My be the only way, just looking for ideas where the problem may be...........

What props and rpm were you running before?

What were you using to measure speed, GPS?

With same props, drives and slippage, at the same RPM, I would think you would duplicate the same speed regardless of max horsepower :confused:

28 pitch at 5800rpms

GPS

Exactly!!!!!

DYNO
 

Also, you did not mention a cam change.
What PSI are the blowers set to?

If using the same cam, well your not pushing any more air/gas through.

You have to dyno to find the results, one engine should do.

Wannabe

We did not change the cam because we felt it wasn't necessary wth the motor already being set up for a blower. We have locked the timing on the engines and we are running 5lbs of boost.

Why do you say we aren't pushing more air? Bigger blowers, larger fuel line, larger carbs, how couldn't we be?

You think 1 engine is safe?

Are you pulling more RPM's??

I would think a cam change would be needed with such a big change in Blower volume.

But, heck I'm just a undertaker:cool:

B&M used to have a comparision chart that showed with nothing more than a blower change on the 525's and a few hundred rpm would result in 700-750 hp. i would be looking at timing. you must be using an aftermarket ignition system in order to get the rpm's up to 5800 as mention above. i would think nothing else changed with drives and props you should have been all over 5800, meaning you should of had to add 2-4 pitch sizes. good luck and let us know the results

later

We've gone from 5200 to 6000rpm's with different props.

Why do you think we need to do a can change. Is the blower that much different?

I appreciate the help, keep it coming!!!

Matt still has the boat and he's been more than helpful. That group over there is amazing. We are looking at the MSD box now because it has some technology in it that allows it to retard the timing depnding on the boost. We thought we had bypassed it by locking the timing at 34, but we may not have been totally successful. Does anyone have experience with this type of MSD boxes?

TTT


Sorry, just need help. Want to boat this summer...............