Just looked at the weather forecast for Summit Point Mar 22-24. Thursday night low is 26. Was planning on driving down Thursday to the hotel on the 200TW but now plan on leaving at 0500 Friday. Recently moved to Central PA so its a 2 hour drive verses the 65 minutes from NOVA. Worried that the 26 is too low for the 200TW Thursday night. Am I being too cautious? Working on a tire trailer and hitch.

2013 Boxster S PDK, SC, PTV, 3rd radiator, DIY Cobb tune

 

See if the tire manufacturer publishes a minimum temp for your specific tire. My personal cutoff is around 40 degrees.. but I'm also in the South.

 

Not concerned for 200 TW tires. Concerned for 40 TW tires.

 

Glad to hear from an expert. I was following thread for same reason. Driving to NJMP later this week with predicted leaving temp 30 or so. I've driven 400 TW tires safely on the road well below 40 a lot and never given it a single thought - I just avoid single digit temps when tires can crack.

I was 90% sure the 200s would be OK but you know what they say about 90%.........................

 

I think the real issue is that they are more susceptible to shock damage (potholes, curbs, etc.) below freezing.

There is, of course, an issue with R-Comps, but when the OEM replacements for my wife's BMW are 260 and there is no warning, that's a good indicator, too.

 

^ I have run 200tw in cold conditions on transit drives. I do up the starting pressure into the 30's to help prevent possible damage from flexing. I have been on track at ~32 degrees and other than starting pressure a couple of pounds higher then normal for track, taking several easy laps to build heat and pressure by hard braking I have never had an issue. It's my favorite scenario for setting PB laps.

Peter

 

FWIW - Tire Rack lists the following for Bridgestone RE71RS:

 

So, even if they are RE-71RS, would have to be below 20 degrees F to have this bulletin be applicable,

Still think that this situation does not require special car other than to make sure they’re set to at least recommended cold pressures at the ambient temp when you leave.

 

Thanks for finding this. I'm on RE71RS and I will be fine and complying with factory recs. If it's below 20F, I'm going back to bed, not to the track!

 

I'll be at SPM this Friday to Sunday as well with you guys and I'm running the Hoosier R-7's. Just gonna go out early Friday and slowly warm them up.

Have run them in the cold before and never had an issue as long as I warmed them up slowly first laps.

Also, I am not driving the car to the track, so I think they'll stay a little warmer in the trailer.

Looks like overnight lows at SP will be mid 30's over the 3 days on track with temps warming in to the mid 50's all 3 days.

I think you'll be fine. Just don't wail on the tires early on. Take the time to heat them up slowly if you can. Safety first always.

See y'all in a few days.....

 

I'll be there and on R7's as well and that has been my experience...bring them up slow, especially that first session and all should be good. I think it was our first event last year at Summit that it never really got out of the 30's either day so I took 3 laps before I really wailed on the tires and they were solid the rest of the session.

 

Yessir…..

Slow and steady wins the cold tire on track race..

 

Hhhhmmm... I can't quite recall when you were, "slow"!
See ya on Friday!

 

As stated above, be sure to gradually bring temperature into the tire during that first session. The RE-71RS (like many other 200TW) is sensitive to having the outer tread temp a lot hotter that the core of the tire. Allow some time for that heat to gradually transfer inward.

 

Kind of tough to do that (highly localized heating), especially in cold ambients. That would result in severe graining and tearing to the tire tread face.The tire tread temp overheating can occur on taller, unsupported tread blocks in unshaven 200 TW (or any other treaded tire with more than 4/32nds tread depth, but then it tears or chunks.

Those of us monitoring inside tire temp, pressures as well as the tread surface temps simultaneously rarely see thermal shock in the warmup process on the tread face of the tire and a big temp delta on it’s own. Maybe Matt will chime in on this, since I know he’s got a lot of personal data on this.

If you’re driving quickly enough to get the tread face to the 180-200 degree F operating window, especially with ambient 40 or 50 degrees less than a nice late spring or early fall day (say 75-80 degrees F), you’re not going to be able to do that independently of raising the carcass temps, hence pressures.

When tire engineers work with drivers testing tires (BTDT), they’re far more concerned about the support provided to the carcass by reaching the target range of internal pressures. They say don’t push it when below a pressure threshold, but they say the most efficient and quick way to heat the internal carcass is accel/braking to allow the belts to generate friction, hence heat, thus raising the tire pressures without shock or potentially doing damage striking the curbing, for instance.

I test and race on slicks frequently in the 32-42 degree ambient range (since the temp swings are so wide here in VA/NC, was on track yesterday) and my cold pressure at normal ambients are 14/16 cold on my car. In the 32-42 degree ambient, I start 2 lbs high each end and still are shooting for 20 hot all around. Thats what I did yesterday and it worked perfectly. Never had graining or tearing, either.

In cold ambients, just go easy, exercise the tires with fore and aft loadings to bring the internal temps and pressures up, then as the grip comes in, go.