Higher MPH without more RPMs?
 

Trying to decide if my 22' Scarab with a 23Mirage+ could be labbed. I'm currently running about 62 at 4600 rpm on a non-mag 454. It has an aftermarket distributor so I don't know how to adjust rev limiter, but would like to keep same or close RPMS and pick up a few MPH.

Is it possible to lab a prop for more top end without adding RPMs?

does it have a msd box , or does it not have a rev limiter, if it is not running a stock dist for merk it might not have one , and labbing would help a little on the rpms it only has 330 hp stock , look at a prop slip calulater and do the math, and yes my spelling sucks

It has a MSD marine distributor like this one:
http://www.jegs.com/i/MSD+Ignition/121/8560/10002/-1

I don't see a box anywhere, so I'm assuming no rev limiter. Not that I want to push the motor any more than it needs to be, but was wondering if it was possible to gain top end without pushing the max RPM.

On some props, Cupping can be added, which can make the props bite harder, and give some bow lift where needed. However, it will drop your WOT rpm. Then the blade area can be reduced, to get some rpm back.

This is something to talk to bblades about. However, with your setup, i dont think theres a whole lot to be gained. Might get you a mph or two. No point in turning the non mag 454 much more than 4600-4700. It pretty much runs out of steam after that.

Is it possible to lab a prop for more top end without adding RPMs?[/QUOTE]

Yep, decrease the slip% while maintaining the propellers rpm. Not every set up can handle that. Can it or can't it? That's where BBLADES comes in.

Brett

+1, i had dana exhaust on my 454 and was running above 4700 in a hammer with the mirage plus 23, switched to a 25 m+ and rpm's went to around 4500 and was roughly 2-3 mph quicker, labbing a 25 might be your best bet

Brett do you think that I'll have a better shot labbing my 23 Mirage+ or stepping up to the 25 Mirage to see some gains? It is only the 330hp non mag 454.

How much will labbing the 23 run me?

Thanks

After some research is looks as though the rev limiter for A Stock 330 Hp 454 Is 4850. I'm currently running 4600.

Do you think by labbing my 23 Mirage+ will add any MPH and bring the RPMs up by 200?

If your sure it is 4850 and not 4650 max rpm.
Yes, Labbing your prop to gain 200 rpm is the best option since you slip % is only just over 7%.
Gains of up to 3 mph are possible.
Let me know any other questions.

Brett

with a 23 you get on plane easier , but you will run faster with a 25 maybe 2 mph have fun

It pretty much runs out of steam after that. http://www.bdoh.info/7.jpg