|
|
05-22-2011, 04:00 PM | #1 |
Major
101
Rep 1,086
Posts |
Tire Chunking PS2
Hi Guys,
I have attached some pics of my RF tire (PS2) that I ran on stock 18s at the track. I have 3 days on these and I've experienced major chunking of the tire on the outside edge yet the rest of the tire has a lot of tread left. The rear tires are still good as is the LF. These events were all at AAA Speedway which is harder on the right tires given some longer sweeper lefts and of course the oval. If you look closely you can see some steel in a couple of the shots. I have a lot to learn as I only have 6 events under my belt. Obviously coming into corners too hot, understeer, etc. are things that I need to work on. My question is simply: In your opinion, is this tire still safe to use at an HDPE? Thanks for your feedback! |
05-22-2011, 04:54 PM | #3 |
Brigadier General
97
Rep 3,246
Posts |
agreed, unless its raining. That tire is toast.
__________________
mods: track ready stuff
|
Appreciate
0
|
05-22-2011, 05:14 PM | #4 |
Major
433
Rep 1,286
Posts |
No, that tire is no good anymore.
However, this will happen to you again if you don't follow a couple of precautions regardless of brand of tire. First, give the tires time to warm up before you start pushing it. When the rubber is not uniformly heated i.e. the surface is hot and the lower carcass is still cold you are going to experience chunking. Let the tires heat up for a couple of laps before you start pushing. Your second comment about corner entry speed is probably true. If the car feels like it's understeering then you are grinding off the outer edge (assuming your run the stock suspension alignment). Try to slow your corner entry, which allows you to properly position the car so that you can exit faster which will be quicker around the track and less of this type of wear on your tires. |
Appreciate
0
|
05-22-2011, 06:24 PM | #5 |
Major
101
Rep 1,086
Posts |
|
Appreciate
0
|
05-22-2011, 06:26 PM | #6 |
Major
101
Rep 1,086
Posts |
|
Appreciate
0
|
05-22-2011, 06:33 PM | #7 | |
Major
101
Rep 1,086
Posts |
Quote:
I need to work on a number of things, but of particular notice is corner entry speed and exit as you've stated. The car has stock suspension and alignment. |
|
Appreciate
0
|
05-22-2011, 06:34 PM | #8 |
Major
101
Rep 1,086
Posts |
OK, so given:
1. I need a new RF tire, period. 2. The LF tire is going bald in the same location as the chunking occured on the RF 3. My rear tires are still good to go Do I purchase 2 new front tires of a different brand (I'm thinking Advan AD08) or get another PS2 for the RF and wait for the LF and both rears to go and replace all 4 (again thinking about the AD08)? I've also read many good things about the NT05, but I think I'd have to stretch one pair to get them on the stock 18s. |
Appreciate
0
|
05-22-2011, 07:26 PM | #9 |
Moderator
673
Rep 4,737
Posts |
Generally, I would not recommend mixing tires because you would want your traction at all four corners to be similar and consistent. I would recommend replacing all four tires.
However, regardless of what tires you get in the future, you need to address the problem that your front tires are obviously not being loaded properly. If you don't correct this, you will find the same thing happen to your new tires. What tire pressure are you using on the track? What about alignment? If you have stock suspension, you should consider pulling the pins on the top mounts to get you some more camber. |
Appreciate
0
|
05-22-2011, 07:59 PM | #10 | |
Major
101
Rep 1,086
Posts |
Quote:
Will "pulling the pins on the top mounts" create any issues for my DD set of wheels & tires, warranty when I go in for service, etc.? Also, can you direct me to a DIY thread on how this is done, or whether a shop needs to perform the work? |
|
Appreciate
0
|
05-22-2011, 09:09 PM | #11 |
Captain
69
Rep 957
Posts |
Pressure seems ok - I've ran higher and lower without such severe issues. You probably do not want much lower, as your tires a rolling an a sidewall already.
The problem is mostly because of severe understeer and scrubbing, caused by either too high entry speed, too much steering input or too abrupt steering input (or a combination of all three). Try going in slower, emphasizing exit position and ability to come on throttle early - that'll save your front tires and help you be faster and have more fun (going through a corner with understeer, not much you can do, and you are just a passenger hanging on through a corner, while with oversteer you can make the car dance with throttle and steering inputs along the way). As for new tires - AD08 are a good choice, and there are a few other similar options (Potenza RE11 or NT05) |
Appreciate
0
|
05-22-2011, 09:36 PM | #12 | |
Moderator
673
Rep 4,737
Posts |
Quote:
You would simply undo the three nuts that hold your top mount to the strut tower, and then move the strut slightly to remove the pin. Should be a fairly easy job. It should not affect your warranty/service. |
|
Appreciate
0
|
05-22-2011, 10:29 PM | #13 |
Major General
892
Rep 9,032
Posts |
That shit will happen at AAA until you get some camber plates. Three track days in my wife's 335 and the right front was toast too on the outer edge.
It's that damn left turn after you come out of Nascar 1/2 into the infield. I have the Vreds with -2 camber up front (with plates), and have no issues after 4 days there, and I was much faster those times out since it had been a few times. Most people who don't track wear out the rears first, but if you do AAA, the fronts get tortured, especially the right front. I thought you had some aftermarket wheesl? Are you using the stock 18's as your "track wheels?" I ended up selling the stocks wheels/tires, and getting the APEX wheels and NTO5. First time out with them should be at Laguna Seca and then AAA in June with the CCA. Hope to see you and your new ride out there. .
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
|
Appreciate
0
|
05-23-2011, 12:08 AM | #15 |
Major
101
Rep 1,086
Posts |
Thanks. I'm gonna do some more research on this and potentially try a DIY.
|
Appreciate
0
|
05-23-2011, 12:24 AM | #16 | |
Major
101
Rep 1,086
Posts |
Quote:
I'm running the stock 18s for track use, not perfect but it works for a leased car. The aftermarkets are for DD. The better track set-up of course might be a square set-up of maybe 18x10 all around. I guess it's just a money thing at the moment. I may be getting NT05s mounted on the 18s considering the performance/cost benefit. I'm not signed up for AAA with CCA yet, but maybe you've just pushed me over the edge. |
|
Appreciate
0
|
05-23-2011, 12:47 AM | #17 |
Captain
50
Rep 873
Posts |
Beef the pressures up even higher. A tire rolling on it's side is a good indication of simply not enough pressure. Depending on the track/heat you might have to go awkwardly high (45+psi)
Again though, the PS2 is not a very good application for the track neither are most Z/W/Y rated tires. On heavier cars, you'll see street tires de-laminate, gew/grease up or chunk like this when driven by someone who can get 10/10ths out of it regardless of pressure (again this is tire/track dependent). You'll spend more money running street tires on the track then track tires on the track if you are 'fast,' period.
__________________
|
Appreciate
0
|
05-23-2011, 11:01 AM | #18 |
Colonel
87
Rep 2,464
Posts |
Don't you have an instructor? He should be able to tell you this and show the correct line and speed.
__________________
2011 MINI Cooper S
previous cars: E92 M3, Z4MC, Z4 Roadster, E36 328 Sedan |
Appreciate
0
|
05-23-2011, 12:00 PM | #19 |
Second Lieutenant
8
Rep 222
Posts |
At this point in your learning curve, 2 tires will be fine. There will be a difference in traction, plus or minus, but there's always some difference in traction depending on setup and individual corners.
|
Appreciate
0
|
05-23-2011, 02:37 PM | #20 |
First Lieutenant
37
Rep 390
Posts |
suggestions:
add negative camber. slow down a little. run a sqaure setup, so you can rotate your wheels. These cars are heavy, and while they use camber preety well, it does not save the front tires on tight low speed corners. |
Appreciate
0
|
05-23-2011, 02:45 PM | #21 |
Major General
2760
Rep 5,483
Posts |
Agreed, chuck the tire, take the advice above, and if you're having uneven wear issues at a track, ROTATE THE TIRES left to right. Don't just let the outside tire die a quick death. You can't see the tire while you're driving, and if you wear through the belts in the middle of a session you're going for a ride
I posted a DIY on pulling the front alignment pins in the DIY section
__________________
|
Appreciate
0
|
05-23-2011, 07:59 PM | #22 |
Major
101
Rep 1,086
Posts |
Yes, I've had 3 days of instruction at AAA Speedway specifically. This is a new car, more power and I had a few events with no instruction which is where I've obviously made more mistakes.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|