502 in my 96' 22 Scarab.. Prop help?

Longrange4u · 08-05-2006, 07:19 PM

Ok I am running a Mirage+ 25P currently... I have a rev limiter at 5k rpms. It hits the rev limiter pretty quick and feels like it still has allot left in it.

502 has ~450-500 HP... Thought about getting the prop labbed to a 26, but would that be enough? Do I just need to look for a 27 or more?

throttleup · 08-06-2006, 01:29 PM

What is your GPS speed?
What is the base motor? Do you have a dyno sheet on the motor?
Does the Mirage have any problems with ventilating when getting on plane?
Does is ever "blow out" in turns?
Do you know the history of the motor? I am wondering why the rev limiter is set at 5000 rpm.

Matt

Longrange4u · 08-06-2006, 06:52 PM

Quote:

Originally Posted by throttleup

What is your GPS speed?
What is the base motor? Do you have a dyno sheet on the motor?
Does the Mirage have any problems with ventilating when getting on plane?
Does is ever "blow out" in turns?
Do you know the history of the motor? I am wondering why the rev limiter is set at 5000 rpm.

Matt

Hmmm didnt dyno it.. (sorry Army dont pay much) But it is built right with all the same stuff that many 500HP+ motors are built with.

Dont know the GPS speed... I will have to check that.

ventilating when on plane? I am not sure what that is... (Sorry guys I am a noob to the sport)

Hell yes it blows out on turns...

I set the rev at 5k.... brand new build... once I run it for a while I may up it to 5200 or 5500 rpms.

throttleup · 08-07-2006, 07:38 AM

Most motors built in the 500 HP range need to turn 5200-5400 for max HP.

By ventilating I am referring to "blow out" when you get on plane. I assume you have this problem getting on plane since you have it in turns. I had a 22 Scarab and it was similar to Baja's in the respect of getting on plane and turns.

Based on your HP I would expect the boat to run in the low to mid 70's. Considering a max rpm of 5100 a 26 pitch prop should get you right about where you need to be. If you raise the rev limiter you may find that the 25 Mirage you have now is adequate if it is stock. If you were to turn the motor up to about 5300 you should be able to run about 75 with the prop you have now.

You may want to consider a 4 blade prop to address the "blow out" in turns and plane issues you may be having now.

Matt

Longrange4u · 08-07-2006, 04:49 PM

Really? A four blade even for my little 22 Scarab? That would make sense cause it seems to have a hard time "digging" in. But if I go 4 blade you think I should go with a 24P?

throttleup · 08-07-2006, 06:35 PM

For a 4 blade you may want to go with a 26. It may need to be modified a little to get it to work well on your boat.

Matt

Longrange4u · 08-07-2006, 07:17 PM

So then would it be smarter to have my existing 25P mirage labbed to a 26? I am in the Army... that means budget! LOL

bbladesprops · 08-07-2006, 08:02 PM

You need to consider what the main goal is here.

Top speed or all around performance. If all around performance is the goal, try a Revolution 4 propeller in 25 inches of pitch. If it turns out to be a little small, the Bravo 1 family may be next.

If top speed is of the essence, continue to work with the Mirage family or a Turbo TXP.

We should be able to get you dialed on a Uncle Sam budget.

jctexas07 · 02-22-2011, 01:30 PM

Friend of mine has a 502 in his offshore boat. He runs a 14.5 x 28 pitch Bravo 1 4 blade and gets about 80 mph at wot. Does great.

A.O. Razor · 02-22-2011, 04:28 PM

Quote:

Originally Posted by jctexas07

Friend of mine has a 502 in his offshore boat. He runs a 14.5 x 28 pitch Bravo 1 4 blade and gets about 80 mph at wot. Does great.

jctexas

Have you seen the age of this thread.