Bullwings

Wow!!!
Notes taken. This will definitely be helpful for when I finally decide to get coilovers. I'm not an auto-xer, but this info is very valuable regardless. Thanks!

oinojo

Tires have their own spring rate independent to the car. This is why some tires work really well for certain cars and how they are setup. The z2 has a higher spring rate compared to the z1 and that is part of why people state it as being more responsive. It also helps with tire wear especially for stock classes. The bfg and dunlop have stepped up in that regard by having a tire that wont kill its sidewall quickly because of the cars Lack of camber.

oinojo

Oh and sorry Matthew, I misinterpreted what you were trying to say. Setups are not cut and dry so I try to teach a person to know what they want out of the cars suspension and how to get there. I could probably post everythinf down to the dyno plots of my penskes but that wont help anybody try and optimise what they currently have. The best I can do is point in the right direction.

mLeach

bingo.

Aristoi

This is one reason why sharing is caring: http://forum.miata.net/vb/showthread.php?t=436286

I can also respect the give vs teach a man to fish approach.

Some people will be better and more knowlegable at some things than others: driving, tires, shocks, alignment, overall setup, lot specific last minute fine tuning. Nobody will be the best at everything. Everyone benefits if everyone shares. Even if everything was openly shared, it will still come down to putting it all together to your personal preferances and driving style on what it takes to win. Obviously some people with more money and/or experience will have less to gain in sharing. I can admit i have benefited from peoples contributions in areas i never though i would. We also all weren't born with what we know today, i am sure we have all learned from others along the way.

Realistically it will take many data points, trial and error from mutliple people to see what ends up working in general for this tire, and how it stacks up to the other new contenders. It wont be until next season until the dust settles and people will actually gain from sitting out on the sidelines waiting for everyone else to spend the money and do the work. I prefer to be part of the process, and am taking a leap of faith in buying the Rivals, but they are on backorder until 4/8. I have probably flipped flopped my decision several times back and forth between Rivals and D2's. I have been following this thread specifically for any indicators to help in my decision process because i have a little more time until i am committed. I thank all of you for your contributions.

berny2435

Tires have their own spring rate independent to the car. This is why some tires work really well for certain cars and how they are setup. The z2 has a higher spring rate compared to the z1 and that is part of why people state it as being more responsive. It also helps with tire wear especially for stock classes. The bfg and dunlop have stepped up in that regard by having a tire that wont kill its sidewall quickly because of the cars Lack of camber.
[/quote]

thanks. that makes sense. I've read that before in some articles. Some of these details seem to slip my mind as I tend on focusing

Some people run lower pressures on Z1s that have higher tire spring rate than RS3s. This is why I went with lower pressures on the ZII to start out with. you've posted higher pressures(38psi) than I would have thought would be needed and on top of that, lower compression. to the amature, this appears to be variables that are heading in different directions. You also reduced camber front.

With more camber, would you be able to run less tire pressure successfully?

I realize I made a mistake in my assumption that a stiffer tire, can automatically run lower pressures if you have enough camber. much more to it than that.

imstimpy

In my testing, the Dunlops have had a very wide usable pressure range from ~32psi to ~38psi, rarely showing the pressure difference on the clock. The difference was not in time but in feel. Lower pressures tend to widen the slip angle and decrease the peakiness while higher pressures keep the tire sharper but are a little more unforgiving.

berny2435

Did you take tire temps?
How was that performed and if you can, let us know some results.

imstimpy

We've done temp testing with pressures in the past, but not with the ZIIs unfortunately. Our recent methods have simply been to check temps immediately upon returning from our run. That is far from perfect but my car shows a 10-15*F increase from outside to inside, slightly warmer in the front I believe.

When we did a bunch of initial investigation we set a traction circle (I forget the diameter), used a MaxQ, and went around until we were dizzy, took temps, then looked at logs. We found time with other things but not on pressures of the Dunlops.

mLeach

and tire temps aren't always the best indicator of performance, especially in something like autox where you are doing many different things at different corner phases. It's also totally course dependent. Sure on a skid pad, you might find that you can optimize loading via temperature analysis, and get good results, but if if this done at the cost of entry/exit stability (where the car may be using more of the top and bottom of the traction circle) you've could be giving up quite a bit of time and the ability to really move the car around during the more difficult phases of the corner.