Keeping up with the track – Setup

Here is my problem, the more grip the track gets the slower and more bound up the kart feels, and people gain 2 kart lengths coming off a corner. I have tried lowering tire pressure, widening the rear track, adding caster, long hubs, axles, etc.

What I am looking for is a process to follow to find a setup that works and keep up with the track conditions.
 
Here is my problem, the more grip the track gets the slower and more bound up the kart feels, and people gain 2 kart lengths coming off a corner. I have tried lowering tire pressure, widening the rear track, adding caster, long hubs, axles, etc.

What I am looking for is a process to follow to find a setup that works and keep up with the track conditions.
Wiping too much.
 
If you got it right early you don't touch set up, Tires, pressures and prep, and gearing, and if the track is gaining grip you certainly would not lower air pressure, the more it grips up more air, less prep with a different set of tires not just less on the same set, and you would lower rear gear a tooth or so. And if you would tweak set up it would be left side and maybe cross, not track width, caster, hubs, axle.
You guys notice this is in the sprint section?

Most of this advice should be irrelevant for sprint racing.
 
The gem rp offered that relates to sprint racing is about air pressure.

More air pressure generally lowers overall grip.
The balance of the kart can be altered by varying front to rear air pressure.
Keep good notes.

The next thing to consider is that fast isn't always the most comfortable, although comfort adds confidence.

That's all I got.
Hopefully someone will chime in with more advice.
 
My thinking was that either A) there rear axle is stuck to the track or B) I'm having to put too much steering input in causing the front to scrub, which could point me back to A(understeer or push). It just seems like no matter what I try I'm not finding a setup that works well all day. I might hit it in one round of practice but as the track changes the karts tightens up and slows down.

Here is my base setup.
Coyote Zenith
Front Weight 41%
Cross 50%
Side to side is within a few pounds
Caster 10-12°
Camber -0.5°
Toe 0, with me in the kart
Front Width: 2 spacers inside
Rear Width 49”
Tires: 4.5/6.0 Vega reds(12psi typical)
Rims: 5.25” Van-K / 8.5”Van-k
Axle: Righetti H2(C) axle
Class Masters 390 lbs
 
One thing you have to realize is that all these adjustments will reverse at some point so, knowing what they do and how they inter react is key.

390 Lbs. on 6" tires ouch. If you go up in psi you'll build heat and get more grip until your tires get greasy and loose grip in a bad way but dang it'll feel good for the first couple laps. Now if you lower psi at 390 your tires will become over loaded and build heat and grip. Wide rims help with side wall support. So lower your psi until you feel the tires getting mushy in turns then come up one psi and live with it. Probably be around 12 psi anyway.

You need to get your front weight up to 45 - 48%

Rear axle depends on lateral G force and vertical center of gravity available. Usually you want to go wider with more flexibility. Do you have short hubs, are you allowed to go out to 55".

For the front end you can go wider for more jacking effect. If you feel it pushing coming out of a turn you've gone way too far. Caster is the devil, if it helps put some in but try to minimize it or you'll lose contact patch real fast. Also minimize ackerman effect unless you're on a very tight track. Negative camber and slight toe in is good for a long track, it helps keep the kart steady on long straights. For short track go straight up with a touch of toe out and it will help your turn in.

Coyote use to put out a booklet with the chassis to explain base line set up and adjustments for track conditions. Maybe contact the factory.

Let us know how you progress.

Sundog
 
Last edited:
In
"Cross 50%"?
2 spacers?
On my Sprint kart, I always measure to the inside of the tread. I tended to keep the front and back pretty much the same measuring on the inside of the treads. Of course our tires then were not nearly as sticky as they are now. Will

I wonder if you're having trouble with the air density. Tell me about the weather. Sometimes the air density doesn't change through the day, but when it does, it usually goes down, and that can slow you down quite a bit. Cool mornings and warm afternoons can be an indication. Don't discount the possibility.

Tell me about your gear ratios, changes if any, and changes in lap times. Is somebody taking lap times for you? I always used split times. Tells you what part of the track your gaining or losing.

Do you have a gear ratio chart? Do you have a gauge telling you RPM? Do you have an exhaust gauge (EGT)? You'd be amazed at how much that will tell you!

I'm not a big fan of the term "binding"! And

One observation; the front of the kart is attached to the back of the kart, they work in concert with each other.!! The front pushes because there's too much rear bite, the rear slides because there's too much front bite.

When you get the front to rear weight balance where you like it (your front weight seems a little light) a lot of handling problems can be solved by widening/narrowing the front & rear tread width. Narrow the front, for more front bite. Narrow the rear, more rear bite. The opposite being true.

10°/12° caster doesn't seem like much.
 
My thinking was that either A) there rear axle is stuck to the track or B) I'm having to put too much steering input in causing the front to scrub, which could point me back to A(understeer or push). It just seems like no matter what I try I'm not finding a setup that works well all day. I might hit it in one round of practice but as the track changes the karts tightens up and slows down.

Here is my base setup.
Coyote Zenith
Front Weight 41%
Cross 50%
Side to side is within a few pounds
Caster 10-12°
Camber -0.5°
Toe 0, with me in the kart
Front Width: 2 spacers inside
Rear Width 49”
Tires: 4.5/6.0 Vega reds(12psi typical)
Rims: 5.25” Van-K / 8.5”Van-k
Axle: Righetti H2(C) axle
Class Masters 390 lbs
Go up on front nose weight and increase rear track width to 49 1/2". Try going up in air pressure as well.
 
One thing you have to realize is that all these adjustments will reverse at some point so, knowing what they do and how they inter react is key.

390 Lbs. on 6" tires ouch. If you go up in psi you'll build heat and get more grip until your tires get greasy and loose grip in a bad way but dang it'll feel good for the first couple laps. Now if you lower psi at 390 your tires will become over loaded and build heat and grip. Wide rims help with side wall support. So lower your psi until you feel the tires getting mushy in turns then come up one psi and live with it. Probably be around 12 psi anyway.

You need to get your front weight up to 45 - 48%

Rear axle depends on lateral G force and vertical center of gravity available. Usually you want to go wider with more flexibility. Do you have short hubs, are you allowed to go out to 55".

For the front end you can go wider for more jacking effect. If you feel it pushing coming out of a turn you've gone way too far. Caster is the devil, if it helps put some in but try to minimize it or you'll lose contact patch real fast. Also minimize ackerman effect unless you're on a very tight track. Negative camber and slight toe in is good for a long track, it helps keep the kart steady on long straights. For short track go straight up with a touch of toe out and it will help your turn in.

Coyote use to put out a booklet with the chassis to explain base line set up and adjustments for track conditions. Maybe contact the factory.

Let us know how you progress.

Sundog
I run masters in Cup karts at 390# and Medium in Club Racing. For CKNA they all run 4.5/6.0, for club racing we can run 6.0 or 7.1 rears. I have over driven the kart and know exactly what it feels like when the tires get overheated, then it is really slow.

I'll try a higher front percentage that's an easy change. I've never gone above 43%.

We can go up to 55.125" rear width. I've never been above 51.5". Most of the Coyote Combat and Zenith the manufacturer said the base if 50.5. I think I will be out of axle by 53" maybe less.

I was thinking more caster to lift the inside tire but didn't consider that it also reduces contact patch on the outside tire. Is it better to use front width for jacking or caster? It was a little quicker with lower caster last weekend. I'm in the middle holes for Ackerman. It's also easy to try different ackerman.
 
In
"Cross 50%"?
2 spacers?
On my Sprint kart, I always measure to the inside of the tread. I tended to keep the front and back pretty much the same measuring on the inside of the treads. Of course our tires then were not nearly as sticky as they are now. Will

I wonder if you're having trouble with the air density. Tell me about the weather. Sometimes the air density doesn't change through the day, but when it does, it usually goes down, and that can slow you down quite a bit. Cool mornings and warm afternoons can be an indication. Don't discount the possibility.

Tell me about your gear ratios, changes if any, and changes in lap times. Is somebody taking lap times for you? I always used split times. Tells you what part of the track your gaining or losing.

Do you have a gear ratio chart? Do you have a gauge telling you RPM? Do you have an exhaust gauge (EGT)? You'd be amazed at how much that will tell you!

I'm not a big fan of the term "binding"! And

One observation; the front of the kart is attached to the back of the kart, they work in concert with each other.!! The front pushes because there's too much rear bite, the rear slides because there's too much front bite.

When you get the front to rear weight balance where you like it (your front weight seems a little light) a lot of handling problems can be solved by widening/narrowing the front & rear tread width. Narrow the front, for more front bite. Narrow the rear, more rear bite. The opposite being true.

10°/12° caster doesn't seem like much.
I'll have to take a measurement to the inside of the tread. It's easy to keep track of spacers. I start with 2, 10mm spacers on the inside of the front spindle. Positive cross is more weight on the right front and left rear.

I have my biggest trouble on hot days but this is a spec motor class so we should all be affected in a similar way. I don't see people making float or carb needle changes much in the pits.

I always gear so that I get to the rev limiter maybe 2/3 down the longest straight. I don't get the most top end but it will also pull off the corner.

When I am following someone and feel like I am running the same line and they pull 2 kart lengths off the corner, I describe that as binding. Maybe there is a different term, maybe it is something else.

You bring up a good point about front to rear balance. Maybe it is as simple as having too much rear grip and I need to bias it to the front for better balance of front to rear grip. With a low front percent this could be the case.

I'll do some testing and report back.
 
Here is my problem, the more grip the track gets the slower and more bound up the kart feels, and people gain 2 kart lengths coming off a corner. I have tried lowering tire pressure, widening the rear track, adding caster, long hubs, axles, etc.

What I am looking for is a process to follow to find a setup that works and keep up with the track conditions.
I was on the other end of that. I was gaining a second or two in the corners. I recommend keeping as much momentum as you can, brake minimally and stay on the edge of sliding, but make sure not to go too far. I also run a 59 gear.
 
I'm going to make a suggestion, and I'm anticipating that you will disagree with it.
I had a driver with the same problem you're probably having. His driving style was causing it. He would go into the corner too far, trail breaking to get slowed down enough to make the turn, almost overshooting the corner. Then get back on the gas and try to recover the time lost. The trick is to keep your speed up, as much as possible,

What I'm saying is through the corner

I discovered myself doing this very early in my karting career. By accident I discovered the solution. Break as late as you can, in a straight line, when you'vr slowed enough, start your turn, and as soon as possible get back on the go pedal. Keep your line as close to the apex as possible.

The point is; get through the corner as smooth as possible, but make up your time coming out of the corner, not going in.In
 
I'm going to make a suggestion, and I'm anticipating that you will disagree with it.
I had a driver with the same problem you're probably having. His driving style was causing it. He would go into the corner too far, trail breaking to get slowed down enough to make the turn, almost overshooting the corner. Then get back on the gas and try to recover the time lost. The trick is to keep your speed up, as much as possible,

What I'm saying is through the corner

I discovered myself doing this very early in my karting career. By accident I discovered the solution. Break as late as you can, in a straight line, when you'vr slowed enough, start your turn, and as soon as possible get back on the go pedal. Keep your line as close to the apex as possible.

The point is; get through the corner as smooth as possible, but make up your time coming out of the corner, not going in.In
I suspect I am a big part of the issue. Last year I was running a Coyote Combat set up for CIK(upright seat etc) and was having similar issues. I bought a prepared engine and a new chassis and am still having issues. I worked with a driving coach last weekend and it did help somewhat. BUT, at the end of the weekend when we both thought I had the lines down and I was following someone who could turn fast laps, following their line, I was still losing kart lengths off the corner. So the driver, me in this case, is probably a big contributor but the setup is still critical.

I went out in practice and followed 2 fast karts and was consistently 0.8 seconds faster in that round but never got there again the rest of the weekend.

I'm really looking forward to moving 5-10lbs(43-44% Front) to the nose and seeing how it drives.
 
Don’t underestimate the importance of driving. It’s easier to be fast on a green track for less experienced drivers. Once you’ve exhausted every reasonable setup option don’t be afraid to try something different. Jump in a friends kart etc. Too many seasons are wasted on karts that don’t suit certain drivers whether it’s due to size, tires being used or just a bad kart.
 
Like Gary says, jump in somebody else's kart OR have one of the faster folks take yours out for a few laps.
They can tell you whether it's you or the kart or both. Don't be shocked at what they tell you!!! Or they're lap times in YOUR kart.
Clark Gaynor Sr.
 
Ho2 about this, how much toe are you running? I’ve found, with a 206, even a little too much tends to cause drag coming off the corners
 
Gary10 & ClarkSr,
I know a big piece of this puzzle is the driver. I had one of the fast guys take my kart out after the last race. He was more than a second faster a lap, with no changes to the kart. It seems like there is a narrow window of setup where I am quick. I also assume I am over driving and overheating the tires trying to improve my lap times, because by the end of a race I tend to have slowed way down.
 
We have rarely raced at any track where the setup was good all day. YOU HAVE TO STAY AHEAD OF THE TRACK. Racing at a track frequently should help that. Take good notes on fast and slow sessions.
 
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