[Mikko Nassi]

What are the main things that you used for setup changes, that are things that you actually have to change on the kart? Or are you happy with what the kart came with?

Things like axles, hubs, rims and seats. Do you have a set of different axles and hubs (especially rear ones), or do you even have different stiffness seats?

I think the no.1 thing from that above that people should have in their toolbox are rear hubs - compared to axles and seats they are easy to change and cheaper, while still making a big difference to handling.

Changing axles when you get in the flow doesn't take long, and it provides a great way to change the kart when the track gets more grip for example (throw in a softer axle).

Then there are rims, but I most just use what came with the kart and are happy. On occasion I've thrown on different rims on the rear to free up the kart for example. There are different materials (mag vs alu), different construction, and different offsets that all affect how the rims perform.

Finally there are different stiffness seats which hardly anyone changes around.. probably because it is so expensive to carry around a set of seats and it takes a while as well. Most buy a tillett but don't know what stiffness it is, but most likely it's standard.

You use any of the above as setup methods, or only change 'em when they break?

[RocK]

Most of the setup work I do is ride height on the rear and caster on the front.

Only time I use alloy rims is for quali on a green track.
Swap axles if the track is rubber-up before pre-final or final.
If time is limited for axles change, rear hubs is plan B

Never swap seats. For me it effects the kart handling from front to rear. Only time I touch the seat is when i want to move the center weight balance on the kart.

But these days, I'm lazy and anything goes. If any thing breaks, pack up and go home.

[CRG Asia]

Hahha... I like your analogy. Pack up and go home when something breaks. For me, it definately has to be the hubs first. It provides me with a fast changing solution. Not to mention tire pressures or new tires for different handling requirements. But like rock, i don't like to touch the seat. It brings a whole load of headache to me.

i rather just do with different hub lengths and tire pressures. Thats the best solution for me. And not to forgetting the alignments like camber caster and toe which is very important to me too.

[David Goldman]

Alright, I have some setup questions, on a fairly fast and straight track, would using a lot or a little castor be better? Also, should the kart be really free or would a tiny bit tight be better for a straight and high speed track? Heres what the track looks like, i only brake for turn 2, and the hairpin (turn 8. And what does castor actually do? For instance what are you changing when you change the castor amount? All the same questions for camber also. Thanks.

http://concepthaulersmotorspeedway.com/track_map.htm

[TJ Koyen]

I don't change anything. Ever. My kart is perfect all the time.

Kidding of course.

We usually mess with front track width, rear hubs, caster, and camber. We almost never move the seat on race day. Sometimes we change axles but this usually results in my dad saying a lot of bad words.

David,

You want your kart to be as free as possible without scrubbing off speed. Usually we shoot for "free" but not "loose". The kart should rotate instead of slide. Drivers in tune with their chassis can feel the inside tire lift off the ground, which is what you want. CHMS is interesting in the respect that the 10, 11, and 12 complex is brutal on tires. Everytime we go there, the tires show signs of understeer and its because of those corners. Being excessively loose is bad at CHMS because the last corner is one of the most important ones and if you are sliding off that corner, you sacrifice all your straight speed. But you don't want to be tight either, otherwise you'll bind up off that corner.

Caster = the angle of the spindle. By changing it, you change the tilt of the spindle so that when the wheel is turned, the tire digs into the ground more or less depending on what way you go on the adjustment. This either jacks more or less weight to the opposite corner. We used to run a lot of caster but not as much anymore.

Camber = the angle of the top of the tires when looking at them from the front or back. | |------| | (neutral) / /---------\ \ (negative)
\ \---------/ / (positive)

Camber can affect tire wear, how quickly a tire heats up, contact patch...etc. Many people change camber just for qualifying to heat the tires up faster.

[David Goldman]

Thanks so much, and one more thing, does more caster= more jacking effect? and does negative camber give you more or less grip?

[TJ Koyen]

Yes, that is what caster does.

Camber is tricky. We always get different results. It depends on the weather and track conditions. Usually we get more grip with closer to neutral camber. The kart starts with some camber already and we even it out a bit to get more front bite.