Olitho

What are the tire pressures you guys are using on track for the A6?

Falcon

26# front, 24# rear and some guys are even going lower.

Carolina C4 Racer

This is COLD, I assume??

I'm an autocrosser so I'm playing a different game but that is WAY below what Hoosier recommends for hot pressures.

Bimota Guy

That is hot for road race. I am in that same area.

BEZ06

I've never done Autocrossing and I've never run on the A6. I run the R6 on road race courses. Here's a Hoosier site that talks about pressures for both tires:

https://www.hoosiertire.com/Tctips.htm


You can see that for the A6 it says:

and the hot tire pressures that Hoosier recommends for a Corvette weight car are 38 to 43+ psi. I find the R6 performs great with hot pressures up in that range.

I'm just a rookie track driver and I'll defer to the guys like Falcon that have a lot of track experience, but I'm surprised their advice is so much different from what Hoosier recommends.

Bob

gonzalezfj

For cars with proper negative camber.

Frank Gonzalez

Sidney004

What are your cold starting pressures to achieve these hot pressures?

fatbillybob

Wow seems low to me too. Acedemically I would say that underinflating a tire adds heat pretty quick and part of what helped to damage sidewalls on the infamous ford exploder causing rollovers. The A6 not designed for roadracing is ment to heat up fast and do short runs so I would think it would even be more subject to the abuse of an underinflation. But the pyrometer does not lie. I guess if your temps are even for the way you drive all sins are forgiven.

Wicked Weasel

I started with the higher psi with the R6s, but they did not do what I wanted. Eventually I found 31F - 28R hot was a good place for me. I will probably start there with A6s and adjust based on feel.

Falcon

Those are my cold starting pressures. I've found those pressures will get me to 33'ish when hot. In hotter weather I go a pound or 2 lower since the track will have a bucnh of heat in it.

There are guys out there who start in the high teens from what I hear.

Everett Ogilvie

Cold; 20 front, 22 rear. This in a 2450 lb rear engine car. Just posted this to show how low the factory (the car maker) recommends for a track setup in a non-Corvette car.

So in a 3120 lb Corvette with A6s I would go 24 front 22 rear.

BEZ06

WOW!!!!

Like I said earlier, I defer to the experienced track guys here, but I'm absolutely ASTOUNDED that many of you have found the tires to work well at pressures WAY below what the manufacturer recommends.

Here's an excerpt from the Hoosier website:

So....even at the minimum safe pressure, if you calculate it as above for a fully loaded C6 (I guess mine would weigh at least 3500 lbs with fuel and my 220 lb butt in it), the minimum safe (cold) pressure would be 35 psi, and that's about what I've been running in them cold - then they warm up by 6 to 8 psi above that by the end of a 30 minute session.

I really don't think Hoosier is giving out numbers here just to CYA for liability purposes. I truly think they're trying to put out info that will help their customers get the most out of their product.

Like I say, I'm amazed that Hoosier recommends 10 to 15 psi higher than what guys with a lot of track experience have found to work best.

Here's a picture of my nice Longacre pyrometer:




That unit has a nice memory feature, but my plans were to keep a log of temps and try changing my setup and pressures to get to the Hoosier recommended 180 to 200 degrees across the tread. I set up my alignment to close to the Hoosier recommended #'s. I had about -2.5* of camber up front and about -1.5* in the rear, with about 1/8 inch toe-out up front and 1/8 inch toe-in for the rear.

At my last HPDE I couldn't pull into a hot pit after hot laps - after a cool down lap I had to drive through the paddock area to my garage before I could take temps. They were all mostly around 150 to 160 on the left side and 170 or so on the right (this was at Daytona, running counter clockwise with big left turns around the banking, so the right side was taking more of a beating) and very even across the entire tread up front, and the outside shoulder a little warmer on the rears (I attribute it to the less camber back there), so I didn't keep a log or make any changes. Here's a picture of my rears after about 450 miles of track time at Daytona over 5 days (one day was raining in the afternoon so I did very little track time that day):



You can see on these rear tires that the outside shoulder (easiest to see on the tire on the right) has a little more wear. I'm of the opinion that it would have a lot more wear if I was running less pressure.

The fronts are even wear - if you didn't know how they were mounted on the whell you'd have a hard time figuring out which side was on the outside of the wheel.

Does anyone have recommendations on the temperatures I should be getting at the end of a session?

Thanks to all for the info - I guess I'll have to try a lot less pressure and see how it works.

Bob

Bimota Guy

There is nothing on that page which deals with road racing the Hoosier A6.

Z06Fix

I was about to say 22-24 hot I just couldn't imagine that.

22-24 cold and 33-35 hot sounds more like it.

I'm going to try running some higher pressures this year for autox to see what it does. Last year I ended up running 34frt 31rear hot. I'm going to bump that to 36-34 this year. Hoosier says they will be faster and last longer. We will see

Bimota Guy

If you bring your Exlporer to the novice school they will kick you out.

doje

It should be noted that the OP is talking about the AAAAAA666666 which is a WAY DIFFERENT TIRE than the R6. It is designed for short runs where you don't pick up a whole lot of heat. The A6 should be run around 40psi on a Corvette in a Auto-X - which is what this tire is made for. If you are going to run road courses, get the right tire - R6. Start with the tire at 40 and as the tire gains heat, just let out a little air after each run - keeping it at 40psi.

Note: this is from experience. I used my first set of A6's at 30-32 psi and corded the outside edge very quickly. At 30-32 psi, the tire will roll onto the edge in corners and destroy it quickly.

BEZ06

That's true.

And I never thought the OP had any intention of running them on a road course. I figured he would be running an A6 on an autocross course. I figured if he were running a road race track that he'd be running the R6.

However, the website fully addresses the A6, and basically says to run the A6 at the same hot pressures as the R6. To do that it says:

Recognizing that A6 hot pressures should be the same as R6 hot pressures, they're recommending to start at a higher pressure at the beginning of an autocross run, I think due to it being shorter and slower speed runs which will only increase the pressures by 1-2 psi during a run.

I don't know why you'd run an A6 on a road course, but if you did I guess you'd be running very similar pressures to the R6, i.e. start at a lower pressure so by the end of a longer session you're up to their recommended hot pressures.

Again, I'm an inexperienced track guy trying to learn, and maybe there's some advantage to running an A6 on a higher speed track for 20 or 30 minute sessions that I don't understand.

BTW, my only reason for getting involved in the thread was to bring up what Hoosier recommended because it seemed to vary significantly from what others were saying to run. Not having a whole lot of experience, I've been using their recommendations, and I thought I was getting good results. Hoosier seems to recommend the same hot pressures for the A6 and the R6, but I don't think they are expecting people to run the A6 on a road course, and neither was I.

Bob

Bimota Guy

The OP races on the A6 regularly. Notice his question uses the word "track." And I race with him. Every Hoosier-shod national caliber T1 driver races the A6. If you run the R6 in a sprint race you will be left behind. Simple as that.
Not really. The website addresses how to use the A6 in autocross conditions only. That is one 60-second-ish lap, sit still for typically 10 minutes or so, repeat.

Bimota Guy

Let's try this again.
1- This is not a thread about autocross use of the A6
2 - EVERY Hoosier-clad national caliber T1 driver runs the A6. It is the right tire IF you want to win in a sprint race. If winning and/or being competitive in such racing is not a concern, then you can run the R6. We can discuss what tire pressures work for different drivers, but you need the A6 to be competitive if someone else is running them.

fatbillybob

Oh then what I posted is not an issue.