originalmotorhead

Seems like I have a bit of excessive inside wear on the fronts of my 944. thinking either I have a bit too much camber or toe in. Hoping to check it later this week. Rears are wearing very evenly but fronts tend to be abusive to the inside 3 inches worth of the tires.

Originally I set it up with 3 degrees camber and 1//8" total toe in. might back it down to 1/16" or zero toe.

Ideas?
Tom

atr911

Camber will wear tires gradually from one edge to the other. Toe typically wears the shoulder excessively.

todinlaw

it could be both. its normal to have more inside wear depending on the track but the camber only evens out the tire when turning. doing your tire temps the middle and inside are always hotter due to the camber. toe should wear even across what ever surface is on the pavement. so it could be a combo of camber and toe. Having said that I like zero toe, its a bit more edgie and less rolling resistance.

RedlineMan

Hey;

Of course there are lots of other things involved - like spring rates, bushing material, etc. - but your toe-in is fine, and not causing your wear. Toe-in is very kind to tires, even well past where you are. Just a little toe-out is not. Besides, NA's don't have the power to waste scrubbing along with toe-out. You have too much negative camber. If you are racing other than SPEC, then tire wear is usually a moot point because you change tires (Hoosiers) long before they wear out. If you are looking for better tire wear on your RA1s (or similar), then -3 is too much.

I run pretty hard and get quite even RA1 wear at -2.7LF/-2.5RF/-2.5Rear, 0 toe front & rear, all spherical, 500F/450RR. You also have to consider drag wear, where the inside of the inside tire in a corner is being dragged sideways significantly. Note my differential front settings. If you run equal left and right turns, you'll get even drag wear. Most tracks are predominantly rights, so....

I'd flip the tires and back off the camber to -2.6> and see how it went. I'm betting it would be just what you are looking for.

car_slave

If John is right then your car will take a major leap forward in performance. What are your spring rates and sway bars?

Matt Romanowski

What John said. Plus, toe wear will usually produce some chop on the tires. Camber wear will be flat.

M758

Toe....

I run zero toe in front and 3.5 degrees of camber. I don't see excessive inside wear and in fact see hotter temps on the outside edge. The only exception is you can get inside shoulder wear on inside tire of turn. For example a long left hand turn can put wear on the inside shoulder of left front tire. This is due to the natrual scrubbing when turning. Ideally you would run less camber, but that might not be possible given the other corners on the track.

If I run less than 3.5 degrees on RA-1 I get understeer where I don't want it. More camber brings the balance back. It might cause more tire wear than less camber, but the car is faster (at least mine is) with more camber.

I have never found excessive tire wear from these camber settings so I keep using them. I have seen excessive tire wear from a driver on R888 with -4 deg of camber. That was too much, but then again the R888 required less camber to work.

The best thing to do is to move the fronts to the rear every track day. This way you don't put too much wear into one tire. Every track you go to will tend to wear down certain tires more than others. It is just the nature of each track. Sometimes it is the right front, sometimes the left rear. Often times you cannot get perfectly even tire wear and still get good lap times. So the best plan for a budget racer is to rotate the tires to limit the abuse for each tire. In this way they will tend to all be worn down to the same level at the end of their life and you can run alignment settings that get you the balance you need on track even if the resulting wear is not perfect.

mdrums

Toe will wear the tire more than camber...inside or outside of tire...depends on the amount of camber as to wear the tire will wear.

originalmotorhead

I'm still running all the stock rubber suspension busings (i know i know, new bushings are this winter's project. only so much cash to spend) and I have 425lb springs up front and 30mm tbars rear. The sways are the dinky ones, not the m030's.

The wear pattern on the front is a fethering like, which might mean too much toe. I'm wondering if the rubber bushings are causing flex and changing the toe to point that under breaking the tires are peeling a bit.

When running some used 888's, wear pattern looked smooth, just noticably more so on the inside area of the fronts. I have a new set of non shaved ra1's and those are the ones that started to feather a tad on the insides.

Thinking for the next track event I'll just set the toe a tad closerto zero or right at zero and give it a try.

Tom

Sterling Doc

Tom, with 425lb front spring, 30mm rear torisons, and stock antiswaybars, your car would tend to push in corners, leading to more front wear in general. This would not cause more wear on the inside itself, but may be speeding up wear in general on the front tires.

North Coast Cab

Sure you are running Toe In up front?

originalmotorhead

Will double check the toe setting this weekend while prepping it for Autobahn. Will also snap a photo or two of the tire and post here too.

Tom

diveganesh

this was posted in another forum, somewhat related to the topic here.

i clearly don't have the technical background/understanding to gauge whether this is truly a breakthrough as the inventor believes, but i wonder why this is something that hasn't been done (successfully) before.

http://www.jaylenosgarage.com/video/...-tires/1236995

RedlineMan

Honestly;

Only toe-out will shred the inside shoulder quickly, and it takes very little of it to do so. Negative camber will also do it, but less rapidly, and you can beat it by swapping corners and flipping tires. Bottom line is that everyone has their own sweet spot, and it takes a couple sets of tires and a lot of adjusting to find it. Keep tweaking.

atr911

In combination with neg camber, any toe (in or out) will shred the inside.

Under straight line, with lots of neg, a disproportionate amount of weight is applied to the inner shoulder. When you toe in or out, you are now scrubbing the inner shoulder.

The same would apply to an outside shoulder under positive camber but I cannot see ANY situation that would take advantage of positive camber.