My kart won't turn

chall · Joined: 25 Aug 2001 Posts: 16

I just started racing after 5 years off, I haven't been on a short road corse since 1987 so I have forgotten vast amounts. At my first pratice The kart wouldn't change direction untill ti was almost stoped. If the front would have changed directioin just a little bit I could have broken the rear loose and slid it around the turn but I got no change in ether direction. the track was wet but not enough to puddle. The kart is a old Bandit with fixed castor but adjustable camber. Weight distribution is 43.5/56.5, tires (tryes) are Dunlop DAM with 13 psi.
The way I see it my only choices are to lower tire pressure, add Ackermen and add some toe out. Anything I'm missing

Rick Crow · Joined: 18 Jul 2001 Posts: 49 Location: Albany NY

Tight on a wet track with DAM's? try widening the front track to increase the weight jacking effect. set toe at zero to +1/16 tighten the front bumper and floor pan. I had an old bandit and it flexed so much I couldn't run anything softer than an SL4 tire.
BTW just for the heck of it check that your kingpin bearings are not binding under load

Rick

chall · Joined: 25 Aug 2001 Posts: 16

Rick, Toe was 0 with me in the kart. I am an auto tech and as so +1/16 means toe in. I assume you me toe out, as in would decrease weight jacking. Front bumper is tight but has some inherent weakness in the mounting that I think I and stiffen. Floor pan is tighter then I have ever run it before.
Thanks to the ideas.

Rick Crow · Joined: 18 Jul 2001 Posts: 49 Location: Albany NY

chris yes I meant 1/16 toe out. the toe out doesn't reduce the weight jacking as much as it helps the intial turn-in. The other things that come to mind now is,That instead of reducing tire psi go the other way 16psi and above when you overinflate you will reduce the tire contact patch and this will free up the kart also. When you turn don't lean into the turn remain upright in your seat so the inside tire will unload.
If you can borrow some harder tires give that a try too.

Rick

Jimmy Moore · Joined: 26 Jul 2001 Posts: 664

Move your seat forward about 2 inches.

Tim Paul · Joined: 21 Jul 2001 Posts: 326

How does the kart have adjustable camber and not castor? I have never worked with a bandit?

John Learmonth · Posted: Wed Aug 29, 2001 5:20 am Post subject: My kart won't turn

quote:
Originally posted by Tim Paul:
How does the kart have adjustable camber and not castor? I have never worked with a bandit?

If the king pin bearings are housed in the chassis itself then caster and KPI are non adjustable. With such a kart only camber is affected by rotating the eccentric adjusters.
I would always choose a chassis with adjustable caster and KPI (which is what you actually change when changing camber, camber change being a by-product of changing KPI, except of course on karts with king pin bearings in the chassis), as caster is an important variable.

John Learmonth · Posted: Wed Aug 29, 2001 5:29 am Post subject: My kart won't turn

quote:
Originally posted by Rick Crow:
chris yes I meant 1/16 toe out. the toe out doesn't reduce the weight jacking as much as it helps the intial turn-in. The other things that come to mind now is,That instead of reducing tire psi go the other way 16psi and above when you overinflate you will reduce the tire contact patch and this will free up the kart also. When you turn don't lean into the turn remain upright in your seat so the inside tire will unload.
If you can borrow some harder tires give that a try too.

Rick

Not meaning to be picky, but toe in will decrease jacking because it affects Ackerman geometry. The steering arms are attached to the spindle shafts at a fixed angle, and increasing toe in will also change the angle of the steering arms to be more parallel with the centreline of the chassis which lessens Ackerman. Conversely, increasing toe out makes the steering arms more inwardly angled relative to the centreline, increasing Ackerman geometry.

Increasing Ackerman will result in more steered angle of the inside front, and thus result in more lowering of the the inside front (relative to the rest of the chassis).

Mike Goebel · Posted: Wed Aug 29, 2001 12:05 pm Post subject: My kart won't turn

quote:
Originally posted by John Learmonth:

If the king pin bearings are housed in the chassis itself then caster and KPI are non adjustable. With such a kart only camber is affected by rotating the eccentric adjusters.

I have the eccentric adjuster in the bottom of the kin pin housing. If I change the position of the eccentric it should change all of the geometry's associated with this king pin. The top sort of stays in its original position and the bottom is in a new position. It would seem impossible to independently adjust camber without affecting KPI and Caster.

Mike G.

John Learmonth · Posted: Wed Aug 29, 2001 1:51 pm Post subject: My kart won't turn

quote:
Originally posted by Mike Goebel:

I have the eccentric adjuster in the bottom of the kin pin housing. If I change the position of the eccentric it should change all of the geometry's associated with this king pin. The top sort of stays in its original position and the bottom is in a new position. It would seem impossible to independently adjust camber without affecting KPI and Caster.

Mike G.

Mike,
If the king pin bearings are in the body of the spindle itself then adjusting caster will probably change the KPI setting (and if KPI changes camber will also change).

Depending on the exact adjustment to caster you make, KPI may or may not change. EG if you move from max caster to min caster then the KPI will remain unaltered, or if you move from having the caster half way between max caster and central caster to halfway between min and central the KPI won't change etc.

This is also the case for adjusting KPI, ie if you move from max KPI (= max neg camber)to min KPI (= max pos camber) then the caster won't change etc.

Eccentric cam adjusters are really quite a clumsy method of making these adjustments since the KPI and caster angles can only be adjusted independantly to a very limited degree, forcing you to choose which one to give priority to, and compromising one, the other, or both.

Charles Pou · Posted: Mon Sep 03, 2001 4:06 pm Post subject: My kart won't turn

Try mounting 3 to 5#'s lead on the front of your kart, i.e this is easier than moving your seat forward.

Also, drive a different line. Stay out of the groove (for a dry track) and try driving outside in the marbles.

If available, watch some F1 races in the rain, for some good examples of the proper line on a wet track.

Marc Miller · Advertiser Joined: 18 Jul 2001 Posts: 1835

ALSO:

Lossen bumper bolts, bellypan bolts, etc... loosen seat struts if you have any. Widen the front out to max width and narrow the rear to a point where your center line of the front and rear are close to being the same. When you drive, lean to the outside throughout the turn to plant that outside rear, 13-15 pounds should be fine for pressure, a little toe out will help, and 1/32-1/16 sounds fine. Most importantly, have a good time because rain racing is a blast. Adding front weight is fine too.

Marc Miller

Rob Hogenmiller · Posted: Mon Sep 10, 2001 6:31 pm Post subject: My kart won't turn

quote:
Originally posted by charlespou:
Also, drive a different line. Stay out of the groove (for a dry track) and try driving outside in the marbles.

If available, watch some F1 races in the rain, for some good examples of the proper line on a wet track.

GREAT advice I was surprised it wasn't the first thing given. If you attempt to drive a WET Track on the racing line, 99.9% of the karts out there won't turn. I don't know the reason why but I know it's like ice. Stay off the traditional race line and square off the corners the grip should be atleast 3 times the amount, as the track starts to dry you can test out the traditional lines, as they will come back in before it is completely dry generally.

Atleast that's one guys experience.