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Perhaps you should mix up your marathon training with a speed bag!

Andy Hollis:

No pyro, just the clock.  I've been burned by the pyrometer too much in the past.

And I did make a few adjustments to the car before the test.  More rear bar.  Did not hurt the Bridgestone performance, but did help the Toyo.  Learned this from an informal test session at the Driveway just before Dixie.  Car would not even turn on the Toyo.

No doubt that my "feel" preference is the Bridgestone.  Some because of experience on the tire, as you say, but also because I personally prefer a more responsive tire.  What's ironic is that just a year ago we were all saying that the Bridgestone was sloppy compared to the old Falken RT215.  I can't even imagine back-to-back between the RT215 and the R1R. 

The Toyo just likes to run at big slip angles and you have to get used to that.  Very much like an old-school bias ply.  Maybe if I had power steering things would be different...

--Andy 

I see.  That's pretty annoying about the pyrometer hurting you.  That's the tool I rely on to set my tire pressures and I ran 38psi on my toyos to combat the sloppy feel.  Maybe that's too much.

I'm in the same boat as probably everybody is with the "feel" of the B-stones being nicer. 

glagola1:

[

I see.  That's pretty annoying about the pyrometer hurting you.  That's the tool I rely on to set my tire pressures and I ran 38psi on my toyos to combat the sloppy feel.  Maybe that's too much.

What I have found with the pyrometer is that it's great for gross adjustments, but not as useful for fine tuning.  Kinda like air-fuel ratios and dyno output.  The latter is what matters, and the former is a measure of contributing factors.  But a wide range of AFR's generate the same dyno output, in my experience.

BTW, what works on a Miata may not work on a CRX.  Weight balance is quite different.

--Andy
 

Yeah, Bell shared some theories you have about slipangles and weight balance... I can't quite get my head around them to the point that I'm convinced.

Andy Hollis:

Back from the dead...

Car has been out of hibernation with a win at the Fort Worth Tour.

More importantly, we've got some Toyo vs Bridgestone tire testing up on the blog.

This is from March. 

Enjoy! 

--Andy

 

 

Thanks for sharing Andy.  Most helpful.

Sincerely,

Charlie

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Charlie Thompson
'04 JCW Cooper [STX]
NER Cannon Fodder

cmt52663:

 

Thanks for sharing Andy.  Most helpful.

Sincerely,

Charlie

 

Yes, thanks so much for sharing.  Most of us lack the resources (time, $, talent) to do these kinds of comparisons.  That you freely share your findings with everyone is really appreciated by many of us "little guys." 

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Once you go Mac, you never go back!

+1 on the pyrometer. I've been saying it for a while now. A pyrometer is nearly useless compared to the data you can learn from an hour on a skidpad.

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Nate Whipple
NER
188/88 DSP ITR

What are you using to gather data from the skidpad? An accelerometer, a clock, a pyrometer?

 

They all produce metrics, but without the clock, which most people dont have, the skid pad is going to produce little measureable, or interpretable data. The clock only shows the resultant, atleast the pyrometer gives an indication of something specific that can be changed by the driver/tuner.

gary p:

cmt52663:

 

Thanks for sharing Andy.  Most helpful.

Sincerely,

Charlie

 

Yes, thanks so much for sharing.  Most of us lack the resources (time, $, talent) to do these kinds of comparisons.  That you freely share your findings with everyone is really appreciated by many of us "little guys." 

 

Plus one on that.  Your data is a tremendous help in dialing the car in quickly and easily.  Thank you very much.

 I'm interested in the common point that the Stones are sloppy.  This is my first year in STS2 and I'm on the Bridgestones.  If anyone can describe what a good run on this tire feels like I'd appreciate it.  Should a good run feel sloppy and possilby un-smooth?

 Thanks.

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1991 Miata STS2
Recovering former member of the pushrod posse

For me... the Bridgestone's don't fall off until they are squealing for some time, even in longer slaloms and offsets... so if you don't have them squealing you are not going fast enough.  Squealing all the time = overdriving...

 

Rick 

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Rick Cone
Atlanta Region Director

STS2 #98
1991 Mazda Miata - Aqua

mleach:

What are you using to gather data from the skidpad? An accelerometer, a clock, a pyrometer?

 

They all produce metrics, but without the clock, which most people dont have, the skid pad is going to produce little measureable, or interpretable data. The clock only shows the resultant, atleast the pyrometer gives an indication of something specific that can be changed by the driver/tuner.

Assuming you interpret the pyrometer data correctly. Stop watches are cheap, usage is simple, interpretation self explanatory. The level of driving focus in a skidpad is not so intense that you can't also operate a stop watch. Use some sort of mark on the surface for a start/stop point, get up to speed, start your timer, run 10 laps, stop the timer, find your average. While it isn't perfect, its better then assuming a particular temperature spread is the best for the tire you're on. Having a buddy work the stop watch from outside the car is even better.

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Nate Whipple
NER
188/88 DSP ITR

10 laps?  In my skidpad experience (ironically, with the RT-615, RE01R, and AD07), the outside tires will be overheated after about 4.  You guys and your light cars... :)

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--Jason Rhoades

solo-x:

mleach:

What are you using to gather data from the skidpad? An accelerometer, a clock, a pyrometer?

 

They all produce metrics, but without the clock, which most people dont have, the skid pad is going to produce little measureable, or interpretable data. The clock only shows the resultant, atleast the pyrometer gives an indication of something specific that can be changed by the driver/tuner.

Assuming you interpret the pyrometer data correctly. Stop watches are cheap, usage is simple, interpretation self explanatory. The level of driving focus in a skidpad is not so intense that you can't also operate a stop watch. Use some sort of mark on the surface for a start/stop point, get up to speed, start your timer, run 10 laps, stop the timer, find your average. While it isn't perfect, its better then assuming a particular temperature spread is the best for the tire you're on. Having a buddy work the stop watch from outside the car is even better.

Nate, will there be any timing on Saturday?  If not it's time for me to buy a watch...

I've been tuning off the pyrometer and the lateral and longitudinal acceleration data.  Better than nothing, but the clock is the bottom line.

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Charlie Thompson
'04 JCW Cooper [STX]
NER Cannon Fodder

It's questionable if we'll have a skid pad or not. Even if we do, it won't have any timing setup. Only one timer means it'll be setup on the test course. Combine your stop watch numbers and your accelerometer data to get an even more accurate picture.

Good point Jason. Every time I've done skid pad testing, it's been 50* out. Light car + low temperatures = very little concern of overheating tires in a skid pad. The point is that a stop watch and a large enough sample set still gives you a better idea if you've optimized the tire then a pyrometer does.

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Nate Whipple
NER
188/88 DSP ITR

conekiller:

For me... the Bridgestone's don't fall off until they are squealing for some time, even in longer slaloms and offsets... so if you don't have them squealing you are not going fast enough.  Squealing all the time = overdriving...

 

Rick 

 Thanks, this helps.  I didn't hear a peep from my tires and was ~2% off the pace.  As my car is competitive locally I can only blame the driver.

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1991 Miata STS2
Recovering former member of the pushrod posse

The Z3 is such a beautiful car to start with, it would be even better in STS trim! 

What else would a potential sponsor ask for?

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GregHavener

Deleted post not relevant to Andy's STS2 Miata.

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David Avard
89 Honda Civic Si black (STS)
07 Mazda 3s (HS?)

Davard:

With all this skidpad talk, would it drum up more entrants for the Kansas Divisional (Aug 1-3) at HPT if you knew that there would be a skidpad available on Friday?

How is that related to the subject thread?

--Andy

 

Deleted 2nd post not directly related to the subject.

 Although, I imagine that it will at some point be related.  

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David Avard
89 Honda Civic Si black (STS)
07 Mazda 3s (HS?)

Davard:

Skidpads? Testing opportunities?

"Andy's STS2 Miata Project" ??

Or are you looking for places for me to test?  

--Andy