I have converted my boat from SSM II to TRS drives. I was spinning Labbed 15x23 3 blades on the SSM II's ( I was not able to got to WOT to see what my RPM's were with the SSM's before I blew them up) Now I have installed TRS and am spinning 15x 22 3 three blade cleavers. The other day I put the throttles all the way down and got up to 60 MPH @ ~4700 RPM @ 6 psi of boost. I am estimating that the motors make 575-600 HP at 6 psi. The boat is a 1980 38' Scarab with side by side motors. I am looking to get the RPM range up and a little more speed
As a foot note, The guy I bought the boat from said it would do 70 MPH @ 15 PSI. I have turned down the boost pressure to about 6 PSI. What would be a good prop to try next?

What's your rpms range and goal? Cruise or top end?

Good Morning,

After reading your post I thought I would suggest props for your boat. We have done many 38 Scarab's w/ TRS drives over the years. You never said what rpm you require. I assume 5200-5400 rpm is the range. That said, I would like to recommend our 21 " pitch Quad IV's. These are 15 1/2" diameter and hybrid cleaver style props. We also build it in a 20" pitch if required. The added weight of the blowers, oil coolers etc mandates more stern lift. Our Quad IV's will provide just that. These will work well right out of the box, but can be labbed for additional performance. We have a 30 day exchange program to get you dialed in. Please visit our website www.hydromotive.com or give us a call.

Thanks,

Thom