Drive heartburn
 

I've been running a modified 454 Mag with Pro Charger, I have taken out another Bravo drive. Any thoughts on XR, Imco, or others?

Re: Drive heartburn
 

xr great drive imco a step up!!!!! same gears heavier housing :evilb:

Re: Drive heartburn
 

1998 Velocity 260 same as 280 today 26' hull about 4400# runs mis to upper 80's depending on prop gps havn't totally dialed it in yet.

Re: Drive heartburn
 

How big is the boat, weight, and what prop and gear ratio? How much power does it make. I put a Bam XR upper on rebuilt lower, 28' Checkmate, 650 hp. He has a couple of weekends on it. Another one is on a 260 Velocity, with blower motor 750-800 hp.. several weekends on a rebuilt XR. Both were at Hardy pond this weekend and I did see the Velocity run it real hard. Another is 25' (24'?) H2x Baja. 966hp procharged. XR upper, new design with Imco shortie.. 70hrs and upper gears were done, but did not hurt anything. But they tell me he ran it like he hated the drive.. Now it is running 1150hp and 1050ft/lbs and it went 109mph at LOTO . We'll see how long it runs. A properly setup XR will live for a while if driven with respect.
I hope that helps.
Dick

Re: Drive heartburn
 

Blew two IMCO Extreme SC's this year. First one at 20 hrs, second at 30 hrs. :mad:

Giving someone else a shot and having the latest blown drive rebuilt with Max Machine internals. We'll see what happens. :(

Re: Drive heartburn
 

cool panther please let me know how you make out or if I can help out in any way!!!

Re: Drive heartburn
 

It's a 1998 260 Velocity 26' same as the 280 or VR1 about 4400#'s questimations are about 800h.p.
1.50 gears has run a Bravo 34 lab finished to 35 at 4900, running a stock 32 bravo that needs some massaging to get it right.

Re: Drive heartburn
 

Max machine worx gets my vote. I just broke a drive 1 week ago,lower gears started chipping teeth away,ruined most the bearings thru out drive,60 hours on drive since it was freshened-(30hours w/750hp-30 hours w/950 hp). The upper xr gears still looked good,no broken or twisted shafts this time. Drive breakage is going to happen at 800 plus hp if your running any kind of bravo derivative,its just getting it to last a reasonable amount of time. Is there a reason your running a 34/35 pitch prop at only 4900rpm's?If you torque load the drive hard down low like that it will break quicker.If your any where near Michigan mr gadgets can build you a good drive using max parts or any combination of parts you want. I was at hardy pond this weekend, both races I got in were against velocitys like yours,1 had a mph on me ,the other walked away,pretty fast hulls :eek: ,Smitty

Re: Drive heartburn
 

Hmmm, I'm turning a 32 Bravo 1 to 5000 rpm with a full load of fuel and 5300 with 1/4 - 1/2 tank of fuel.

I wonder if a 30" pitch would be better at 5300 full tank and 5600 1/2 tank?

The Valvetrain is set up to run 5200 - 5600, we spun them to 5800 on the dyno. I'd loose cruise speed but if the drive lasts longer than so be it.