Umax Buggy Cross question

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DennisM32

New member
I have an 02 Octane buggy that i ran last year with the cross around 53%. The previous year I had it around 56% but after 5 laps or so the kart would turn into a dump truck. The 53% seemed to work better but was wondering if going into the mid 60's would be of benefit or work against me?
 
Try it with a hard left rear tire and around 3.5 RF camber.
If that doesn't work, maybe just stay at the low cross.
 
I am going with a zero inside prep & minimal trackside prep on left rear. RF camber always been between 3.5-3.75. It's a maxxis series pink/blues only
 
DennisM32 said:
I have an 02 Octane buggy that i ran last year with the cross around 53%. The previous year I had it around 56% but after 5 laps or so the kart would turn into a dump truck. The 53% seemed to work better but was wondering if going into the mid 60's would be of benefit or work against me?
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I wonder if that increase in cross was getting the LR and the RF hotter. If your stagger is not right, getting the tires hotter, (more grip) is going to hurt. If I knew how a dump truck handled, I might be more helpful. lol
 
I ran mine mid 50s on pavement. I have an 04 flat kart, on dirt, the left rear HAS TO BE AT LEAST 8 points harder on durometer or it will push
 
KKania17 said:
I ran mine mid 50s on pavement. I have an 04 flat kart, on dirt, the left rear HAS TO BE AT LEAST 8 points harder on durometer or it will push
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so that tells me that your stagger is so far off you have to slide the LR. A sliding tire bites far less than a rolling tire. And so your tire is sliding, but still has too much bite, so you have to make it harder so it will slide easier. I don't really know, but I would guess it's something to think about.
 
It actually takes forward drive out of the kart from apex out, similar to pulling the left rear hub out. Any kind of stagger is going to cause a tire to be "drug" or "slid", especially down the straights. The hard left rear is a known thing with older ultramaxs, and honestly stagger has nothing to do with it. I was all over the place on our local bullring with my driver from 1" to 1.5", kart kept reacting positively to 1.25" with the correct durometer difference, any softer it would push, add stagger it would be out of control loose on entry. We set a new track record (by .3sec and won by 3/4 of a lap) on a bent and twisted 04 blaze with junk parts on it in our third race out with a driver than only races maybe 5 times a year running against state series contenders. I'd say our setup was pretty on point....contenders
 
KKania17 said:
Any kind of stagger is going to cause a tire to be "drug" or "slid", especially down the straights.
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especially down the straights? Pretty obvious. Maybe I'm not clear on why oval karts use stagger. I thought the whole point was to have both tires rolling around the turns rather than having one being "drug" or "slid".
 
alvin l nunley said:
especially down the straights? Pretty obvious. Maybe I'm not clear on why oval karts use stagger. I thought the whole point was to have both tires rolling around the turns rather than having one being "drug" or "slid".
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Ive explained to you before Al that stagger has to do with more than just "rolling around the turns".
Most will use the same stagger at 95% of the tracks we race on, at an extreme different track we will change stagger some.
 
alvin l nunley said:
so that tells me that your stagger is so far off you have to slide the LR. A sliding tire bites far less than a rolling tire. And so your tire is sliding, but still has too much bite, so you have to make it harder so it will slide easier. I don't really know, but I would guess it's something to think about.
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Yes his left rear would have less grip or as you put it sliding but in this case it has NOTHING to do with his stagger, properly tuned forward drive WINS races plain and simple, that's why Earl is telling you stagger is so important to maintain forward drive vs little drag in the straight, in some of the older chassis if the Left Rear was to soft it created to much left rear drive it would not allow the kart to ever start max Rotation thus PUSH.
 
racing promotor said:
Yes his left rear would have less grip or as you put it sliding but in this case it has NOTHING to do with his stagger, properly tuned forward drive WINS races plain and simple, that's why Earl is telling you stagger is so important to maintain forward drive vs little drag in the straight, in some of the older chassis if the Left Rear was to soft it created to much left rear drive it would not allow the kart to ever start max Rotation thus PUSH.
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no one wants to admit to Alzheimer's, but I am getting older, and after reading this, I think I should make a doctors appointment.
 
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