Kart setup tips for the wet

kartincolin

Hello lads and lassies

I just bought a Rotax Max kart and am looking for some helpful tips for setting it up to run in the wet.

Seeing as it is Ireland, the likelihood is that a lot of races will be wet, so you would need a good wet setup, right? What are the general set up adjustments made for the wet? I know you narrow the rear axle, widen the front axle, but what tyre pressures do you run front and rear, camber etc...

Any tips appreciated, thanks!

SouperComputer

What chassis do you have? There's a plethora of things you can do, but what you mentioned already will get you started. Other things you can change..

Set caster to max
Ackermann to max (outer holes in steering column, inners on spindles)
Short rear hubs
Raise seat and or move forward (or sit on some styrofoam or a towel)
Add toe out
Add 2-3 teeth to rear sprocket
Drop needle a clip (since its a max)
Soften up the front end: remove torsion bar(s), loosen floortray bolts.
Leave your seat stays in
You could try putting rear torsion bar in some karts it helps in the wet, other it can hinder.
You can go to a "softer" rear axle.
Cant really advise on tire pressures, generally the higher the average speed or the wetter the track, the higher the pressure you will run. In the absense of any other info, lob 16psi in there and give it a go.

If you are fortunate enough to have a full day thats wet and make all these changes, you might well find yourself moving the rear wheels out a touch to get some exit bite.

kartincolin

SouperComputer wrote: »

What chassis do you have? There's a plethora of things you can do, but what you mentioned already will get you started. Other things you can change..

Set caster to max
Ackermann to max (outer holes in steering column, inners on spindles)
Short rear hubs
Raise seat and or move forward (or sit on some styrofoam or a towel)
Add toe out
Add 2-3 teeth to rear sprocket
Drop needle a clip (since its a max)
Soften up the front end: remove torsion bar(s), loosen floortray bolts.
Leave your seat stays in
You could try putting rear torsion bar in some karts it helps in the wet, other it can hinder.
You can go to a "softer" rear axle.
Cant really advise on tire pressures, generally the higher the average speed or the wetter the track, the higher the pressure you will run. In the absense of any other info, lob 16psi in there and give it a go.

If you are fortunate enough to have a full day thats wet and make all these changes, you might well find yourself moving the rear wheels out a touch to get some exit bite.

I have a Tonykart Racer EVR chassis. Thanks for the multitude of setup options, and I hope some of the above will help me get some front end grip in the wet.

SouperComputer

Move your weight around as you drive. Dont be afriad to lean your body out of the corner to help lift your inside rear wheel to get rid of the understeer.

Here's some guides to get you going

Kosmic Knowledge Packet. You might already know this, but Tony//Kart's parent company is OTK who also make a lot of other chassis (Trullii, Exprit and Kosmic). While the Kosmic's aren't identical, a lot of the same tuning theory applies. Worth a read.
Guide for caster\camber eccentric pills. Should be the same system as what's on your EVR
Rotax FR125 Max packet I threw together. This one's a zip of a collection of docs for Max. Jetting and powervalve setting, maintenance etc etc. Personally, I loath the Max, but that's a rant for another day LOL.

Happy studying.

kartincolin

SouperComputer wrote: »

Move your weight around as you drive. Dont be afriad to lean your body out of the corner to help lift your inside rear wheel to get rid of the understeer.

Here's some guides to get you going

Kosmic Knowledge Packet. You might already know this, but Tony//Kart's parent company is OTK who also make a lot of other chassis (Trullii, Exprit and Kosmic). While the Kosmic's aren't identical, a lot of the same tuning theory applies. Worth a read.
Guide for caster\camber eccentric pills. Should be the same system as what's on your EVR
Rotax FR125 Max packet I threw together. This one's a zip of a collection of docs for Max. Jetting and powervalve setting, maintenance etc etc. Personally, I loath the Max, but that's a rant for another day LOL.

Happy studying.

Once again, your handy work is appreciated. It would appear that you are a karting guru

SouperComputer

Nah, just good a regurgitating info...

alanca

hi im wondering does anybody know much about karting i have a decet knowledge of karting and engines but i dont know too much about carbs like jetting if someone could enlighten me please id appreciate it. one of the things i dont know is it just the main jet that gets changed or other jets too when you are using a different size

SouperComputer

alanca wrote: »

hi im wondering does anybody know much about karting i have a decet knowledge of karting and engines but i dont know too much about carbs like jetting if someone could enlighten me please id appreciate it. one of the things i dont know is it just the main jet that gets changed or other jets too when you are using a different size

Depends on what you are trying to remedy. Obviously the main jet gets changed mostly for full throttle mixture. For transition and other stages, depending on rules then you can change slides, needles and atomizer nozzles.

Generally speaking you would use an air density gauge, find a baseline for your main jet and pick your jet based on that. Needle could be moved, or changed depending on how the throttle responds. If you have a Max then I guess you could run whatever others are going with and be OK. KZ not so much because of the differences across motors.

To be honest carb jetting isnt a topic for a single post, theres books upon books on it.
What kart\carb combo are you asking about?