Is a 32p labbed 4 blade bravo the same as a regular 30p 4 blade bravo? What is the rule when comparing a smaller sized regular prop to a bigger labbed prop?

Thanks in advance

I believe that each inch of pitch is equal to around 200 rpm. So going from a 30p nonlab to 32p nonlab would decrease your rpm's by 400. Then by labbing the 32 you would gain back around 250-300 rpm's, so they would be pretty close to the same depending on the labbing technique.

A labbed prop will slip much more and not be as strong as stock. I'm not a huge fan of labbed props since gains are typically only seen at wot, which usually leads to a decrease at cruising speeds.

If you're looking to get every last mph out of your boat and not care about a decrease in performance everywhere else then that's the way to go.

I'm with ya Harper, but, some tuning of a prop is a good thing as in extra/less cup ect... to change the attitude of the prop.

Harper 220 is correct. A lab 32P Bravo I will run within 100 RPM of a stock 30P Bravo I.

Julie

Agreed, however,

BBLADES has many different recipes to use while Lab Finishing. "Lab Finish" is a general term used by everyone but created by Mercury Hi-Perf in the late 60's. The term stands for Laboratory Finish. It is like calling tissue "Kleenex". Prior to leaving Merc Racing, we tried to patent the term. Because of its general usage in the industry, we were only able to get "Mercury Racing Lab Finish", trademarked. We really wanted to keep it to ourselves, the creators. I do think now however, it is good to have an industry acknowleged term to reference. Anyway, it does suggest a process of finishing the propeller to a matched and blueprinted spec. It can be adjusted and should be for the application it is going on.

In other words, We can Lab a prop to gain very little rpm or quite alot of rpm. You must adjust as needed. Our "standard" recipe for B1 prop pulls an additional 300 rpm.