What Prop -- 280 Silencer
 

dropping a procharger on my 502 EFI -- boat is a 99 spinning a 25p mirage now.

what prop do you think i'll need with the extra 150HP ??? what speeds should I be able to get?

right now with my 25p i'm hitting the rev limiter at 5100 and get about 72 on the speedo (non GPS)

should have the procharger installed in about 3 weeks and want to get some test props lined up.

thoughts?

Speedo is most likely 6 mph off. I would not put a supercharger on any black engine. Save your money and put in a hp motor
if it's more speed you want without the headaches.

Prop
 

I have a procharger (M1) on my 502. My prop is a 30. I splashed yesterday. I'm a newbie to perfomance boats but had mine doing 55 and I backed off, a friend of mine who was with me had it up to 70 at 4200. There might have been another 10 MPH in it, had we cranked it up to 5000

supurised your running a 3 blade? I have a 26p Bravo on mine, I would think a 28-30 bravo would be a good start?

I have a upgraded 509 om my 260 and it is pushing 550 hp It has a 25 pitch 4 bladed merc prop and pushes it well. 5200 rpm its running around 78 mph. All around it rocks out..

i'm just running the prop that came on it. I really never thought it was the "right" prop -- simply because i could hit the rev limiter so easy.

procharger was picked up saturday -- should install in a few weeks.

that brings up the question - what did the factory use for a "stock" prop?

well -- i've obviously killed a few brain cells since i last looked at my prop - i was WAY off...

its a MR Bravo 1 24p.....

that is the stock prop,

any update?

had to send "that" procharger back -- it was missing too many pieces. Ordered a new on and got it last wednesday. I did a lot of the install work over the weekend. Moving the oil cooler and stuff like that. what a PITA....

should have it done in the next week or so.

I'm running 650 hp in my 28 and I run a B1-28,great cruising rpm.Might be a little faster on the top with a smaller prop(more rpm)but 80(gps) is fast enough with a hull designed for 70 - 73 mph.It deffinately gets my attention after 75mph.

I am running b1 28 4 blade 496 with 3.5 boost procharger. Prop seems to break loose when just about on plane. I have to back off throttle then ease back in. Is this normal? My prop is beat up and needs some attention. Had it at 74 on gps without really staying in it long. I think about 4800 rpm. What kind of crusing speed should i see at 3500 rpm?

the prop blowing out getting on plane is normal, typically you cant have both, you either have a speed prop or a holeshot prop, mine is a labbed 26P and I have blowout.

looks like i'm at a B1 30P -- turning right at 5050 rpms i'm getting 81 on GPS.

That is very impressive speed. How many lbs of boost are you running. Is it a stock 502? I am bouncing around 73 on gps at 4900 rpm. Starting to think I am really missing out on something.

its a 5psi pulley -- however my boost gauge is only indicating 4psi - so not sure where i'm loosing that 1lb at (could be how I have the gauge plumbed)

yes -- its a completely stock 502 with the exception of the upgraded fuel system that is part of the procharger setup.

Did you use that kit with the bigger fuel injectors? By any chance did you pay attention to the speed around 3500 rpm? I am driving myself nuts trying to get cruising speed around 48-50 mph and keep it under 4000 rpm.

as long as i run the 5psi pulley you can run the stock injectors. the 7psi pulley requires the injector upgrade.

at 4000 rpm i'm running right at 60-62 on the speedo - i did not test that speed with GPS -- so probably more like 56-58 gps speed.

hope that helps!

great numbers, does it get squirelly?

do you have the stock insta-tabs? I replaced my 12" plates with 16" plates, I bought them from instatab for $350 and reused all the rams, fit the same holes in the transom, seems to help with chine walking

I have kplanes

if you aren't careful it gets squirelly at 80'ish - but as long as you are driving it -- i've not had any problems.

It's nice to hear you guys are making some of these 280s flat out rock!!!!!! Way to go!!!!
I have an 03 with a 496 HO with the 525 Raylar and I can see 74 on gps.
I was thinking of putting on CMI E-tops this winter for added power and was considering doing something like a 2" shorty but I'm not sure ......some input would be great!
Thanks,
Mike

I either have very bad luck or am seriously doing something wrong. I pulled my procharger and went back to a stock 502. Fresh motor, Diamond pistons, XR Drive, extension box. I splashed today and took it out for about a half-hour. I hooked up with a great guy on this site who offered me the use of his 26P and 24P hydromotive props to see which one works best (I had a bravo 1 30P). Well, I tried the 26 and am really bummed. It got up ok, but I maxed out at 4300 and barely touched 45 MPH with full trim.

This "go fast" stuff has been a real bummer experience for me all year. I need to get it right. Everyone tells me, stock 502, running a 26P should be pushing 5000 RPM and hitting low to mid 60s.............that's fine with me if I can just get it!

I was cruising today at 3000 and 25 MPH. Not good. Any advice?

The 24 and 26 pitch should be a Bravo 1 4 blades.
Are your speeds on the speedo or gps verified?

GPS.

A few guys on here have suggested in the past that I contact B Blades (Brett) and consult with him. Another friend of mine told me not to get a prop labbed as it is very expensive and the thinning of the blade results in not getting much time on the prop.

I'm going to call Brett tomorrow. Hopefully, I won't need to have one labbed..........or, if I do it's more durable than I've been told.

My old 30P was a bravo 1. What I borrowed is a hydromotive 26P (and a 24 I haven't tried ). I don't know if the style of the hydromotive would make this drastic of a difference, but it was really a dog today.

24 pitch B1 is what you should probably be running. The 26 prop is really lugging the motor. Extension box might be hurting you also but I dont have any experience with them. 4000 rpm 40 or so is most likely where you will be if the step is still in the water, but you should still have throttle left to get to 5000. Make sure the motor is working properly also. If you have access to a scan tool make sure there are no failure codes. Dont lose hope! This is supposed to be fun!

Like specialk suggests, its best to start with the motor, making sure it is at 100% capacity and work from there.
I dont think it would be good to jump all over, try the 24 Bravo 1 once you have determined that the engine is operating as it should.
Keep us posted.