If you wish to make the case that the very last thing a BMW M4 Competitors wants is extra efficiency, you received’t battle to seek out others who agree. The newest G82 era mannequin and its G80 M3 sibling push the idea of a automotive punching above its weight class to extremes.
A 503-horsepower straight six makes world-beating acceleration the norm, whereas an optionally available all-wheel drive system all however assures backroad dominance. For many who need extra, BMW answered the query earlier than you requested it, first with the stripped-out M4 CSL after which with the spiced-up M4 and M3 CS. What, then, is there left to enhance?

CarBahn, the most recent enterprise by legendary tuner, racer, and engine builder Steve Dinan, believes it discovered a compelling counterargument within the type of its $20,599 CB3 Signature Bundle.
Earlier than the primary miles come, there’s good purpose to count on greatness from this automotive. Whereas CarBahn isn’t but a family title, Dinan actually is, along with his robust fame for fame for modifying and racing vehicles stretching again to the early 80s. Though he’s now not a part of the corporate that bears his title, Dinan’s philosophy of upgrading vehicles to OEM or higher requirements whereas matching the manufacturing facility guarantee endures.
Understanding that mindset is essential to know what this automotive is in the end going for. At first, if you learn that this BMW M4 Competitors now not produces the inventory 503-hp determine however as a substitute a McLaren 720S-beating 735 hp, it might be simple to imagine that CarBahn dials up energy past manufacturing facility limits and calls it a day.

The other is true. The surge in efficiency begins with customized engine software program, additionally boosting its torque output to 668 pound-feet, an upgraded warmth exchanger, and a brand new chilly air consumption to make sure this two-door stays as dependable as doable. The ultimate piece to CarBahn’s Stage 2 Energy Bundle is a brand new stainless-steel exhaust. Nevertheless, this tester swaps it out in favor of lighter pipes made from titanium for $3,500.
Whereas an additional 232 hp and 189 lb-ft signify a leap ahead performance-wise, these aren’t essentially the most impactful upgrades bolted to this all-wheel-drive-equipped M4.
For that, you’ll have to show to its reworked suspension. The primary merchandise on the record is what the tuner calls a “coilover equipment,” nevertheless it isn’t so within the conventional sense that it replaces each the spring and damper. As an alternative, it provides height-adjustable springs whereas retaining the inventory damper, making certain that the flexibility of the manufacturing facility suspension modes stays. Nevertheless, CarBahn crafted adjustable bump stops to help it, which could initially appear comparatively minor however considerably impacts experience high quality.

Because the spring compresses, these bump stops can soak up extra vitality produced by highway imperfections, limiting the roughness felt within the cabin. This makes this BMW M4 Competitors firmer whereas enhancing its capacity to stay completely settled on a bumpy highway. It determination additionally leads to a extra compliant experience for day by day use.
Alongside the coilover equipment, CarBahn’s CB3 Signature Bundle consists of adjustable anti-roll bars, Monorail bushings up entrance, and upgraded toe hyperlinks within the rear. A five-point carbon strut brace improves chassis rigidity, whereas stainless-steel brake traces help constant efficiency whereas barely firming up the pedal. It’s value noting, nevertheless, that the tuner optioned this explicit M4 from new with a set of $8,150 carbon ceramic brakes.

The costliest CarBahn possibility fitted to this automotive is one you shouldn’t skip. For $4,000, it features a widened set of 20-inch solid wheels, seen right here in a darkish bronze end, and Michelin Pilot Sport Cup 2 R rubber. This automotive’s monitor broadens due to tires that measure 295/30 up entrance and 305/30 within the rear.
Cosmetically, the Signature Bundle hundreds this automotive’s exterior with carbon fiber goodies. It begins beneath the hood with an engine cowl, works its means out to a motorsport-inspired grille, and finishes off with a whole physique equipment made from the light-weight materials. The result’s a two-door with an aesthetic and a stance way more aggressive than something BMW would ever mass-produce.
Now that you already know all the small print, how efficient are they?

The reply is that they’re nothing in need of transformative. On a winding again highway, you’ll really feel the results lengthy earlier than you choose up the tempo. Whereas a inventory BMW M4 Competitors incorporates an ultra-quick steering rack in hopes of constructing you suppose that this practically 4,000-pound two-door is lighter and extra agile than it’s, there’s nonetheless a split-second delay as its heft catches up.
This isn’t the case within the M4 by CarBahn. Because of its upgraded suspension and wider tires, this two door modifications course with out hesitation. With a sharpened response from the entrance finish, tackling a winding highway now appears like a way more cohesive and seamless expertise. You get precisely what you ask of it the second you flip the wheel.
Whereas these updates don’t unmute BMW’s completely useless electrical energy steering system, you get barely extra weight as you load up within the bends, whereas suggestions from the chassis is improved. Braking efficiency is implausible, however then what would you count on from a automotive sporting an almost five-figure set of carbon ceramics?

It helps that you simply’re lugging round much less weight, too, with CarBahn’s solid wheels and titanium exhaust shaving a couple of kilos. In keeping with CarBahn, with these choices fitted alongside BMW’s carbon ceramics and carbon seats, this automotive weighs 200 fewer kilos than a base xDrive-equipped M4 Competitors.
At the same time as you choose up your tempo, this BMW M4 Competitors stays effortlessly composed in each open and tight bends. Even giant bumps battle to unsettle it because it feels considerably extra hunkered down than a manufacturing facility automotive would. But, regardless of feeling extra planted, it by no means interprets highway harshness to its occupants, thanks partly to its new bump stops.

The result’s a automotive that strikes completely instep with its driver whereas delivering a driving expertise extra targeted on offering enjoyable than outright efficiency.
That stated, its further 232 horses are actually all accounted for. But regardless of it accelerating extra ferociously than a inventory automotive, it’s by no means overwhelming. Because of its xDrive system, it doesn’t battle for traction. It stays completely composed at the same time as you route the facility completely to its rear wheels.
Its titanium exhaust permits its 3.0-liter inline-six to be way more vocal however by no means excessively on the freeway or throughout on a regular basis commuting. Nonetheless, it’s restricted by the truth that BMW’s raspy S58 engine is much from its greatest sounding.

Extra magic could be discovered as you flip off the twisty highway and assign this BMW M4 Competitors day by day driving duties. Regardless of its huge 295-width entrance tires, it doesn’t tram line, neither is the in-cabin noise extreme. Nevertheless, the plushness felt on a bumpy highway stays, considerably rising this automotive’s consolation and flexibility. When you’ll get a slight trace of fender and tire contact whereas maneuvering at full lock, it quiets down the second you flip the wheel again.
Whereas the CB3 Signature Bundle prices $20,599, this tester sports activities the aforementioned $3,500 titanium exhaust system, a $4,000 wheel and tire bundle, and a $1,500 factory-matching four-year/50,000-mile guarantee.
The M4 Competitors xDrive used for this construct prices $98,145 due to extras similar to its $8,150 carbon ceramics and $3,800 m carbon bucket seats. This brings the full price as much as $127,744. that’sThat’s corresponding to the M4 CS’ $124,675 base value for context.

To reply the unique query, this BMW M4 Competitors by CarBahn isn’t designed to seek out fault and enhance an in any other case implausible sports activities automotive. That’s the route chosen by the CS and CSL fashions, successfully amplifying the inventory expertise with a extra hardcore method.
As an alternative, Steve Dinan employs masterful tuning work to supply us one thing completely different. This M4 doesn’t fall wherever inside the CS to CSL binary. It modifies sufficient to face by itself. It doesn’t make the case that this automotive wants any further efficiency; it as a substitute asks: “What if we not solely provide you with extra, however we make it extra approachable, fulfilling, and day by day usable?” because it exhibits, that is the query really value asking.