Chinewalking
 

Hey Guys, I could use some info about an '88 steve stepp velocity that I purchased. I have an '88 22' steve stepp velocity hull that I just purchased with a 454 and 7.4 alpha drive. The engine was blown so I rebuilt it. Bored it .30 over with mild cam. Engine has 450hp and I replaced the drive with a 1.50 Bravo 1 drive. I have a 23p mirage prop on it. I can get around 5000-5100 rpms as max. Problem is I'm only getting about 62 mph out of the boat and I was told the boat should be faster. The other problem is right around 61 mph the boat chinewalks violently and the ass end begins to slide. I can't get it past 60-61mph without the chinewalking. I was looking at doing more work to the boat and motor to get faster speeds but I need to correct this chinewalking first. Does anyone have any ideas of what it could be and/or how to fix it? Does that top end speed sound about right also or is something off? Thanks

If the engine is putting out 450 hp you should be spinning at least a 25 or 26 inch prop. My 23 (Regal) Velocity ran a 25 inch Mirage with a stock 454 mag with headers. Topped at 70/71 mph with light load and chop. Is there a rev limiter on the engine? You may me up against it.

The Alpha drive is not going to last with that power. Upgrade to a Bravo and add external steering to help with chine walking.

Brade he did the bravo upgrade he just bought it with the alpha. Agree on the Hydra steering all velo's need it but need to get that up on the pad, thats where they fly.
-Mike

is the X the same depth as the Alpha if so good. i have never seen one of these boats work right with w 3 blade prop and yes a 25 should be close i would try a 25 hydromotive also make sure there is no side to side play in the drive, if there is you have something in the steering loose.

Thanks guys....I may try the 4 blade, I was thinking about a 25p but thought with the engine running around 5100 rpm's with the 23p if I went to the25p I would be working the engine more than it should. Machine shop said 5200 rpm's are max for this engine. I was thinking about putting trim tabs on the boat. The boat just gets real squirly @ 60 mph. The drive is tight, no play

The 23 (Regal) Velocity ran faster with the three blade Mirage. I don't know if the 22's do although I would think they would be lighter in the bow and might like a hydro better.

Is there a rev limiter on the motor?

I don't believe there is a rev limiter. I was told the boat should easily reach 70mph with my set up. But I'm only reaching about 62mph @ 5100 rpms but like I said as soon as I reach about 60mph the boat starts to porpoise and chinewalk bad. I try to correct it and the ass end starts to side

That hull should run 70 mph ! Something is wrong . Are you sure that is a 1:50 gear ratio in that drive?

24 Tempest Plus

Your pad bottom won't like 4 blades; more blades = more stern lift. Let the pad hull do what it was designed to do.

Tempest Plus has a smaller diameter than your M+ which is why you can go up in pitch.