Speed Gain Documentation: Stock to Stage 1

[RXP-REX]

I was looking through my speed notes on my ski from being stock last year to a Stage 1 now. I did some math and found this to be kind of interesting. All speeds were recorded with a Garmin eTrex GPS unit.

Stock average: 67.55mph
Stock best: 68.8mph

blocks, pf, & grate average: 69.25mph
blocks, pf, & grate best: 69.4mph
gain average (stock): 1.7mph
gain best (stock): 0.6mph

blocks, pf, grate, rp holes filled average: 69.67mph
blocks, pf, grate, rp holes filled best: 69.8mph
gain average (stock): 2.12mph
gain average (previous): 0.42mph
gain best (stock): 1mph
gain best (previous): 0.4mph


Stage 1, blocks, rp holes filled average: 70.86mph
Stage 1, blocks, rp holes filled best: 71.3mph
gain average (stock): 3.31mph
gain average (previous): 1.19mph
gain best (stock): 2.5mph
gain best (previous): 1.5mph


*blocks = RIVA pro OPAS blockoffs
*grate = RIVA intake grate
*pf = RIVA power filter
*rp = rideplate


One side note is that I didn't install the wedge or solas until the I listed the Stage 1 numbers. Also, the stock tach showed 8100 RPM during all setups, so Im not sure how accurate it is.

[GTXX]

you only gained .4 mph from ride plate holes filled? you must not have done it right because I've seen some report gaining almost 2 mph. Now I don't feel so bad about "only" gaining .4-5 mph after filling mine.

[Ultra/RXP]

My gain for ride plate holes filled is about .4 to .5 MPH also. I have got to wonder about those 2 MPH gains!

[RXP-REX]

I don't think its possible to fill in the rideplate holes wrong. I have a small amount of sanding to do with the rideplate holes, but they're pretty good now. No way will I pick up another 1.5mph from that (I wish). I think its a 0.5~1mph mod.

You can go to my site and see what they look like.
http://putfile.com/rxpkid

I also have to silicone the intake grate in and silicone its bolt holes. But I don't believe you can get 2mph from filling in the rideplate bolt holes. Maybe someone forgot that they installed a wedge along with filling in the rideplate holes, and then reported a 2mph gain.

[GTXX]

just to clarify, I'm sure you did you ride plate holes correctly. I was making a reference to reported 2 mph gains because my and your gains were the same. Some may have gotten a 2mph gain, and I wish that I was one of them.

[jawz]

IF you really bring the nose up and reduce the drag you can get 1.? mph with the holes filled. depends on the sequence you doo the mods.

[Hydrotoys]

I think you need to put an aftermarket tach on the ski. You very well may be bouncing off the limiter.

[GeoRXT]

I think you need to put an aftermarket tach on the ski. You very well may be bouncing off the limiter.

Not good.

[RXP-REX]

IF you really bring the nose up and reduce the drag you can get 1.? mph with the holes filled. depends on the sequence you doo the mods.

I filled in the rideplate bolt holes before I added the wedge.

Take it for what it is...data. It is not a perfect test. I will agree with you though, I think certain mods will produce different gains depending on the sequence you install them and the other mods you run with them.

[RXP-REX]

I think you need to put an aftermarket tach on the ski. You very well may be bouncing off the limiter.

Damn, that was stupid of me. I didn't post the RPM I was turning with each setup. Completely stock I turned 8100 RPM, never lower, never higher, and it didn't matter what the weather was. After removing the stock intake and replacing it with the 3" riva powerfilter my RPM dropped, yes dropped, to 8000 RPM with the stock prop. However my speed went up and I would consistantly run over 69mph. After installing the 14/19R prop my RPM went up to 8100~8150 RPM and I will turn that in any weather.

I agree though hydro, I think something is goofy with my tach. Im going to install an aftermarket one this year and compare its readings to my stock tach.