Formula 353 Overpropped? Need RPM's
 

I'm new to an '08 353 with 525's and 30' Maximus props. (Boat is a leftover with 8 hours on it). I'm only able to get about 77 mph out of the boat turning 4700 RPMs.

I'm surprised at this as I would think this boat should be low to mid 80's with these motors.

I believe these motors make max power at 5200. Is this corrrect? If so, I need 500 more rpm and I think that could get me to 83-85 mph in ideal conditions.

Should I go down to 28's or lab the 30's to dial them in?

What do you guys think?

Rev limiter is at 5400. We would like to see you in the 5000-5400 range. We can Lab your props to get 5000-5100. This would be the most economical route. 28's will give you better acceleration and the same top speed. The 30's will have the better cruise speed.

Let us know if you want to test any 28's

Brett

I believe it is way to much prop. Most 353's with 525's are running right around mid 80's with 4 blade Bravo ones. Jeff Wurl

It's only to much prop if you can't run in the 4800-5200 recomended rpm range.
So, he's 100 rpm low with the props on the boat now. We can maintain 30 inches of pitch and gain up to 400 rpm with Labbing Maximus propellers. So this isn't too much prop.

This can all be done provided the props aren't already Labbed. Formula does put Labbed props on most Fastechs. I took monthly orders from them for years while I still worked at Mercury Racing.

Brett

I would try a set of Bravo 30" four blades. My friend had a 353 with 500EFI's on boxes and ran 82mph.

bret from bblades is the man,if it were me,id try 30p 4 blade bravo1.bblades has a test program,call&ask for brett.

x2. brett is a genius and will never steer you wrong. go with him!

I'm assuming the Maximus is an overall more efficient prop than a 4 blade. I like the idea of a higher cruising speed and I'd rather have that than better acceleration. I wouldn't think it's going to have great acceleration in either case. It's a heavy boat.

If they are already labbed, why am I only turning 4700? I'm going to assume they are not. If Bblades can tweak them to get to 5200, that seems ideal.

If I do this, will I now have blow out issues getting on plane?

A test program makes sense too. I will look into that.

Finally, Brett, how's your turn around time looking?

I just took delivery of a 2004 353 with hp 500's no boxes. The props on the boat which the seller said were original are bravo 4 blades but they are stamped 31 pitch. It is obvious the blades were worked some as they are thinner than stock bravo ones and I don't believe you can get a stock 31p? I can run 5200 rpm's light on fuel and 4900 to 5000 with a decent fuel load. Speedo reads 80 mph at 5000 ish rpm which equates to 17% slippage (assuming speedo is anywhere near accurate) I would think 17% slippage on this setup with labbed props is a reasonable number for slippage? Any thoughts? Bret?

Thats the pretty standard speed of a 353 with 500EFI's. Boxes add a couple mph.