Time (almost) for new tires. What to get for street/track dual purpose?

[steved0x]

I'm in North FL right now so we don't get much cold, but we do get a lot of rain.

Right now I've got the Sumitomo HTR Z III in the stock front 205/50/17 (almost down to the wear bars, maybe 3/32) and rear 255/40/17 (a decent amount left; I don't have the number). I've been happy with them, but then again I probably just don't know enough to tell the difference, as they are all I have ever had on it, and it has been 25+ years since I had a "sports" car (A Fiat X1/9 and a Corolla Hatchback, I think it was an AE86 but who can remember. The guy I bought it from replaced it with a Porsche 944 variant with the eyeball popup headlights, I just remember that it was always in the shop)

My experiences with these tires is around 7,500 miles of driving, including 2 track days at Roebling and an autocross. I am pretty sure I never got to the limit (no squealing or under/oversteer) on the track days, and I did get some understeer at the autocross.

It will be time to get some new tires pretty soon, and I am evaluating my options.

I have heard/read that some tires give a lot of feedback when you do get near the limit, in terms of feel/noise, and if that is the case I would probably prefer that.

I am not at a point where I would be running a second set of wheels for track days, both for $$$ reasons and because my suspension is stock with a street alignment (2000S M030, not ROW)

I am considering going to 225/45/17 in the front, which opens up the door to a greater selection of tires, and I have heard helps with understeer. Although for a beginner is this a good thing? Does this mean I am more liable to hit the limit and oversteer?

Options:

1. New Sumitomo HTR Z III in 205/50/17 for the front for now and re-evaluate when the rears wear out
2. New Sumitomo HTR Z III in 225/45/17 for the front for now and re-evaluate when the rears wear out
3. 4 new tires of??? Hankook RS3? Ventues V12 evo? Nitto NT05? S-Drive? S-04 Pole Position is priced competitively and is getting good reviews in the other thread

I don't want to spend the same money twice by buying the wrong tires and then needing to upgrade before they wear out. But I don't want to waste money using up expensive tires that I may not be able to tell the difference on. (And do you wear out tires faster if you are new to track days and driving wrong?) I plan on doing 6-8 track days a year (3-4 weekends) and a few autocrosses.

Anybody got any hot tips for me? Is it worth it to get a second set of wheels to drive the track even with a stock suspension and a street alignment? or is that for more advanced folks.

Thanks!

Steve

[Dlirium]

Give the pilot super sports a good look. I know a bunch of folks that use them for DD and DE both, and absolutely love them.

[rfuerst911sc]

Bridgestone Potenzas
Dunlop Direzza
Continental
BFG KDW ( I think )

[LAP1DOUG]

For dual purposes in your location with one set of tires, you probably need a set that is good for rain as well as dry warm to hot conditions.

With this requirement, the very best tire is probably the Bridgestone RE-11a.

The Dunlop ZII is faster, but a little more hazardous in the wet, and the BFG Rival would be about the same as the ZII, but alot more hazardous in the wet. The Hankook RS-3 would be very good in the middle of Summer dry conditions, but very scary in a cool rain.

The Michelins are all a step down from these in performance, but are very user friendly, and if you are not using all the tire, could be a good tire for you.

With stock front negative camber, you will wear out the outside of any tire you use once you start pushing it regularly. With the poor stock front camber, and stock sway bars, it should remain in a "safe" understeer attitude even with 245 fronts, so 225's should be fine. I ran for about a year with 255 front / 265 rear before I fixed my front camber. Of course your results may vary...

[The Radium King]

i like my yoko ad08's

[LAP1DOUG]

Originally Posted by The Radium King

i like my yoko ad08's

Oh yeah, I forgot about those. I used to have AD08's on my M3, and they were very good. Probably just as good as the other top Extreme Summer tires. The only negative at all is they are a bit more expensive for similar performance.

[Stroked & Blown]

Originally Posted by LAP1DOUG

The Dunlop ZII is faster, but a little more hazardous in the wet, and the BFG Rival would be about the same as the ZII, but alot more hazardous in the wet. The Hankook RS-3 would be very good in the middle of Summer dry conditions, but very scary in a cool rain.

I run the Dunlop Z1 star specs as my DD and in the wet at AX - they're great! Not sure how their wet performance compares, but the ZIIs tread looks a lot more closed.

[pharaohjb]

I'm running Kumho Ecsta XS tires now, after doing 2 DEs on crappy all-season tires. My laptimes improved by about 5 seconds a lap at Brainerd International Raceway. I'm sure some of that was just due to the additional seat time/experience, but I'll chalk most of it up to the tires. The Kumho tires are cheap enough that I don't really mind *too* much if I end up going through a set a year (3 DEs, maybe 1 autocross, and about 8,000 street miles per year).

The tread will be fine after a year, I'm sure. It's the outside edges that are going to get worn and show exposed cording from the DEs that will likely be the limiting factor in tire life. Especially since you're running a street alignment.

[steved0x]

Should I consider a track alignment, or maybe some type of compromise? Or does that just move the wear to a new place when I am street driving? Does the stock m030 suspension have enough range to allow this?

[LAP1DOUG]

Originally Posted by steved0x

Should I consider a track alignment, or maybe some type of compromise? Or does that just move the wear to a new place when I am street driving? Does the stock m030 suspension have enough range to allow this?

Yes, you should get the best track alignment possible, but it still will not be enough front negative camber, unless you install GT-3 lower control arms with plenty of shims, or camber plates. With the stock components, you cannot get more than about -1 degree negative, which is not enough to effectively use all of the tire width at high cornering loads. You need more like -2.5 to -3.5 degrees depending on how stiff the rest of your suspension is. The m030 is little or no help in this regard.

The basic problem is that these cars are McPherson Strut suspension designs, and for any McStrut design whether it is on a BMW or Porsche or a Kia, the amount of camber change is about the same as the roll angle in a turn. So, in a high G load turn, if your car rolls 4 degrees, your wheel/tire is going to roll over 4 degrees. In this case your paltry -1 degree front camber becomes + 3 degrees in the turn. Not good.

The only other thing you can do about it is put on a stiffer front sway bar to reduce the amount of roll, but if you go too stiff, the bad effects of weight transfer will override the good effect of less body roll, and cause more understeer.

[stephen wilson]

Figure out what percentage of your miles will be on the track, vs. the street, and bias your alignment setting based on that. If you just want to adjust the balance, there are other ways, like adjustable sway bars.

[thstone]

The Kumho Ectsa XS, Hankook R-S3, and Nitto NT-05 are my favorite street/track tires. Great grip and affordable.

+1 for everything Lap1doug wrote.

Max out the alignment for performance/track. While that might sound extreme, the stock suspension has such a limited range of adjustment (around -1deg camber) that there is almost no benefit or reason to consider swapping the alignment back and forth.

As a novice, you are not likely to wear tires faster by "driving wrong" because you're also driving relatively slowly. The more skilled you get, the faster you'll drive and the faster you drive, the quicker you wear the tires.

Keep driving and getting better/faster and eventually you will find that you are a better driver than the stock suspension with street tires (the car is holding you back). At this point, you'll have to consider tires with more grip (r-compounds) or a suspension upgrade. But don't worry about that until you get there.

[jsceash]

My experience is
The Continental Sport Contact tires are OK road tire Personally a would not buy another set. Slowest AX times My car has a horrible push with them almost a 4 wheel drift. They were scary in the only DE I used them at.

HTR ZIII are about 1 step up but I still have a slight front push. better AX times. I used them at 1 DE in the wet a Cayman with PS2 lapped me in about 10 lap

Pilot Sport PS2 was the best track/road tire I drove but cost is high. Good AX time improvement. They felt safe in the wet at the AX. I notice a little looseness and some push after 5-6 laps running a DE event.

Hankook RS3 had better dry performance than the Pilot Sport 2 They are loud but be careful in the rain. Fastest AX time in a street rated DOT tire that doesn't cause a time penalty. They did not loose grip after 6 -7 laps in DE events

[Topless]

+1 for Hankook RS-3s. I continue to be impressed by this tire.

Did not care for the NT-05s. I usually run NT-01s for track days and really like those tires. I wanted to like the NT-05s but never did. Grip was fair and they melted off my rims very quickly.

[steved0x]

Awesome, thanks for all the feedback.

I will try to find a performance oriented shop that knows Porsches to check my alignment. We have a Tire Kingdom here (that has done my other cars) but they say they can't do the Porsche.

I mostly leave it in the garage and only drive in good weather; I probably should have mentioned that in my first post, so some of these "Extreme Performance" tires might be good for me.

With regard to oiling problems due to high-G cornering - I am still a long way from that, right? I understood that those mostly occur with "R" spec tires and long high speed turns. With my regular street high performance tires I am not generating sustained G's like that, correct?

Thanks!

Steve

[rfuerst911sc]

stevedox where in FL. are you ?

[steved0x]

Originally Posted by rfuerst911sc

stevedox where in FL. are you ?

North Central FL in Lake City, just a few miles east from where I-10 and I-75 meet.

[steved0x]

Originally Posted by pharaohjb

It's the outside edges that are going to get worn and show exposed cording from the DEs that will likely be the limiting factor in tire life. Especially since you're running a street alignment.

Does anybody unmount the fronts (and/or rears) and move them to the other side to gain some extra life out of the tire? I guess that wouldn't for tires that have an asymmetric "inside" and "outside" tread, but if you had a symmetric tread (and/or directional? a quick check of Tire rack shows that all of the Extreme summer performance tires are either asymmetric or directional) then could you swap them side-to-side? Or does the expense of making such a swap negate any extended usage received.

Does anyone do this?

Thanks,

Steve

[rfuerst911sc]

If you were closer to Orlando I had a shop to recommend.

[LAP1DOUG]

Originally Posted by steved0x

Does anybody unmount the fronts (and/or rears) and move them to the other side to gain some extra life out of the tire? I guess that wouldn't for tires that have an asymmetric "inside" and "outside" tread, but if you had a symmetric tread (and/or directional? a quick check of Tire rack shows that all of the Extreme summer performance tires are either asymmetric or directional) then could you swap them side-to-side? Or does the expense of making such a swap negate any extended usage received.

Does anyone do this?

Thanks,

Steve

Some people "flip" tires to even the wear. This can be done with symetrical tires like a R888 or a ZII, but not with an asymmetrical tire like an NT-01. As I understand, it involves unmounting the tires, and flipping them on the same wheel, but I have never done this. I guess the economics depend on your cost of labor at the tire shop vs. cost of the tires you are flipping. If you modify to achieve proper camber, there is no reason to do this.