Track Tac

How to tell when too soft?

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Unocal76

Member
How do you tell when you are too soft of pavement? Runnning clone 365. Kart snaps loose at the apex then sets. I put a rolled set of tires on and a 6.00 on the LR and picked up 4 tenths but the problem is still there. On dirt I would be suspicious that I’m too soft on tires but not so sure in pavement
 
Unocal76 said:
How do you tell when you are too soft of pavement? Runnning clone 365. Kart snaps loose at the apex then sets. I put a rolled set of tires on and a 6.00 on the LR and picked up 4 tenths but the problem is still there. On dirt I would be suspicious that I’m too soft on tires but not so sure in pavement
Click to expand...
What about percentages? Staggers? Track turn radius? Track name?
 
I’m on 47.5 nose, 60 left and about 66-67 cross. 1.5 stagger in the front and 1.25 in the rear which is what we typically run about everywhere. Kart is a 17 Trick Titlist
 
Unocal76 said:
I’m on 47.5 nose, 60 left and about 66-67 cross. 1.5 stagger in the front and 1.25 in the rear which is what we typically run about everywhere. Kart is a 17 Trick Titlist
Click to expand...
There's a lot of weight on that LR, which is not necessarily bad, but you need the staggers to be right!!

Match the rear stagger to the turn radius. Tires loose grip if they get too hot.
unocal76_1 9 22 20.jpg
 
I can only guess that there are, in this country, somewhere, tracks with the configuration you illustrated. I'm pretty sure I haven't seen them all, but I know I haven't seen one like you illustrated. Not that I remember anyway. Maybe you have some pictures of the ones I've missed? For all I know, the OP may be racing on a track like you illustrate.

I was at least trying to help, maybe in vain, maybe misguided, but I was making an honest effort!
 
My point is simply that on many ovals that are not overly long, a kart (or car or motorcycle) never really stops turning. Inside radius of the corners probably doesn't have much to do with anything since most any race vehicle never follows the inside of a corner all the way around.

If a kart is turning most if not all the time around the track, where exactly would you be measuring the radius to determine the stagger that should be run? The thread I quoted above from 10 days ago asked the exact same question.

PM
 
Unocal76 said:
How do you tell when you are too soft of pavement? Runnning clone 365. Kart snaps loose at the apex then sets. I put a rolled set of tires on and a 6.00 on the LR and picked up 4 tenths but the problem is still there. On dirt I would be suspicious that I’m too soft on tires but not so sure in pavement
Click to expand...

I'll try to answer your question...
Too soft of tire builds excessive heat (earlier in a run) and subsequently falls off once the tire is overheated.
With excessive heat, comes excessive wear.
If you are killing tires by feathering them each time you are on the track, then they are too soft.
Now, some internal preps will soften and add grip, while other internals will actually help disipate heat and maintain consistent lap times through a run. What internal prep you use is critical. 9 times out of 10, we'll use a conditioner oil only for pavement racing (to pull fresh oil to the surface of the tire and replenish oils that are heat cycled out of the tires.)
Our Medium Rare internal does a great job at that.
Typically, you do not run a 6.00 on the LR on pavement ovals, however, on big momentum ovals, it does help carry the load (and heat) better. Generally, you will run the smaller size 4.50 or 5.0 on the LR for pavement ovals, and size accordingly.
Now, for the car snapping loose at apex, this may be caused by not enough stagger, too much left rear drive, or incorrect camber settings in the front.
Does the problem exist from the drop of the green, or does it develop as the tires get hot? That might help us tell better if it's a "tires too soft" problem, or something with the set-up.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
First I would get the right wheels on it to start.

6.5" LF
6" LR
10" Right sides

Yellow vegas if allowed.

Also cross seems high to me.
 
CarlsonMotorsports said:
I'll try to answer your question...
Too soft of tire builds excessive heat (earlier in a run) and subsequently falls off once the tire is overheated.
With excessive heat, comes excessive wear.
If you are killing tires by feathering them each time you are on the track, then they are too soft.
Now, some internal preps will soften and add grip, while other internals will actually help disipate heat and maintain consistent lap times through a run. What internal prep you use is critical. 9 times out of 10, we'll use a conditioner oil only for pavement racing (to pull fresh oil to the surface of the tire and replenish oils that are heat cycled out of the tires.)
Our Medium Rare internal does a great job at that.
Typically, you do not run a 6.00 on the LR on pavement ovals, however, on big momentum ovals, it does help carry the load (and heat) better. Generally, you will run the smaller size 4.50 or 5.0 on the LR for pavement ovals, and size accordingly.
Now, for the car snapping loose at apex, this may be caused by not enough stagger, too much left rear drive, or incorrect camber settings in the front.
Does the problem exist from the drop of the green, or does it develop as the tires get hot? That might help us tell better if it's a "tires too soft" problem, or something with the set-up.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Click to expand...
The kart was snapping loose at the apex the entire run. It would break loose, then immediately set and go. The driver was having to lift before the kart broke loose to try to keep it settled.

I rolled 60cc in the outsides of then prep we had left over from when we ran some maxxis a few years ago. We are running cobras (tire rule next year) and I wanted to get a set from 60 down to about 55. The tires did not feather at all. The first set that we tried were straight up and a 4.50 on the LR. The second set was what we ran in the race. This was the rolled set with a 6.00 on the left rear. We picked up nearly 4 tenths when we went to this set. Our camber settings are 3.5 RF and 0 on the LF.
 
Slick27 said:
First I would get the right wheels on it to start.

6.5" LF
6" LR
10" Right sides

Yellow vegas if allowed.

Also cross seems high to me.
Click to expand...
Those rim widths are what we are running. We are using Cobra tires right now because that will be the tire rule here for next year.
 
Pete_Muller said:
My point is simply that on many ovals that are not overly long, a kart (or car or motorcycle) never really stops turning. Inside radius of the corners probably doesn't have much to do with anything since most any race vehicle never follows the inside of a corner all the way around.

If a kart is turning most if not all the time around the track, where exactly would you be measuring the radius to determine the stagger that should be run? The thread I quoted above from 10 days ago asked the exact same question.

PM
Click to expand...
This will get you close.
aaa stagger_1 50.jpg
 
My experiance on asphalt you have to much rear stagger. But the last time I ran asphalt was in 2004 3/4 rear stagger. running a PRC Gauntlet one of my favorite chassis. owned 3 of them
 
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