Tuner Tuesday Double Take: 2002 and 2003 BMW M5 Dinan S2s

There are a few select automotive tuners who can take an impressive package and refine it into an even better entity. That group includes legends such as AMG, Alpina and Ruf – all of which are staples of this segment.

Yet they are far from alone. Given the task of improving on what is generally considered to be one of the greatest sedans ever made is no small feat, but if there was one group up to it, it was Steve Dinan’s eponymous company in California.

While just about anyone can take a turbocharged engine and crank up the boost, slap a few stickers on it and call it done, the E39 M5 didn’t come with forced induction. On top of that, it was a motor which wasn’t exactly underdeveloped before it went into production. Nor were the brakes, suspension, or any other aspect of the third gen M5. But Dinan thought they could improve upon them, and with a tremendous amount of work, did.

Dinan went to town on the S62 from start to end. Out came the factory air boxes, air meters and velocity stacks, replaced by Dinan units of larger diameter and better flow qualities, along with larger throttle bodies bored out by the company. This necessitated reprogramming of the computer controls for the engine to match the new flow characteristics. To help the exhaust side of the motor, unique tubular headers were fit to a free-flowing, lightweight exhaust system. While this sounds a bit like old-school engineering, it was successful; the result was an additional 76 horsepower and 51 lb.ft of torque – basically, this was like adding a 1980 Rabbit’s worth of power to an already powerful car.

Dinan coupled the engine mods with a shorter final drive and higher rev-limiter to reach fantastic speeds. The S2 was capable of 0-60 runs around 4 seconds flat and, in unrestricted mode, geared out around 190 mph in 6th.…

1990 BMW M5

From the “Cars that need no introduction” file, witness the M5. So ingrained into the halls of automotive Valhalla is the M5 that it seems as though there was never a time without one. Yet while there were fast sedans that predated the Motorsport 5-series, the reality is that this was the blueprint which all subsequent fast sedans (tried to) emulate.

If you look up “benchmark” in the dictionary, the M5 should appear as an alternate definition.

But enough of the hyperbole, hoopla and heady praise. You know the details of what makes this car great. So what makes this particular one special?

CLICK FOR DETAILS: 1990 BMW M5 on eBay

1991 BMW M5

While I love my W126, I miss the E34 that I sold back in May. Mine was only a lowly 525i, but with its tight suspension and fun-to-use 5-speed manual gearbox, it drove more like a go-kart than I was expecting, when I picked it up on a whim. I hope to own another E34 someday, perhaps one with a bit more grunt than my old car had. So I’ve been keeping a watchful eye on the M5 market for a while now. Values on these cars have risen steadily over the last few years, as buyers looking for a bit of old-school, hand-built M GmbH magic have woken up to the charms of this generation 5-series, with its 3.6 liter inline six powerplant. Of course, this means that an E34 M5 will most likely be out of reach before I can afford one. But for those with cash on hand right now, the last year or so has seen a steady supply of neat examples coming to market. Right now, buyers looking for a tidy, daily-driver quality example can expect to pay between $15,000 and $20,000. Grab one while you can.

CLICK FOR DETAILS: 1991 BMW M5 on eBay

Litmus Test Double Take: 1988 BMW M5 and M6

Neither the E24 M6 nor the E28 M5 need an introduction on these pages. Legendary even when new, they both captured the imagination of generations of German car enthusiasts and established the benchmarks for sedan and GT performance in period. Both went through a relatively long downturn in value, as well. And today, as each has moved firmly into classic status and the market ///Madness continues, each has increased in value considerably over where they stood a few years ago.

But with so many shared components, which is the one to get? While a lot of that boils down to personal preference, more so than ever it’s also dependent on your budget. We’ve seen asking prices for nice examples of each chassis hovering between $50,000 and $80,000 depending on mileage and condition, and with a hot market there’s no letup of good ones to choose from.

But what I have today is not the best examples of each. Both are higher mileage and neither is pristine. However, the real draw here in both cases is a no reserve auction format, giving us the opportunity to really see what’s what in the M market today.

CLICK FOR DETAILS: 1988 BMW M5 on eBay

1991 BMW M5

The E28 M5 that Carter wrote up the other day was a nice piece of kit. But the E34 remains my favorite version of the M-powered 5-series. Sure, it was heavier than it’s predecessor. But even with the additional heft, the dynamic chassis and dialled-in suspension setup meant it was still a spritely, potent car. It was also subtle, distinguished from lower models only by a few, discreet M-badges, restyled lower valances and unique alloys. That’s no bad thing. Super sedans should be understated, in my view, and the conservatively styled E34 was handsome then and remains so now. That understated exterior conceals a glorious, screaming 3.6 liter inline six, replete with six individual throttle bodies, a motor that was good for just over 300 hp when new.

CLICK FOR DETAILS: 1991 BMW M5 on eBay

All Black Everything: 1988 BMW M5 Euro Clone

Let’s get the elephant in the room out in the open: this 1988 BMW M5 has 225,000 miles, and the asking price is $42,000. It’s also pretty far from original.

Still reading?

That’s good, because there’s really a lot to like in this particular example of the legendary chassis. First off, it’s one of the very, very few of the already scarce U.S. spec E28s that were imported with option 0232 – full black leather. That makes it one of 101 imported to North America as such, and of those only 30 were sold in the U.S.. That alone makes it quite desirable. But then this M5 goes a step farther, and by a step I mean several flights of stairs. Outside we have a European bumper and headlight swap; I know, some people prefer the U.S. setup in the same way that some people consider Marilyn Manson a musical artist. It’s also ditched the original M5 rolling stock for wider, modular and forged BBS RS wheels. And that high mileage? No worry, the S38 has been rebuilt and turned up a few notches, while the upgraded suspension has dropped down and stiffened the ride.

The result? Boy, does this look like one mean super sedan.

CLICK FOR DETAILS: 1988 BMW M5 on eBay

1993 BMW M5 Euro 3.8

At first glance, I was sure we’d covered this car before. After all, it’s not often that European specification 3.8 liter M5s come to market in Daytona Violet.

Or, is it?

Believe it or else, this is actually no less than the third Purple Porsche Eater that we’ve covered for sale in the U.S.. Back in September, Craig spotted chassis GD63734for sale. If that wasn’t surprising enough, I was pretty sure when Craig wrote that car up that it was the identical twin of chassis GD63657 – a car I thrice covered with three different sellers. But, no – today’s car is a chassis GD63375, produced before those other two 1993 examples, yet in the same outrageous shade of Daytona Violet Metallic:

CLICK FOR DETAILS: 1993 BMW M5 Euro 3.8 on eBay

Ending Soon: What We’re Watching

Last week’s What We’re Watching post seemed to be a hit, so I’ve lined up another group of auctions. This time, they’re all affordable no reserve classics (or soon to be?). Care to wager on what each will sell at? Let’s start with a 5-speed Euro Porsche 928.

Click for Details: 1981 Porsche 928

It’s far from perfect, but here’s a 1981 Porsche 928 5-speed in Euro trim. The BBS wheels might look more at home on an early E39 540i, the paint is tired and the engine hasn’t run in some time (and what the heck is up with that shifter surround???) but hey, at time of writing the whole package can you yours for $3,000. Certainly it’s worth at least that in parts?

Click for Details: 1960 Volkswagen Bus

I said “affordable”, right? Well, with VIN tags of 23 Window Sambas selling for upwards of $11,000, this no reserve auction on a lovely restored ’60 seems like a deal. The color combination and condition are spot on, and it will be interesting to see where it ends.

Click for Details: 1993 BMW 740iL

Back to great values, and this 1993 BMW 740iL seems ready to please. It’s got lower mileage, the great E32 shape, a nice color combination and very good overall condition. Usually the big money has been reserved for the follow-up E38, so I think someone will get a great deal on this very nice ’93.

Click for Details: 1988 BMW M5

There’s been a lot of speculation on the 80s BMW M market, so seeing a no reserve auction on an M5 is both rare and offers us the chance to litmus test the market. Usually the cars that come up in no reserve format aren’t the nicest ones out there, but this one generally looks great.…

1992 BMW M5 Euro 3.8

It really does feel as though the market is finally waking up to the E34 M5, as values on nicer examples continue to climb. Bring a Trailer recently sold a U.S. spec ’93 with only 14,000 miles for what seems like a staggering $68,000! As they should have, considering the package. The E34 is a surprisingly great driver’s car, even in non-M guise. But in full blown M5 spec, it’s sublime, a throwback to an era of hand-built sport sedans that offer a satisfying analog driving experience. To make it, BMW sent the regular E34 chassis from the production line at Dingolfing over the geniuses at M GmbH in Garching, who dropped in the screaming, six cylinder S38 motor with six individual throttle bodies. In US-spec form, the 3.6 liter motor put out just over 300 hp, although a larger, 3.8 liter unit became available in Europe from 1991 onwards, which increased power output to 335 hp. The 3.8 never reached US shores by official channels, though these cars are now old enough to be imported without the need for expensive modification

CLICK FOR DETAILS: 1992 BMW M5 3.8 on eBay

Double Take: 2001 and 2002 BMW M5 Dinan S2s

“Dinan’s latest work of art, he has not only fixed a car that wasn’t broken but also sought to perfect a car that everyone considers to be as close to perfection as is humanly possible: the BMW M5”, Car and Driver wrote in 2002. Dinan had, at that point, already made a reputation for themselves as the premier BMW tuner in the United States to the point where they became offered straight from the dealer. Considering that’s just occurred for Alpina here, the endorsement of the level of engineering from the California firm was resounding. Yet that is in part because Dinan’s modifications are far from just slapping a badge and some wheels on a car and calling it done. Take, for example the M5 S2.

Dinan took what many considered to be a very highly developed 4.9 liter V8 in the S62 and went old-school to up the power; and up it a lot, he did. There was no supercharger or turbocharging here; revised intake and enlarged velocity stacks were met on the other end with tubular headers and a bespoke exhaust. Each throttle body’s bore was increased, too. These changes required a reflash of the computer, but were both lighter and more powerful. As in 76 horsepower more. That’s the best part of a 20% gain on a motor that many considered to be close to peak performance! Dinan further upgraded the suspension, brakes, wheels, and final drive, along with adding a lighter flywheel. As a result, the new S2 was, well, about 20% better than the already awesome M5. But that perfection cost, and it was more than a 20% increase. A lot more.

On top of the M5’s $73,400, if you wanted a fully spec’d out S2 you’d tack on $36,000 to the price. For that amount, you could have grabbed a nice 330Ci in addition to your standard M5!…