Checkmate 219 7.4 bravo One Gen 1 - HP rating of outdrive

[maddog2020]

Going to perform some HP upgrades at what HP should I stop. Everything has it's limits
Boat performs well does ~ 65 MPH - four blade 21 degree Prop with minor cups on blade
looking for 75MPH are not we all - LOL

 

[HT32BSX115]

Re: Checkmate 219 7.4 bravo One Gen 1 - HP rating of outdrive

Going to perform some HP upgrades at what HP should I stop. Everything has it's limits
Boat performs well does ~ 65 MPH - four blade 21 degree Prop with minor cups on blade
looking for 75MPH are not we all - LOL

Howdy,

At what (verified) RPM?, drive ratio? (probably 1.5:1) and are you measuring speed with GPS?


Welcome aboard!

I think most people expect the Bravos to be good for about 400 (continuous)
hp. There's certainly people who have exceeded that.

If your engine is stock and carbed, it's probably rated for about 330 (crank) HP

You can probably up the HP to about 450 easily....I don't know if that will give you 10mph though. A 3 blade prop might be a little faster at the top end probably, with a slight reduction in holeshot.



Regards,


Rick

 

[Bondo]

Re: Checkmate 219 7.4 bravo One Gen 1 - HP rating of outdrive

Going to perform some HP upgrades at what HP should I stop. Everything has it's limits
Boat performs well does ~ 65 MPH - four blade 21 degree Prop with minor cups on blade
looking for 75MPH are not we all - LOL

Ayuh,... At those speeds,...
I believe the rule of thumb is 100hp, per mph increase...

You'll need an Extra 1000hp to make 75mph...


Btw,... Props are measured in Inches, not degrees...

 

[tpenfield]

Re: Checkmate 219 7.4 bravo One Gen 1 - HP rating of outdrive

Are we talking the 365 hp 454 magnum or the regular 330 hp 7.4 L ?

Anyway, take the mph desired divided by the current mph and then 'cube' that number X your current HP. I'll assume the 365 hp engine.

So, (75/65) ^3 X 365 = (1.54) X 365 = 562 hp.

You will need the high performance outdrive as the Bravo1 goes to about 400 HP

 

[maddog2020]

Re: Checkmate 219 7.4 bravo One Gen 1 - HP rating of outdrive

Thanks
I will use information wisely
Mike