Thread: Thoughts on shimming rideplate
04-10-2007, 02:18 PM #1
Thoughts on shimming rideplate
O.K. guys, follow me on this one. The way a rideplate on a GP hull bolts up, puts the plate recessed and above the intake grate. This would seem to allow for less drag, however I have a thought about this.
With the plate being higher up and above the flowing water coming off the center of the hull & intake grate, shimming the ride plate down in the front or back would not have as great an effect as it would if the plate was even with the intake grate. J-ME's plate is shimmed down to where it is even with the intake grate. Now, if we bring the plate down in the front to where it is even with the intake grate, but do not shim the back of the plate down or bring it down some but to where there is still an angle, would this provide more bow lift than if we just shimmed the plate down in the front but the plate was still recessed. I am going to try this in a few weeks, but would like to hear some thoughts on this. The last post in the Old School Section was yesterday, can we get off our asses?
04-10-2007, 03:04 PM #2
Iv'e been thinking along roughly the same lines.
I need to go out and do some baseline stuff first before altering anything.
At the moment i have a sealed Riva intake, stock plate and Riva sponsons set so the blades are level with the top of the backing plates.
I have a Pro -Tec plate which i was going to do exactly that with after getting some #'s.
It's about the same angle as stock, but about 2,1/2 inches (actually 65mm) longer than the stocker. I was going to run it back to back, just bolted on, and then shimmed in the front.
I have a gps, but my pet 2100 is fu****. If I can get a tach sent out for the weekend, I will post my findings.
It won't be conclusive, but it will give me an idea as to which way to go.
04-10-2007, 03:19 PM #3
Shimming down in the front will give us more bow lift. I am wondering what the difference will be between shimming the plate even with the intake grate, but leaving the front lower than the back, versus just shimming the plate down in the front, but not even with the intake grate.
04-10-2007, 03:20 PM #4
shimming the plate down sould lift the ski higher while on plane , thou this may expose too much intake... we may have to run a scoop grate to fill the pump.. maybe that big jet dynamics scoop .... find the ideal setpoint and make a filler out of milled aluminum barstock to fill the gap ,or a polly filler like a section of aftermarket sponson or one of those poly cutting boards of the same material
04-10-2007, 04:02 PM #5
I have attached a drawing of what I am trying to compare. You may have to rotate the drawing, the text shoud read from left to right.
04-10-2007, 04:31 PM #6
right .. as i see it you would then bring the back of the plate up to raise the nose.. this would expose more of the intake to dirty water,IMO that you would need a bigger scoop for the intake..Now if you think of it, this would put your pumps outlet further from the water surface.. would this thrust change be noticeable? we may have to then change the cones angle or the nozzle/trim adjustment minutely
04-10-2007, 04:35 PM #7
Some people have their plate shimmed down in the front, I know Flying Scotsman does. If it is shimmed too much it will porpoise, but I am pretty sure I can shim mine a good bit before porpoising becomes a problem. My ski does not porpoise, even in superman with the R&D plate with the Group K Mod.
04-10-2007, 04:42 PM #8
just a thought what about mounting a wedge onto a plate?blending it into the trailng edge??? this way the wings on the plate are still flush with the hull and that angle opening is not exposed??? keep the plate still at the o/e position, letting the ski ride on our new pad .. I fear that if you 'jack' down the whole plate you may be creating a rocker condition that would force the nose down...
04-10-2007, 05:10 PM #9
Dont forget your sponsons I think the stock sponsons are pretty good because they are fairly wide if you angle your plate like I do I keep my sponsons down.
I have Beach house as well as stock I like both.
Stock can be improved some if you want to take the time.
If I try and get to speed with the sponsons up I get violently beat up and dont get to speed.
With the sponsons down its awesome I will porpos around 40mph I think it was but only if I try and ride at that speed.
My riding style is from 0- top speed as fast as possible so I dont porpouse at all.
I do get good air from time to time but that makes things fun.
I say we need sponsons for lift and ballance.
04-26-2007, 09:20 PM #10
Brandon you will have to some massaging and shimming to get some results with this plate. it went out priority to you today
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