's."......??????