What kinda Numbers ?
 

Well I going to run a set of blower motors in My 85 302 Im running trs drives and straight through hull exhaust We figure The motors will be pushing between 550 and 600 hp a peice I have only had this boat for a about 4 months that I could run it I figure on running a 25 to 26 pitch prop? What kind of top speeds do you think Ican get out of her in ideal conditions?

Well geez guys thanks for all of your opinions your thoughts and info was great

My guess...70ish

LOL :D
Sorry you didn't get more input. I'm surprised, usually everyone has an opinion.

Personally, I run stock so I don't consider myself qualified to guess at possible speeds. Where's Axa, he'll have thoughts.

ttt

if you have a true 550-600 hp it should run around 76-78 GPS. with a 25P 3 blade.

My friends 311 had around 580-600 hp and we saw 80 once, mostly ran 78-79, all GPS readings
That was with 25P labbed mirage props, TRS boat.
I thinka 302 is a slight tad lighter then a 88 311 so you may have a small advantage there.

Biil Formula: I Dont Know If This Helps Or Not, But My 83 302 Has Seen 90 Gps In Fresh Water. 420,s Worked Over A Bit With 250 Blower Shop Blowers On Then. 1 Dynoed At 595 The Other At 615. The Only Difference Is I Am Running Kaama Surface Drives. Maybe This Will Shed Some Light On Your Project. Good Luck Bruce

Thanks everyone I hoping for upper 70s So maybe I get ther we will see

I'm going to say with the right labbed props and the motors on their best tune, and everything perfect 75-78 mph.

Let us know!

Dave

Give me the weight
Drive ratio
Aprox HP
Max RPM

I'll calculate the pitch for you.

Dave

Question: Have you done anything with the transmissions? There will be a certain amount of Hp loss to contend with using stock transmissions over reworked ones. My thoughts,