As I type, the M135i will be going back to BMW tuning specialists Birds for good within a couple of weeks, but not before we’ve put it up against an M2. It’ll be an intriguing comparison. Since its engine remap, the M135i has more power than the M2, so it will probably be quicker in a straight line. Everywhere else, though? We’ll have to wait and see.
Finally, I’ve been reading about BMW’s plans for the 1 Series. Reports suggest the third generation will switch from rear- to front-wheel drive next year, with high-performance models set to use four-wheel drive. I get why BMW would want to move away from a rear-drive layout for the 1 Series. The overwhelming majority of hatchback buyers would never appreciate the benefit of a rear-driven chassis, or even notice the difference. What they certainly would notice and appreciate, however, is the extra cabin space such a change in layout would bring. Rear leg room has been a problem for the 1 Series since day one.
But BMW has spent many decades telling us rear-wheel drive is best. And all of a sudden, it isn’t. A pity, too, that the really quick models will almost certainly drop the current six- cylinder turbo engine in favour of a four-pot. (Try making six cylinders fit in an east-west installation...)
If these reports are accurate, the next high-performance 1 Series will share the same mechanical layout as the Audi S3, Mercedes-AMG A45 and VW Golf R: four-wheel drive with a four-cylinder turbo motor. Who knows, it may well become a better car for it. But that loss of variety in the hot hatch sector will be lamentable.
Life with a used BMW M135i: Month 4
Turning the wick up on our used BMW M135i – 24 January 2018
The plan for our M135i project car was always to get the suspension sorted first to make it ride and handle the way we wanted it to.
Next, we would fit a Quaife limited-slip differential, (LSD) and only then would we go anywhere near the engine.
That is exactly how it has worked out so far, but with the engine now having been remapped to liberate a good wedge of extra power and torque, I felt somewhat sorry that the project was close to coming to an end.
Which is precisely why I’ve twisted the arms of the good people at Birds – the tuning company we’ve been working with on this project – to let me keep the car a little longer and make an upgrade not in the original plan. At some point in the next few weeks, then, I’ll be telling you about the M135i’s lovely new brakes.
But that’s for then and this is now. With just a remap, Birds is able to wind the N55 3.0-litre turbo engine up to almost 400bhp. In a car the size of a 1 Series, that really is a huge amount.
According to company founder Kevin Bird, the N55 motor can be extended even further, but that causes some fairly major issues further down the line. “We did push one of these engines beyond 400bhp,” he says, “but we found that the ignition timing was being retarded at maximum torque revs in the higher gears. If you kept the throttle pinned for more than 10 seconds, you could also see that the throttle was beginning to close, ultimately triggering limp mode.