J.P.

I just purchased a 2000 model 26 Mach DCB with a 572 cubic inch motor with intercooler and 1471 littlefeild blower. It has a Bravo I XR drive and has a little sticker on the port side that says 1:50 R. It has an Imco SC lower on it and the only number I can find on it is a 0 -. Imco says that is a 1:50 standard lenght lower. Does this sound like way to small of a gear for this big of a motor. I have only had the boat out once for about 30 minutes and I ran it up to approx 5k rpm for a very short burst and the speedo was pulling up to 88 plus mph,... I was not all the way in it. I was thinking this boat could use a 1:25 or at least a 1:36. I know very little about the motor as far as what the max rpm is. Are all the Bravo 1XR's geared the same in the upper and the change is made in the lower for a different ratio? The drive does not have a drive shower on it do you recommed one. I need this thing to live and have been told that the 1:50 is easier on the drive than the 1:36 or the 1:25 would be. Also could this boat benefit from installing a 2" shorty on it. Any advice would be greatly appreciated.

Joel

tcuda499

You ran 88 plus and still want to go faster in a 26 footer????IMO thats haulin. Congrats on the boat. Yes, install a drive shower, cheap insurance. I dont know whats up with a 1.50 gear to 1.36 gear.... Couldn't you just put a bigger pitch prop on it and get a little more speed or are 1.36 gears stronger than 1.50's?? A -2 shortie might help speed but might hurt handling, dont know much about DCB handling but I'm sure someone else that knows will chime in.

Mr Gadgets

On the XR, the gear ratio is changed in the lower. Neither are stronger than the other. If you run out of prop, you will have to change the gears.. The 1.36 are more money than the 1.5 lowers.
With the blower you have, be very careful applying torque in the mid range, it will snap the drive, very easily..

Dick

GPM

What prop are you running ?

J.P.

It has a 15X32 Bravo I 4 blade prop. I was told that running the 1:50 gears in the lower puts less stress on the upper gears. I have read alot of people don't like the bigger pitch props. If your saying I could put say a 34 or 36 pitch prop on hear and be ok then I would and not worry about the gear. I would like to be able to run up to 110 (Am I dreaming). Oh and when I ran the boat up to 5k it was making 6#'s of boost.
Thank you all for the feed back and Merry Christmas.

J.P.

Oh and couldn't I just change the gear ratio in the lower if I wanted to go to the 1:36 or the 1:25? Is'nt that close to the same price as new big diameter prop?

GPM

You might want to take the boat out and crank it up before making any changes. If your numbers are right, 6200 rpm with your current set up would put you right about 110. The lower the gear ratio the less bottom end you're going to have.

GPM

Yes you could change the gears, but the gears and install would cost more than a prop.

J.P.

Thank you all for your response. Do people turn the big cubic inch motors say 540 to 600 cubic inch up over 5500 rpm. i thought that was the reason for having the cubes was to turn less rpm and load the motor. I will let you kow what the max rpm is when ever I can run the boat again.

Thanks

GPM

I run a Procharged 598 in a Mach 26, I've run the 1.26 and 1.35. You probably don't need the 1.5, without knowing how your boat runs top end it's hard to make any recommendations.