Even with its lowered stance, lightweight wheels and extra badges, CarBahn's BMW M8 doesn't immediately scream "tuner car." And when I'm putzing around town, it doesn't feel like one different, either. Sure, the suspension's stiffer, and you can definitely feel some extra power lurking behind the throttle. But by and large, it's an M8 unlike any other M8. That is, until you open it up.
CarBahn Autoworks is a tuning company helmed by Steve Dinan, one of the most prominent names in the world of BMW aftermarket performance. In addition to being a generally rad dude, Dinan has had a hand in a whole mess of hi-po BMWs over the years, and recently got into tuning Audi, Mercedes-Benz and Porsche vehicles through his CarBahn startup. You might remember the my coworker Kyle Hyatt tested in 2019.
In other words, Dinan knows a thing or two about making fast cars faster. CarBahn takes BMW's 4.4-liter twin-turbo V8 and fits new air filters, larger heat exchangers, bigger intercoolers and reprograms the engine software, and the result is a smoldering 824 horsepower and 779 pound-feet of torque when running 93-octane fuel -- increases of 207 hp and 226 lb-ft versus a standard M8 Competition coupe. If you've got access to 100-octane race gas, CarBahn says the output raises to an even sillier 882 hp and 795 lb-ft. My goodness.
Given the crazy power numbers, a lot of the M8's chassis hardware is upgraded, too. New coilover springs retain BMW's stock electronically adjustable dampers but the ride height is nearly an inch lower. High-performance suspension bearings, negative camber settings and adjustable antiroll bars round out the upgrades. Finally, lightweight 20-inch wheels are fitted at all four corners, wrapped in sticky 295/30 front and 305/30 rear Michelin Pilot Sport Cup 2 tires. (Actually, my test car has regular Cup 2s up front and even more aggressive Cup 2 Rs out back.)
The one thing absent from the upgrade list? Brakes. But I don't really think that's an issue. Spec the M8's carbon-ceramic brake option and these high-performance stoppers have no trouble handling the added CarBahn power.
As you can imagine, this M8's straight-line performance is simply staggering. A normal M8 Competition is already no slouch, able to accelerate to 60 mph in 3 seconds. But in the CarBahn M8, it's... well, it's quick. The company doesn't quote an official 0-to-60-mph time, but suffice it to say this thing goes like hell. Dinan even removed the M8's speed limiter, so if you want to crest 200 mph, go right ahead.
Launching this M8 is the best kind of brutal, and BMW's stock eight-speed automatic transmission has no trouble managing the extra force. But even more impressive is the CarBahn M8's overall level of finesse. I'll be honest, I expected this car to beat the crap out of me, since tuner cars like this are often super harsh and not for the faint of heart. But holy smokes can this thing hustle like the best of 'em, delivering pancake-flat handling without any bump steer or mid-corner skittishness. Those Cup 2 R tires are obviously a godsend for a car like this, offering unyielding levels of grip no matter how hard I push. And while I still don't get much feedback through the M8's standard electronic steering rack, the wheel itself is heavy and turn-in is plenty sharp.
The CarBahn M8 never squeaks or rattles or bottoms out over bumps. It also retains all of BMW's usual customizable drive modes, including the M8's two-wheel-drive drift mode, so you can tailor it to your heart's content. Whether you like it softcore or want to drive on full attack, the CarBahn M8 is happy to play along.
Leave the M8 in its default Comfort drive mode and you won't get tired of it in traffic, and the throttle isn't so touchy that you're constantly having to hold back. Sure, there's 824 hp, but it's delivered in a civilized fashion (unless you stomp on it, and who could blame you?). Plus, since CarBahn's treatment only focuses on performance, you're still able to use all the driver-assistance systems and creature comforts available to every other BMW M8 customer. iDrive 7 works a treat,connects wirelessly and the leather bucket seats are comfy and supportive.
This M8 test car has the most basic CarBahn GT package, which costs $22,900 including the optional wheel-and-tire upgrade. Dinan's working on an even more ludicrous GTC option, natch, capable of producing 1,000 hp and 795 lb-ft of torque on 100-octane fuel -- though it'll set you back $52,200 including the lightweight 20s and Cup 2 Rs.
That said, I can't imagine ever needing more than the 824-hp CarBahn GT upgrade; this turns the already great M8 into something extra special. And considering the donor car already costs $130,995 including destination, what's an extra $23K? It's rare that aftermarket cars genuinely feel worth the extra cost of admission, but then again, Steve Dinan isn't like all aftermarket tuners. If you're debating plunking down for a CarBahn upgrade, I'm 100% in your corner.