1st AutoX event of 2024

[MatthewAMEL]

Well, the Central Florida Region (Orlando/Tampa) kicked off the 2024 season today with an event at the Orange County Convention Center.

Fairly chilly start (for Florida) in the morning led to perfect weather for the later run groups.

1st event on the Falken RT660s and I have to say they are far superior to the PS4S. Where I used to be 2-3 seconds out of 1st in AS, today I was less than a second behind a 911 GTS and 718 Cayman GTS.

On a side note...managed to beat EVERY Corvette that showed. C6Z, C7Z, C8 Z51...raw timed them all. That felt nice.

Same run, but from the GoPro on the window. Amazing the sense of speed you get from the GoPro video that the PDR doesn't convey.

 

[99sport]

Well, the Central Florida Region (Orlando/Tampa) kicked off the 2024 season today with an event at the Orange County Convention Center.

Fairly chilly start (for Florida) in the morning led to perfect weather for the later run groups.

1st event on the Falken RT660s and I have to say they are far superior to the PS4S. Where I used to be 2-3 seconds out of 1st in AS, today I was less than a second behind a 911 GTS and 718 Cayman GTS.

On a side note...managed to beat EVERY Corvette that showed. C6Z, C7Z, C8 Z51...raw timed them all. That felt nice.

Same run, but from the GoPro on the window. Amazing the sense of speed you get from the GoPro video that the PDR doesn't convey.

I have a soft spot for the Azenis. The 615s were game changing when they came out 15 or so years ago. I bought many sets and put them on all my daily drivers. However, Grassroots Motorsports has a huge tire comparison chart (page 83 in the Feb issue), and the Michelins look better in that table - and the TPCs are supposed to have the sticker cup compound on the shoulder, so should be even better than the other PS4Ss. The Michelins are only $100 more per set. And a couple of weeks ago Jason Cammisa released a podcast absolutely gushing on the PS4Ss - more grip than every other street tire, 4X the life, progressive at the limit, wonderful in the wet, etc - although he mentioned almost every major manufacturer, he didn't mention the Azenis.

Based on all of the above, I figured I'd stick with the PS4Ss, but now you have me reconsidering. Wet and cold temp performance is irrelevant to me, and comfort would be nice, but is negotiable. Progressiveness at the limit and ultimate grip are most important to me.

Would love to hear if you have any back to back comparisons with the 4Ss and Azenis. Also, did you ever run the kumho v710s? How do the current 200tw tires compare? My S2000 was incredible on the Kumho slicks, but every other tire I've put on it feel like ice skates in comparison.

Edit: just looked at the GRM table and looks like th 4S is better for track days and RT660s are better for autocross - might need 2 sets of rims

 

[MatthewAMEL]

So, the BW is the 1st car I have had PS4S on. I was initially skeptical for several reasons, but I will admit to being happily surprised by how good a tire it is. Relatively quiet for it's level of performance, great in the wet, wears like iron (until you just go ham in quest for PB at Time Trial - pic below). I was greatly impressed. In fact, when it came time for a new set, I initially considered only the TPC PS4S...but then I tried to buy them. Nope.

Tire Rack had the rears, but no fronts. And no production even scheduled until July and then slow boat over...land here sometime in August/Sept. Costco doesn't have the TPC version. Called several dealerships...no joy.

So I was forced to pick another tire. I went with the 660s because I loved them on my SS 1LE. I don't drive very much, so comfort wasn't a priority. I wanted something I could put on and run at AutoX and track.

I have a set of Apex wheels, but I haven't mounted anything on them yet. I think I am going to wind up with three sets of wheels like I had for the Camaro. One daily set (PS4S on OEM wheels), RE-71RS for AutoX (305's avail in the spring) and Goodyear Supercar 3R for track.

The TPC PS4S is a much better tire than the retail PS4S. It will get you to 90% of where you want to go. The 660s finally got my non-competitve car within a second of the fast guys in AS in my region.

 

[99sport]

Did you ever run R comps back when that was the legal tire for stock classes? Any idea how close the RE71RS is to the old V710s? Everyone says how much better tires have gotten in the last 15 years - at some point the current 200 tw tires will be as good as R comps from the end of the era when R comps were legal.

Are you running the full track alignment in the manual? My alignment guy said he could only get - 2 in the front. I bought the factory service manual the day before my alignment appointment and discovered the rear eccentric bolts are torque to yield and could only find 1 of 4 in stock locally. The alignment shop and local dealer didn't have any. So I left the back alone. I was pretty happy with the tire wear pattern with that not-even-close-to-track alignment after my track day (wet course with lots of traffic so there weren't many flat out laps)

 

[MatthewAMEL]

Did you ever run R comps back when that was the legal tire for stock classes? Any idea how close the RE71RS is to the old V710s? Everyone says how much better tires have gotten in the last 15 years - at some point the current 200 tw tires will be as good as R comps from the end of the era when R comps were legal.

Are you running the full track alignment in the manual? My alignment guy said he could only get - 2 in the front. I bought the factory service manual the day before my alignment appointment and discovered the rear eccentric bolts are torque to yield and could only find 1 of 4 in stock locally. The alignment shop and local dealer didn't have any. So I left the back alone. I was pretty happy with the tire wear pattern with that not-even-close-to-track alignment after my track day (wet course with lots of traffic so there weren't many flat out laps)

Fire your alignment guy. No problems getting to -2.5...he said he could easily get -2.8F. I left at OEM Track spec and I have been very happy with it. Not at all 'darty' on the road. The rear TTY bolt is a long term issue that even my dealer now ignores. No one has any idea why GM would spec a TTY bolt in a part designed to be adjusted. Most consider it a weird typo. Even the Caddy dealer who did my alignment ignored it.

The RE-71 was already better than the old 'r-comp' of times past, imho. The 'next gen' 200TW - RE-71RS, Nankang CR-S and Tempesta P1 are all VASTLY superior to the R-comps. In fact...the Tempesta is so good, the SCCA banned it for use in competition. It was running near Hoosier A7 times. The only R-comp I would say still hits the mark is the Goodyear Supercar 3R. THAT is a fantastic tire.

SCCA bans Vitour Tempesta P1 | Tire deemed not eligible for 2024.

The SCCA has banned the Vitour Tempesta P1 from both its Time Trials and Solo programs in categories where tires are restricted to 200tw.

grassrootsmotorsports.com

 

[99sport]

Not sure if you saw it, but the latest issue of GRM has an article about the history of that Vitour and tire test. It was blisteringly fast on its first lap, but was a second slower on it's second when it started to overheat - I'm guessing it's better with a Miata or Elise than a Blackwing (although it sounds like it only comes in smaller sizes currently).

My alignment guy said the same thing about the TTY bolt, but as a mechanical engineer I'm not going to risk it. My days of competitive autocrossing are behind me so I'm more concerned with maximizing tire life when the car is driven aggressively. I've never driven a car with strut suspension before, and strut suspensions have a poor camber curve - and need a lot more negative camber for decent tire life. I was pleasantly surprised at the amount and pattern of wear on the rear tires after the track day with the factory rear alignment, but the front tires had significantly more wear and definitely could have used more negative camber - even with the increased negative camber compared to the factory front alignement. Given the amount of street miles I do, I think I actually stumbled into a pretty good compromise alignment, but we'll see how the tires continue to wear. I'm curious what your tire wear is like, but it sounds like you get very few street miles and it might be an apples and oranges comparison to my use. Are you wearing the inside edge out?

 

[MatthewAMEL]

I killed the PS4S at the FIRM (GRMs home track - friends with JG) while chasing a PB during Time Trial. They only had about 6,000 total miles on them. 2 Daytona, 3 Sebring and 5 FIRM days. As well as about 6 AutoX events.

Inside edge was holding up fine when I did my inspection before the TT.

As for the TTY bolts, YMMV, but I ran my SS 1LE for 6 years and never once replaced the bolts. It spent A LOT of time on track and specifically Sebring which beats the heck outta cars. The bolts are a non-issue.