The biggest drama was the utter lack of drama.
Although the 2025 edition of the SCCA’s Time Trials Nationals was held at a new track–moving from its previous home at NCM Motorsports Park in Kentucky to western Pennsylvania’s Pittsburgh International Race Complex–our BMW 435i project car, now nearing the end of its second season of development and sorting, didn’t miss a beat on the way to another class podium finish.
Dead-nuts reliability hasn’t always been the theme with our 2015 BMW, but if you scroll back through the project updates, you’ll see that some of the issues were self-inflicted, and some, though frustrating, stayed fixed once we fixed them.
It gets back to what our friend Rennie Bryant at Redline BMW Performance once told us: “BMWs are 100% reliable as long as you fix everything that breaks.”
BMWs have low tolerance for deferred maintenance, and every time you lay a wrench on one, you’d better make sure you do a good job. If you can meet those two conditions, you’re likely to only have to ever add fuel during a track weekend.
Pre-Event Prep
Some of our most labor-intensive jobs surrounding our event prep came when we stickered up the car and mounted some new rain rubber.
For decals on our dual-duty machine, we love Oracal 631 removable vinyl. Although it comes in a limited range of colors, those colors include red, white and black, which go nicely with our corporate livery.
Photograph by J.G. Pasterjak
For large events like this that require a lot of mandatory stickers, we just slap a sheet of Oracal 631 on the lower door and then stick on all our required decals. Then we can easily peel off everything after the vent.
Photograph by J.G. Pasterjak
The Oracal 631 also works great for cutting die-cut stickers on our plotter. They stick well enough to survive automatic car washes and even months of use. And when it’s time to remove them, they cleanly peel off with a fingernail and leave zero residue behind.
Our other big project was finally getting some rain rubber in case nature had plans for the forecast. The highly regarded Continental ExtremeContact Sport 02 comes in the same 275/35R18 size as our Vitour P1 200tw track rubber.
[Tire Test: Kenda Vezda UHP Max KR20A vs. Yokohama Advan Neova AD09 vs. Continental ExtremeContact Sport 02]
The ExtremeContact Sport 02 is one of Tire Rack’s highest-rated wet-weather performance tires–and one of the most common rain options you’ll see at the pointy end of 200tw time attack classes. These will also serve as our primary street tires, as the car will see more road miles as the “build” phase is winding down.
Photograph by J.G. Pasterjak
We mounted the Continentals on a set of BimmerWorld’s TA8S wheels, going with the same 18x10-inch ET33 size we use for the BimmerWorld TA5R wheels paired with our Vitours. Both models feature flow-formed construction along with knurled beat seats to prevent tire slip, recessed stem pockets for increased protection, and lots of room for big-brake kits.
Photograph by J.G. Pasterjak
BimmerWorld even sent some Continental TPMS sensors, which not only saved us a few bucks over the OEM sensors but seemed appropriate to pair with the Continental rubber.
Photograph by J.G. Pasterjak
At some point, we’ll do a proper instrumented track test of the Continental ExtremeContact Sport 02 tires, but that’s going to require rain, which we do not control, so it’s hard to list a date for that test at the moment. We’ll keep an eye on the weather at the Florida International Rally & Motorsport Park, however, and be ready to roll when the skies turn. We’ll let you know how it goes.
On Track
Really, the greatest hurdle to on-track performance that weekend was unfamiliarity with the circuit. You can soon check out my extended blog on learning a new track online–like, look for it early next week–but Pittsburgh International Race Complex is, as the name implies, a complex ribbon of asphalt that stretches in three dimensions through the western Pennsylvanian countryside.
There’s a bit of a learning curve, and as I dialed in my skills and knowledge, the track actively rebelled by losing grip to heat and rubber as the weekend progressed.
Photograph by Chris Tropea
Our complaints weren’t the only ones, as many drivers groused about the circuit shedding grip and predictability once the temps came up after about 11 a.m. each day. In many spots, overall grip seemed to fall off each day of the three-day event.
This certainly isn’t a criticism of the track–it simply is what it is–but it did make acclimating to a new circuit even more challenging, as the character of many corners seemed to change with conditions. This made developing a plan tricky.
Rubber–in particular, everyone else’s–was also a factor. In many spots, if you strayed off the perfect line, you’d pick up a boatload of OPR, effectively ending your session, or at least your chance at bettering a previous lap time. These conditions combined to put all the pressure on the morning sessions when the track was the coolest and cleanest.
Despite these tough conditions, we had high regard for the Vitour P1 tires. Although we didn’t do any back-to-back testing, Andy Hollis, our tire test editor, did: He replaced fresh Hoosier Track Attack Pros on his McLaren 720 with a set of Vitours that had already done an event at Carolina Motorsports Park and picked up more than a second and a half.
[Tire Test: Vitour Tempesta P1 vs. Nankang Sportnex CR-S V2, Yokohama Advan A052 and Bridgestone RE-71RS]
Our P1s had been heat-cycled nearly a dozen times at this point, and they showed very little grip falloff along with practically zero loss of predictability. They’re every bit as drivable now as they were when new.
As for the competition, though, just like last year at NCM, we simply didn’t have enough for the E46 M3s in the class, particularly Matt Hugenschmidt’s. He backed up his 2024 win with another victory; Dennis Barrett followed in another E46, with our 435i in third.
[Woot, GRM lands two podium finishes at SCCA Time Trials Nationals!]
Looking at their data versus ours, it was just a matter of a lighter car–by nearly 500 pounds–with similar power on similar rubber going faster everywhere. Add to that a couple stellar drivers, and it’s hard to complain too much about our comfortable, fully equipped, air-conditioned luxury coupe not taking a higher podium spot.
Photograph by Chris Tropea
And it’s particularly hard to complain when our BMW has been so bulletproof at its last few track events. A few weeks ago, we ran at Daytona in near triple-digit heat with no issues.
Now we were at a track we’d never run before hunting down top cars in the class, and all we did was add 93-octane Sunoco. Okay, we did do a couple of one-click adjustments on the MCS dampers, but that was as much mental as anything. Sometimes it feels like you’re banging your head against a wall, so you tweak something, allowing your brain to reset. Next time out, it all just goes smoother, particularly when facing a track that’s challenging to learn.
Takeaway Lessons From the Outing
Two back-to-back, high-stress track events with zero drama has us really liking the state of our 435i. It may not be the ultimate car for the pointy end of our SCCA Tuner 2 Time Trials class, but it’s certainly in the conversation. And when the racing is done, it’s an absolute delight on the road.
If there’s a big question mark still out there, it’s on the car’s back–the differential, to be precise. Our car still runs the mechanically open e-diff; it uses tiny brake pulses to curtail unloaded wheelspin.
In many long corners, like Pitt Race’s Turn 17 complex, a long right-hander that also adds some challenging road camber into the mix, we can actually hear some telltale chirps from the Hawk DTC-60 pads as we apply throttle past the apex.
The rub here is that installing a mechanical limited-slip is a complicated and expensive procedure. The stock ring gear is welded, not bolted, to the carrier, so it needs to be machined off before installing a traditional mechanical LSD. Then the e-diff functionality has to be coded out of the factory computer.
Photograph by J.G. Pasterjak
It’s a “nice used Miata money”-level operation, and while we know it will be faster, making that investment without knowing how much faster has us biting our lip and furrowing our brow.
Maybe a letter writing campaign will push us one way or the other. And no, there’s not a junkyard solution out there that’s any less expensive. If there were, we’d have already done it.
For now, though, we’re content with our super-easy-to-drive, super-satisfying BMW 435i and celebrate its profound competence and lack of drama (once we fixed everything that broke).
