I think it's definitely worth driving them until they completely fall off in performance.
Photograph by RJM Media
What makes The FIRM’s Track Attack Series so unique? It uses a different track layout for each round.
So far, we’ve competed on the Florida International Rally & Motorsport Park’s traditional layout that we use for all of our car testing, a truncated version of that skips Turns 5 through 8, and a reverse-direction configuration.
For this weekend’s fourth round of the five-round series, we’ll return to the standard direction of travel, but the course will also incorporate the “Shoebox” section that adds four additional corners to the mix, as well as some elevation change. It’s a cool opportunity to run a unique layout in a familiar setting.
Photograph by RJM Media
We’ll be there with our 2015 BMW 435i project car that’s currently leading the TA4 class championship battle, which we could theoretically lock up this weekend with another win.
But while the awards are nice, the data gathering is even nicer.
The big question this weekend: Just how far can Vitour P1s wear before they become unusable?
Photograph by RJM Media
We’ve been running this same set of P1s since spring, and they currently have over a dozen heat cycles on them between FIRM testing, hot laps at Daytona, and a podium drive at the Tire Rack SCCA Time Trials Nationals.
[How we scored another podium finish at SCCA Time Trial Nats]
We were planning to replace them before TTN, but a chat with Vitour’s Dallas Reed changed our minds. Reed insisted that the performance stays consistent throughout the life of the tread, so long as they aren’t showing any obvious signs of abuse like chunking or outer shoulder discoloration from overheating.
Our 275/35R18 P1s still look, well, pretty darn good. Running a square set of BimmerWorld TA5R wheels has helped things, as we’re able to easily rotate tires both front to back and side to side, so the tread depth has certainly diminished over time, but it’s done so consistently.
Photograph by J.G. Pasterjak
We’ve seen slight rounding of the shoulders, but it looks like the tread surface is still doing most of the heavy lifting when it comes to cornering. Performance has been steady as well.
Looking back at the data, it’s honestly difficult to point to the tires truly falling off in any definitive way during their tenure. A couple test days in the summer weren’t as fast as our best laps in the spring, but the track temps were also much higher.
Even with the higher track temps, while we may have seen slightly lower cornering speeds in a corner or two, those lower grip numbers weren’t universal, and just as many corners were as fast or even fractionally faster in the heat.
So, objectively, we can, at worst, call any notable tire degradation inconclusive. Subjectively, however, they definitely had a sweet spot roughly between the second and fifth heat cycles, when they just felt invincible and rock-solid. After they started showing noticeable wear and mild graining, they got a bit edgier and more sensitive to shock loads, but still seemed capable of producing the same kind of numbers they had when they felt their best.
At any rate, this weekend will likely be the swan song for this set, although if there’s anything left of them. We might go back and just run them until the air shows to see how they perform to the bitter end. Ultimately, having a set of tires that remains drivable and competitive through their entire lifespan is a win.
Aside from having that plan in our head, there was very little prep necessary to get the BMW ready for the track this weekend. It was pretty dirty from TTN at Pitt Race, so it got a bath in Griot’s Track Spray to get rid of all those rubber marks, then a fresh coat of wax since that stuff can also remove the protective finish. But whenever you’re talking about your track prep in terms of “we wiped the car down,” that feels like you’ve put together a pretty reliable and dependable track machine.
Photograph by J.G. Pasterjak
If you’d like to join us at The FIRM this Sunday, October 19, it’s open to everyone, whether you want to compete or not. There are timed sessions as well as untimed lapping available, so show up and experience our official test facility in a way that you may never get the opportunity to again. The FIRM will also be hosting a special “Pop-Up” open track day in addition to its regular Friday/Saturday/Sunday open track schedule on Monday, October 27.
If you’re down for an early week lapping day, you might catch three of our project cars there that day doing some testing as well.
I think it's definitely worth driving them until they completely fall off in performance.
In reply to Austin Cannon :
The first time I read your comment, I really thought you wrote "I think it's definitely worth driving them until they completely fall off."
Which is certainly a choice, I guess. 
Colin Wood said:In reply to Austin Cannon :
The first time I read your comment, I really thought you wrote "I think it's definitely worth driving them until they completely fall off."
Which is certainly a choice, I guess.
Years ago I made a sticker "shred till the wheels fall off" and gave one to a Formula Drift guy that finished a run missing a tire. I'm pretty sure he still had the sticker on the dash when he sold it a few seasons later.
I'll be there! Though I can't technically win the class, I'd love if I end up finishing 2nd in class. Not sure if that's possible. I need to check the standings. I know that I need to hit the last TT in December to qualify. I missed one of the earlier ones.
wvumtnbkr said:I'll be there! Though I can't technically win the class, I'd love if I end up finishing 2nd in class. Not sure if that's possible. I need to check the standings. I know that I need to hit the last TT in December to qualify. I missed one of the earlier ones.
Yeah man it's awesome you've made so many. Nice to see the car getting a little more reliable each time, too.
Is TA 4 a class in SCCA? I have a 2017 BMW m240i in the T2 class in the WDCR SCCA. Glad to see a modern BMW racing.
I was not aware the time trial series used different configurations each time. Thats pretty cool, and also kind of appealing as far as geting out to the Firm again to use the asphalt track. I've pretty much been doing just rallyx there for the last couple years.
Lof8 - Andy said:I was not aware the time trial series used different configurations each time. Thats pretty cool, and also kind of appealing as far as geting out to the Firm again to use the asphalt track. I've pretty much been doing just rallyx there for the last couple years.
I'm not sure if this was an intentional decision at the beginning of the year. The change to the track due to the airport stuff forced us onto the "little" track. It seemed to just go from there.
I really don't remember if that was the plan all along!
mherbert4701 said:Is TA 4 a class in SCCA? I have a 2017 BMW m240i in the T2 class in the WDCR SCCA. Glad to see a modern BMW racing.
I don't believe so. It's just the FIRMS class for cars between 12:1 and 14:1 pwr.
Lof8 - Andy said:I was not aware the time trial series used different configurations each time. Thats pretty cool, and also kind of appealing as far as geting out to the Firm again to use the asphalt track. I've pretty much been doing just rallyx there for the last couple years.
The plan was always to mix it up, but I think the original plan was to start and finish with OG FIRM GRM test course. When we had to do little track because of the troubles that got altered.
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