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Definitely need to get it in the air to check properly.
Slick tires will push urethane bushings to their limits. And sometimes new parts can cause more headaches than the parts they were meant to replace. I have seen it too many times not with aftermarket chassis parts. Urethane lower compression arm bushings are a touchy one, and as low as you are I can guarantee you they arent happy at static, let alone dynamic loads.
Ive run split friction before in a pinch, its drivable but frustrating because one axle will give sooner than the other and you will notice for sure. Especially if one axle is running new green slicks and the other has slicks out of their prime zone.
The inner tread of all these tires is facing down, outer tread facing up...the two on the bottom are NT01s with about 35 heat cycles. The rest are RRs decent but out of their prime. As you can see the outer treads were taking a beating, too much PBIR on these tires, and also as the tires get older they tend to slide around more which just beats them even further. I needed more camber. There is some wear on the inner shoulders that the pic doesnt illustrate very well, but not enough to prevent these tires from lasting their course.
The inner tread of all these tires is facing down, outer tread facing up...the two on the bottom are NT01s with about 35 heat cycles. The rest are RRs decent but out of their prime. As you can see the outer treads were taking a beating, too much PBIR on these tires, and also as the tires get older they tend to slide around more which just beats them even further. I needed more camber. There is some wear on the inner shoulders that the pic doesnt illustrate very well, but not enough to prevent these tires from lasting their course.
Not sure if this helps.
Thanks for the pic... I wound up saying I will just take pics of mine off the car this weekend. Curious to hear your thoughts when I post them. My wear is very much on the inside, very! and you even see signs of feathering on the inners too, so much that when you rub your hand on it small rubber falls off everywhere.
Your's don't look bad, I think I still see the small wear indicator circles on the inside? Also, are those cuts across the tire on some? The bottom Nt01s, are those shaved or just worn to hell? LOL I see no tread left the Nt01s have.
The wear I have seen is definitely very good overall...Interested to see how yours look.
I will take the pics this weekend. Its funny, I noticed on one of my tires a small slice, i didn't know what it is... I thought it was from me strapping my car in my trailer or something. It is smaller than yours, almost from the start of the tread surface to one wear line on the tire... You still drive with yours like that? I see they talk about the leading edge and trailing edge, but not sure what to make of that exactly...
Took some pics of my tires.... I labeled the 2 fronts.... As you can see, the ones with the cord showing slightly is the driver front side. Besides the cords showing, you can see how much drop off of rubber is on the inside of that tire, even noticeable in the last picture from far showing it. The last picture has 1 rear unlabeled, I didn't take the other off since the 2 rears are fine. However, most of this much have happened on my last track day at Homestead... Because I been rotating them in the X pattern, and the 2 fronts were wearing on the inside more than anywhere else, but this time the driver front took the cake. I checked everything again! all bushings are fine! same with tie rods again! Wheel bearing and ball joints... Only thing I can think of is that side having just a little more negative camber and for some reason sitting a little lower than the other side which I should fix.
Doesnt look so bad, and the pass side looks pretty normal, drivers does seem excessively worn based on the amount of outer tread wear. But your drivers side does have significantly more camber (3.3Left, 2.9Right) based on the alignment sheet from Apex, so maybe you need to dial it back based on your setup (eg spring rates), track and driving. The only way to know for sure is to get a tire pyrometer and take your tire temps and see what is happening.
This wear can also be caused or exacerbated by driving style and braking. One slide or session where you push it a little too hard and give it a little too much slip or get a little liberal with the trail braking...
My guess is your suspension components are fine, raise it up some in the front (1" is too much rake imo), get it scaled by Apex and re-aligned. Even out the front camber.
Doesnt look so bad, and the pass side looks pretty normal, drivers does seem excessively worn based on the amount of outer tread wear. But your drivers side does have significantly more camber (3.3Left, 2.9Right) based on the alignment sheet from Apex, so maybe you need to dial it back based on your setup (eg spring rates), track and driving. The only way to know for sure is to get a tire pyrometer and take your tire temps and see what is happening.
This wear can also be caused or exacerbated by driving style and braking. One slide or session where you push it a little too hard and give it a little too much slip or get a little liberal with the trail braking...
My guess is your suspension components are fine, raise it up some in the front (1" is too much rake imo), get it scaled by Apex and re-aligned. Even out the front camber.
I appreciate the reply... I will raise the front up and make sure its even. When you measure rake are you doing it from ground to fender? or somewhere on the chassis? I have not found a consistent spot to measure from. Should I have any rake at all on this car? I will then have it re aligned. I am just bummed now I need to buy 4 new tires
I am running roughly 1/2in or so, but I wouldnt worry about it too much. Getting overall ride height correct is much more important. Have you noticed that even at 26" ground to fender how angled the spring bucket is relative to the ground? The front same thing. No good, that means sub-optimal roll center, camber and toe curves. The net result is bad bump steer and an increase in body roll.
How many heat cycles on the tires? I would probably just replace that one tire with a scrubber to be honest, not recommending thats just me. If you keep your old ones around as spare just in case you flatspot or cord another tire.
The two nt01s on the bottom in the picture prior were the rear set I saved when this happened...my alignment didnt change from the NT01s to the RRs, but see how the torn up tires inner tread looks so much like your left front? Obviously the flat spot was my fault, but it happens much more easily on old tires, and the nt01s always seemed to heat cycle out before I wore them out, which lessens the sting of flat spotting a set. Usually time for new tires at that point anyway.
I am running roughly 1/2in or so, but I wouldnt worry about it too much. Getting overall ride height correct is much more important. Have you noticed that even at 26" ground to fender how angled the spring bucket is relative to the ground? The front same thing. No good, that means sub-optimal roll center, camber and toe curves. The net result is bad bump steer and an increase in body roll.
How many heat cycles on the tires? I would probably just replace that one tire with a scrubber to be honest, not recommending thats just me. If you keep your old ones around as spare just in case you flatspot or cord another tire.
The two nt01s on the bottom in the picture prior were the rear set I saved when this happened...my alignment didnt change from the NT01s to the RRs, but see how the torn up tires inner tread looks so much like your left front? Obviously the flat spot was my fault, but it happens much more easily on old tires, and the nt01s always seemed to heat cycle out before I wore them out, which lessens the sting of flat spotting a set. Usually time for new tires at that point anyway.
I haven't noticed the rear spring bucket angle much, Ideal should be flat? you measure from the fenders to get the 1/2" rake measurement?
I have 4 DE events on these tires, with an average of 4 or 5 sessions per day I'd say maybe 16 to 20 heat cycles max. I was contemplating doing something stupid, and that was having that 1 tire showing the cords flipped so its on the outside and put it on the rear on a side that gets the least amount of load. In my case of my next track event at Road Atlanta, I would put it on my passenger side rear. But this may just be stupid of me, I don't know if I will do it yet...
Wow, you got your moneys worth out of those NT01s!!!! Did that section of rubber come off due to the flat spot that took place?
I use the fender to ground clearance, which is also how the FSM specifies ride height. Stock rake is about 1" but measured with 225/245 size tires.
That corded section on the NT01 was due to the flatspot. I think I would shave the NT01 if I were to run them again.
You could maybe get a session or two out of them, but I wouldnt use that corded tire even though it is tempting. It would be a better option to find a used tire IMO. They are already out of their prime so you should be fine.
I use the fender to ground clearance, which is also how the FSM specifies ride height. Stock rake is about 1" but measured with 225/245 size tires.
That corded section on the NT01 was due to the flatspot. I think I would shave the NT01 if I were to run them again.
You could maybe get a session or two out of them, but I wouldnt use that corded tire even though it is tempting. It would be a better option to find a used tire IMO. They are already out of their prime so you should be fine.
You ever run a real slick? such a a Pirelli race slick? I know someone selling a slightly used set in a good size I may try out.
Pirellis are great, you will love them. I have to run DOT, so Hoosiers are the stickiest option available. Otherwise I would be running Pirelli or similar that I could get my hands on. Switching compounds has almost always necessitated a setup change to the car and a re-calibration of my inputs. So it can be costly in that sense.
Pirellis are great, you will love them. I have to run DOT, so Hoosiers are the stickiest option available. Otherwise I would be running Pirelli or similar that I could get my hands on. Switching compounds has almost always necessitated a setup change to the car and a re-calibration of my inputs. So it can be costly in that sense.
I am sure it will definitely be a change I will feel and will have to adjust accordingly. I may give this used set a try before I would ever dump a lot of money on a set brand new... Too bad this thread and forum is not active anymore, we need more track guys with the Z.
I agree, need more track Zs. One more just started to run w/Nasa down here, so there is still hope yet. Plus with all the companies running regular track days down here in FL its hard to get the Zs at the same event.
I think Nasa ST is the most attractive class because it is P/W based and doesnt force you to buy spec parts/is wide open for bushing and drivetrain choices. But you have to be dialed in because the ST4 field is STACKED. There are a handful of American Iron/SI Mustangs that would happily jump ship to be competitive in ST4. Not to mention an S2k that has crushed every single lap record in the SE. SCCA doesnt do much in Florida so its either Nasa or FARA for w2w.
I agree, need more track Zs. One more just started to run w/Nasa down here, so there is still hope yet. Plus with all the companies running regular track days down here in FL its hard to get the Zs at the same event.
I think Nasa ST is the most attractive class because it is P/W based and doesnt force you to buy spec parts/is wide open for bushing and drivetrain choices. But you have to be dialed in because the ST4 field is STACKED. There are a handful of American Iron/SI Mustangs that would happily jump ship to be competitive in ST4. Not to mention an S2k that has crushed every single lap record in the SE. SCCA doesnt do much in Florida so its either Nasa or FARA for w2w.
I've noticed that, seems NASA is the best hope, but I agree with you on the class... FYI I bought these Pirelli slicks, however they seem too old and feel hard, I don't think I am going to use them I gave the guy 100 bucks after seeing them, but even when I brought them home and looked and felt them closer seems like a bad idea. Shame too! they are almost brand new as far as wear.
Are they DH or DM? Can you find a manufacture date on them somewhere? Once you get a heat cycle in them youll be surprised how they soften and feel softer. Did he say how much they were run?
Are they DH or DM? Can you find a manufacture date on them somewhere? Once you get a heat cycle in them youll be surprised how they soften and feel softer. Did he say how much they were run?
They are DH. And I actually called the Pirelli race tire distributor in the US, seems there is only one, the guy was actually not sure if these tires have a date stamp like a DOT tire. Not sure how he doesn't know. I see only this one series of numbers, not sure what to make of it. He said he got them from a "friend" who used them once and didn't like them. Not sure the real story however. When looking at the wear indicator holes they really seems like they were barely used. Its just they feel so damn hard! Even my Toyos still feel softer to the touch. I would throw them on a set of wheels if I had an extra set, but when I went to a square setup I wound up selling my others and only go to the track with one set of wheels now...
Hard to say for sure if they are like hoosiers they dont have the date, but do have a code you can call them and they will tell you the mfg date. That he couldnt tell you is interesting. But you usually do see them heat cycle out before they wear out.
10-16-2018, 04:37 PM
