hsb1001

This weekend we were able to successfully test the new AR1 in OEM RS Sizes, 265 front and 325 rear. The car was a .2 RS with a DSC controller and alignment -2.7F and -3R camber. The testing was done with back to back against a new set of Dunlop Max Race 2's and the data from my .1 RS with a much more aggressive setup on Cup 2's and Cup R's as I have quite a few laps around Sebring now. Weather was nice and cool in the 60's and the .2 RS was new to me as the alignment / height etc needs allot of work to dial the car in for any tire and the results from previous tires was done in very similar conditions.

Impressions:
First session I thought these tires are quite hard compared to the MPC and Dunlops as out of the gate I could feel more bumps and undulations as compared to the other tires. PSI Set to 25 cold and it rose to 28 at the end of lap 2 and the car comfortably put down a lap 2.16.5, quite allot of understeer in the car which was due to the setup which needs adjusting, as the same understeer came from the Dunlops only a session earlier which were also fresh with back to back heat cycles tested. The grip compared to Dunlops and Michelins was 10-15% better in session 1 although I didn't want to push too hard given the amount of understeer the car had in high speed corners.

Session 2 - Tires set to 25psi again and the bounciness had almost disappeared compared to session 1, the PSI rose to 29 on lap 3 and I pushed harder, under hard braking these tires are immense compared to the other street tires, same braking threshold as Cup R's on Sebring and definitely better thresholds than the Dunlops and Cup 2's. I pushed 3 hard laps and the tires remained consistent, the PSI rose to 33 at 1 point on lap 6 due to the setup of the car and squirming around allot but the grip levels felt almost the same as lap 3.

Session 3 - Tires at 24F and 25R to minimize a little understeer, Lap 2 hot lap immediately after the out lap, the tires were on at 28PSI and I pushed more, immediately set a 2.15.5 lap time and it was consistent for 3 consecutive laps with almost no loss of grip as the long laps kept continuing, i only slowed down to to traffic and cooled down to 30PSI and went again, still the grip continued and I could tell that this tire was far more capable than a Cup 2 or Dunlop any day of the week. The grip on mid to high speed is incredible as those who know Sebring it can take some commitment and Bishops was showing 135mph without pushing super hard.

Session 4 - Tires 25PSI all round cold, 1 out lap and then straight onto a hot lap at 28PSI and the lap time was an immediate 2.14.9 with no real commitment to push hard as I was getting more comfortable with the new car. Then consecutive 2:15.2's for 2 more laps due to all the mistakes I was making to push even harder on a car I unfamiliar with. The theoretical showed 2:13.2 consistently if I had the understeer fixed but that can wait for the next event. The grip levels continued to come on more with continued laps and the braking became a little deeper with the tire holding steady between 30-31PSI which seems to be their peak performance zone.

Checked the wear and it was fairly minimal after 4 hard heat cycles with just the outer edges showing the heat cycle as the tires still look great as though I had been driving on light road use.

Conclusion:
For a tire that is incredibly cheaper than the competitive brands like Michelin/Dunlop/Hoosiers etc, the performance is incredible at its price point and the consistency remains on point as the others drop off quite quickly after a hot lap or even 2, i noticed the other brands require some cooling before you push again and the AR1's just continued to get better with more laps. The AR1 exceeded and outperformed Cup 2's and Dunlops is my opinion, compared with a Cup R they can keep up for sure but not as quick we all know in a first few runs. I can now understand why all my Euro friends back home use this tire in allot of sizes as it stays consistent and can perform as good as all the others with the right settings and obviously needs a better driver.

The AR1 will allow flat out cornering compared to the others, those who know Sebring understand that it can take some hard commitment. Bishops Bend with the AR1's is a Flat Out Turn with Vmax of 138MPH+ on a fast street alignment setup. I am confident that this tire will continue to hold up over more heat cycles as the car gets dialed in and can achieve times and consistency way better than the expensive brands.

Roll on to the next testing ventures., pictures below are after 4 hard heat cycles showing almost zero wear.

SB27

Great write up. Fantastic. Thank you.

Questions:

1. What size wheels are you running on your .2 RS? Look like BBS?
2. What size tires (F/R) did you use and from where did you source them? (Tire Rack or other).

Tnx.

hsb1001

OEM Sizes on the new forgeline GS1R wheels which are the same offsets as factory. 265 35 Front / 325 30 21 Rear

The AR1 is in the process of being released in the US later this month or next I believe, quite a few sellers out there like Phil's Tire Service who are an importer.

DHI

Good write-up.
Thanks for sharing !

I have been using AR1s for the last 15-20 track days on a stripped out 6GT3 and played around with tire pressures keeping them between 32 and 38.
I have settled on 34F 36R as target pressures.

I never even thought of trying pressures as low as you have.

Maybe you can see what higher pressures work out for you?

Nankang UK has the following recommendations...Optimum camber settings between -1.0 to -3.0 degrees

HOT Pressure settings

<800kg 23 - 27.5psi

800-1000kg 24 - 32psi

1,000-1,400kg 27.5 - 37psi

1,400kg> 34 - 42psi

Tay101

Thanks for the review.

A little off topic, but is that Forgeline Satin Race Gold or is that Porsche Satin Aurum on your wheels? They look great by the way.

M3the01

Did you collect any tire temperature readings? What are the target temps one should aim for? Optimum operating window 71-104 degrees celsius [0]
Directional tire so no rotation, is that going to impact it's use?
Do u have the official specs of the tires (20"/35/265 27.3") to compare absolute diameter vs dunlop's vs michelin?
What's the cost? $300-$465 retail.
How many laps per session at sebring for the 4 sessions? Just trying to gauge where the tires are at now.
Looks like fronts are 4lbs heavier and rear 1lbs heavier than the MPSC2, so 10lbs overall.
Can we have a close up of the center lock side? as they look very small. Thoughts?

Ty for providing the info, ive filled in what i could find.

[0] https://www.nankangtyre.co.uk/products/motorsport/ar-1/

hsb1001

Hi, the engineer recommended starting at 25 cold which worked quite well, i personally would not run these above 34psi as they would become loose i thought. I would think those are recommended pressures for longevity above, i will try at 28psi as 34 will be seen in a full lap at sebring.

hsb1001

• Hi, no tire temps were taken although should have been to find the right alignment setup.
• Rotation would only be side to side, i wouldn't flip inside out if its not recommended
• Specs below although i don't have Dunlops or Michelins, i would say google has them
• Cost is via Phil's Tire Service who are a distributor, some others out there too
• Each session was 10 full laps which is 3.75 miles I recall so 37+ miles, plus out-lap and in-lap. Total around 165 miles on them plus 10+ street driving to set tpms and see how they felt in general

Thanks

DHI

Thanks!
Can't wait to hear your findings!

Mech33

Thanks for the review. Does the rear 325 on the RS look as stretched as the 305 does on the 12" GT3 wheel?

hsb1001

When the tires are off the car, they look like they are just a few mm wider than the 12.5 rim, when on the car they look almost like the others. The AR1's don't have the curb protector built in like the OEM Tires which is why the sidewall petrudes.

For a track focused tire the sidewall protector isn't required like slicks, very similar to some slicks when mounted as they look flush with the wheel, but once on the car it all looks normalized with weight including the front.

lisocayman

I ran the 305s on my 12” wheels on my GT3. While the price is great, I found them too stretched and didn’t find them faster than OEMs. Maybe I need to try another set but I corded them in 3 days with 330 track miles.

DHI

3 days is a lot less that what I am used to on a 6GT3.
What is your regular go-to Track Tire and how many days or sessions do you get from those?

hsb1001

Interesting your feedback as my tires looked like new after half the miles you did, I push pretty hard and try to be smooth as possible so I don't over heat tires. What PSI were you running hot?

A friend of mine has the 305 size and his are still going after 22 or so heat cycles. I will ask him to get some pictures.

usrodeo4

Very complete review...thanks for all the detailed information. I tip my hat for all the track time at Sebring, that is a big boy's track.