Waterboxes

[Vumad]

From what I have read, a waterbox will increase your horse power throughout the entire RPM range and change the sound of your ski.

How much benefit is an aftermarket waterbox? I know an aftermarket pipe can give you 10% more power than stock, but how much power will an proformance waterbox give you? do different boxes change where in the RPM range you get that power?

Sound is not hugely important, although I will ackowledge that they may make the ski sound cooler and more "throaty" and some are louder than others for the same amount of improvement.

How is the flow of water affected? and how does weight come into play? and any other benefit or negitive of a box come into play that perhaps I don't know about?

Specifically, I'm dealing with a 650 Kawi engine, but I wouldn't mind a more generalize answer. I'll be playing with some Yamahas in the future.

 

[LBE]

I don't believe they make any more power. Mostly louder, may sound faster, but generally water boxes are very simple and not really restrictive. That I know of, the sonic wave is not affected by the waterbox, which is where pipes create more power, as well as from increased flow. I have replaced several boxes on various skis throughout the years and have never felt any increase in power.
Don't waste the $$, IMO.

 

[Waste Land]

90% of waterboxes are just pretty much sound with some weight shavings.

The XMW waterbox weighs nothing, holds little water which lets it rev quick snd keep the nose/ski weight lighter.

Suppose to make a nice difference in pop/response but not making horse power

 

[Matt_E]

90% of waterboxes are just pretty much sound with some weight shavings.

The XMW waterbox weighs nothing, holds little water which lets it rev quick snd keep the nose/ski weight lighter.

Suppose to make a nice difference in pop/response but not making horse power

That has been my experience.

A lot of folks will mistake a louder/brappier sound for an increase in power.

 

[Vumad]

Well, if it revs faster then that would be an increase in the bottom end snap, no? Not more horse power but better response?

 

[Matt_E]

Yes.

You could achieve almost the same result with a flow control valve.

 

[thegoldenboy]

A lightened or aftermarket flywheel will also help gain RPM's faster. It is a better mod than a waterbox IMO.

Many people go with an aftermarket waterbox when they run front exhaust. The reasons they do are:

1) Exhaust exits the front and does not create (as much) exhaust in the pump area. Air in the pump area will give you prop slip. Helps for tailstand oriented tricks.
2) Weight savings
3) Wanting to run dual scuppers

I'd guess that a waterbox would provide small gains on a bigger displacement motor, but I don't have one so I don't know.

If you want your ski to sound cool, just get an exhaust T and run your stock waterbox with front/rear exhaust. Keep in mind that officials and bystanders generally don't like front exhaust. Especially if you are on a landlocked body of water.

 

[Idok]

Yes.

You could achieve almost the same result with a flow control valve.

or proper water restriction to the stinger... :drive:

 

[Shonuff]

When I put my first TDR box in, the sound was tremendous.

http://www.pwctoday.com/showthread.php?t=106608

 

[Vumad]

That sounds cool, but sound alone isn't worth that much money to me.

I'm going to lighten the flywheel reguardless of the waterbox.

How does the flow control valve work?

 

[Matt_E]

http://www.x-h2o.com/threads/26074

 

[5810]

I'm thinking about running a straight pipe made from PVC where my water box is, i know it will be loud but i only have rear exhaust & the stock sxr box is a tank. Will this setup work, i don't want to loose bottom end, but don't care about top. Or should i go with tdr box

 

[Shonuff]

Don't use PVC for exhaust applications. (ducking and running)

It might attract attention due to the sound but I bet it would sound sweet.

 

[whitca]

I put a little pjs aluminum box off a 550 in my 650. Really no power gain and it's a lot louder. The biggest advantage was the weight. That little aluminum box weighs nothing...especially compared to that heavy stainless box with the giant rubber boots that are in the kawi 650. The nose instantly felt lighter which was a huge improvement.