XR...what ratio to run
#1
XR...what ratio to run
I'm getting a new XR drive and was trying to figure out whats the best ratio to run. In my head I was thinking the 1.26 with a small prop will make for a happy long life behind 550 hp. I was running a 26 Bravo prop with a 1.5 Bravo 1 @ 5200. So maybe a 22 or 24 Bravo on a 1.26 XR. What do you think?
It will be on a 26' single engine so planing and acceleration should not be a problem.
It will be on a 26' single engine so planing and acceleration should not be a problem.
Last edited by jdub; 10-23-2007 at 05:23 PM.
#2
I've learned that hulls will react differently to certain pitch/geometry changes. So on the surface it might look like the thing to do, to change the gear ratio and prop, but the boat might not like that pitch of prop. I run a 1.5 with a 26 Bravo (summer, 28B winter) and the boat is very happy with that setup. If I remember right, the 27 Fountains worked best with a 28" Bravo and they came with a 1.65 gearset as do Formulas 292's. You might be good where you're at. If you're not leaving the sticks WFO during launches or planing at WFO, then an XR should be ok with that power. Get some slip numbers and talk to other Corsa owners about their setups would be my recommendation.
#3
Registered
iTrader: (1)
Join Date: Apr 2005
Location: Long Island New York
Posts: 762
Likes: 0
Received 0 Likes
on
0 Posts
I changed from a 1.5 to 1.36 and I gained a few mph on the top. The accelleration dropped off and the boat is more sensitive to weight, fuel load, and water conditions. The top end speed is not always consistant. Somedays I run 80-82 and somedays only 77-78 If your not looking for the ultimate top end your better off with 1.5's. Overall it's a better choice. At least for my boat. Good Luck.
Nordic Heat with 525 xr/its now with labbed 26 bravo.
Prior to gear swap stock 28 bravo.
Nordic Heat with 525 xr/its now with labbed 26 bravo.
Prior to gear swap stock 28 bravo.
Last edited by raytart; 10-23-2007 at 06:29 PM.
#7
Registered
I went from 1.5 Bravo with a 32B to a 1.36 bravo with a 28B and am now with a B-Max with a 1.3 and a 26B. The 1.5 by far outperformed the others. I have no other options under my current set-up and am freshning my motor this season anyway. We will make up for the loss with a little tweaking.
Bob
Bob
Thread
Thread Starter
Forum
Replies
Last Post
saulesses
Prop Talk
1
06-13-2007 09:12 PM
saulesses
Prop Talk
0
06-11-2007 11:01 PM
FASTERDAMITT
General Q & A
27
03-18-2005 10:39 AM