Factory Z28 Wheel Question..

[MrRaZ28]

I actually have never had Trofeos on. When I bought the car, the dealership put S-04 Pole Positions on it. I would expect the Trofeos to have better grip than these due to the compound make up. However, these were excellent in comparison to the Pole's by a significant margin as I never felt like I was losing traction at any time. They also broke loose when I wanted them to when I was throttle steering through the corners. They are a very progressive tire, and I really felt the difference in contact patch through the steering wheel. When they warmed up, I felt no sidewall flex at all, in comparison to when I first put them on and had 25 psi for the street.

In comparison, my best time at Eagles Canyon, as a novice, was within 2 seconds of an experienced BRZ driver who is the fastest BRZ in the country, so I'm told. And he had Falken track tires. Even more so, the track-owned Porsche 718's run these tires and are absolutely stupid fast.

[MrRaZ28]

No camber changed on these. Wear is surprisingly even. You can see they go all the way out to the edge of the tire.

I expect the more I track them, the more I will wish for negative camber, but I can't bring myself to set the camber for track and not be able to really drive it again until I pay a shop to set it back. $170+ for track alignments IF I can find a shop with the proper stuff to do it each time pains me to think about right now.

Edit: Also, zero rubbing.

[Tankslapper]

Originally Posted by Chevy2tehBone

No camber changed on these. Wear is surprisingly even. You can see they go all the way out to the edge of the tire.

I expect the more I track them, the more I will wish for negative camber, but I can't bring myself to set the camber for track and not be able to really drive it again until I pay a shop to set it back. $170+ for track alignments IF I can find a shop with the proper stuff to do it each time pains me to think about right now.

Edit: Also, zero rubbing.

Re the camber, I wouldn’t worry about the wear. I run two sets of wheels, my street set are the same as yours(except in 305) I maxed out the camber on the front,I think it’s around -2, and have done 26k miles on the fronts...and while there is some wear on the inner it’s absolutely fine. I am on the 2nd set of street rears and suspect I will get thru them and then replace all 4. I don’t track these tires.. Probably why I am getting the longevity...I don’t count the track tires anymore $$$$ but worth every penny...to someone’s question earlier, grip on the trofeo/supercar r’s is much higher once they are hot, completely different league to the Conti
Steve

[z28monster]

Excellent insight, Chevy2tehBone - much appreciated

[51LE50]

Originally Posted by Chevy2tehBone

Running 28 psi cold all the way around. Gets up to 32 when normal driving. Goes WAY up on the track... had it go to 38 on the final session and they started getting greasy. Going to knock it down to 25 or 26 and see what happens.

When I raced motorcycles we would compare cold to hot (just off the track) pressures. Dunlop tires liked about a 7 psi rise. If pressure rise was more than 7 psi, we'd ADD pressure, and bleed 1 or 2 lbs. if the pressure rise was less. Dunlop told us that tire carcass flex was the cause of the pressure change ( flex = heat ).
Willow Springs in the summer is stupid hot
More starting pressure = less heat and less pressure increase, and so on.
Does this not hold true for auto tires?

[MrRaZ28]

Originally Posted by 51LE50

When I raced motorcycles we would compare cold to hot (just off the track) pressures. Dunlop tires liked about a 7 psi rise. If pressure rise was more than 7 psi, we'd ADD pressure, and bleed 1 or 2 lbs. if the pressure rise was less. Dunlop told us that tire carcass flex was the cause of the pressure change ( flex = heat ).
Willow Springs in the summer is stupid hot
More starting pressure = less heat and less pressure increase, and so on.
Does this not hold true for auto tires?

Entirely possible. I will give it a go next track day and see.

[TWOFORTYZ]

Originally Posted by aris

That's not really accurate. The sport cup 2 are a 180 treadware and the trofeo r are a 60. The sport cup 2 will last almost 3 times longer than the trofeo r under the same driving conditions.

My personal opinion - if you are not daily driving this car and plan on tracking it at least a couple times a year, go for the cup 2. The super sport are an extremely hard compound by comparison and will not serve you particularly well on track. I think to truly appreciate the Z/28 you need to run the right tires. Putting Super Sports on the Z/28 would be like Usain Bolt wearing a pair of orthopedic walking shoes.

Also consider going up to a 315 if you choose to run the cup 2. If you take a look at the stock dimensions of the Trofeo R, you'll see that they are very very wide for a 305. For example, the tread width of the 305/30-19 Trofeo R is 11.6", whereas the 305/30-19 cup 2 has a tread width of 11", and the 315/30-19 cup 2 has a tread width of 11.7"

Just some food for thought.

You made a good point about the compounds.

If you actually drive hard, a softer tire can last longer due to the reduction of sliding and wheel spin. I found R compounds lasted atleast twice as long under my 240Z than all season tires because they spent a lot less time sliding and spinning. Sometimes softer is better.

[TWOFORTYZ]

Originally Posted by Tankslapper

Re the camber, I wouldn’t worry about the wear. I run two sets of wheels, my street set are the same as yours(except in 305) I maxed out the camber on the front,I think it’s around -2, and have done 26k miles on the fronts...and while there is some wear on the inner it’s absolutely fine. I am on the 2nd set of street rears and suspect I will get thru them and then replace all 4. I don’t track these tires.. Probably why I am getting the longevity...I don’t count the track tires anymore $$$$ but worth every penny...to someone’s question earlier, grip on the trofeo/supercar r’s is much higher once they are hot, completely different league to the Conti
Steve

If you are having wear issues with only 2* camber adjust your toe. I've ran up to 3.5* negative while commuting without any adverse effects. If you are already toe'd in, pick up your cornering speed. It will help even out the wear and saves a lot of gas. Carry that momentum like you're in a miata.

[TWOFORTYZ]

Originally Posted by Chevy2tehBone

No camber changed on these. Wear is surprisingly even. You can see they go all the way out to the edge of the tire.

I expect the more I track them, the more I will wish for negative camber, but I can't bring myself to set the camber for track and not be able to really drive it again until I pay a shop to set it back. $170+ for track alignments IF I can find a shop with the proper stuff to do it each time pains me to think about right now.

Edit: Also, zero rubbing.

That's a wild assumption. As an ex mechanic that performed hundreds if not thousands of alignments, I have done well over 60,000 miles commuting in race spec cars with no issues. My tires wore evenly, mostly because I always corner quickly and have PROPER toe. Toe out is the primary reason for instability and poor tire wear. Try it. You'll be fine and will not regret it unless you are SUPER slow and only drive straights.

[MrRaZ28]

(Edit: Posting when not awake fully is bad). Thankfully, I'm neither slow nor stick to straights when I'm not daily driving it.

It's not entirely wild. I was under the assumption that having some offset toe along with the camber was a good thing, from what I read. Finding a shop around here that is capable of doing it is the problem. Setting the camber is easy. Doing it on the Z with someone that is knowledgeable is not. I found ZERO shops that could align my third gen properly, and none of them would let ME do it.. ex-technician here with hundreds of alignments. I also daily drive this car, it's not just a track car... not yet.

[vdshenoy]

Are you in Austin? Because I'm in Austin too, and apparently, my car is your motivation!