saulesses

I have a question when you are trying out props should you get your max RPM Limit with the full drives in or with the boat trim correctly and the drives out because you gain some rpm by pulling the drives out.

Thanks

Pat McPherson

Trim for max speed...

saulesses

Yes i know that when you trim you get higer speed but also the RPM increases so if i can push my boat lets say at 5000 rpm without trim in the drives i woul be able to get 200 more rpm by pulling the drives out is this the way it shoul be or i should rev without trim to 5200 which is my limit and then increase while triming the drives even more maybe 5400 i would be passing the engines limit.


Thanks so much for your help

bbladesprops

Continue trimming till the speed stops climbing or the handling goes away. That is the rpm you will use as WOT.

However, some props will allow you to trim further than others so this must be used in the decision too. Some props may blow out at 5000 where another may run to 5300. In this case 5300 is the number.

saulesses

B blades I think i talked with you 2 weeks ago regarding props for a formula 311 SR1, I am trying props locally to see what works best I will call you when ready to order. I think what you suggest is the way to go 25 Pitch labbed but I have retuned my engines because the timing was of will try the 25,s Mirage tommorow again.

What is the difference between Mirage 25's and Mirage plus 25's is there a difference in speeds handling crusing speed or getting on plane.

bbladesprops

There can be differences. Some slight and some not as slight.

Mirage non Plus will be fastest on a select few boats. The Plus's will out preform on most everything.