fatbillybob

Well I know nothing about driving, less about tuning and I'm trying like hell to keep up with others. I'm a good wrench and that's what got me into racing because things break and I like to fix them. I'm always the slowest guy in the race group. I though I was not driving hard enough and the marbles would not scrub off. I never though I was perhaps overheating or over drivng the tires making them mushy, slick , gressy and me slow. The very few times I have used a pyrometer I've been in the 140 F range but only in the cold pits. I have all this safety junk on and it takes forever to get myself out of the car. I hear about 200 degree F range is proper hot temps which I have never taken since I always go by myself and that really needs to get done in the hotpits. I will need to pay better attention to basics. The camber I run is what racers who raced my type car used back in the day. I just coppied them out of ignorance. It appears that there is too much camber and I'll drop a degree out and see what happens.

Thanks for all the good advice.

FBB the backmarker

RedlineMan

Hey all;

I'm a little dissappointed that no one commented on my theories regarding where those snards come from. Did everyone just think I'm nuts, or agree?

FBB;

The cheap way to optimize this sort of thing is with a friend and a pyrometer. The expensive way is like you are doing it; burning up tires. You are not necessarily over-driving the car, but that setup is clearly not right for your driving. You need to have a really hooked up car and drive REALLY quickly to make good use of -3.0 in a door slammer. Sure, lots of guys do it, but the majority don't need it. I'd drop to -2.5.

Would that have been the R/F tire? Then we see the spectre of Drag Wear come into view. Differential camber time!

sweanders

Looking at the tire you can almost tell that the snot is coming from the corded area since they seem to have been pressed from there. Why do you wonder?

RedlineMan

Anders;

Traditionally, it seems that most prople look at this as strictly pickup, and I thought that was the assumption at the beginning of this thread. No one said otherwise, so I figured everyone was on that boat together. When I said something contrary, it sparked no reaction. I just wondered what everyone thought. Looking for confirmation!

SundayDriver

I would be surprised if that could come from your own tire. Seems to me (and this is pure conjecture) that little peices come off your tire. Then someone rund over them and adds a little bit of their tire, etc, etc. You would have to peel off a huge amount of rubber from your own tire AND have it always stick to your own tire. When I am driving in the wings 'n things group, I get peppered with an awful lot of flying rubber if I am behind anyone.

I could surely be wrong, but that is just how it seems to me.

BTW - I am dissappointed that FBB never told us exactly what tire he was running. If this is a bias ply, then his alignment is way off.

fatbillybob

Not sure what this means but the tire was a rear tire on a tail heavy old 348 ferrari which is basically a detuned 355 missing about 100hp.

fatbillybob

I know nothing about tires except they are round and I have a machine to change them. I have been running Goodyear scrubs full slicks the softer compound just for the sake of availabilty. Since I have a changer it is nothing for me to whip a set off and put another set on. I though camber setting was something that was more car dependant that tire dependant and that even tire pressures were related to car weight and loads the car could put on the tire and definitively when you have even tire temps. So since I am completely clueless on such things...I welcome your comments and a tire lesson. I always thought that my abilities or lack there of were 90% driver related. If clues to a proper set-up come my way maybe I could get that to 80/20.

Thanks.

ltc

The title of your thread had me a bit confused, as Tire Snot is a product used by many karters to lubricate the bead during mounting:
http://www.cometkartsales.com/store/...s/tiresnot.jpg

Your pic looks very similar to what I see on my son's kart after he comes in from his cool down lap. He tends to pick up everyone else's rubber (which is of a different compound) if he goes a bit offline during the cool down lap. He can normally 'clean' his tires after about 2 flying laps.

kurt M

Then why is the pickup all laid out in rows in the tire center? I would get the same pattern when I had a tire running too low a pressure. The tire would run on the shoulders and the center would catch the resulting strings that were rolling off. My car makes long thin strings like a kid with playdoh when I am on Hoos. They collect all over the oil cooler lines in underside of the wheel wells. I was looking at other cars and the marbles that come off them look different and more ball like. When drive through marbles on the track I get a different looking set stuck all over.

SundayDriver

Camber is mostly a function of the tire and that is why I ask about whether the tires are bias ply. Radials roll with load and tend to change the footprint quite a bit. 3-4 degrees of negative camber for a radial race tire is typical as the tire will roll and give a full footprint under load. Now a bias ply tire will not do that, and typically wants 0 - 1/2 degree negative camber. If you start with -3, it will never give a good footprint under cornering.

Beyond that, even different radials will need different camber settings on the same car to be optimum.

It is them somewhat car dependent, as the body rolls and the suspension causes camber changes as it travels but that tends to be a small issue relative to the tire issues.

Where I am going is that if you have bias tires, and do not plan to regularly run those, then your camber is way off but there is no reason to chase that problem. You need to pick a tire and try to stick with it, or something close, in order to set the car up. Ain't easy, is it? Also, it is really important, if you are going to chase setup, to find a pyro and someone to take temps when you come in. Do NOT do a cool off lap and have a friend measure tire temps. I would think there is some racer at an event that would be happy to do that for you a time or two. If you can't do that, then do it yourself in the hot pit. Jump out of the car and measure. Three readings per tire (outer, center, inner) and you will learn a lot.

If you can find some numbers on the tire and post them, we can prolly find what tires you are using.

Now pressure is also very much a product of the tire and partially the car. Tires are mechanical structures and the air pressure mainly supports the sidewall. As an extreme example, I have run A032's on a sports racer and they need ~30 psi cold. Goodyear slicks want 9-10 psi on the same car.

I am also concerned about your comment as to soft compound. You may be running a tire that is way too soft for the wieght of your car and it will have no longevity at all.

SundayDriver

I have never seen evidence of those tire snakes being my own. If I come in hot, staying on line and looking at the tire in the hot pits, there are no snakes. This is mostly stuff you pick up off line, and in the paddock.

As far as being in the center, it may well be that the tires were underinflated, but he also said he scraped some off so we are not seeing the tires as they came off track.

I think you guys are putting too much emphasis on the existence of these worms. Remember he is running soft compound slicks, not DOT R tires. These pick up EVERYTHING, even small children.

Professor Helmüt Tester

All readers should print this out, and re-read it daily. Post it on your wall. Burn incense in front of it. If you think that air pressure holds the car up, read it 3x daily.


Tire worms are a fact of life. The softer the tire, the more worms/boogers/snot you'll collect...but you're collecting other people's worms, not your own. I get tire marks all over my helmet, due to the whole "open cockpit/flying rubber" thing. Sometimes, it's like dodging surface-to-air missiles.

Dave E

I definitely think you can pick up (some of) your own snot by having the tire just a little too hot, during a longish sweeper, the rubber will roll off and "migrate" across the surface, adhering when, on the next revolution, the loosely stuck snot (the pieces that don't get flung off) is pressed back onto the rubber in a spot that is just a little lower in temp than where it came from. I see this on my R compounds anyway.

kurt M

Let me put it this way. If I change my tire pressures the pattern of the marbles I "pick up" change too. I can feel it in the wheel when I have driven through track trash and loadded up the tires. track trash looks all diferent, color, hardness, shape, and amount of dust and dirt in it. Your own snakes have a consistent look, placement and hardness to them. (Yes I am still talking about tires but my answer might be $hit )

But we digress...

Rich Sandor

On a similar note: What do you guys use to clean the marbles off your paintwork? (for those of you that bother to do so...)

I have a ****load of little black boogers on the side of my freshly painted 951 and the only thing that brings them off is a little WD40 (immediately followed by Dawn Soap and a rinse!) But I hate using WD40 on the paint.

Is there anything else that removes the boogers without harming the paint?