OPR

General chat that fellow COM'ers may be interested in.
offcamber09
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Re: OPR

Post by offcamber09 » Wed Aug 05, 2009 8:58 pm

breakaway500 wrote:measured very even temps across the tire surfaces,with a real tire temp guage
By even temps, I hope you mean linear. Hottest on the inside and progressively cooler as you move outboard (ie. 150 inside, 140 middle and 130 outside). If they are, in fact, even then you do not have enough negative camber. Agreed- the Atom does not need 3 deg.negative.
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breakaway500
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Re: OPR

Post by breakaway500 » Wed Aug 05, 2009 11:28 pm

They were an even 160 across the face.The tires also show an even wear pattern (excluding the OPR residue..) The feel of the car to track was excellent. I was mostly thrilled to see them come up past 100 degrees,as this is the first set of tires that has ever heated to full working temperatures. I am sure some more tuning is in store for both car and driver.. :wink:
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John F
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Re: OPR

Post by John F » Fri Aug 07, 2009 3:09 pm

My tires didn't look like that after any of the run groups (maybe a little) but looked worse than that when I completed the time trial and came in through the gate after 1. Picked up a ton of rubber and then a ton of rocks in the construction site. Made for some interesting noises while driving to the garage area.
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ctkag
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Re: OPR

Post by ctkag » Sat Aug 08, 2009 7:32 pm

You'll also pick up a lot of crap on the tires in the pit entrances as you drive back to the garages. You can usually clean off a lot of the stuff if you jack up the car and do it immediately upon coming in.
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Re: OPR

Post by grovefromnh » Tue Aug 11, 2009 3:33 am

After I would park the car, I would put on some work gloves and run my hand over the tires before they cooled down. That got rid of the pebbles and some of the pickup. Don't forget to clean off the inner wheel of tire pickup!
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horizenjob
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Re: OPR

Post by horizenjob » Sat Sep 12, 2009 10:30 pm

I did have 3 degrees negative all around,and the car felt very twitchy and nervous
That's a lot of camber. It will cause camber thrust and also drag in a straight line. The camber thrust will make you twitchy as the weight moves around from bumps etc. If you think about it you are forcing the contact patch to move outwards from the car's centerline as the wheel rotates and then back inwards.

If the pickup is when your not lapping at speed don't worry about it. You should be able to tell how fast a person with slicks is running just by looking at their tires. No need to actually time them. So keep looking at your tires and learning from them. They should have tiny little waves going across the tread from one side to the other.

The tire temps are probably evening out by the time you get into the pits and measure them. Maybe your car is a little heavy for the tires? What do you use for tire pressure?
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zip4zat
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Re: OPR

Post by zip4zat » Sun Sep 13, 2009 9:34 pm

Troy,
How do you think I can get a whole season on baloney skins? :wink: run'em to the cords and then you can pick up some more rubber before you go home!

Honestly, if the tire bugars dont come off in your first few laps, your tires arent coming up to temp properly. (sounds like all hell just broke loose into your wheel wells). Mark 160* is barely making it into the operating temps of most tires, might need to check your alignments and suspension (or go with narrower tires???)
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breakaway500
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Re: OPR

Post by breakaway500 » Sun Sep 13, 2009 10:32 pm

I figure they are working out on track somewhat warmer than 160. Narrower?Never! :wink:
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mr2sc
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Re: OPR

Post by mr2sc » Mon Sep 14, 2009 4:39 pm

I usually use Keith's method after the last session of a day, just run my glove over the tires while they still have some temperature in them, but I just saw how an ALMS team was cleaning OPR off tires.

They were heating a 1" wide paint scraper with a blow-dryer and easily removing all the OPR...
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Re: OPR

Post by cuda6666 » Mon Sep 14, 2009 10:41 pm

Hey Tommy,

We come up to your back yard once a year without fail. How come you never come down to NHMS? Canadian border guards too much of a PIA on the way back? :D
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mr2sc
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Re: OPR

Post by mr2sc » Tue Sep 15, 2009 9:34 am

Well, I was there once, and it was wonderful seeing everyone. Bruce did a great job of showing me around and by the end of the 2nd day I wasn't tripping up too badly.
Nonetheless, it somehow didn't justify all the travel for me (No insult intended...I know its COM's home track).

I'm about the same distance to WGI and slightly closer to Mosport, so I end up at these instead...along with a few dates at LCMT of course, and the odd Calabogie or Shannonville thrown into the mix. I even have the new ICAR (Mirabel airport runaway facility) closeby.

Ahhh...so many great tracks...so little time! :D
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Re: OPR

Post by cuda6666 » Tue Sep 15, 2009 10:12 am

So, what's that Mirabel track like? I used to love airport courses.
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mr2sc
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Re: OPR

Post by mr2sc » Tue Sep 15, 2009 10:39 am

Its flat. Actually, its 'ok', but i've become hopelessly spoiled by natural terrain road courses with fast, sweeping, and often blind corners.

So...while its nice to add some variety to one's repertoir, given a choice, I'd rather spend time traveling to tracks that are steeped in legend and history and muse that they sure don't make them like this any more! In other words, I like tracks that give me a rush
Tommy
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