Are you getting the most speed out of your ski you can?

[Lucander]

I agree whit zone5 Or at least our raceboat is quicker on salt water than fresh water.

[dennisb20]

Jet Ski speed mod's

Hitman, what did your final prop pitch come to, to get to 81.9?

[zone5]

I'm very interested in what people think the mechanism is whereby the ski is faster on fresh water compared to seawater. Now, disclaimer, I don't chase top speed much, so don't have a lot of personal data, but had always assumed that sea/salt water, being of a higher density, would be quicker. This is due to greater buoyancy (4-5%) making the ski ride higher and thus less wetted surface drag, and the higher density through the pump giving a greater impulse (momentum change), fairly important at top speed, since as speed increases thrust decreases, assuming the same exit nozzle velocity...

This is genuine curiosity, not disputing anyone's experiences.... I know I get more speed on salt, but it's hard to separate the engine's performance gain going from the fresh water lake where I usually ride @ 3000' AMSL down to sea level (10% more air) from the water induced factors...

Always assuming water conditions the same, of course.... I've never had the pleasure of glass on seawater...

[FZS-RIDER]

I have seen a fZR tunnel split bad on a sk that was only running 74 mph and had never seen any rough water conditions at all. Tommy Jordan

I have seen more than 4 ski cracked stock class
sea riders

[jccycle]

hi have a fx sho 2008 does the speed of fz are a lot difrent from a fx

[bryantjopplin]

So they don't make one for the VXR, what do we do?

[2fast4u]

I have seen a fZR tunnel split bad on a sk that was only running 74 mph and had never seen any rough water conditions at all. Tommy Jordan

[yol937]

Honestly It can happen to a stock boat or to a 90 mph boat! It's really just your luck of the draw.. It's just a insurance mod that u can do so u don't bust the tunnel and be left with a messed up hull.

[yamahamiamiski]

At what point does the tunnel reinforcement need to be done. Would it be needed with stock wheel and a r3 tune?

With an E1 wheel and stock ecu running 79-80 I was already starting to get some cracking, so anything above 78 I would be cautious.

[Mowerpan]

At what point does the tunnel reinforcement need to be done. Would it be needed with stock wheel and a r3 tune?

[2fast4u]

Bumping this back up for thr new guys since I see lots of questions from these new guys, Tommy Jordan

[rcapone]

Thanks all for the replies, now I just need the $$
I'm thinking about
Reflash, C3, RRFPR, 13/24 Prop, I have the Riva Water Cooling

[2fast4u]

Thanks for the reply, I'm considering teh reflash but I'm just worried about the higher rpms and engine longevity. But I've seen a lot of people running them with great success so I may just take the plunge. Would the R1 be OK?

The R 1would be a great choice since thr rev limiter is 8500 which seems very safe on these motors. Just prop you ski for 8300-8400 rpms and you will be good to go with your mods and a c-3 Tommy Jordan

[mikeFZR]

Thanks for the reply, I'm considering teh reflash but I'm just worried about the higher rpms and engine longevity. But I've seen a lot of people running them with great success so I may just take the plunge. Would the R1 be OK?

I talked to Glenn at R&D many times via email about the safety of the R1 and it is a great option! The soft cut will start at 200 (or 250) rpms before the hard limiter and you can have the limiter custom set for free if you need to. Glenn also informed me that if the gas is 10% ethanol than the R1 will be a better choice than the R2 on stock boost because the ethanol counteracts the more advanced timing on the R2.

"Hi Mike,

Your questions are very difficult to correctly answer. You must understand that the timing in the OEM ECU is rpm/boost referenced, therefore it is a continuously moving target. So the timing will vary depending on what rpm range you are in and what boost pressure you have at that particular moment.
What would help me more to suggest the best program, is to determine what fuel you are using and what percentage of ethanol is in it. If your local station has 10% ethanol in the fuel I would recommend the R1. If there is less than 10% ethanol, the R2 is the more powerful choice.
We always keep in mind the clutch when developing ignition curves for our ECU programs. We have successfully used both the R1 and R2 programs in offshore racing. Last year we used the R2 with a C3 boost wheel (13 pound boost) and finished second place on an FZR in the Pro class at the Mark Hahn 300. In the race the engines are at peek rpm for 5-6 hours with the only break being a few 65-95 second fuel stops. We understand the reliability thing, because we do a lot of offshore racing ourselves. The reliability is definitely there.
If you choose to go with the R2 and want the rev limiter at 8400 we can do that for you at no extra charge. Just specify that detail in a note when you send in the ECU."


Glenn Dickinson,
R&D Racing Products
12983 Los Nietos Road
Santa Fe Springs, CA. 90670
p. 562.906.1190
f. 562.941.5563

[rcapone]

When you add a higher boost wheel it is hard to get the engine proped correct for the stack ecm. I tried and tried to get the most I could out of a ski while using a stock ecm. One day I would have it proped just correct and the next day with better weather I was all over the revlimiter. I finally went with a reflash and boy was everthing much easier to get going the speed numbers I was looking for. DO YOUR SELF A BIG FAVOR AND GET YOUR ECM REFLASHED ( or a after market ecm motec or vipec if you like them better and have the extra $ ) till you do this you will never be happy . You have all the right parts in your signature so far. A c3 and a reflash will put you over the top. You are working with your hands tied till you get around the low rpms the oem ecm has on it. Tommy Jordan

Thanks for the reply, I'm considering teh reflash but I'm just worried about the higher rpms and engine longevity. But I've seen a lot of people running them with great success so I may just take the plunge. Would the R1 be OK?