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What brand of tire? I’m using sc3r’s, and they’re almost an inch wider than some other 305/19’s.
is rolling the fender lip an option?
Sport Cup 2s, I have Front camber plates, and rear LCA's on it, -3.1 in the front and -2.5 in the rear. ET 46 offset on 19x11 Apex wheels on the back, just getting a touch of contact, may be able to roll the fenders a bit
Yeah, stock sizes. I feel no need to deviate from that. With the wider front track from the APEX wheels and the little more stretched front tire (from the wheel also being wider), the turn-in is much more immediate and my car is already set-up to feel pretty neutral. I wouldn't want it anymore oversteer biased.
I have the solid caster pucks as well, so I also feel that if the steering was anymore direct or sensitive it would be too much for a street car.
You could do a 255 front and get a little more grip and then just rebalance the car from there. If you wanted more ultimate grip for the track maybe. Most of the guys at my track are moving to the bigger fronts. If however your car is in the sweet spot for street driving, and you are very happy with it, then I would agree to not mess with a good thing.
Had another great day at Laguna Seca this past weekend, and first with a new set of AD09 in OEM sizes (245/295). First set of new tires after coming of the Dunlops from the factory. It was a little greasy out there after having just had rain and snow on track the day before, but thankfully the sun came out and helped the track a little bit to offer a good comparison.
The track was getting better and better throughout the day as it warmed up and more rubber was being laid on track. This was my first time trying this tire out, and at first I didn't like them as much as the Dunlops as it was pretty slippery out there. I wasn't sure how much was the tire vs the track surface itself. I was a little frustrated with the lack of grip, and ended up overdriving quite a bit in my second session. But took a break for some food, decided to calm down and focus on cleaning up my driving, and everything started to get better. It probably helped that the sun was coming out and helping with the tire temps. After two more sessions, I felt much more comfortable with the tire and was putting in consistently quick and smooth laps. By the last session I beat my best time by close to a second before hitting traffic.
A few more observations on the AD09:
- They take a couple of laps to get up to temp and perform well. After the out lap and the first full lap, I felt very comfortable pushing for times.
- They maintained throughout the whole session (20–25 min). I observed no drop-off even after pushing for 10–12 laps in a session.
- Turn-in feels quite good.
- I noticed it lacked some traction under heavy braking and would skid a bit, but I think that might have been due to the track condition as it got much better as the day went on
So far, I'm happy with it, and excited to see how long they last. It's a terrific OEM size option for us, and the longevity and price point is a big plus (approx 40% cheaper than the Dunlops!). Hoping to get 20+ heat cycles out of these.
Thank you for this great report. I wonder if the new tires still had some mold release on them which can make them pretty slippery until it's worn off? Did you put any miles on the tires before you got to the track?
Thank you for this great report. I wonder if the new tires still had some mold release on them which can make them pretty slippery until it's worn off? Did you put any miles on the tires before you got to the track?
It's possible. I drove about 100 miles to the track, and had about 30 miles from the street before them...so not a ton. I did not get them heat cycled. I read about the mold release and was hoping that ~100 miles would help. Maybe it wasn't quite enough and I needed a few sessions to really get that off properly.
One thing I forgot to do was reset my G-meter before starting the day. With the Dunlops at Laguna, I had measured 1.76/1.82 lateral Gs. I'll reset the meter the next time I'm there for comparison.
I doubt it was mold release, I'm guessing it was condition based. The endurance 200 tires, do not like cool damp conditions. They do take longer to heat up than say RE71RS or A052s. Heat cycling does help with ultimate grip.
I doubt it was mold release, I'm guessing it was condition based. The endurance 200 tires, do not like cool damp conditions. They do take longer to heat up than say RE71RS or A052s. Heat cycling does help with ultimate grip.
Makes sense. It was certainly cool and damp, especially in the morning.
First session I started at about 28/30. It was COLD outside, like 40 degrees. (For us NorCal weaklings, 40 is cold). Pressures ended up getting predictably too high, up to 36/39 or so at the end of the first session. I usually don’t worry too much about the first session anyway.
Lowered it down to about 34/35 hot for the second session.
Then to 33/34 hot for the last three sessions, and everything felt quite good.
Coming from a 997 my go-to track tire is the Nankang CR-S. Curious to hear feedback running this tire on a GT4?
So far, the feedback from GT4 and GT4 RS that have been running the CR-S has been great. They don’t have OEM sizes, but they do have 255 or 265 fronts, and 285 or 305 rears. Faster than the AR1, and wears pretty well too. They also have relatively decent street manners!
If they release a 295 rear, I’d like to try the CR-S next.
Only downside is that there’s been a bit of a shortage—hard to find them in stock sometimes.
Coming from a 997 my go-to track tire is the Nankang CR-S. Curious to hear feedback running this tire on a GT4?
👍 been running CR-S V2 on my GT4 245/35 295/30 19" fast, handle heat well just take a lap or 2 to come up to temp. Nankang has a kerfuffel with the DOT and had to send some containers back. New shipment is supposed to be on the water arrival in ~May.
First session I started at about 28/30. It was COLD outside, like 40 degrees. (For us NorCal weaklings, 40 is cold). Pressures ended up getting predictably too high, up to 36/39 or so at the end of the first session. I usually don’t worry too much about the first session anyway.
Lowered it down to about 34/35 hot for the second session.
Then to 33/34 hot for the last three sessions, and everything felt quite good.
Thanks for the update. I'm installing the combination of A09's with Apex wheels. I need to weigh the rear wheel/tires still but the fronts were about 4.5lbs heavier then the OEM wheel cup 2 combination which had about 3, 200 miles on them.
Other observations I'm swapping the pads DS312. After about 750 track miles at Road America they had less than 50% pad material remaining. I'll do the rear wheel swap but I think the rear pads are closer to 70% remaining.
Y The other thing I meant to add is the break caliper seals are definitely busted. I didn't replace them because I didn't have them on me. But something that I'll have to do in the future. Didn't take a photo should have.
I'm doing text to speech and I know how to spell break but apparently text to speech does not
Thanks for the update. I'm installing the combination of A09's with Apex wheels. I need to weigh the rear wheel/tires still but the fronts were about 4.5lbs heavier then the OEM wheel cup 2 combination which had about 3, 200 miles on them.
Yeah, AD09s are heavy, probably because of the stiffer sidewalls. CR-S is also a heavy tire for the same reasons. For the street, there may be a mpg difference compared to a very light tire like the Dunlops, but the benefit is potential improvement in dynamics.
04-04-2024, 04:04 PM
