Flogged: DTM5 – The First Track Test of our 1993 BMW M5

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by CFlo

I’m out here in the high desert outside of Los Angeles with millions of dollars in track day toys. McLarens, Audis, and Porsches litter the pits like crew cab F150s at the local Home Depot parking lot. It’s a Speed Ventures track day at Streets of Willow, part of the Willow Springs International Raceway complex in Rosamond, CA. Of course, the requisite smattering of Miatas, Civics, and E30s are out here too. There’s even a new rented Camry with masking tape numbers on the doors. Camaros are represented in full force, with a fierce and costly lineup of Z28s, ZL1s, SSs, et al.

Streets of Willow in the DTM5, with our buddy’s Exige giving chase.

photo: caliphotography.com



And here I am in my hand built, 22 year old executive express. This track is short, twisty, and bumpy – the kind of place best suited to an S2000 or STI; smaller, nimbler machines with transient response like nobody’s business. An E36 M3 would be just about perfect out here with enough power for storming down the post-bowl straight and climbing the hill into Turn 1, but still telepathic in its reflexes and ability to go precisely where the driver’s thoughts command.

The E34 M5, in contrast, is a heavy pig.

It was designed in the mid ’80s before CAD and FEA bore optimized chassis from the bowels of Munich’s design departments. It weighs in at a hefty 3860 pounds, clearly a class beefier than the track day tools of choice (an E36 M3/4/5 is about 3200 lb in comparison; NA Miata…2100). As an aside, the E34 is smaller than the current F30 3 Series in every dimension but length. When used as a firm but refined mode of transportation to the desert, the M5 is sublime. This 3.5 liter inline six started life in BMW’s E9 3.0CSL race cars and progressed to the mid-engined M1 before evolving into S38 form, and as such it’s understressed on the highway and when short shifted. This is an Autobahn machine, for sure. Keep in the throttle past 4000 rpm though and it howls to life, urging the driver to play in the 4000 – 7000 rpm range like it was born to live there – because it was.

For trackday prep, I installed a new clutch master cylinder, bled the clutch and brakes with ATE Super Blue.

I then drove to the track and applied clever numbers to the doors.

So what am I thinking, pulling out of the hot pits and onto the front straight of this tight little course with “Streets” in its name? Truth be told, I’m primarily here with my wife as she gives track days in general a trial run, doing her first ever performance driving event in our 2010 Volkswagen Jetta Sportwagen TDI / 6MT, of all vehicles. I figured that Streets would be a great introductory track, with its lowish average speeds, fewer corners to memorize, and tight configuration that would help mask the 2.0L diesel’s lack of top-end horsepower (only 140 at the flywheel).

But hey, I figured, why not take the M5 along on the day trip and out for its maiden excursion on a racing course, while I’m out there? Initially I was a bit skeptical that the high velocity 4-door sedan was going to prove to be anything more than an understeer machine. Its mass and wheelbase aren’t modest. The antiquated steering box and semi-trailing arm rear suspension are not the stuff of sports car spec sheets and haven’t been since the ’60s and ’70s. However, the bargain 178k-mile sedan proved my inhibitions to be unfounded. Sure, it doesn’t acceler-explode like an LS7 powered Z28 or brake with the might of a GT3, but if I’d been thrown into this car without being told what it was, from feel and sensations alone I’d have guessed it was a smaller early 2000s sport sedan. Feedback is sufficient through the (non-stock) tire, wheel, and suspension combo, and both high and low frequency motion is damped well by the Koni yellow dampers.

I had my iPhone running the Harry’s Lap Timer app for data acquisition, secured to the windshield via RAM Mount.

Turn-in is not E36 crisp but not soggy either; it’s just nicely weighted with no on center dead zone. The 14″ Nardi steering wheel helps with that, I’m sure. I found it effortless to get the car to rotate smartly going into the tighter, lower speed corners like turn 2 and the skid pad. I didn’t attempt to intentionally induce oversteer but didn’t encounter it unwillingly either. In the rhythm section near the middle of the track, quick transitions from right to left to right again plus a semi-ambiguous track layout had me over-driving the car just a bit, betraying both my amateur tendencies as a driver and the M5’s propensity to push just a scosh on high speed corner exit. Fortunately I had the perfect amount of track available to unwind the wheel and let the car run a bit wide, allowing the understeer to run its course without getting me into trouble by dropping wheels off into the dirt.

Going through the banked Bowl that is Turn 8.

photo: caliphotography.com

Much of the praise heaped on the DTM5 in regards to drivability, predictability, and overall grip is of course due to the tires. The Falken RT615Ks were a huge upgrade oven the ancient dryrotting donuts that were fitted when I bought the car in 2013. Falken’s top street tire communicates at the limit and is easy to recover before total control is lost, at least in a car that’s set up like this M5: fairly squishy with noticeable body roll on track, even though it feels quite stiff and firm in traffic and on rough public streets.

The DTM5 was a surprisingly willing trackday companion despite its heft.

photo: caliphotography.com

Surprisingly, I was even able to hang with a Lotus Exige, driven by our friend Sara who was acting as driving instructor to my wife that day. And don’t worry – Mrs. CFlo got to ride in the Exige several times, getting a taste of the pure sports car experience. Granted the Lotus was riding on older Toyo R888s which Sara’s husband Bitter Dan hates with a passion, but for some indeterminate reason he keeps buying them. The subpar fast wearing R-compounds took the Exige’s potential down a few notches. At the end of the day (literally) I was quite happy to be only ~3 seconds off Bitter Dan’s best pace. His fast lap of 1:33.whatever kept the Lotus in the same hemispherical arena as compared to my best of 1:36.something in the M5. Oh yeah – Bitter Dan and Sara are 2/6ths of the legendary Eyesore Racing 24 Hours of LeMons team, so they know how to party at the track, both behind the wheel and in the paddock.

Logging data for this oh-so-official test of an outdated used performance car was handled not by a $1500 VBox, but by a $20 iPhone app from Germany called Harry’s Lap Timer. This little gem of a data acquisition package includes a lap time display for best & last laps, a circle of traction showing both lateral and longitudinal acceleration in g, vehicle speed, and GPS track position. It will even take video shot through the phone’s own camera and let you overlay your lap data and track position in post processing. See the semi crappy video above as an example! Video quality and available storage was lacking on my 8GB iPhone 5C, but you can use 3rd party software like Dashware to overlay the Lap Timer data on pretty video from a GoPro or your Chinese action camera of choice. At least my RAM Mount “Universal X-grip Holder” held the phone securely during high-g cornering and braking loads.

Tire wear and klag pick-up was minimal with the RT615Ks.

These are not the grippiest DOT-legal street tires, but provide great bang for the buck and predictable behavior.

Overall, I could not have been happier with my sub-$10k obsolete ///M car. The black leather “sport” seats let me slide around more than I’d have preferred, and the balky 3rd gear synchros meant that I had to shift slowly and methodically into that gear to prevent the sickening graunch that happens whenever I forget and am a bit too enthusiastic. But the seats were only intended for support on backroads at most, and the Getrag 280 gearbox is a known weak point in the otherwise stout E34 M5 drivetrain (and mine in particular). We must remember that this is not a race car; not designed to excel on the track, it was meant purely for high-speed cruising dominance.

Understeer manifested itself slightly during steady state cornering through turns 5 & 6, but that’s it.

photo: caliphotography.com

I drove the car to the track and spent less than $140 with Speed Ventures for about 100 minutes of track time. I got to hang out with friends, ogle exotics, and introduce my wife to a new hobby and a whole new side of driving that she’d never experienced until that day. I drove home with zero problems and enjoyed the hell out of an undervalued, depreciated, and epic performance car that the previous owners happened to spend most of the money on. THAT’s what I was thinking when I brought it out here. And isn’t that what the Daily Turismo ethos is all about?

Sources

Sadly, a 993 Turbo does not quite fit into the DT trackday budget.

This post is part of DT’s Project Car series – an account of our follies and foibles with undervalued / underappreciated but fun and interesting older cars.

This is more realistic. A rental NA Miata track rat – yeah, that would work.