Thread: Jims FF GPR plate tuning
07-16-2007, 08:59 PM #1
Jims FF GPR plate tuning
We all know how good the FF plate is. I just thought I would throw some questions out there.
How do we make it better ? I ran mine for a while with no washers anywhere and 1 washer under the trim tabs and there was no bounce.
I currently only have 2 washers under the rear (nozzle side) since I have been riding in some rough waters.
I have seen where some run one washer under each bolt - Why ?
Is the step from the shoe to the front of the ride plate relevant ?
Is the magical .950 - .980 measurement is for everyone ?
Why do we measure from in front of the intake and against the shoe ? Seems to me the measurement would be more accurate if we held it flat against the hull in front of the intake grate. (I get a whopping 1.287 when I do this).
How does the 2" extension change things ? I do not have yet.
If the plate is angled why arent the trim tabs ?
07-16-2007, 09:04 PM #2
you need to angle the front of the plate, the part that is closes to the pump shoe. Put 2 washers under each front bolt. Leave the rear one flat up against the hull, the one thats by the nozzle area. That will give you more angle.
07-17-2007, 06:57 AM #3
So the step from the shoe to the plate isnt relevant then ? Should I be working towards making it even ?
07-17-2007, 07:10 AM #4
Imo they are all different and relavent. On my 03 I have a measurement of .017 step from the shoe to the plate I am using the two supplied washers and a .0125 shim on the front side of the plate. With a straight edge from just behind the keel I have a measurement of 1.010 at the rear of the plate with .025 shims at the rear of the plate. My trim tabs have .105 under all four corners. But like everything else all these boats are a little different close maybe, but different.
07-17-2007, 08:43 AM #5
Unfortunatly there isn't a golden numder for all boats. Every single one has to be set up differently and measurements are only relevant to that ski.
Generally I like to get the front of the FF plate as even as possible with the shoe but not past. Some take 2 washers some 3. This is because of hull variances and shoe setting. If boat A has the shoe set at 60 thou recess and boat B is at 80 the measurements at the tail of the plate will be completely and dramatically different to achieve the same angle.
So many things effect perfect rideplate angle that its impossible to just give a number and expect good results. For example, my daughters 1200 has to be set at .800 for her to ride it without bouncing. She wieghs about 120 but can still pull off high 74s sitting on the seat. With me on the same setup in a superman I barely hit 73. With the angle at 1.00 I can superman into 75s without a bounce but Christina can't even ride it.
I hope this makes some sense and all I can recommend is that you go out and find the best setting for your ski without bouncing and then take a measurement for reference in the future when something is altered.
07-17-2007, 09:09 AM #6
Thanks for the help...I must have confused things early on with the plate. I kept thinking it was best to run it with no washers if I wasnt bouncing .....
From reading old posts and this one I am thinking I should start over....
1 - Start with front of the plate as close to the shoe as possible
2 - Work the angle (rear mounts) to my liking
3 - Kill the bounce with washers under the tabs or angle of the plate ( I would need to do this with back to back testing ?)
What would tell me to increase the gap between the shoe and the plate ?
07-17-2007, 10:38 AM #7
Just start with the 4 washers that were supplied with the plate put 2 on each side on the front bosses. Don't put any on the rear at this point. It will probibly measure around 1.030 to 1.050 take it out and try it. If it starts bouncen then add a little to the rear untill you achieve the performance you are looking for my guess you will end up in the .990 to 1.020 range. Remember you want to keep the plate about .020 to .030 step at the plate to shoe the lesser is more optimal. Also you want to know what it's like when your fuel is getting low for your high speed runs.
Last edited by injected2stroke; 07-17-2007 at 10:43 AM.
07-17-2007, 10:41 AM #8
Hello mrbtd, You first want to set up the front with washers without going lower than the shoe once that adjustment on the front of the plate is done you do not touch the front again. Take it for a ride with no shims at all in the back and see how you like it if it feels good leave alone, If it feels to loose then put 20 thousands washers on the back and try again. You can add 20 thousands at a time till you find the sweet spot for your ski and your weight. I like making adjustments with a 1/4 tank because if you do with a full tank when the fuel goes down it might feel loose again, If any questions feel free to give me a ring. Thank you, Jim
08-08-2007, 03:19 PM #9
08-08-2007, 03:30 PM #10
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