Auto-X Race Tire / Street Tire
 

This seems to pop up a lot in threads so here is one dedicated to it.

Example stuff:

1. Patty Evans ran a 52.xxx in Bob's Mom's S2000 on Sunday on her first run. She usally improves by a second or less later in runs. That put her at a mid 51. Pat and I ran a low 51 I dont; think I am as good a driver as Patty but dang.

2. Evans said they are swiching to street tires after their Kumhos run out.

3. Lucas does well in a street tire Vette.

4. Vegas Autoxr's are up in arms

etc.

Plus Scott won PAX on Saturday in Eric's car, which ruined autocross.

I heeeear that.

ADD affected teenagers in the timing bus is ruining autocross too. And so is sunburn.

Stead's surface is ruining race tires, I mean autocross...

But seriously do you think the surface affects race tires pretty badly?

Yes, I do... Though, I still think there is close to a 2 seccond difference.

Patty was likely not driving 100% while she was instructing. And to be honest, I think PFR Racing was a little off the pace this past weekend.

2 seconds per what 45, 50, 60 secs?

2 seconds per 60 second course = 0.968

oh, I never actually did and street tire calculations, it's pretty evident.

Is there a question as to whether street tire is going to be more competitive than race tire?

It sure would be nicer to have that asphalt breakup cleaned up before making runs. My question is how much the additional gravel on the course is affecting run times, wondering whether it is now faster to run earlier vs. later on a day like this weekend.

Are you saying Patty took more than 1 run in Barb Danger's S2000 in the morning (with a 51.x time?)? Or is that speculation from historical data?

Then, are you saying that because that S2000 is on street tire (I assume), but youi guys are on v710's, that you guys should have been up to 2 seconds faster?

I only have one example of the possibility that running in the morning was faster, that was MikeK's 49.x in the morning, following by a 50.x during RNP runs in the afternoon. Dunno....

I think race tires still have an advantage over street tires. Past historical data suggest that race tires were good for 2.5s per 60s over street tires, even though we only set the street tire PAX at 2s per 60s.

With the breaking up of the surface at Stead, I think the street tires aren't hurt quite as bad as the race tires, but I think the math still favors the race tires. Where the gravel advantage comes is with the AWD cars. Those of us w/ AWD should be beating up on the RWD cars due to the lower traction created by the bad tarmac.

I certainly feel the gravel, I'm still new RWD and race tires, hopefully I can get a better feel. I did much better running in the morning than I did in the afternoons in the S2000.

Debbie, that example is sepculation from historical data. She did run an easy 52 in the honda. I bet she could have got a low 51 in a run or two.

did the top 10 pax people change a lot form last year, as far as race/street tire standings, Matt is doing pretty good so far! Scott dominated sat in an awd, street tire car!!

werd.

Break up/debris has always been a problem at every event in the later part of the day no matter the location. You have to drive the line that is still clean even if you don't want to...

As far as awd VS. rwd, not sure surface is a huge contributor as long as you are not in the super loose stuff. 7th place in pax in an underprepared CS Miata ain't bad for proof... Top 5, look out, here I come... :)

Underprepared? Sue's car. Bah. :p

Still less than optimal camber in the right front. -.5 deg
Stock shocks w/30K+ miles.
Stock front bar.
Stock exhaust
Stock wheels
Stock Air filter
Stock, stock, stock...
Oh, and she has been using 87 octane until I found out Sunday night... :eek:
:P

Sounds familiar.

Totally unknown alignment that has seen 2 spring changes.
Blown out left rear shock.
Stock exhaust
Stock header
Stock cat
Stock intake w/ old paper filter I still haven't changed
Stock plug wires
Stock clutch (slipping) and flywheel
Stock brakelines
Springs too soft
Shocks single adjustable
Narrow tires
No timing bump
Soft top not removed
Heavy car

My car would be underprepared for ES too if I took off the springs and wheels. :p Also, with factory timing, why would her car need 91 octane? News to me, but I haven't spent much time reading up on the NBs.

I feel dumb, this weekend would have been a good time for me to experiment with tires. I laid dwn a fast street tire time in the morning, and I should have RNP'd the afternoon on my Toyo RA-1's, just to see if there is any difference, I know th are not ideal Auto-X race tires, but I think I would have been a good deal quicker on them. Oh well, maybe next time.

NBs call for 91 according to the owners manual... Assume it is for more timing advance.

RA1s <<<<<< Victoracer v700s....(personal experience from the Stealth on 275/40-17s) Don't know where they land vs. ST, but probably not much better. They just don't heat up and get sticky like they do at the track.

Damn, they do. What a crock, they only have like 3-5 more horsepower than the '99/'00 engines.

this isn't a god damn miata thread.

Really? Then why are there so many Miata related posts? :p

Hola, bienvenidos a la MECCS... Miata Enthusiast Car Club of the Sierras... :P