ACR track questions re: tire life

[moldowan]

Ok so i drove the car back from houston to san antonio, put 300 miles on her and plan on putting another 300 before i take her to the track next friday.
here's the question; With the sport cup tires approx how many track days will i get out of these tires?
Lets assume 3-4 sessions each day with 10 laps around the 1.8 mile track.
also the drive is 50 miles each way to and from home.
thanks in advance for your input!
-Marc

 

[VIPER GTSR 91]

A lot of variables such as how aggressive you are on the track with them, track temp/ surface conditions, and tire pressures, so you may get a few weekends out of a new set.

 

[Steve-Indy]

I would add that the 50 miles each way can have more effect on tires (and bearings) than you might think if you are using an aggressive track alignment with lots of camber.

 

[gilly6993]

impossible to answer....so many variables....

 

[moldowan]

well i was just trying to get an idea if i am spending one day at the track a week am i going to be buyiing 2k worth of tires each month??
i figured there had to be a few guy with vipers that track often and could let me know what their experience has been with the tire life.

 

[01sapphirebob]

well i was just trying to get an idea if i am spending one day at the track a week am i going to be buyiing 2k worth of tires each month??
i figured there had to be a few guy with vipers that track often and could let me know what their experience has been with the tire life.

While I am no track expert. What the others are saying makes a lot of sense. Just no way to really tell how long you will get out of them. One suggestion might be to buy another set of rims and tires just for the track. That way you extend the life of both your street tires and track tires.

 

[hou99gts]

well i was just trying to get an idea if i am spending one day at the track a week am i going to be buyiing 2k worth of tires each month??
i figured there had to be a few guy with vipers that track often and could let me know what their experience has been with the tire life.

One day a week at the track! You are very lucky! I think you will get 1-2 months out of the tires depending on how hard you run it. Your outside edges will wear out with the street alignment. The track alignment will help your tire life (and handling), but will be bad for street driving. You will have to decide what is best for you.

 

[Bobpantax]

Read this thread:

Hoosier R6 versus Michelin Cup heat cycles - Viper Club of America Discussion Forums

 

[bluesrt]

about 3k miles

 

[moldowan]

thanks all,
i guess we'll see soon! tommoroow is my 1st crack at the track with the car.

 

[PDCjonny]

Be interested in your impressions of the car after a track day.
Keep us posted.
Us New Yorkers are very jealous we are still battling 8 foot piles of snow.

 

[Shandon]

Ok so i drove the car back from houston to san antonio, put 300 miles on her and plan on putting another 300 before i take her to the track next friday.
here's the question; With the sport cup tires approx how many track days will i get out of these tires?
Lets assume 3-4 sessions each day with 10 laps around the 1.8 mile track.
also the drive is 50 miles each way to and from home.
thanks in advance for your input!
-Marc

Lots of variables but if your not a track rat (pushing the the car to its limits) and have a mild alignment setup 14-25 (1/2hr) sessions would be doable. Thats roughly 3-4 track HPDE weekends. Like many have said the surface, alignment, type of driver etc all play a role in the life of the tire. Its a good tire though and I have grown to like it a lot. Takes an extra lap or so to warm up (compared to PS2's) for some reason but it will stick well after that. It's not an R6 though

 

[Bobpantax]

The bottom line is that they get a bit less sticky after each event. The first time I ran mine, the adhesiveness was phenomenal. An incredible difference between the PS2s and the stock Gen IV ACR tires. The decrease in adhesion each time thereafter was noticeable. Driving the car on the street with the tires accelerates the wear. Breaking traction on the street with the ACR tires is a complete waste of money. So if you intend to drive in a spirited manner on the street including the breaking of traction and you do not intend to go "all out" on the road couse, I would say you are better off staying with the PS2s although they too will degrade after so many heat cycles - but at least far more of them since they are not made of the same special compound as the ACR tires.

 

[fireball]

Of course it all depends, but......

I'll guess that if you do a track alignment you'll make it past halfway through the season. The brakes will likely last the entire season.

Since you're new to the track it'll be several track days before you really start using the tires. It'll be late in the season before you really start using the tires completely.

Here's a real tire saving tip. Get a track alignment. Your tires will last WAY longer with a track alignment. The price of the alignment will be saved on the very first set of tires.

I'm at the track about 3 times a week and I see many, many new folks as part of my schools. You'll find the tires lasting notably longer than you expect if they have an appropriate alignment. If you run with the factory alignment the outside edge will wear very quickly - especially the front.

One tip. Check the shock settings right away. Mine were all over the place when my car was delivered - none matched.

Enjoy your car, you really have a good one!

Greg

 

[Bill Pemberton Woodhouse]

Have a street/track alignment on my car and drive 50 miles to one track , no problem. Would suggest the Pilot Sport Cups over the Hoosiers for two reasons;

1. The PSCs will definitely wear longer.
2. The PSCs will work better in the heat, as they stay pretty consistent throughout a run, and the Hoosiers when they are hot can get pretty greasy. You are in San Antonio so they are definitely going to get pretty warm during the Summer.

The one adage that will be true ,is the faster you go, the faster you will go through tires.

PS - the PSCs run a bit more air than the Hoosiers , cold, so keep that in mind.

Good luck.

 

[Dom426h]

Check the shock settings right away. Mine were all over the place when my car was delivered - none matched.

Its not necessarily about the # setting on the shocks matching. Its about the Rate matching. Sometimes a set of shocks end up being on diff settings to be dyno'd equally. (Ex. one shock set to 7 and another set to 6 for them to have the same rate) Exactly how far "off" were yours?

Did you actually dyno your shocks?
Is it possible that the SRT engineers are smart enough to instruct the assemblers to dyno each set of shocks prior to installing to insure that they are set properly?
I personally have no idea what they do at the factory. But i am concerned that you could possibly be ignorantly undoing what someone purposely did.

Perhaps a Q for the next SRTEngineers Q/A Session...

 

[gb66gth]

Blah! Blah! Blah!
The answer is 4
You will get four track days out of your tires.

 

[fireball]

Its not about the # setting on the shocks matching. Its about the Rate matching. Sometimes a set of shocks end up being on diff settings to be dyno'd equally. (Ex. one shock set to 7 and another set to 6 for them to have the same rate) Exactly how far "off" were yours?

Did you actually dyno your shocks?
Is it possible that the SRT engineers are smart enough to instruct the assemblers to dyno each set of shocks prior to installing to insure that they are set properly?
I personally have no idea what they do at the factory. But i am concerned that you could possibly be ignorantly undoing what someone purposely did.

Perhaps a Q for the next SRTEngineers Q/A Session...

I did not dyno my shocks - but I do have more than 30 years racing experience including championships (and holding the current lap record at my local track in my ACR) so I'm fairly good at setting a car up, understanding how changing the settings will change the behaviour of the car, etc.

I forget the exact positions of the shock settings (plus one of the shocks has been replaced) but I do remember that a couple of them were set at the end of their adjustments - one was one way and another was the other way. Making adjustments really did transform the car. We all have different driving styles and we're all on different tracks but I know that fiddling with my shocks, tire pressures and ride height made a big difference.

If your shocks are factory set to a variety of positions and that suits you, then I'd leave them. For me it made a big improvement to make the adjustments. I keep the left and right sides almost always set the same.

FWIW, I did leave the shocks alone for the first couple of track days and I thought a tire was low on air. It wasn't - it was the shock setting.

Greg

 

[Dom426h]

To be clear. I am Not against changing shock settings to be stiffer for the track, or street for that matter. I was specifically commenting on the fact that two shocks can be adjusted to the same Setting while producing a different rate. The only way to know for sure is to use a Shock Dyno wich the SRT Engineers might have done.

Again. This will be a good Q for the SRTEngineers as to why some of your ACR's are being recieved with varying shock settings as this is not the first i have heard of this.

 

[SoCal Rebell]

Blah! Blah! Blah!
The answer is 4
You will get four track days out of your tires.

I got 4 days out of a set of Pilot Cups before I corded and had to replace the fronts, rears had maybe 1 or 2 track days left. Pretty much the same a R3SO6s.

 

[Yellow32]

In my experience with a factory alignment (not much negative camber so you aren't driving off the inside shoulder of the tires) and fairly agressive track (1:55 around TWS) use, 16-20 "twenty five" minute sessions before the cords start showing on the outside shoulders.

Now Harris Hill is really rough on tires even if you drive "mildly", so, even with it being a shorter and lower speed course than TWS I would venture a guess you might get 14-16 sessions on sport cups without adding lot of negative camber. Even if you did add a lot it might get you 18-20 sessions, maybe ...because a lot of negative camber will drive off the inside shoulders and that is a real pain to check for cords as you cannot easily see the entire shoulder without doing something like putt the car in the air, rolling it back and forth as you look under, etc.

But, hey, glad to hear you drove her back from Tomball, nice way to start the relationship!

 

[Yellow32]

If your shocks are factory set ....Greg

My car's "factory shock settings" were all over the place, none of them were the same. So definitely worth the effort to get them to a 'known' setting/baseline before you ever hit the track so you can knowingly adjust them...

 

[moldowan]

Thought i would revist this.
It has been 10 months since i joined the track and i have put 3000 miles on my ACR. about half of those are going to and from the track the other half track miles..... so my It appears that my sport cup tires lasted aroung 1500miles of track days or around 20 track days.
I have just put on some hoosier R6 tires to replace the stock ones and also put on the front splitter...HOLY hell does this thing grip now!!! I am 4 seconds away from the track record (also done on an ACR with R6's) on my stock tires without splitter so i think i might be able to get real close to breaking it with the new setup..we'll see
-Marc

 

[fireball]

Thought i would revist this.
It has been 10 months since i joined the track and i have put 3000 miles on my ACR. about half of those are going to and from the track the other half track miles..... so my It appears that my sport cup tires lasted aroung 1500miles of track days or around 20 track days.
I have just put on some hoosier R6 tires to replace the stock ones and also put on the front splitter...HOLY hell does this thing grip now!!! I am 4 seconds away from the track record (also done on an ACR with R6's) on my stock tires without splitter so i think i might be able to get real close to breaking it with the new setup..we'll see
-Marc

Fantastic! Good luck chasing the lap record!

I'm quite pround that I managed to reset our local lap record in October - and now the track has been torn down and is gone forever, an ACR will hold the production car lap record forever. Yay!

Just out of curiosity, since you're changing tires, what lap record are your going for? The production car record would require you to be on stock rubber. Or is it an outright record? Now that would be something extrodinary.

Greg

 

[moldowan]

our track isn't that formal on records, PRICE COBB holds the all time record there (he won lemans one year) in a GT3 cup car ( no one will beat that time - 1:16.00)..... so I'm talking about the record for a non-professional in a street legal car. we don't really distinguish the records based on rubber at Harris Hill Road course in San Marcos Texas the best time after him is 1:20:00 and I'm at 1:24:00 with stock tires