Ultra-tight?! Please help!

Just because your tires are punching that low does not mean your making bite that the kart needs to turn. All of these recommendations on what he should be doing is great if the tire program was up to par. I'm not sayin it isn't buy with those numbers and the kart is not turning especially with that rear stagger at that track, something else is missing. Do Not adjust castor or take out left to compensate a pushing/mis handling kart from apex off.

JR Curtis
JRC Performance
Ultramax Racing Chassis
 
So this weekend guys I took out two washers of cross out of the lf and rf. Only because I didn't have time to scale. Moved the wheelbase back to even on both sides as I had the rf a half inch forward. Then I know y'all said not to change caster but I put two more degrees on the rf to get it to turn down in to the corner which it seemed to like. All in all didn't handle to bad. But again still was tight. Not near as bad as last week tho. My problem is I'm fighting a tight condition with what I feel is a lesser motor than the competition. I'm sending the motor off to be rebuilt now tho as this was probably my last race of the season. Just want to get the tight out of this thing!
 
Your motor will not feel right if you can't get your kart to roll out of the corner. Your motor maybe fine and you are just off on set-up.
 
If he's at Woodleaf, he's not tight, he just thinks he is.

That kart is setup for GKK on 90 deg afternoon and a 600 kart count.

Way too much leftside, should be around 57. Way too much RF camber for well pretty much anywhere with that kart, try -2.5. Can't remember LF camber but I'm thinking .75 or 1. Stagger should be 1 1/8-1 1/4. It's not a Phantom and it's not a 2010+ kart and should not be setup as such. It's a one of a kind design and operates in its own world.

This time of year you probably don't need to be more than 48 on the duro.

You're getting to the center of the corner, you have no front bite, it's just setting sail for the cornfield and you think you're tight. Put some front bite in and it will go center off. We probably walked $10,000 out of that place with the Inferno over about 2 years.

Caster is 10 and 7 stock and that's fine for Woodleaf.
 
You know JWD I think you may be onto something there. I'm definately lacking drive off the corner. I will try that stuff for sure. Any recommendations on cross and nose? Or are they good where they're at? Also should I lengthen the wheelbase on the right or run the same on both sides?
 
try increasing your rear air pressure split, left rear is building heat and size and creating more and more drive throughout the race. less air in left rear will keep it cool and more consistent for 20. good luck.
 
over 46 on the nose, 62-64 on cross. The nose is very important, cross not as much. I've seen these things all over the place on cross, but I know 62 works at Woodleaf.
 
alvin l nunley said:
Don’t know if this will be any help, but my spreadsheet says that with a ¼ mile track, with a turn radius of 119’, the rear stagger would be closer to .750”. Assuming a 34” RR tire. It would be less with any banking. Just a starting point, but maybe worth trying.
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This is why you don't consider spreadsheet data. The guy said the track is 1/4 mile. He's pure guessing (and guessing badly). The track is give or take 900ft. If memory serves, it's about 6 teeth shorter than the local 1/5mi.
 
inferno respones very well to caster change but you do need a caster gauge i use the jones gauge the factory marks are very close but you need a gauge and a slight push off on an inferno isnt a bad thing listen to JWD one of the best on umax set ups there is between him and KB at umax got me going and i won a lot of races onthe inferno, element,and badmax
 
JWD said:
This is why you don't consider spreadsheet data. The guy said the track is 1/4 mile. He's pure guessing (and guessing badly). The track is give or take 900ft. If memory serves, it's about 6 teeth shorter than the local 1/5mi.
Click to expand...
That makes me wonder; if he was wrong on the length of the track, what would that have to do with my spreadsheet? Just wondering.
And if the track is 900 feet long, how does that tell you what stagger to run? Or even what gear. Again; just wondering.

Comments, Complements, Criticisms and Questions are always welcome.
 
alvin l nunley said:
Don’t know if this will be any help, but my spreadsheet says that with a ¼ mile track, with a turn radius of 119’, the rear stagger would be closer to .750”. Assuming a 34” RR tire. It would be less with any banking. Just a starting point, but maybe worth trying.
Click to expand...

I really wish you would quit saying this to people, as it just isnt 100% correct. Some tracks, as ive told you this before, require more stagger with the banking.
 
SoCo Tire Treatments said:
I really wish you would quit saying this to people, as it just isnt 100% correct. Some tracks, as ive told you this before, require more stagger with the banking.
Click to expand...

I’m always surprised when someone tells me I can’t say something.
I don’t race dirt, but the math says I’m right, so I put it out there for people to “try”.
What could it hurt to try??

Comments, Complements, Criticisms and Questions are always welcome.
 
alvin l nunley said:
I’m always surprised when someone tells me I can’t say something.
I don’t race dirt, but the math says I’m right, so I put it out there for people to “try”.
What could it hurt to try??

Comments, Complements, Criticisms and Questions are always welcome.
Click to expand...
Hurt their wallet or break their neck !
 
Al, is your spreadsheet is always calculating the widest possible arc? Sometimes that's not the fastest line, and sometimes you want the stagger matched in different parts of the corner.
I suppose it's ok for a starting point, but, then again, an inch (or anything for that matter) is a good starting point. :)

As an aside about stagger, and I hesitate to post this-
One weekend with too much time on my hands, I put sighting marks on the top and bottom of the left rear sidewall. Put the kart on the stand, inflated the left rear to 10 lbs and measured the circumference.
Then I put the kart on the floor with 150 lbs of weight in the seat and measured the exact distance the left rear traveled with one revolution.
Then I put the kart back up on the stand and reduced air pressure enough to take a quarter inch from the circumference, put it back down on the floor and did the same thing.
No change in how far the tire rolled.
Scratched my head, and decided to do the same thing, except this time I measured from the floor to the centerpoint of the axle with weight in the seat.
Then I reduced air pressure enough to reduce the floor to center axle distance by an eighth of an inch, rolled it out and, again, no change.
I thought about it for a while, then just filed it away.
 
Bob Evans said:
As an aside about stagger, and I hesitate to post this-
One weekend with too much time on my hands, I put sighting marks on the top and bottom of the left rear sidewall. Put the kart on the stand, inflated the left rear to 10 lbs and measured the circumference.
Then I put the kart on the floor with 150 lbs of weight in the seat and measured the exact distance the left rear traveled with one revolution.
Then I put the kart back up on the stand and reduced air pressure enough to take a quarter inch from the circumference, put it back down on the floor and did the same thing.
No change in how far the tire rolled.
Scratched my head, and decided to do the same thing, except this time I measured from the floor to the centerpoint of the axle with weight in the seat.
Then I reduced air pressure enough to reduce the floor to center axle distance by an eighth of an inch, rolled it out and, again, no change.
I thought about it for a while, then just filed it away.
Click to expand...
I’ve spoken about this before. With the lower pressure, the axle might be closer to the ground, but the circumference of the tire shouldn’t change at all. In order to change the roll-out, you would have to shorten the tread length, rolling on a flatter surface doesn’t change that. If you change the circumference of the tire, the roll-out will change, yes, but just letting air out of the tire will not do that. Of course if you put a huge amount of air in the tire, and change the circumference, then the roll-out will change.
Did you measure the circumference before and after the pressure change? Only a change in circumference will change the roll-out.
A change of 2-3 pounds, (that’s a lot from what I hear) most likely isn’t going to stretch the tire and increase the circumference. It may change the flat part of the tire where it sits on the ground, but that’s only a change in the height of the axle, not a change in circumference.

Comments, Complements, Criticisms and Questions are always welcome.
 
alvin l nunley said:
I’m always surprised when someone tells me I can’t say something.
I don’t race dirt, but the math says I’m right, so I put it out there for people to “try”.
What could it hurt to try??

Comments, Complements, Criticisms and Questions are always welcome.
Click to expand...

Does your math take into account g forces applied, weight transfer, among other things?
 
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