Tire Tech

[sps3172]

Now that we've had some time to put some laps in, I thought I'd post some tire info to get new visitors up to speed (should they need advice)....

For the foam tire classes (Sprint, EDM, etc...)

BSR or Custom Works Silvers (I'm running them all the way around) seem a 'safe' choice. I've had some sucess with Pinks and "30's" but I don't understand the why's and when's well enough yet to suggest them as a starting point. I haven't had a chance to spend much time with the RC4Less Silver (only 3 runs), but they seem promising as well.

For tire treatment, simply cleaning the tire with Gojo hand cleaner seems to provide good results. Recently, I've also had luck with the Truespeed (Custom Works) as both a cleaner/treatment. I apply this stuff directly to a dirty tire after a run, and wipe off before the following run.

It seems like a brand new tire needs to 'break in'...the grooves seem to open up after a few runs and the tire seems faster. Also, tire life seems best if you do NOT rotate the tires from left to right. Mark them as LF RF LR RR and try to keep them in the same spot on the car. When I tried rotating the tires, the grooves started wearing on the other edge (makes sense), but at a much fast rate than they were prior to being rotated.


For the rubber tire classes (MDM, Truck)

These tires seem ultra forgiving. Most 'slicked out' offroad tires seem to provide almost too much traction (wheelies and traction rolls....woo hoo!!). Best results seem to come from leaving the tire dirty from the preceeding run. Some guys will use a little 'Buggy Grip' on the tire at the start of the day. The super firm inserts (Trinity Ultra Firm, I think) prooved to be a bust. Stick with something on the firmer side, but still in the offroad spectrum for foam inserts.

[smac]

The Trinity ultra firm foams, so far, have only had success at cutting down on traction. I made up a set wit JC Double Dee's and Rounder's. For any of you that have tried I am sure that you know that they are difficult to work with. You have to carefully mount them on the wheels first without tearing them since they are so difficult to fit over the wheel. Then I found that mounting the tire directly on them made them WAY too tall so I chucked them up in a drill press and turned them down in height. I had to turn the fronts down even shorter so that the tires did not look like wagon wheels.

After a long battle, I finally got them to where they looked right and felt right. Unfortunately it took only a very short time for me to find out that all they do is slide across the dirt!

The stock inserts, on the other hand, work almost too well. The rear traction is so good that you find yourself pulling wheelies and traction rolling if you are not carefull!

I am gonna get a hold of some other inserts that fall somewhere in the middle and give them a try. There are a couple of other companies that make Ultra Firm inserts that are not nearly as firm as the Trinity ones.

[paco62]

Luckily I just finished gluing my Ultra Firm inserts into my new tires...literally minutes before I read this.

Ooops. :eek:

[smac]

I took a set of the Custom Works kit rubber tires (Street Spec) in the soft compound and made them into slicks the other day. I tried the on my EDM and found them to push quite a bit.
Matt Morton brought his Sprint car over on Sunday with his Maryville set up on his car, but no intention on running it because he did not have any foam tires. I asked him to throw the slicks that I made up on it and give it a try. After a few laps he had it running laps in the 4.9's and was faster than any car on the track to that point. The fastest laps turned on the track that day in sprint were a couple of 4.8's and several 4.9's by Eugene and a some 4.9's by Ron Roy.

Looks pretty promising to me!!

[smac]

Found this post by Arnie Fie of Custom Works that may be helpfull to SmacTrac racers...

CW silvers are much gummy-er than the RC4Less ones. The density is roughly the same. Our silvers work best when the track is wet and not abrasive in any way. Sometimes with the sprint cars they can be too gummy.

Grooving the tires helps remove the small dust and dirt on the track. Not grooving the tire will give you a more out of the track feeling...not too good. People can get carried away with all the different patterns. A good starting point is use a small flat screw driver to make 5 grooves across the diameter of the tire. Use a small cut-off wheel on the Dremel to make the cross-grooves. Put a groove at every lug on the wheel, then one between each groove. This is a pretty good and standard starting point and brings you within 95% of anyones "trick" grooving job.

[sps3172]

This is a pretty good and standard starting point and brings you within 95% of anyones "trick" grooving job.

Kelm, I'd love to hear your comments on the topic.

[MK Race]

Sounds groovy to me.:D

[sps3172]

Sounds groovy to me.:D


Care to elaborate? :)

[sps3172]

Sounds groovy to me.:D

Care to elaborate? :)

Ok, I'll be more specific. Do you think that the 45 degree traction bar cuts towards the outside of the tire make a difference and if so, what? Do they need to face a certain way?

So far, I made tires that had traction bars extending all the way across the tires and some where the cuts stopped inside the outer-most radial groves. It didn't seem to make a difference so I just went with what looked 'cooler' :).

[MK Race]

I really don't know if there is a difference between the straight cut and the angle sides because I have allows done mine with the angle cuts. IA old time go kart racer who ran on dirt showed me how to groove them. The direction of the angle does matter. Ron has a pair of rears that I grooved for him, ask him if there is a difference. I would like to know.

[sps3172]

I really don't know if there is a difference between the straight cut and the angle sides because I have allows done mine with the angle cuts. IA old time go kart racer who ran on dirt showed me how to groove them. The direction of the angle does matter. Ron has a pair of rears that I grooved for him, ask him if there is a difference. I would like to know.

I think you did some BSR silvers....he's been running RC4Less silvers.

The compound change might cover up any grooving differences there.

[sps3172]

When I took my EDM car off the track last Sunday, it was running easy 4.2X laps....ocassional 4.1X laps. I changed nothing on the car aside from truing the tires down and cutting new grooves.

I put in on the track the following Wednesday and it would barely run 4.5's. It took 2 batteries in practice and 2 full qualifiers to get the tires to 'come back'. The car eneded Wednesday night just like it ran the previous Sunday....

I knew there was some 'break in' involved but I had no idea how long it took or how much of a difference it made. It might be worth keeping this in mind the next time you're chasing a setup.....

- SS