Anyone run race scrubs on their cars? How did you like them? What pressures were you running? Impressions? Im just looking for input on setup. I've never ran them until now...

I bought some Grand-Am Continental "Hoosiers" this year and ran them over the weekend in and event.

I had some strange results, opposite of my buddies who were running their mustangs.

I read they run best between 36-38 hot, and love negative camber.

These tires were amazing for about the first 5-10 laps, I would set my best times within the few first laps, but after, I don't know why, they would almost become greasy but still very controllable and predictable, its a strange feeling.

So I dialed in more negative Camber in the front probably around -3.5, about -2.0 in the back, and I dropped the hot pressures to about 35 to see if I could get gain back the traction I seemed to be losing.

Then in my 3rd race, I corded my driver rear tire and was done early, I was getting alot of wheel spin, but still fully controllable drifting.

I have a TTG35 Coupe, gutted rear, Adjustable sways, solid rear bushings, solid links, Ohlin PCV (full stiff in front, 14-18 clicks in rear, didnt make a difference).

Heres some footage of my chasing my buddy this weekend

<iframe src="http://player.vimeo.com/video/25691806?title=0&amp;byline=0&amp;portrait=0" width="800" height="450" frameborder="0"></iframe><p><a href="http://vimeo.com/25691806">2 Laps of me chasing Yan</a> from <a href="http://vimeo.com/user2080412">RandomHer0</a> on <a href="http://vimeo.com">Vimeo</a>.</p>

 

I've been speaking with the person I've been buying the scrubs from, he believe my wheel spin would have caused my issue, also advising perhaps a wider rear tire would help me.

Problem is I only run a 17x9 wheel, and I'm think 275/40/17 would be the widest I want to go. I'd also lose my square setup.

Thoughts?

 

Without tires temps its hard to tell what your issue might be. But, if you're getting wheel spin then that would contribute a lot to the tires going away after a few laps.

Also, if you're still running the stock VLSD then all bets are off. That diff is so bad it really screws up any attempts at handling adjustment.

 

Nah I run a Cusco 1.5 with 80% lock.

2 nice black strips lol

I suppose I'm just shooting in the dark, Im going to start with a Corner balance I think.

 

You have to remember, hoosiers will grip even when they cord. Gotta love hoosiers! Without a proper corner balance & alignment, your tires are a waste of money especially with Ohlins (great setup btw).

Just from what you posted, your tire pressures were to low. Hoosiers love high tire pressures. You were losing traction because you didn't run a wide enough tire.

 

Unfortunately the widest Grand Am Continental the gentleman I buy through can get is the 275/40/17.

I could switch to an R6, maybe try a 295/35/17, but I only have 17x9" wheels.

I never really had an issue with the width before trying these, I'm assuming my issue is tire pressure/setup.

 

If you have a TTG35, depending on hp I would recommend going wider. Don't let wheels or tires hold you back from lateral grip. 295's will help you without a doubt but your tire pressures & suspension setup will help even more.

 

Pressures really depend on the car and the overall setup. Collectively we (The FFR challenge cars) have had much better times with low pressures on the hoosiers than high. Cold starts in the mid to high 20's with hot pressures in the lower 30's. We have even started around 24 to make sure we ended up around 28 to 30 hot.

We found that if we run higher than say 32/33 then the tires go away a lot faster (3/4 laps) before the ol' greasy feeling comes in.

 

Don't forget, as far as the cording goes, these are used Gran Am tires could have come off after a long race/practice stint. What was the depth markings at when you started?

Also, how comparable are the basic Hoosier A/R series to these Conti's? Does the Conti's fit in between, lower, or higher as far as grip goes?

 

The conti's are an enduro tire so they are harder than the standard R6

 

When you run low pressures, have you ever experienced overheating with the hoosiers?

 

No, we overheated them at 35-37 PSI. But then again we were 2400 lbs with driver running 275's. Runing higher pressures meant less contact patch overall.

 

They looked nearly new, even had the 4/32" dots.

Its funny, on both sides of that chord, you can still see those dots, so theres still meat on them.

 

wait these are already corded? I would not run a corded tire for safety reasons. they could separate

 

Where they making contact with something in the suspension? Check, I think that may shed a little light on the odd cording.

 

lol me not that dumb

I corded it on track and ended my day early, I didn't run the tire like that.

Thinking about what to do next, I got 3 good tires and 1 bad one, ugh.

 

Your driving is smooth, which I like. You could work a little bit on connecting the turn-in/apex/exit dots though.

275 max for track use on the 9" wheels.

I agree. I have been running both the A6 and R6 tires at lower pressures as well.

 

Thanks Scott, appreciate it, can you explain what you mean by "turn-in/apex/exit"? Any particular section (time in the video)?

Continuously learning

 

Oh c'mon Scott, don't give away tire pressure secrets.

 

Most are minor, but if you fix 10 minor things you'd probably knock a second off your lap time:

-Missed apex at 1:04, making exit tough leading to big apex miss at 1:10
-Get all the way left @ 1:24
-Late turn in at 1:45, and missed apex
-You leave room at 2:22 - I want to see some berm love!
-Late turn in at 3:21 leads to missed apex and early exit
-It's hard to tell from my comfy chair the fastest way through 3:32-3:42, but I think I'd do it differently
-More left at 3:54
-Late turn in at 4:16

Overall - good job, but see what you can do about using all the track and then some.