I have 1998 38' PQ with stepped hull, 502's with blowers that put out 620 hp on the dyno. I am currently running Bravo props 30" pitch four blade and I am very dissatisfied with the performance. I can run consistently high 70's but I feel the boat should run close to 90 with these motors. Any advice on props or other areas of concern I should look at? The props seem to blow out too soon and cavitate before trimming the boat.

Call Tom at Hydromotive tell him PK with the power quest sent you. Tell him exactly what your specs are, drive ratios, hp and tq numbers at rpms and he will be able to get you a prop that will be best for your current sytem.

330-425-4266
http://www.hydromotive.com/

You might want to post this under the Prop Talk folder too so that Throttle Up or BBlades can help you out. No matter what props you go with, a '98 38 PQ with your motors will not run 90 MPH.

Keep us posted on what you hear from Throttle Up. My guess is they will stear you to a 32 four blade or a 30 five blade. Hydromotive most likley,
Either should get you better speed but no way you will see 90. I have a 2001 38 with the good steps and 575sci's. Top is 84 and I am looking at some prop changes to mabey get me to upper 80'S

Robert,

Does your boat happen to have an all yellow deck and hull with a Mitcher T. paint job? If so, I know the the boat and it's had issues since day one. Not with the boat, but with the power.

Props and Superchillers could get your boat to 90 MPH. Have you given any consideration to adding intercoolers?

Hay Knott

Up here in the north country a Supperchiller is an intercooler.
See below

I know that, which is why I asked if you had given any consideration to adding them. Your engine pics in post #4 don't show any intercoolers on the motors. That is why I said props and Superchillers could get you to 90 MPH. It would appear that you have already added the Superchillers. But thanks for trying to make me look like a dumba$$.

Just spreading a bit of the Christmas cheer while I yanked your chain.
Relative to the Super Chillers on my 575's they really didn't add that much to the top end. Best wiith them was about 88, around a 4 MPH gain .

I ran a set of 29 5 blades last summer and they did the best for me. Throttle up help me alot on this.

Rich.