Tire Contact Patch and Vehicle Stability - Alignment

[ZDan]

Yeah, weird wear pattern but I think you're assessment is correct, lotsa deformation due to flimsy sidewall and smallish treadblocks.

Yeah, car is a lotta fun! You'll really love it at the track on better tires

[Racecomp Engineering]

That's great! Glad you had a good time.

- Andrew

[strat61caster]

That's just how the edge of the tread looks on the oe tire when it wears, the rubber compounds are different at the edges hence different wear rates.

[gcmak]

Originally Posted by ZDan

Yeah, weird wear pattern but I think you're assessment is correct, lotsa deformation due to flimsy sidewall and smallish treadblocks.

Yeah, car is a lotta fun! You'll really love it at the track on better tires

I was thinking I'd try the RT660 tires and keep everything else the same for the time being. I think it should hold up much better overall but not be overly aggressive so I can still learn.

[ZDan]

Originally Posted by gcmak

I was thinking I'd try the RT660 tires and keep everything else the same for the time being. I think it should hold up much better overall but not be overly aggressive so I can still learn.

FWIW I kinda disagree with the notion that decent tires for the track inhibit learning. With track-appropriate tires you'll have a better time and learn more, quicker, IMO!

[gcmak]

Originally Posted by ZDan

FWIW I kinda disagree with the notion that decent tires for the track inhibit learning. With track-appropriate tires you'll have a better time and learn more, quicker, IMO!

Fair and heard. It's a different kind of learning is what I was getting at, never the less, new tires are in the cards.

[treedodger]

Depends on your goals and budget.
I generally recommend novices spend more time/$$$ on car control/skid pad/coaching/seat time and less on expensive rubber. Unfortunately, most new track drivers focus more on their lap times than on their car control skills. Learning slide recovery is a critical skill most don’t worry about until after their first scary 4 off.

Originally Posted by ZDan

FWIW I kinda disagree with the notion that decent tires for the track inhibit learning. With track-appropriate tires you'll have a better time and learn more, quicker, IMO!

[treedodger]

Originally Posted by gcmak

I was thinking I'd try the RT660 tires and keep everything else the same for the time being. I think it should hold up much better overall but not be overly aggressive so I can still learn.

GT Radial SX2 are hard to beat for an inexpensive and fun tire (TW260). Stock class record in 86Drive Challenge with this tire is 1:50.xx at Laguna Seca.

[NaturallyAspirated]

What alignment settings did you even up going with for the re-alignment?

[ZDan]

Originally Posted by treedodger

Depends on your goals and budget.
I generally recommend novices spend more time/$$$ on car control/skid pad/coaching/seat time and less on expensive rubber. Unfortunately, most new track drivers focus more on their lap times than on their car control skills. Learning slide recovery is a critical skill most don’t worry about until after their first scary 4 off.

There's a LOT more residual sliding grip and a LOT more control in a slide on good Extreme Perf trackworthy tires than on OEM Primacies. IMO a novice is going to be more likely to keep the car on the track on Extreme Perf category tires than on lower-perf tires that will overheat sooner and won't have nearly as much grip once a slide is initiated.

[gcmak]

Originally Posted by NaturallyAspirated

What alignment settings did you even up going with for the re-alignment?

I didn't get another alignment. A completely unmeasured adjustment of my bolts to balance out negative camber up front based on the 'before' numbers, is all I used.

The assumption (and that's all this is) from others here including myself is that the shop may not have touched the toe much/if at all so changing the camber back to negative shouldn't have too large of an impact.

I'll get an alignment when I replace these tires / before next track day. The car drives perfectly straight on the roads and aside from abuse on-track there are no visible signs of odd wear from excessive toe in/out.

This is NOT my daily driver. I'm very lucky and thankful to be able to have this as a second car to use as a weekend/fun/HPDE vehicle.

[treedodger]

Originally Posted by ZDan

There's a LOT more residual sliding grip and a LOT more control in a slide on good Extreme Perf trackworthy tires than on OEM Primacies. IMO a novice is going to be more likely to keep the car on the track on Extreme Perf category tires than on lower-perf tires that will overheat sooner and won't have nearly as much grip once a slide is initiated.

Good points. I have nothing against using good tires. If you have good car control skills, you can deal with whatever tires you're driving.

IMHO, I would suggest that the quickest way to make a novice safe on track is for them to spend enough time on the skidpad so they can catch a slide without having to think about it...and it's a lot of fun!

BTW: Ian's blog touches on this. Always entertaining:
https://yousuckatracing.wordpress.co...aining-wheels/

[racingfool]

Originally Posted by ZDan

There's a LOT more residual sliding grip and a LOT more control in a slide on good Extreme Perf trackworthy tires than on OEM Primacies.

This seems to say otherwise.



I like this.

A squealing tire is a happy tire. A screaming tire is a screaming tire.

[ZDan]

Originally Posted by racingfool

This seems to say otherwise.

How old do you reckon that is? For sure that plot is going to be different for every tire, and IMO it's not necessarily giving an accurate picture of grip vs. slip angle for current race tires vs. extreme perf street tires vs. "normal" street tires.

Most modern "Extreme Performance" tires have *amazing* grip at very high slip angles. This has been the case since at least the Dunlop Z1 *spec (I remember being dumbfounded at the sliding grip those tires had in the wet as I tried to do donuts in a parking lot).

Meanwhile the OEM Primacies are kinda known to not have this property. I had a student a couple of years ago who was afraid to even run "sport/track mode" at the track, let alone the 5-second hold on the traction control button, based on how many times he'd looped his car at a skidpad test day with the Primacies. But he soon found the proper Extreme Perf tires he'd gotten for the car to be *way* more confidence-inspiring and was able to drive hard enough (in sport/track mode) that I signed him off for his license after he showed great car control throughout the day (along with excellent awareness of traffic and flags and consistently good clear-headed responses under changing conditions).

Regarding noise, some tires make a lot of noise while still providing grip, some tires slide without making much noise at all, I haven't found an absolute correlation between noise and sliding grip.