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Building a street car that can theoretically survive a track day is one thing, but what does the data actually say? Does the car quickly become a hot mess or does it remain composed?
The E46-chassis BMW M3 came from the factory with all sorts of neat bits–big brakes, limited-slip diff, wider track–so our prep has been a bit minimal as we’ve aimed to ready the car for the occasional track day. You can call our chassis setup OE plus: Bilstein B16 coil-overs, Vorshlag camber plates, Powerflex bushings and 255/45R17 Falken RT615K+ tires.
Before taking the car to the Florida International Rally & Motorsports Park, our official test track, we didn’t do anything special other than check fluids, lugs and tire pressures.
[How we track test cars and what the numbers mean]
Our Bilsteins were left on full soft, while we retained our usual alignment settings: 2 degrees negative camber up front and 4.25 degrees of caster. Brake pads were StopTech 309 Sports–same ones we’ve been running for a while.
Once at the track, we put J.G. Pasterjak behind the wheel. What would he and the data report back?
“The M3 was a hoot to drive, feeling way more modern and accessible than any two-decade-old car has the right to. With relatively narrow (by modern standards) 255s at all four corners, it’s maybe giving up a bit of grip, but its neutral balance and communicative manner–especially in mid- and late-corner areas–still make it a highly rewarding driving experience.
“If I can complain, I have two main nits to pick. Corner entry can be a little imprecise. Honestly, it felt a lot like the new M2 we recently tested, just needing a little bit of extra reassurance on turn-in to make me truly comfortable and taking a bit of time to generate cornering force with all four wheels. So we’ll chalk that up to being a BMW sedan thing.
“The other area I’d criticize would be the brake pads. They had great release characteristics but lousy bite on initial supplication. Honestly, I’m surprised the peaks of the GPS data graphs look as sharp as they do, because I expected them to be much rounder just based on the subjective feel of that lack of bite. I guess I’m just good at compensating.”
We also found oil and coolant temperatures to remain normal. Brake fluid didn’t get mushy. (We ran Red Line 15W50 motor oil along with the company’s RL-600 brake fluid.)
What about lap times? Back in the day, the E46-chassis M3 was fast–maybe not supercar fast but definitely able to run with the day’s pony cars. We watched all of them duke it out at the day’s Grand-Am contests.
[E46-chassis BMW M3 | Buyer's Guide]
Fast-forward more than two decades, and today the M3 faces a different benchmark. We again hand it over to J.G.:
“Let’s throw the chart of the M3 up against a more modern but closely matched competitor. In this case, we’ll compare the M3’s 1:22.48 to the 1:22.08 turned by the Hyundai Elantra N.
The Hyundai Elantra N can outrun the M3? Let’s take a minute to look at some facts and figures before going back to JG:
“That four-tenths is easily within the margin of error of track conditions from test to test, and it’s also well within the margin of error of the fact that I was driving David’s increasingly rare and valuable car while he was totally standing right there. I figure the OPC (other person’s car) correction is easily three- to four-tenths.
“Anyway, these cars are closer in more areas than I suspected. Somewhat surprisingly, the M3 (blue trace) pulled the Elantra N (red trace) down the fast straight toward the FIRM’s Turn 5, even after a less impressive negotiation of the right-hand kink that is Turn 4.
“Through the square Turns 5 and 6–between about the 800- and 1000-meter marks–the cars are surprisingly dead even. The rear-drive BMW and the front-drive Hyundai accelerated, braked and cornered in almost identical fashions.
“The BMW was also quite good through the esses–from around 1200 to 1400 meters. Credit the excellent Bilstein shocks, which were every bit as good over the curbs as the modern, electronically controlled shocks on the Hyundai.
“The most notable difference was the entry to Turn 8 at 1700 meters, which requires a car with exceptional stability and predictability. Here, the Hyundai took the crown.
“The M3 had more ability there–with a dozen laps, I could have narrowed the gap–but the Hyundai just walked all over the BMW’s turn-in indecisiveness here. The M3 made up some ground mid-corner, but late in the corner, those relatively narrow 255s showed their limitations.
“Acceleration out of that big sweeper was great for both cars–a drag race between the two would mostly be decided by how quickly you could shift the BMW, since the acceleration curves were nearly identical.
“And the braking, despite the BMW not feeling great, is actually quite good, equaling the Hyundai’s decel rate past the 240-meter mark, which is the hardest braking point on track.”
So, good news, right?
Well, until we went to drive home.
The engine ran rough–like, really rough. We let the car sit for a bit and then all was good.
To see if it was heat-related–the weather was extra Florida that day–the FIRM staff let us take a relaxing lap around the track during lunch just to get air through the engine bay.
Still, no issues, no weirdness.
We went from there to lunch near the track, where the M3 again ran rough at startup and threw a code. We had a reader: No. 4 misfire.
The issue quickly cleared up, and the car sounded fine on the 90-minute return trip. Everything has been A-okay since.
Bad coil pack?
We checked the info that came with the car and didn’t see any mention of replacement, although we did have a note about ordering a spare. We walked out to the garage and found a Bosch replacement in the box of parts that came with the car.
Something else? According to the car’s documentation, the plugs were last replaced 52,000 miles ago in 2009. We’d changed the fuel filter since owning the car.
In theory, we could move the No. 4 coil to a different cylinder and try to replicate the problem, but we decided to order a fresh set of Delphi coils from BimmerWorld, our partners on the project.
We figured that all six coils were old. Plus, Delphi is BMW’s current preferred replacement, we live in a rather hot climate, engine issues are rarely fun, and if we’re going to remove the top engine cover to access the coils, why not just replace all of them?
Part numbers for those playing at home:
Parts should be here shortly.
What about brake pads?
“E46 M3s and newer start to get a little tough for the Goldilocks pad,” notes Phil Wurz, BimmerWorld’s operations manager. “When the cars had less power and were lighter (think max an E36 M3), you could get away with a dual-purpose. A novice can typically still get away with a dual-purpose pad in an E46 M3, but when you start to push it and really abuse the brakes, it may be time for a street set of pads and a track set of pads.”
So we’ll work on that before our next track outing.
