BMW M4 Dinan S2 Review: 550 Horsepower of Rowdy Fun

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It’s a party animal wearing a finely tailored Sakhir Orange suit.

Dinan has been in the business of making BMWs faster since 1979. The brand is both ubiquitous and prolific, if you have a BMW, they have performance parts for it. Their unique selling point is that Dinan parts are recognized and backed by BMW, with many BMW dealerships being equipped to sell and install Dinan parts on your ride. Additionally, Dinan parts keep your Bimmer warranty-friendly, a definite perk for people who want to upgrade their cars and keep that four year, 50,000 mile safety net intact. BMW M4 Dinan Stage 2 Review

The new generation of BMW features turbocharging across the board, meaning that enterprising owners can unlock massive power, should they choose to do so. As a result, aftermarket support for BMWs is larger than ever. That brings us to the Dinan BMW M4, a new car, with a new engine, modified by one of the biggest names in the business. Can Dinan hang with all of the new tuning options popping up out there?

I don’t think I have ever seen a more photogenic car. Parked in a nondescript industrial complex outside of Los Angeles, the vibrant Sakhir Orange paint glows like embers flickering off a campsite fire. The paintwork adorns an aggressive shape. It wears an angry look on it’s face, scowling at all who pass, and you can’t help but stare back. It looks fast, even when parked. This BMW M4 means business. It’s no ordinary BMW M4, either. This car has been fitted with a plethora of go-fast parts from Dinan.


The car lets you feel every bit of its 550 horsepower. Cue the maniacal laughter as you do rolling burnouts into the sunset.


An industrial complex is not where this extraordinary BMW belongs. No, this car needs to be somewhere much more fun than that. Fortunately for us, the canyon roads of Malibu were beckoning, quiet and traffic-free on this Tuesday morning. Though, they wouldn’t be quiet for much longer. BMW M4 Dinan Stage 2 Review

It’s a handsome brute.

The 4 Series is generally a good looking car, regardless of guise, but the M4 does the body style such justice. With angular, aggressive fascias and punched out fenders the M4 is a looker. This particular F82 chassis BMW M4 is wearing the full carbon fiber range from the BMW M Performance catalog. The splitter, mirrors, rear lip spoiler and diffuser are all carbon. It all goes well with the carbon fiber roof panel that all M4 models receive from the factory.

Check out the wheels. The black rolling stock on this M4 are 20″ Forgeline GA1R wheels, built to Dinan specified widths and offsets. They measure 9.5″ in front and 10.5″ out back. Paired with the steamroller wheels are steamroller tires, specifically a 60-treadwear Pirelli P-ZERO Corsa track tire, measuring 275/30R20 in front and 305/30R20 for the rears. They look fantastic, though, the pragmatist in me knows that 18 or 19 inch wheels will offer cushier ride quality. Los Angeles roads are no joke.

More show, and a lot more go with the Dinan S2 package.

Starting with the basics: off the showroom floor, the M4 packs a 3.0-liter, twin-turbocharged straight-six engine, code named S55. BMW claims this recipe is good for 425 horsepower and 406 lb-ft of torque. However, anyone who has experienced a recent BMW turbo engine knows that they come packing a lot more than the claimed figures. Dinan states their test car produced 484 horsepower and 446 lb-ft bone stock.

The Dinan party really gets going under the surface, where the bulk of the upgrades are hidden. Under the hood is a Dinan carbon fiber intake. These dual airboxes force cool air into the turbo inlets. After the charged air leaves the turbos is when things get interesting. With the M4, BMW has used a water-to-air intercooler to keep that charged air as cool and dense as possible. It is an excellent solution for keeping intake temperatures down, and engine performance up, especially for an OEM piece. Dinan improved upon the existing design by leaving the intercooler alone, what they instead did was upgrade the heat exchanger in charge of cooling that water-to-air intercooler. The Dinan heat exchanger is larger, with more surface area, better able to keep those water temperatures low, meaning that intake temperatures stay even lower.

Paired with the hardware is software in the form of the DinanTronics performance tuner. It uses plug-and-play connectors to pair with the DME (ECU), making it removable, should the owner want to do so. The powertrain enhancements are topped off with a Dinan exhaust setup, which includes an X-pipe center section and rear muffler.

The end result is a claimed 548 horsepower at 6,000 RPM, and 549 lb-ft of torque at 3,500 RPM. So the Dinan modifications are netting about 100 horsepower and 100 lb-ft over a stock car, not bad at all. The power pack will set you back $8420.

More than meets the eye.

The suspension is the most notable upgrade on this M4. This car sports the full range of Dinan suspension upgrades, including stiffer front ball joints, 3-way adjustable sway bars, adjustable rear suspension links (toe arms and front trailing links), and a coil-over shock conversion. Looking more closely at those shocks, Dinan converts the OEM M4 shocks to a threaded perch setup with coil-over springs. This allows for 1″ of front ride height adjustment, and 1.5″ of rear ride height adjustment. Spring rates are 50% stiffer in front, and 10% stiffer in the back, versus the original springs. All of the suspension upgrades total $3874.

Excluding the fancy Forgeline wheels and Pirelli tires, this M4 is packing about $12,000 worth of Dinan parts. A base model M4 is 67 grand, so all-in, you’re looking at an $80,000 cost of entry. Though, the Dinan parts are all a la carte, should you choose to go that route.

Initial impressions of the Dinan S2 M4?

Well, it’s quite loud, for starters. This coming from a guy who drives another very loud, twin-turbo BMW. Granted, it’s not as loud as my car, and it likely won’t scare the neighbors like mine does on a cold start. That said, it’s loud enough for people to know it’s no ordinary BMW. I felt a temporary ounce of dread as I approached a string of police cruisers at an intersection. Fortunately, the fancy paint job and loud exhaust weren’t enough enticement for them, and I continued onward unencumbered.

Around town the DCT gearbox is smooth and generally unobtrusive, at least until you start messing with the “shift ferocity” settings as I like to call it. The engine, in keeping with BMW straight-six tradition, is torquey, and has no qualms driving under 2,000 RPM all day. Though, where’s the fun in that?

Driving out of town, and into the canyons revealed a firm ride quality. The increased spring rates can be felt, though not even the most delicate of passengers would complain. Oh, did I mention that it’s fast? Those Pirellis can’t keep up with the power that the Dinan M4 is packing, at least, not until they are very warm and toasty. First and second gear are hilariously useless around town, as the tires scream for help. The car lets you feel every bit of its 550 horsepower. Cue the maniacal laughter as you do rolling burnouts into the sunset.


Big, heavy, powerful cars will regularly get whooped on by stock Miatas here, that’s just how it goes.


Beyond that, once the lumpy, bumpy LA roads settled down, so, too, did the M4. This car is still very happy to lap up the freeway miles. Shift it into seventh gear and go. BMW M4 Dinan Stage 2 Review

Canyon roads are an unrelenting proving ground.

Malibu is home to some of the best driving roads in the country, but they are far from perfect. Watching reviews shot in the Los Angeles canyons, people often get the impression that they are a piece of driving nirvana. While they aren’t wrong, the way in which these roads twist and wind is breathtaking, equally breathtaking is fear drivers feel when hitting shattered pavement, or a fallen rock. The canyons are just as lumpy, bumpy, patched and broken as any LA city street.

Why do I bring this up? Cars that are too stiffly suspended suffer here, scrambling for traction and praying for enough shock travel to handle the mid-corner bumps and whatever else the changing road conditions will bring. The term “handling” was invented because of roads like this. If your car is slammed to the ground, on really stiff springs, and doesn’t have the baller shocks to match, you’re going to have a bad time. Did I mention how narrow and tight the roads can get? Big, heavy, powerful cars will regularly get whooped on by stock Miatas here, that’s just how it goes. BMW M4 Dinan Stage 2 Review

The party animal comes to life.

Turns out the around town tire slayer can dance. The Dinan “Signature 2” M4 is an absolute riot to drive through the twisties. It’s a handful, especially if you aren’t used to driving fast cars, but it is so capable. The S55 engine, often maligned for its…distinct…sound, is such a charmer, credit this to the Dinan exhaust. If you buy one of these cars, an exhaust upgrade is imperative. Really coming onto boost hard around 2,500 RPM, it zings all the way to its 7,500 RPM red line. It’s not the best sounding M car, but Dinan did a good job working with what the S55 has to give. By the end of the day, I was coming around on the sound matter (see the 6:34 mark on the video).

The engine, with its massively wide powerband, isn’t too particular about being in second, third, or even fourth gear when pulling out of corners. That said, chasing the red line and working through the gears is an absolute joy. With three settings of shift firmness (“shift ferocity”), the dual clutch automatic transmission is ready and willing to snap off brutal up and down shifts. Set at “3/3 shift ferocity” the M4 will change gear hard enough to hurt your neck, it’s rowdy. BMW M4 Dinan Stage 2 Review

Traction issues still abound, even with the tires warmed up, but it’s 550 horsepower going to the rear wheels, what can you expect? When the car does lose traction, it’s never snappy, and provided you are not asleep behind the wheel, the car is never going to send you into surprise oversteer, or understeer, for that matter.

The standard M4 is known for being an oversteer machine, and Dinan went to great efforts to neutralize and naturalize the handling balance and feel of the car. It seems to have worked, though, track testing would be preferable to really find the limits of a car this capable. This car begs for track time.

Performing under pressure.

The suspension does a good job of absorbing bumps, ruts and broken pavement. It still feels like the coil-overs are geared more towards track day performance, but the M4 can still seriously hustle through the canyons. Likewise, the adjustable sway bars aren’t overly stiff. This can usually be best described by the sensation of the wheels feeling “tied together,” especially when one wheel hits a bump, forcing the opposing wheel to also come along for the ride.

Oversized sway bars can often make cars feel uncertain at the limits of grip. For example, a large front sway bar may cause the front end not turn in to corners, or generally make the car feel unnatural on turn-in. Likewise, an oversized rear bar may make the car snappy mid-corner, or increase the difficulty in putting the power down on corner exit. I didn’t feel any of that with the M4, so Dinan clearly did their homework on the suspension setup.

They shouldn’t call it the Dinan difference, they should call it the Dinan school of witchcraft and wizardry, because they made some magic happen. BMW M4 Dinan Stage 2 Review

Qualms with the BMW M4.

To the fine folks at Dinan, feel free to skip this tangent. This is directed to BMW, and BMW alone. After driving the Dinan Stage 2 M4, I was reminded of several missteps BMW made with this car.

The electric power steering is such a let down, especially following the E90 generation cars. Even with the massive 275-section width track day tires Dinan put on the car, the steering was just not communicative. BMW has not had the same amount of development time as some other manufacturers when it comes to calibrating electric power steering, and it shows. Previous BMW M3 models (there was no M4 prior to this generation) all featured lovely hydraulic-assisted power steering racks. Indeed, for a long period of time, BMW’s brand hallmarks were smooth, torquey straight six engines, and excellent steering feel. At least they got the first part right with the F80/F82 M3 and M4. Hopefully the next generation of M3 and M4 bring back the positive steering feel older M cars were known for.

The power steering was my main gripe, this next thought is more philosophical. Do the M3 and M4 have to be so large? Looking at the dimensions, they are both big cars. Sure, the E90 and E92 weren’t minuscule, either, but the jump in size and footprint is quite noticeable. To BMW’s credit, they kept the weight down, despite the increase on overall size, and the car does feel pretty light on its feet. However, there were a few instances of oncoming traffic causing me to slow way down, thinking that the M4 wouldn’t be able to squeeze between another car and the road’s edge. I’m sure that there was plenty of space, but the fact that I had that thought in my head is indicative of the problem.

It would seem the smaller BMW M2 is the enthusiast model to go after if you don’t need the extra interior volume and want the more pure driving experience. BMW M4 Dinan Stage 2 Review

I should dislike this car.

It should leave me howling with rage about how BMW has forsaken the enthusiasts, they have lost their way! But…It is really good looking, and did I mention the speed? To be fair, the M4 is a very capable car. Dinan isn’t helping my crusade against modern BMWs when they make this one so nice to drive, either. Or the sound, how did they make the S55 sound so good? They shouldn’t call it the Dinan difference, they should call it the Dinan school of witchcraft and wizardry, because they made some magic happen, and I have become enchanted with the BMW M4.

Let’s wrap this up: Final thoughts on the Dinan S2 BMW M4.

I came into this experience expecting to not like the M4. On paper, it’s going into battle with two left feet, especially if the driver has experienced any decent older BMW. It’s too big, doesn’t have a hydraulic power steering rack, and the stock S55 sounds like garbage disposal played back through a 1980s digital recorder. It shouldn’t be this likeable, but it seems the Dinan difference really does work.

Dinan made this car so good, and so good to drive, it has me questioning everything I thought I knew about the M4. It has a level of poise and agility that I simply was not expecting. It sounds like an angry opera singer compared to a stock M4. Did I mention it’s brutally fast? With the Dinan M4 the paradox of the daily driven track car may no longer be a paradox at all. It really is the best of both worlds, comfortable enough for the daily drive, and hard-edged enough to make life worth living. I want one. Make it an M3 (I prefer the way it looks), keep the Sakhir paint job, put a 6-speed manual in it, and I’m sold. BMW M4 Dinan Stage 2 Review

Jake Stumph is a lifelong car enthusiast and racer, who has operated as the content editor for Internet Brands Automotive since 2015. He runs Corvette Forum, 6SpeedOnline, Honda-tech, and LS1tech, among other Internet Brands Automotive websites. His work has been featured by several other prominent automotive outlets, including Jalopnik and Autobytel.

He obtained a bachelor's degree in Political Science at the Ohio State University in 2013, then pivoted from covering politics and policy to writing about his automotive adventures, something that, he says, is a lot more fun. Since that time, he has established connections with most of the world's major automakers, as well as other key brands in the automotive industry.

He enjoys track days, drifting, and autocross, at least, when his cars are running right, which is uncommon. You can check out what he's up to on his YouTube channel, as well as his Jake Stumph Racing Instagram account. He can be reached via email at [email protected]

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