A man by the name of Lord Acton was famous for saying, “Power corrupts.” Does it, though? Is that always the case? What if more power didn’t corrupt—what if it just made things more fun for us all? That is the case with what Steve Dinan’s Carbahn tuning company has done for us BMW enthusiasts. For those of you who don’t know, Steve Dinan is a legend among the BMW tuning community. His original company, with his namesake, he sold in 2013.
Who Is Steve Dinan? A Legend in BMW Tuning
Since then, he has started up Carbahn and continued on the path of making BMWs faster. Steve has a unique philosophy on tuning: he prefers to add balance to the car, not just power. The car needs to be able to put the power down and handle better so that it isn’t just fast on the straightaways but faster getting from point A to point B—no matter what track or backroad that may be. Power is great, but without proper suspension or handling modifications, it can lead to disaster. Just look up any Mustang owner leaving a Cars and Coffee on YouTube.
Unpacking the CB3 Package: Powertrain and Suspension Upgrades
This brings us to the 2022 BMW M4 Competition xDrive that was dropped off to me in November, equipped by Carbahn with their CB3 package. What is that? It is a comprehensive overhaul of the M4’s drivetrain and suspension. So to speak, it’s as if you wanted to turn your M4 up to “11.” The package includes powertrain modifications such as a revised engine software tune, an additional air-to-water heat exchanger to handle the power, a stainless steel exhaust, and a carbon fiber cold air intake. The result? 735 horsepower and 668 lb-ft of torque. Carbahn did not provide a 0-60 time, but Car and Driver tested this exact car and recorded 2.6 seconds for the feat, along with a quarter-mile time of 10.6 seconds at 130 mph. Those are very impressive, supercar-rivaling numbers by themselves.
Carbahn was far from finished with their work on this package. The CB3 package also includes several suspension upgrades to improve handling and feedback for the driver. The suspension upgrades include coilovers, stiffer anti-roll bars, front moonball bushings, and a five-point carbon fiber strut tower brace. While the carbon ceramic brake rotors and pads remain unchanged, steel brake lines have been added to improve pedal feel and ensure consistent brake fluid pressure under heavy use when the fluid heats up.
Carbon Fiber Additions: Function and Style Combined
The rest of the package includes numerous carbon fiber cosmetic pieces. While they may shave off a few pounds overall, they are largely there to signal that there’s something a little bit different about this M4. These pieces include a carbon fiber engine bay cover, front grille, front splitter, brake ducts, canards, rear lower skirt, fender vents, and spoiler. Interestingly, the carbon fiber front grille, which is more open than the standard grille, provides 40% more airflow according to Carbahn (and I also think it happens to look better).
There are several additional add-ons with the CB3 package offered by Carbahn that this car came equipped with. The first is a full titanium exhaust. This not only sounds significantly louder than stock, but it also shaves off approximately 40-50 lbs (depending on G80 or G82 configuration) from the stock exhaust and further reduces back pressure to improve throttle response and power. The 20” Carbahn-branded forged wheels shave off several pounds of unsprung mass per corner and, more importantly, come equipped with Michelin Pilot Sport Cup 2R tires in a wider 285 front, 305 rear width setup. These are Porsche-spec tires and among the most aggressive compounds available for a street car. They are remarkable for time attack performance and help control the car during launches.
Altogether, this package costs $20,600. Is that expensive? It’s certainly not an insignificant amount of money. However, considering the parts individually, it is actually priced fairly reasonably given the quality of the parts and the quantity of changes being made. But context is everything, and ultimately it depends on how it makes the car drive and feel. This is where I was most surprised by the CB3 package. To summarize: I absolutely loved the religious experience I had driving this car.
Real-World Test Drive: Angeles Crest Highway Experience
Early one Friday morning, I put Newcomb’s Ranch into my GPS and made my way toward Angeles Crest Highway. While there was nearly no traffic at all on the road, I decided to begin to see what this car was all about. It was cold that morning, and there had been some rain. Steve Dinan set up the M1 and M2 buttons to his liking: M1 for commuting and fun street driving, M2 for pooping your pants—I mean, track driving and more spirited driving. I tapped the M1 button and immediately felt the additional throttle response and sensitivity.
The 502 hp from the original M4 is already impressive, but readjusting to 735 hp on tap was almost comical. The conditions were rough, and any chance to even think of applying too much throttle was met by the traction control light screaming at me and some entertaining slip. Michelin Sport Cup 2R tires are fantastic when heated and in dry conditions but struggled in these conditions. Once the road cleared and dried, and the tire pressure/temperature readings on the M driver’s display showed the tires were warm, it was time to finally explore more about where the $20,600 went into this car.
Steve Dinan said this was the fastest car to get from point A to point B of any car he had ever built. He wasn’t kidding. This car was magnificent on a backroad. What I quickly found was that the power wasn’t the best part: it was the chassis and suspension tuning. Coming into a corner, I could apply an enormous amount of brake pressure, experience no dive thanks to the coilover suspension (still using the stock M dampers), load up into a corner (thanks to the beefy sway bars), and begin applying throttle mid-corner to rocket out of the exit. The rear-biased xDrive system and wonderful electronically limited-slip differential helped put the power to the outside rear wheel and made the car an absolute joy to rotate.
While the coilovers are nearly an inch lower than the standard car, they still allowed for good compliance when hitting undulations in the road and rough pavement. Sometimes a stiffer car isn’t always faster, and Carbahn knew this. This car’s suspension is so well set up because it simultaneously handles imperfections in the road to maintain the contact patch while also preventing body roll and reducing weight transfer in corners. Suspension tuning is a dark art, and they nailed it with this package.
To aid the already great drivetrain, the new rear adjustable toe links and more aggressive alignment made the car feel razor-sharp on turn-in. The moonball bushings actually helped add back steering feel that you might be missing in modern M cars. Altogether, these suspension upgrades didn’t just make the car more capable in corners; they also added feel and feedback to the driver, giving an unparalleled level of confidence. Surefootedness and engagement don’t always go together in the car world, but in this car, they do. This is not just a drag strip or quarter-mile queen—this M car has been refined to be an even better sports car than its stock version.
Then there is the power. For obvious reasons, my lawyers have said I can’t get into specifics, but is the car as fast as you would imagine an xDrive M car with 735 hp and 668 lb-ft of torque going through one of the world’s best 8-speed automatic transmissions? Yes, hypothetically, it is. If your mother ever tells you that you need to do something to bring you closer to God, you could go to church, or you could buy a Carbahn-tuned BMW M4. This car is like a giant middle finger to Isaac Newton because it cheats physics. That’s all I can say about the car’s speed.
Was Steve Dinan lying about this car being the fastest he’s ever built for driving on the street? Nope. I believe him.
What’s funny about all of this power from the Carbahn tune is that they offer a matching factory warranty with it, and you can even opt for an extended powertrain warranty. The S58 is so unbelievably under-stressed in stock form that, even with the addition of more than 200 hp and the subsequent boost, they are confident enough to offer a warranty. There are not many tuning companies that offer that level of reassurance with their aftermarket tunes. Oh, and it will still pass smog.
Daily Driving the Carbahn CB3 M4
After the fun mountain driving, it was time to slug through LA traffic back home. An hour and a half on the freeways and surface streets surprised me yet again. Back in comfort mode, the car felt like a normal M4 all over again. The coilover suspension still used the M adaptive dampers, and on the street, the ride is no harsher. The moonball bushings and toe links do add more NVH as the rubber ends on the standard parts are replaced with Teflon-coated aluminum for a more direct feel. Is the trade-off of a more direct driving experience worth a slightly rawer feeling M4? I would argue that it is. The best way I can describe it is that the car had 20% more feeling but only a 5% penalty for NVH. You can absolutely daily-drive this car and road-trip it without much issue. I also still got 27 mpg on the highway.
Pricing Breakdown: Is the CB3 Package Worth It?
The weekend I spent with the car got me thinking. The sticker price on the M4 Competition Carbahn started with was just over $95,000. The CB3 package is $20,600. The full titanium exhaust ($3,500) and forged wheel/tire package ($4,000) bring the car’s total to $123,100. Is that a lot of money? Yes, when the average price of a car is just under $50,000, this is certainly a considerable amount of money. But is it really, for what you get? BMW M cars have never been known to be cheap, exactly, but this car punches well above its weight, especially with these modifications.
Let’s think about this. For roughly the same power, you are now comparable to a 992 Turbo S or a McLaren 750S. These cars cost double, if not triple, the $123,000 out-the-door price of this Carbahn M4. A C8 Corvette Z06 with a Z07 package offers less power and is several tens of thousands of dollars more. On a backroad, I doubt you would have any issues keeping pace with these supercars. All the while, you can road-trip in comfort with four people and luggage—something those supercars might struggle with.
I regret a lot of things in my life, and handing back the keys to this Carbahn M4 was one of them. This was such an unhinged yet surgically precise car to drive. I always wish for a manual gearbox, but the speed and g-forces this car produces on a canyon road made me have the most fun I’ve ever had in an automatic. Carbahn absolutely nailed dialing this car in, taking away any slack from the M4 and adding precision and even more speed.
Honestly, the CB3 package is a great value for what you get. If you want a religious experience or are suffering from a deficiency in serotonin and oxytocin, you should get this for your car. Steve Dinan and the Carbahn engineers weren’t satisfied with the “Ultimate Driving Machine,” but after you drive one of their tuned cars, I promise you will be.
