05-01-2005, 06:07 AM #1
Franks 80+ mph videos and results from Saturday
Video at the end of this post... NEW videos...
82.5 and 81.5 back to back videos.... to back up the 83.1 mph we hit last week. So we can call Franks RXP a 80mph RXP.
Well, Frank and I went out testing his ski on Saturday and had good and bad results. Bad results....water leak from intake grate area into hull...minor, but still need to pinpoint where it's exactly coming from.
Good new... figured out what actually works as far as Venturi, prop, and wedge.
Frank's a little disappointed because of the leak and that his new venturi and pump wedge that really didn't do much this time out. The 81mm venturi worked the best and these two new venturis didn't do the trick. It's part of testing...sometimes things go good, sometimes they don't work out. Testing went basically like this. The 80.0mm venturi overloaded the pump like crazy and the speeds were in the 78mph range with 8200rpms. The wedge all it did for us was make us jump more. Check out the flybye video to see what kind of holeshoot the wedge gave us. The added up-trim wasn't needed and costed us rpms and mph on top. Once we took that off the rpms went back up to 8300-8350 with the venturi that Glen sent Frank 80.5. We were still short of 8400-8450 so we put on my friend Jacobs stock venturi and back on the limiter...8450rpms but our speeds dropped and we couldn't break the 83.1 we did last week. I think that's the best speed the ski will ever see. The speeds went down to 82.5 and 81.2. The jet ski flies, but Frank wants more and more...and wanted to break the previous speeds we did. I think he's mad about the leak All in all I think the best speeds we seen was with the 81mm frank sent back to GP, because the stock 82 dropped the speeds 1-2mph on top and the 80.0 all the way down to 8250rpms...and overloaded the pump.
Weather today was 50 degrees... Colder then before and if we had the 81mm nozzle we might have been able to back up the 83.1 run. ohh well... 82.5 and 81.2 still says the jet ski is a solid 80mph rxp.
More weather data.....
Atmospheric Pressure (PRES): 29.88 in / 1012 hPa
Pressure Tendency (PTDY): +0.04 in ( Rising )
Air Temperature (ATMP): 50.6 °F
Water Temperature (WTMP): 47.0 °F
Wind Chill (CHILL): 48.9 °F
Dew Point: 32 °F / 0 °C
Wind: 8 mph / 13 km/h from the SE
Clouds (AGL): Overcast 5997 ft / 1828 m
This sucks because I don't think we will have anymore 50degree days to get the best speeds out of this Rxp. Next week the temps are back in the 60-70's..... so we expect to lose some mph.
NEW UPDATED VIDEOS
82.5 and 81.2 back to back runs. 51.3 mb 4.45 min long
Franks wedge jumping, top speed flyby(notice...stable..hooking. and not bouncing on top of the rev limiter) 8.6mb
Best top speed 83.1mph 16mb
78.7 mph video 15mb
78.2 mph video 19mb
77mph video 20mb
76.5mph video 10mb
05-01-2005, 08:53 AM #2
WOW! no porpoising at all in that video!
So i take it the 81mm venturi is the best and you saw a solid 2 MPH gain with it.
Im currently running the 80.5, I may have to switch back.
Good work guys!
05-01-2005, 08:59 AM #3
- Join Date
- May 2005
- cape coral florida
This is amazing,u guys great.Q? what kind of mods make this thing fly?the bottom is stock?inlight me please.great job.
05-01-2005, 10:37 AM #4
It's a Rotax Racing Stage 3 RXP fully done and experimenting with the pump right now. Out of the box speeds are quoted at 78mph standard from Mark Underwood at Race Tech. In the weather here, this thing is flying for now.
As far as a parts list... too much to remember
but here is a brief outline
Rotax Racing ECU,
Rotax Racing Intercooler and intercooler block off,(billet)
158 thermostat, oil pressure jet,
super charger mod,
shims or what ever they do,
racing camchain tensioner,
lightweight aluminum valve spring retainers,
and cylinder head mod.
modded water box,
custom air intake system,
and plenty of holes in the front of the ski for air intake to hull.
14/19 Solas prop/
PPG speed venturi(Best speed was with the 81mm bore)
Riva intake grate,
Originally Posted by Green Hulk
As far as the porpoising goes, none at all and very stable at top speeds. The problem was just hitting the rev limiter on a wake when we were underpitched before.
OHH WAIT.... I FORGOT THIS IS AN APPARITION.... well.... to the Yamaha crowd it will always be a bouncing gumball.
05-01-2005, 12:34 PM #5
- Join Date
- May 2005
- cape coral florida
Thanks Daren. Wichh of those mods have to be done first? or i have to wait to the first 10 hours past?
05-01-2005, 12:46 PM #6
Great videos!! Gotta hand it to ya, the GPR's are going to have their work cut out for them. Guess Yamaha and Kawi have to get motivated!
05-03-2005, 08:00 AM #7
Oh GOD!!! The porpoising... its terrible! The RXP will never do 80 mph.
Great work guys, my hat is off to you.
05-03-2005, 10:05 PM #8
nice video... but why you dont put the camera in front of the speedometre and rpm to see the acceleration ... not on the side :P like in the video of miketrin
05-03-2005, 10:14 PM #9
i think because they are doing 80+ mph and hanging on for dear life. Mike Trin was just cruising around. Trust me, it's very hard to video and point at something at those speeds.
05-03-2005, 10:54 PM #10
Yeah my videos are lame compared to that stuff. I'm on a stock ski holding the camera on the bars with one hand and throttle with another, on glass. There's no way they could do that on these modified skis!!
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