Duo Prop info C7 vs B7

[robjen1019]

This is just some info comparing the two sets of props. Tests were done with a 19.5 foot Sunrunner with aq225 engine, which is a gm 305.
With the B7's, the boat had a maximum gps speed of 46 mph
With the C7's the boat had a maximum gps speed of 50 mph

I really didn't feel a difference in acceleration. I have an accelerometer on my iphone that I might try just to see.

 

[cribber]

Re: Duo Prop info C7 vs B7

When you put the C7s on did your RPMs stay within range?

 

[robjen1019]

Re: Duo Prop info C7 vs B7

Actually neither one is within specs. My duo prop drive is a 4.3 model wich is 2.3 to 1 ratio. But the rpm did raise abit with the c7's. If I remember right, it was 5000rpm with B7 and 5300 with c7, Ill check next time out.\
Im currently looking for a 1.95 ratio for my v8, but until till I find one in the right price range, Ill just keep an eye on the tack.
Ive just inherited a set of A8's, the diesel props. I might just try those out to see what they do.