BMW 1M Notes: Engine, Transmission & Brakes


Over the past two days we ‘ve learned quite a lot about the 1M from Dr Kay Segler and BMW NA M Brand Manager Matthew Russell. For starters yes that is a Z4 35is N54B30TO (aka “n54hp “) engine under the hood. While we had heard that there were various internal changes done by M. We can now confirm that there are no physical changes to the engine.

As you heard in our interview with Matt Russell the Z4 35is has a N54 variant that was itself tweaked by the engineers at M. Specifically they have created two throttle maps (via the M button) and in turn created the most raucous N54 variant yet (based on how it sounded while revving at the show). From the lighter flywheel to the enhanced software and everything in between M went through the N54 thoroughly in creating the Z4 35is. Tolerances are tighter and the soul of the engine has been enhanced.


Dr. Segler was adamant that M had taken the soul of this N54 and turned up several notches to create something that has a different character than the Z4 35is.

Also interesting was Dr. Segler ‘s comments on the development of the car. The time-frame that M had to work within was impacted by of all things the weather. The fact that most of the development took place at the ‘Ring (an M tradition) meant that M only had from April to October of this year to engineer and then sort the car. But what you end up with is “Pure M ” has Dr. Segler calls it. What does that mean? In a quantitative way it means the 1M can do four laps on the ‘Ring generally unfazed (ie without much brake fade etc).

NAIAS 2011

The manual transmission has been something often overlooked when talking about the 1M. Yes the lack of DCT has been referenced constantly in forums and even was the NAIAS floor this week. But what about the actual 6 speed in the car? We can now confirm that it is the same 6 speed found in the 135i with a E46 ZHP shift knob. The clutch however is the same item as in the Z4 35is 335is (due to needing to support the 369 ft lbs of torque on overboost).

Speaking of transplants one of the more interesting things we learned this week is that M not only transplanted the entire suspension and braking system but the sub-frame of the M3. It ‘s easy to compare this car to a E30 or even an E46 M3. But the more you look at the components the more the 1M looks eerily similar to the E92 M3 on paper.


Finally the question of brake ducts. Yes the pair giant holes in the front bumper are not brake ducts as you might expect. They are actually need to bring air to the oil and water coolers. But M hasn ‘t forgotten about the brakes. Instead M has designed paths cleared under the chin to ensure plenty of fresh air reaches the brakes.

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  • Neil

    Gabe –

    Interesting and much appreciated notes.

    Am I correct then that the tolerances in the N54 in the Z4 35is are tighter than in the N54? Matt Russell didn’t say this in your interview, but it seems that you have other sources.

    Also, do you know whether the intercooler, radiators (primary and auxilliary) and oil cooler are the same units installed in the “is” models or have any of them been upgraded?

    Appreciate your reporting on this.


    Neil (aka MDORPHN)

  • Neil

    Oops, meant to say “tighter than in the 335is.”



  • Neil

    One more thing regarding the 135i tranny with the Z4 35is clutch. I’m trying to reconcile the choice of these components with a post that Matt made some time ago when the Z4 35is came out.

    He stated:

    “First, the clutch and the springs used that can not handle the torque at those load levels. The 6MT would be able to handle the torque WITHOUT the overboost function but not be in BMWs range they prefer, since engines can actually produce more HP from the factory than quoted but not less. This is also the reason with the Performance Kit. When you talk to engineers and those that have a say in the design of these products you realize it is not marketing that plays a part into these decisions, unless you consider warranty and reliability marketing. Look up the numbers for the 6MT from ZF and you will see BMW in not BS-ing

    The DCT can handle more than the 6MT (period).”

    Can you clarify? Thanks.


  • Gabe

    Are you trying to reconcile the choice of transmissions or just the clutch?

  • Neil

    Sorry, I was unclear. Matt stated that the Z4 35is was made available only with DCT because BMW engineers determined that the 6MT couldn’t handle the additional torque provided by the overboost. Has the tranny installed in the 135i and 335is been strengthened?

    Also, any insight as to my question about the intercooler, radiators and oil cooler?



  • Gabe

    Sorry, I was unclear. Matt stated that the Z4 35is was made available only with DCT because BMW engineers determined that the 6MT couldn’t handle the additional torque provided by the overboost. Has the tranny installed in the 135i and 335is been strengthened?

    Gotcha. Actually it was the clutch that was the weak point on the stock 135i and 335i and yes that was strengthened in the 335is.

  • JonPD

    A bit disappointed to see no further work on the 35Iis N54 and still the lack of dedicated brake ducts worries me the most. I am glad to hear that they can do multiple laps of the Ring but have serious doubts that they can address brake cooling with opening channels only. Will be interesting to see how it works out. Still believe the first stop for the car will be to have the decent 35is motor turning into something truly interesting.

  • Alex

    I’m kind of disappointed in the transmission choice. I was under the impression that it was the 6 speed out of the M3. Engine at least looks brighter than it did yesterday after the USA M rep. interview.

    I’m sure the chassis will more than make up for the rest though. IND and AMS will have us covered on the power side of things.

  • Bimmer1

    All I’ll say is the clutch in my 135 M sport with Dinan software (420 lb-ft of tq.) has no problems whatsoever after 12,000 miles of hard driving. It does not slip at any time under full throttle. Maybe I’ll eat my words once I hit 30k miles but I think BMW is being way to conservative with the power in the 1MC. I’m sure they just don’t want the 1M to spank the M3, but they shouldn’t care about that. The M3 is almost 4 years old, and your goal should never be to make a product equivalent to one you designed 4 years ago. That’s not progress. Before you know it the M3 will be out of production and we’ll have a 2 year gap with nothing that stands up to the M3. It would be interesting to see if my Dinan 135 would be as fast or faster at the track than a 1MC. I think the extra power I have may still overcome the upgraded susp/brakes of the 1MC, which IMO is a total fail for BMW. I still love the 1MC, I just wish they would have gone the extra step to really make it something special instead of what is essentially a 135iS in my mind.

  • Bimmer1

    P.S. I love that it only comes with a 6 spd MT. Real drivers shift their own gears. DCT is a waste unless you’re at the track all the time.


    It’s a great car no matter how you slice it. For they time they had to create it M has done an awesome job. Regardless if people think its really a 135is is incorrect in my opinion. It’s a great starter for someone looking to get into a new M without the expense of the more expensive cars.

  • JonPD

    I feel its somewhere between a ///M and a 135is. I have no issue calling it a ///M but it does feel like a fairly big departure for them (not as huge as a Momsport Suv).

  • Bimmer1

    Don’t get me wrong, I think it’s a good car as well. It’s just not a great car, which I beleive every M car should be. However I don’t agree with your statement about how little time they had to develop the car. Aside from the body panels/aero there wasn’t much R&D that was involved with this car at all. All they did was swap out the rear axle, subframes, and suspension from an M3 and then tweak the DME programming. Aside from the clutch the engine is exactly the same as every other N54 engine. People have been swapping the M3 suspension parts onto the 1 series since the day it came out. Aside from maybe the aero testing, the R&D for this car was a cakewalk. The fact remains they simply did not want it to outperform the M3. That’s the only reason it did not get the power it deserves. I guess we’ll just have to wait for Dinan to take care of what BMW should have done in the first place. Oh well.

  • Chad

    I’m not sure that dissecting the car to either praise it or express dissappointment is really going to amount to much. This car is about feel, purportedly, and we know the way to determine this is a drive. I am excited, based on the size, components and stats, but I keep going back to Chris Harris’s drive- he seemed excited and impressed. All of this contributes to my high hopes.

  • Jon

    All I know is that if I had the money for any BMW offered currently, I’d choose this car. Lightweight (compared to other BMWs), MANUAL transmission, the aggressive body styling and that amazing orange metallic paint all make this car “the one” for me. You can keep all your other luxury i-Drive equipped models. I’ll take this analog driver’s car, please.

  • spaorz

    HI Gabe, all M cars are built in a certain way, eg the engine is assembled by M, and special machines are used to ensure it is more rigid when they drop the engine into the car. Do you know if this is still the case for the 1M? Thanks 🙂