Bravo One... Which Gear Ratio To Order?

[Chillin The Most]

Insurance company is putting on a complete new outdrive on for me. Boat shop wants to know which gear ratio I want for my outdrive.
I have a 1995, 236 Captiva Rinker, with a 454, 310 HP, Bravo one outdrive. It was originally a 1.5 gear ratio. Speedo reads 63 mph @ 4600 rpm with a 21 SS Mirage, and 66 mph @ 4600 rpm with a 23 SS Mirage, and 68 mph @ 4400 rpm with a 25 SS Mirage, All props are 3 blades and rev limiter is set at 4600 rpm (Thunderbolt V ignition). My question is, if this was your application would you stick with the 1.5 gear or put in a 1.36 gear? I know I may lose some hole shot with the 1.36, but I would rather have more top end. Anyone have the 1.36? Will I have enough HP (310) to turn the 1.36?
Thanks,
Chillin :confused:

[HammerDown]

I would get a hold of Gary Teague and ask him ASAP!

[502procharger]

you have no reason to change your gear ratio. putting a 1.36 on will do nothing for you except make you go out and buy a prop that works with that gear ratio. your doing no improvements to add hp, so why would you change gears. you will get NO benifit at all going to a 1.36

[gnarley]

Change the ratio & be prepared to change the prop!

[Dave F]

502 is correct.
Without more horepower to turn the same prop(s) faster, (which is what the 1.36 will accomplish over the 1.5) you'll need to change the prop to a smaller size.
Now, that's not to say you're not hitting the limiter with the other 2 which is what the math suggests, but theoretically it doesn't matter. You only have enough HP to push X water.
In other words; In theory, you can spin a 25 4400 r's, but you can spin a 21 say, 5200 r's. (rule of thumb is approx 200r's per inch.) So with that apporximation the numbers jive, the down side to all this you're still pushing the same amount of water.
Doing the math; the 21 at 5200 your theoretical speed is 45.95 mph...With the 25 at 4400 your speed is 46.3.
So the theory is proved, assuming you're hitting the rev limiter, therefore not being able to spin the 5200.
Looks like you're getting you best numbers with the 25 anyway.
DAVE

[Chillin The Most]

Thanks everyone for the info. I wanted to go to full MSD ignition this spring and upgrade cam & heads & some other things, I guess if I would of done all that then you would be saying to go with the 1.36. Never got a chance to do any upgrades, to busy, no rain all summer, boating almost everyday.
Thanks,
Chillin
[ September 11, 2002, 07:58 PM: Message edited by: Chillin The Most ]

[502procharger]

you would still not have enough hp to need to change to the 1.36. you could add 100 to 150hp easy and stick with the 1.5 and have your prop banged on at a prop shop to add a few deg of pitch and some extra cup. i run 600hp with a bravo 1 1.5 and a custome bent 28p 4 blade prop. stay with the 1.50