lbzmotofmx

Hello All...First post on here but searched around really couldn't find anything in particular to my boat but here it is....

I have a 1999 Baja 29 Outlaw with Twin 385HP 454's....
I have Merc Bravo 1 24P 4 blade props on it now...Dont know if my speedo is correct or not.. (just hooked up an external hookup one...since the factory one took a crap) and today out at the lake fully trimmed out at 5k on each engine speedo was only reading out 65mph....doesn't make sense..the guy I bought the boat from said it ran around 73-75ish...same props...Is it just that the speedo could be off since its not the stock one?

Mainly what I'm trying to figure out is...If I step up to the next prop..do I get a 25P 3 blade or 4? or which pitch is going to get me going about 75?

Thanks

StillHaulin@63

The very first thing you do is NOTHING ...
until you've been able to confirm your 5000rpm speed on a handheld GPS.

If you're spinning stock 24p Bravo/1s @ 5000rpm, there's no point in labbing.
Labbed 25p Mirage/PLUS props might add a fewe more MPHs,
but you'll loose much of the grip and efficiency you're used to.

Keep in mind, water conditions also have a major impact on top speed!

lbzmotofmx

Which gps would be best to use to determine my engine rpm?

also would moving up to a 26P be better?

StillHaulin@63

Most any handheld GPS will provide fairly accurate speed parameters.
However, a GPS will not provide any RPM data.

If you spin 24p at 5000rpm, a 26p may not provide any more speed.
I'd suggest you get some good data before you do anything else

throttleup

I believe that your motors need to run at 5000 RPM at WOT if they are Mags. SO your there with the 24P props. So if you want to step up to 26P then you will need to lab the 26P props to maintain the 5000 RPM.

Julie

lbzmotofmx

whats a set of labbed 26P 4blade props gonna run me?

lbzmotofmx

I did a slip test online, I have 14% slip on my bravo 1 24P prop...and thats pushing me at 65-66mph on my baja speedo...what prop will put me in the 70's??

throttleup

Remember when you calculate your slip on Bravo I props you have to reduce one inch of pitch from the stamped pitch.

The cost for labbing is $450.00 for a 4B propeller.

Julie

lbzmotofmx

I'm looking to buy a set of props for it this week...just wondering on what Is going to get me into the 70's I see alot of the 29 outlaws on here with my same engine package doing around 75 with their props....seen a few guys runnin around 75 with a 26P 4 blade Bravo 1 and also a guy on ebay says he's runnin about 74 on his with a labbed 25P 3 blade....


I'm just confused of which one to get...i like my 4 blade...so is that the one I Should get? Or will the 3 blade help me get the topend i want?

thanks!

spilman

Throttle-Up can help you...talk to Julie or Matt, they helped me. They even re-worked the props the next season after labbing them; no-charge. They are very knowledgable and have worked on everything. Since your boat is relatively small for twin big blocks I would try Hydromtive 4 blade 26"p. If they seem good but your only turning 4600-4700 rpm's, then lab them & you should get close to 5000. Hydromotives seem to give stern lift when turned outward especially.
BTW, 3-blades are more efficient=slightly more top end, but you lose more hole-shot & usually mid-range too; it's probably not worth it. Plus, the newer 4,5, & 6 blade props have gotten so "good" they usually work better on todays performance hulls. Labbing adds about 200rpm's; give or take. Just my 2.