THSCC Forums

My stock tires saw their last event this past weekend in Laurinburg. They're worn out and need to be replaced. I'll be buying the same tires again and since they're OEM street tires I'm curious as to how many miles should be put on them or some general rule-of-thumb to follow prior to an running an AutoX event with them. I realize that mileage may not necessarily be the best indicator of 'break-in' but it's the best thing for me to go by since I can't really heat them up too much on local roads.

Thanks, Chris

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Beauty is in the eye of the beer holder.

Chris,

For actual "street" tires, break in consists of just driving them, even just to an event which isn't right next to the tire store. The biggest issue with new regular street tires is that most cars will probably tear up the edges of the tires if autocrossed hard on full tread. Since you were faster than my times at the T&T I assume you autocross hard. If there is any way you can save the new tires for street use and have a second set of wheels/tires for autocrossing you will be much happier and maybe better off $$$$ wise.

Dick (who destroyed a lot of regular street tires in the old days)

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Dick Rasmussen

FS 50 2018 Mustang GT

Thanks for the info, Dick. I plan on using my Azenis Sport as daily drivers and the stock tires for Autoxing. I have two sets of wheels to allow me to switch back and forth. (I also have 3 sets of tires as the stock tires are summer use only and I need all seasons in the cold) The stock tires have stiffer sidewalls than the Azenis and that allows for me to be jerky and spasmodic with minimal penalty.

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Beauty is in the eye of the beer holder.

I went to an Evo school right after purchasing tires. I had maybe 1-2 weeks of daily driving on them. Mileage wise that's maybe 300 miles. Once you scuff that top slick layer off from the tire mold that is pretty much it.

Also keep in mind that this past weekend is not typical. A T&T provides lots of runs. Those of us who did setup on Saturday have even more runs on their tires. Many of us corded our tires.

On Sunday alone you probably got 12-16 runs. That is just about half a season in one day. And Laurinburg has a healthy appetite for rubber

Graham

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http://www.greywinds.com

...of course that AWD thing has no affect.

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Vincent Keene
'06 Ford Mustang GT (track rat)
'15 Dodge Charger R/T (yeah, it's got a HEMI!)
'07 Ford Fusion SE (205,000 miles and counting)
'98 Chevy Z-24 (retired)
'93 Acura Integra (Team SWB 24HOL Car)

The STi is a pig in terms of weight. You actually need the stiff sidewalls regardless of the AWD. Plus, if you overdrive like I tend to do, the car turns into a plow. Like the one time I braked WAY too late at worker station 5 on the AutoX course...I was somewhere in the high 80's mph and decided to carry it one extra second. More squealing than in the movie Deliverance. The Azenis would have been much worse.

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Beauty is in the eye of the beer holder.

Holly smokes that STi is fast. Assuming station 5 was the end of the straight. The Vette was probably only doing about 70 mph. Lets see, 85 mph equals about 125 feet per second. The whole straight from the last offset was roughly 500 feet by the way.

Dick

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Dick Rasmussen

FS 50 2018 Mustang GT

Yes, that's the section I was talking about.
I was carrying the high end of 3rd gear. Brian Herring hit 4th on that straight, so he may have been going faster.

EDIT..so, I couldn't have waited an extra second for braking...sure felt like it, though! Seriously, it felt like a long time but I must have just been a 'hair' late in braking.

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Beauty is in the eye of the beer holder.

Must have been carrying some hellish speed out of that lane change to hit 80mph. I was doing low to mid 70's in my C5. Granted I was one of the slowest/inexperienced drivers out there so I might not have carried the speed out of the lane change that the better drivers were.

I hit fuel cut at 56-57mph in second and was shifting at redline to third in the lane change.

Brian H: What speed did you hit in that straight?

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Beauty is in the eye of the beer holder.

Chris,

What is the max mph in 3rd gear in your STi? I found a R&T road test that said 76 mph but I know from experience that R&T specs are, shall we say, not necessarily correct What I always do is find out the actual manufacturer's specs for the trans and diff and then do the math.

I was mystified by the Honda S2000 once because none of the specs matched the road test data . . . until more research indicated that the trans in those cars has an "extra" reduction gear.

It does help sometimes to know what the speeds actually are in each gear for planning purposes (i.e. is a shift likely given the length of the straight or will just hitting the rev limiter be appropriate.)

Dick

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Dick Rasmussen

FS 50 2018 Mustang GT

Dick,

I don't know ... I pm'd Brian H to see what he was running. Now, I'm hoping that it's not 76 mph because I'll feel pretty foolish ESPECIALLY since I made a conscious effort to look at the speedo and actually commented on the speed after one run in particular. But, if you found that max 2nd gear is in the 56-57mph range then I'd expect the numbers for 3rd to be accurate too. And, I'll sheepishly back away from the keyboard with egg on my face. Thanks for being ever so polite while raising the BS flag too.

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Beauty is in the eye of the beer holder.

Thanks. Sounds like you were carrying a good bit more speed coming out of that section. 8-10mph maybe? Given what I have read a stock 6 speed C5 and a stock Sti accelerate about the same rate despite being geared vastly different. Considering the large difference in exit speeds 80+ mph seems much more plausible now as far as I am concerned. Sorry for being skeptical.

Chris,

You still me be correct .. It's a matter of if I was in third which Dick may be correct in stating that it tops out at ~76, or if I was in 4th to get above 80. I *know* I saw higher speeds than 76 but I can't recall which gear I was in. If third..then most likely not. I do recall some mis-shifts during the following turn but have no clue as to what gear I was in..I'm confused now but could swear I was going faster. I'm going to set up my digicam at the next event to follow my speedo, so hopefully the vette guys are doing the course and hopefully they'll make a fast section.

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Beauty is in the eye of the beer holder.

Opinion On:

I beleive you had to be darn close to 80mph. If you topped out 3rd gear and held your braking to the very last second. I managed to get to about 68mph. I couldn't get the car to sit still coming out of the offset and lost acceleration time. I also had street pads still on the car so I backed off on my braking distance for the turn onto the runway.

The C5 and STi may run the same 1/4 mile times. But I would love to see the side-by-side split times for 60ft, 200ft, 800ft, and final trap. I would expect the STi to be quicker out of the gate. AWD and a fast winding 4cyl. I would expect the C5 to catch it mid track where the V8 comes into its own and traction is no longer an issue. Even in Competetive Mode the C5 still gets wheel spin if launched hard.

I would expect the same to happen on that element. The STi transitions quicker and winds up faster. Then the C5 catches it down the straights.

Opinion Off:

Now I got a few rides in that new C6. It makes my C4 look bad, very bad... The car never felt like it was going to loose control. On EMT runflats no less. He almost hit 80mph when I got him to brake a little deeper.

Graham

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http://www.greywinds.com