VP

4CLOZIN,

yep -- loose too much speed though on the radar run with the bow in water -- it works though --

it all seems to go away once i am at 80 mph and over -- things seem to be OK up there -- must be up on its tail more and inertia takes over keeping it straight and level

29goingon42

Hey dirtlawyer
Just curious I have a 2000 29' with a carb 525 SC running about 6-7lbs.(540Hp) I am seeing 72-73 all day and maybe a 75. I turn a 23P Mirage plus to about 5000.

What is your set up and what do you see. It feels kinda low but I know the 575SC factory test only hit 82 GPS so it may be right.

Thanks.

Fountaineer

I have a 1997 29 single with about 700 - 750 HP that will do 90 mph. I usually don't see the chine walking until I hit 80, then just drop the tabs a bit and it mellows out to 90.

VP

Fountaineer -- assuming your tabs are set up to be neutral at 2-1/2, what do you run your tabs at --

I found 2-1/2 is good in rough water with no speed loss, but it does not prevent the chine walk

Chase910

Can't you drive out of the chine walk???
You can on any other pad bottom boat such as a Velocity.
I know Fountain has changed his bottoms over the years, but I assume even the ventilated bottoms are still a version of the original pad bottom Fountain started with. If so, you should be able to keep it balanced on the pad with "bumps" to the steering.

VP

you can't drive through once it starts the hard walk two to three times -- you can read a couple responses above and see what i mean -

Its hard to explain, but there are two different magnitudes of chine walk here, and the one i am talikng about, once it kicks in, it really throws you --

The bumps to the wheel may work if done soon enough - that is what i am trying now - trying to predict and get rid of it before it gets violant - once violant, you have to let off now !!

I am sure part of my problem (and the folks above) is that we are well over the power that any single 29 has ever seen coming out of the factory - so we created our own problem here. Its not Fountain.

dirtlawyer

I have basically the same set up (running 7 lbs boost) but I have gone to an IMCO Upper and -2 lower. I typically run a labbed 28P Bravo RH that has been tuned up a bit. Best I have seen on a handheld GPS was 78.1 - my GPS speedo recall shows 77 right now. Both of those speeds were obtained with a labbed Bravo 30P. The 30P is a little slow to come onto a plane, but once she rollw over, the performance is great.

The -2 lower makes the boat run flat, so I have also taken a lot of unnecessary weight out of it. Typically with 4 people and 1/2 to 3/4 fuel I hit 75 with the 28P Bravo turning 5100 - 5150 rpm.

If I recall, my boat was shipped from the factory with a 27 Hydromotive. If you are using a 23P 3 blade and not banging the h*ll out of the rev limiters all day long, then I would say something is not quite right. How many hours do you have on the motor? If you are over 225 hrs, you should have rebuilt the blower by now (especially since you are using the smaller pulley). Also - have you checked the heads lately? I just replaced the exhaust valves and springs, as well as my manifold - it was probably within 5 hours operating time of letting loose (motor has about 240 hours tt).

Chase910

Well yes, if you wait too long to correct chine walking it does become violent and you're right you want to correct for it before it becomes unmanageable.
Here's how I was taught....you want to keep your eye on the bow, when you see it dip, or fall to the left or right, bump the steering the opposite direction just a bit and then make sure you straighten the wheel. You want to make small corrections or bumps. If you turn the wheel too much you will make things worse. So basically you bump left, straight, bump right, straight...ect, balancing the boat. There is feel involved so make sure you're arms are relaxed, don't stifffen up. It is small corrections...not large ones. It takes practice to get it right and to feel the boat fallen off the pad.
To start, once you feel, see the bow start to fall left and right bump a couple of times first just to the left until the boat feels its not falling to the right...from there just watch the bow, make small bumps until you get the hand of it.
I don't see any reason why you can't drive out of this condition, unless you don't have hydraulic steering.

VP

Thanks Chase910 -- i was given similar instructions by another and it seems to be working -- hasn't done it since but not much boat traffic lately

Pirates Run this weekend with a radar run afterwards --- that will be the real test !

Fountaineer

chambersgc,
I usually drop the tabs to 3 and with a little bit of driving can stay straight and smooth at 90 mph