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-   -   Twin Step Cat X Dimension Positioning. (https://www.offshoreonly.com/forums/general-q/168520-twin-step-cat-x-dimension-positioning.html)

fastlane40 09-12-2007 05:57 AM

Twin Step Cat X Dimension Positioning.
 
Need input here please.I have a new style 27 Daytona cat.X is currently level with the lowest point of the sponsons.My lower is a 2" shorty at 1:27.The problem is with a stock Bravo 34 i'm on the limiter at 5800rpm running 100mph.I still have more than a 1/3 throttle left.I just completed another round of the Australian Offshore Superboat Championship.An 85 mile course.I spent 2/3 of the race on the limiter.Is my x too high?I do get slight ventilation 3 out of 5 takeoffs but once overcome, which is quick, it accelerates well.I now have a Maximus 32 which i will try this weekend,should hook up a bit better.I'm just wondering what the effect will be if i drop it an inch with a spacer.More prop in the water?More drag?If my x was too high would there be any warning signs?

monstaaa 09-12-2007 06:19 PM

what kind of power?

and it sounds as if you have high slip.

fastlane40 09-13-2007 05:53 AM

Around 900 hp.

pstorti 09-13-2007 04:24 PM

go up in pitch until you are in the proper rev range the maximus should help but if you were on the limiter with a 34 bravo you should start with a 34 maximus.

zahndok 09-13-2007 05:31 PM

I agree. You're are a candidate for a 5 blade prop.

bobkatz 09-13-2007 08:19 PM

What drive do you have, extension boxes, etc..? 900 hp is going to hard on the drive with a big 5 blade. Also try filling up the fuel tanks and move some weight to the back, if you see the rpm drop your x may be to high. Also try to stay off the rev limiter for that long.

Turbojack 09-13-2007 08:50 PM

You got a problem but I do not know what it is unless prop. I have 26' (same bottom) 900 +/- hp. standoff box Bravo 1.36 w/ imco 2" shorty. Prop center is 1/2" above where your is. I have no problem with takeoff. Running a 30 lab bravo run 108 @ 5800 rpm. Hydro 5px 28" is not as fast on big end but better for low speeds. With bravo anything under 30 mph and starts falling off plane.

If prop is really 34 pitch and gears are 1.27 you should have a lot more speed for the rpm you are turning.

monstaaa 09-13-2007 09:52 PM

my thoughts too. p5's are also a good prop.should be running 108 110

tssteph 09-14-2007 06:20 AM

Verfiy your tach setting and make sure it is set on the correct setting. If set of 6 cylinder the engine rpms will be 75% (6/8) of what the tach reads. My boat was set wrong, prior owner fought slip numbers and this was why. 6000 rpm on the tach was really 4500.

fastlane40 09-15-2007 07:54 AM

It's a new Eliminator.No problem with tach.At 100 the motor is not loaded,1 PSI of boost.It has to be the X is too high.Just tonight fitted a 1 1/2" spacer.Turbojack maybe your stand off helps you run so high.Speed with a 32 Bravo was 94 before the limiter came in.What are the effects of having a too high X?Obviously take off,what else?

Turbojack 09-15-2007 09:11 AM

maybe your gear ratio is not 1.27? I had a friend that did not have a standoff box and went with 2" shortie where his x is where your is. He had some takeoff problems but boat ran faster

fastlane40 09-15-2007 02:17 PM

I checked the ratio with the turn the shaft and count.Testing with the spacer today.Will let you know.


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