stroker331

I'm installing a lq4 6.0 into my Baja sport 240 you can really crank those motors with a cam just wondering on if there is a rpm limit on a bravo drive plan to spin it to 6700 and about 500 HP

pstorti

iTrader: (2)

don't know if there is an official rpm limit on a Bravo but a 1.5 ratio would have lower prop shaft speed than a 1.36 and theoretically would put less load on the drive, of course a lot would depend on the prop selection and how the boat is driven, one things for sure the boat should haul ass if you are able to spin a decent pitch at those rpms!

stroker331

That is what I was hoping for but I want to make sure that bravo can handle it first I know the motor can with stock internals if I get 70 75 out of it I would be more than happy motor has a little less torque around 465 but HP is 498 so it should ne interesting its also efi

Rookie

iTrader: (4)

I'm thinking that spinning a bravo 6700 with only 500HP with that hull will be the least of your problems. You would need to be around a 15-17 pitch prop to get that many RPMs on that hull. Friend had the same boat with approximately 640HP and spun a 22 bravo1 prop about 5800 @ ~78mph. You are going to try to spin it +900rpm with 140HP less.
I am no expert on the 6.0 but doesn't it make peak power around 4800rpm.

stroker331

I have a gmpp hot cam headers and a real good tune makes max power at 5900 but doesn't drop off much maybe 40 HP at 6700

Rookie

iTrader: (4)

Just curious why you would prop it that far beyond peak HP? That is really backwards and you are losing a ton of midrange performance cause you will have to run such a small prop.
You would be going from 500HP to 460HP on the wrong side of the torque/HP curve.

This would be an all or nothing setup.

articfriends

iTrader: (1)

A local guy built a 540 for his 27 fountain, it had such a big azz cam in it that it peaked at 6600+ on the dyno, he borrowed props from me and in the end he thought it would be turning a 28 or 30 but he ended up with a prop as small or smaller than stock, all or nothing would be a good way to describe his fountain, had no cruising ability, no real midrange and rpm'd to the moon. His oil got hot, it sucked gas like no tommorrow and he hated it.
As far as a "rpm" limit for a Bravo, he never smoked his and I personally turn mine 6200 fwiw, Smitty

Mr Gadgets

Great Lakes Caster's boat used to run 7k with a bravo. Setup properly they can do it, but why?? They were racing, and would see some steep rpms.
Like Smitty said, dont try and reenvent the wheel. It usually doesnt turn out that good.

stroker331

thanks gentalmen i see your point, i was going to try to prop it for 5500 or 6000 where the power is maxed. What mph do you think is possible with my baja half tank of gas with on person??

TooTall

Hey do you have any pictures of your build ? What intake and heads are you going to run?