Tire wear - pirelli p zeros

Discussion in 'Brakes, Wheels and Tires' started by Wotfun, Nov 25, 2018.

  1. Wotfun

    Wotfun TMO Advanced

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    @SavetheManuals, Thank you! That makes me feel better. Thinking back on the YouTube video I included above, the guy is a military flight instructor and seems to know what he’s talking about. BUT, he also said in the video that he “overdrives” the car. So, that’s consistent with your observation that most mustang incidents are, essentially, due to driver error as opposed to electronic nannies intervening. I’m a firm believer that smooth inputs are key.

    Re tires, I used Bridgestone Potenzas on my BMWs and loved them. Also had them in an ‘05 Toyota MR2 and loved them. I’ll definitely add them to my short list of tire options.

    One thing I was hoping for is a tire that can be cross-rotated, vs just front to back, without having to take the tire off the wheel. It just seems like that will enable me to get the most life out of the tires.

    This group has shared a lot of helpful information and suggestions. I need to research all the options and figure out what looks like it’s going to work best for me.

    You all are awesome and I can’t say enough how much I appreciate your support.
     
  2. Wotfun

    Wotfun TMO Advanced

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    @AustinGT350, you mean you increased pressure by 2 psi in the rear to reduce under steer?
     
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  3. AustinGT350

    AustinGT350 TMO Intermediate

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    Yeah, good catch, I left out a word lol.
     
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  4. Eric62

    Eric62 TMO Intermediate

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    The guy on the video knows just enough to be dangerous.... The traction and stability are tuned more to the balance of the car than the ultimate level of grip. This guy constantly refers to "near the stops" while turning. If he IS, he is WAY out of control. It is tracking the car not drifting the car. That alone tells me he doesn't understand. He throws the car around by his own admission and the system is trying to save him. His driving is causing his problems, IMHO.

    His buddy's car is tuned to oversteer so OF COURSE the AdvanceTrac is trying to save his bacon in that car as well. It is trying to prevent him from spinning out. The car has been tuned outside Ford's AdvanceTrac calibrations and the result are predictably poor.

    Just an aside, I used to do early R&D work on these systems which included test driving them for Delphi so I understand what the algorithms are trying to accomplish.

    The car is looking at steering angle, speed and lateral and longitudinal accelerations to determine what is happening and your actual intent. If it sees a large steering angle, but not so much lateral force - understeer so we apply a little front brake to turn it. Consider it has to do that on ice, snow, dirt, gravel, wet pavement, dry pavement and banked pavement. The system has to be designed robust enough to not ditch you on 0.15 mu snow OR 1.0 mu asphalt. Plus it has to hold off braking until things are really getting out of hand or the brake pads wouldn't last a single winter. The addition of higher grip tires is not the problem. The system can handle race slicks. So to answer 1) It won't be optimum but it won't crash you either. 2) it would help but it IS the ABS/TCS/ESP computer and the suppliers don't want you touching them. Ford sells a race-spec version of the ABS/TCS/ESP modulator and computer but I don't know much about it. I think it is race ABS only and no ESP or TCS. There are posts here that discuss it.

    As far as track days go, I've tried everything ON - It wants to burn the brakes right off the car, Sport mode ON - still too hard on the brakes because I tend to throw the car a little bit and AdvanceTrac OFF with ABS on - The best for my driving style.

    I agree with SaveTheManuals, don't worry so much about the nannies. I'd suggest Sport mode for most people. Try to be so smooth it never turns on.
     
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  5. Wotfun

    Wotfun TMO Advanced

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    @Eric62, I appreciate you taking the time to check out the video and share your expertise. It sounds like I put too much stock in a YouTube video. Thanks for alleviating my (unnecessary) worries!
     
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  6. Wotfun

    Wotfun TMO Advanced

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    More tire talk...I grew up having a full size spare and would like to have one for the mustang. A 275/40 18 should fit in the spare tire well in my trunk - understanding it’s going to eliminate my flat trunk floor. But I want to be able to use it at the track if I need it. So, ideally, my tires would be summer performance but not directional. Is there such a thing?

    Do any of you guys/gals keep a full size spare tire that you rotate in? (Meaning, when you rotate tires, you put the spare on.)
     
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  7. Eric62

    Eric62 TMO Intermediate

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    I couldn't get all my track stuff in the trunk if I carried a full size spare! I drive to and from on my track tires. I do carry a tire repair kit, 12v compressor and the mini-spare on the 18 inch wheel - so I know it fits over my brakes!

    Now there is a local guy who carries his autocross tires ON a Porsche Cayman fitted with a roof rack. Carries 2 up and 2 inside. Most bizarre looking sight. Some folks build track-trailers with tire racks and toolboxes based on the trailer kits sold at Northern tools and Harbor Freight.
     
  8. Coz

    Coz TMO Race

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    Your mini spare will fit over the rear brakes on an S197 (regular or with the 13.8" GT500 rotors) but unless you still have the base Mustang sliding calipers up front the spokes of the mini-spare will hit the face of the Brembos. You will need something like a 2" spacer to get them out far enough so they won't rub.
     
  9. Wotfun

    Wotfun TMO Advanced

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    @Eric62 I drive my car to and from the track (on my track tires) too. I also have a similar flat repair kit that I can use to fix a puncture that doesn’t affect the tire sidewall.

    The main reason I’d like to have a full size spare that I can use on track is really insurance. If I get a flat on the way to the track or during a track weekend, I don’t want to lose track time that I paid for.

    I have run on track with a tire that I’ve plugged and didn’t notice any adverse effects. But, if I were to damage a tire sidewall, I would lose track sessions and I’d have to get my car towed home - very expensive. Having a full size spare mitigates both risks.

    The challenge seems to be that most performance tires (with tread suitable for street use) seem to be directional. Directional tires would only work on one side of the car. So, to achieve my insurance goal with directional tires, I’d need two spares. I don’t want that.

    I actually like the idea of a roof rack. Maybe add some LED light bars and have a safari mustang. :D
     
    Last edited: Nov 28, 2018
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  10. xr7

    xr7 Overdosed on TMO

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    I have Falken AZENIS RT615K+ 295/40/18's on 18 x 11 APEX EC7 wheels. These are none directional tires. Put on anywhere you want, I rotate tires and bleed brakes after each event. I autocross with the nannies off. I accidentally left it on at one event this year. Its a fast track requiring 2 and third gear. Main thing it did was shut the fuel off on some severe elevation change thru off camber turns. Now there is a sticky note on the dash, turn off t/c, turn on camera.o_O
     
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  11. Wotfun

    Wotfun TMO Advanced

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    @xr7 That Falken looks like a good option, but they don’t seem to make in the size I want (275/40-18).

    I tried auto cross a few years ago in a BMW 328i. It was fun and I’ve been thinking of getting back into it.

    From what I recall, there was a big variety of cars doing auto cross, but the lighter weight cars seemed to do best. Lots of Miatas, of course.

    Our cars are kind of heavy by comparison. How do you like the mustang for auto cross? Have you done any mods to reduce weight and improve handling?
     
  12. xr7

    xr7 Overdosed on TMO

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    Its true there are several cars that are better for autocrossing but there are plenty of people that are competitive with there Mustangs especially at the faster tracks. I lowered mine a bit, new adjustable sway bars front and rear, watts linkage, rear lower control arms and relocation brackets. Might eventually get a set of coil overs. I haven't run any of the big tracks, maybe in the future, the consumables are my fear. For me I just enjoy the people and the workout throwing the car around, I don't care where I finish or what class my mods may put me. I may accidentally win one, missed a winning time cause I nicked two coneso_O. The other thing I like is passengers. I really don't know they are there but its fun to take them out and do what they are afraid to do. I had a few start autocrossing after riding along. My grandson is next, turns 16 in Feb. Its tyme to get him off the phone and in the car.:)
     
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  13. Wotfun

    Wotfun TMO Advanced

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    @xr7 I was the same with the auto cross. Just having fun and didn’t really care about the class. It is fun to go out and race around a parking lot.

    I guess the biggest reason I haven’t gotten back to it is I got hooked on track driving. My son (now 24) did it with me for a few years and that made it both more fun and more stressful and more expensive.

    It might interest you to know that some of the HPDE track events do allow you to take a passenger out, after you get to the solo level. You and your grandson would get a kick out that.

    Your concerns about consumables is spot on. Entry fees usually aren’t exactly cheap either. But to give some examples, my track brake pads for front and rear were over $500. I don’t know yet how long they’ll last, but they’re way more durable and effective than street pads. Now that I’m driving the mustang a bit faster, I think tires will be the biggest consumable.

    I am conscious of the money but track driving is one the most enjoyable things I’ve ever done. So, for now at least, it’s worth the money to me.
     
  14. SavetheManuals

    SavetheManuals TMO Intermediate

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    I keep a full size tire in the spare tire well as a backup, both for the track and for street driving. OE front wheel when I have the track setup on, and 275/40R18 track tire/wheel when I'm on my street setup. Both fit fine in the spare tire well, but the OE wheels are insanely heavy, don't hurt your back getting it out!
    You never know when you might need a spare wheel on the street or at the track - I had a valve stem seal bust at my last track day and if I didn't have a spare wheel and tire it would have been impossible to drive home. (I also recommend metal valve stems for track use)
    I don't have a 5th wheel/tire to match my track or street set, but since I have different track/street setups I just use 1 from the other set as my spare. Great peace of mind. The OE front wheel fits front or rear, and my track wheels are square.
    So like you mentioned ideally get a 5th wheel/tire that can be used at the track, but you can always use your OE front wheels as a backup for now to avoid towing.
    Also I strongly recommend NOT tracking on a patched/plugged tire, it's just not worth the risk. Another reason for a full size spare.
     
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  15. Wotfun

    Wotfun TMO Advanced

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    Currently, I only have the four oem wheels and an emergency repair kit (plug supplies and portable compressor). But, I decided to bite the bullet and order a set of 5 Apex EC7 wheels. They’ve shipped but haven’t arrived. I still have to get tires but I don’t plan to use them until spring. I’m also planning to get the pressure sensors. (My impression is that most people don’t get tpms for track wheels, but I like being able to continuously monitor air pressure while I’m driving. This phrase comes to mind: a luxury once experienced becomes a necessity.

    I hadn’t thought about the valve stems being a problem, but using metal ones seems like a good idea.
     
  16. domesticpower

    domesticpower Track Addict

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    There's plenty of great advice here. I will agree with some that said the P Zeros are no good. The OEM PZeros that came on my Boss were some of the worst brand name tires I've tried on track. I've driven on various summer tires from Michelin, Conti, Hankook, Bridgestone, Firestone, and BFG's. The only times the Pirelli's were better, they cost A LOT more and didn't last nearly as long. They also turn rock hard at anything below 50 deg F/10 deg C.

    I'm not sure why your tires are wearing unevenly on the inside, though. More wear on one side of the car than the other is normal due to number of left vs right turns on the track like Voodoo Boss said, so that's not an issue, just something you'll have to live with if you don't/can't rotate. But you shouldn't have to replace tires every couple of events. When I had Michelin PSS's, they lasted 1.5 seasons typically with about 2-3k miles on the street and 10+ track days. I had the very same problem you do and couldn't get a second set of wheels, which is why I ran those Michelins, but they lasted a lot longer than your Pirellis. I'm running Indy 500's now and they seem to wear far better than the Michelin's but they lack the PSS's bite, which is saying much because as good as the PSS's are, they are still a street tire. But the Indy 500's are phenomenal value for a street/track tire if you don't care about chasing the last couple of seconds.

    What is your camber in the back? Not enough or too much camber could easily explain uneven tread wear on the edges. I'm not sure what would cause middle treat wear aside from too high a pressure, though. A wheel that's too narrow for the tire will typically result in too much edge/shoulder wear and tire squirm because of not enough tire support. I haven't seen a tire too wide for a wheel wear in the centre, but maybe it's possible. Just keep a close eye on the replacement tires after your next track day and see if they are still wearing in the centre with good pressure.

    Keep in mind that gaining more pressure in the front vs the back doesn't necessarily mean understeer. Mustangs are heavy and have plenty of front weight bias. The front tires have to do a lot of work and should gain more pressure than the rears whether they're understeering or gripping. If you are plowing everywhere, it will be excessive, of course, but I wouldn't judge the balance of the car based on pressure gain alone.

    Congrats on the new wheels! What size?
     
  17. Wotfun

    Wotfun TMO Advanced

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    @domesticpower thanks for weighing in.

    Re camber...It’s factory spec. Although I haven’t had it checked. Didn’t think there was a need. Now I’m not so sure. Maybe I do need to have it checked.

    Wheels are Apex EC7 18 x 10 et43. My goals are: 1) square setup so I can rotate wheels/tires; 2) less unsprung weight; 3) full size spare with wheel and tire that match those on the car; 4) ability to add negative camber for the track and remove it for street driving. (I know a lot of folks here run 305 square, but my understanding is they require negative camber all the time and, of course the tires will cost more.)
     
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  18. Bill Pemberton

    Bill Pemberton TMO Addict

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    Everyone has said it, the Pirellis just don't work well , but a competition alignment, M&M Camber Plates , and new rims, things will drastically changed. The tires are undersized at 275, imho, so with 18x10 Apexes, go with at least 295s!!! Don't worry about running negative camber , as your tires will wear better on track than they do now, and the change on the street is frankly minimal. Price is not much more for many wider tires, and you will be faster!!!
     
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  19. Wotfun

    Wotfun TMO Advanced

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    @Bill Pemberton Thanks for weighing in. I bought the second set of Pirellis mostly because of price. Also, I’ve heard the tires that come on new cars tend not to last very long. Thought maybe the second set would be better. Turned out not to be the case. Regardless, I don’t plan to get any more Pirellis.

    Camber plates and probably some other mods will happen over time. Cash flow doesn’t allow me to do everything and still afford to actually go to the track. Plus, making changes one at a time will allow to see (& feel) effects of each mod. (I’ve talked to people who made a lot of changes all at about the same time. When I asked about the effects of individual changes, they couldn’t tell me.)

    I expect wider tires will be in my future too. But, for now I’m just excited to be moving towards a square setup.
     
  20. Wotfun

    Wotfun TMO Advanced

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    Some advice here was to add negative camber in the front and rear. Does the s550 have rear camber adjustment in stock form? If so can someone point to a diy?
     

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