Unlocking The M235i’s True Potential

Watching the late Tanabe-san from Power House Amuse hammer his Ericsson M3 through the twisty Tsukuba infield will always remain a fond memory for me. Amuse’s exhaust was a match made in heaven for the E92 M3; I don’t think there was a better-sounding aftermarket system available for the car’s naturally aspirated 4.0-liter V8 engine.

Thanks to factory turbocharging, things are a little different – and quieter – these days when it comes to BMWs, but that’s opened up a lot of opportunity in the aftermarket as Japanese tuners like Assist from Kyoto attempt to get the most out of the N55 engine.


Their demo car is one that really stood out at the recent Rev Speed Super Battle. Based on the M235i and not the M2, it boasted a rather JDM approach in terms of visual presentation, starting off with the obligatory trunk lid-mounted GT wing, which is a must-have for any car that hits the track in Japan.


What really set it apart, however, were the front and rear fender flares. These aren’t designed by Kei Miura, but are actually part of the M Performance racing package for the single-make race F22 you can buy from BMW. These carbon fiber overfenders even come with four widened inner fender liners, just because factory-supplied stuff is normally rather well designed and developed.


What sealed the deal was the wheel choice: RAYS Volk Racing ZE40s finished off in the same satin bronze we’ve been used to seeing on legendary rims like the TE37 and CE28s. Behind them sit a set of monoblock Endless racing calipers, and the rubber of choice is Yokohama’s stickiest radial, the Advan A052.


Assist even scored a pretty experienced driver to put the car through its paces at the event. After only a couple of laps, Nobuteru Taniguchi posted the car’s fastest time of the day – a 1:00.899.

Hit play above to see how effortlessly the ZF 8-speed auto-equipped M235i laps around the familiar Tsukuba layout.


Other exterior touches include a carbon fiber hood to take a little weight off the front of the car.


There are more carbon accents, including M Performance carbon side skirts and a rear diffuser section, from which the Laptorr exhaust system peeks through with its large tail pipes.

The two-piece rear fender flares have no problem swallowing up the 11-inch-wide rear ZE40s and the 295-section rubber they’re wrapped in.


So as you can see, function has set the theme for pretty much every upgrade to this car, something that certainly can’t be said for all the overfender-clad cars we come across in our travels.


The interior has been stripped of its stock leather and electric seats and fitted with proper Recaro buckets, fixed into position via rails that Assist has developed for a range of BMW models.

Joining the exhaust system is a GruppeM ram air carbon intake, very similar to the one I run on Project Drop Top. The engine has been custom mapped to take into consideration the upgrades as well as the larger intercooler now employed. Seeing as there is little space to fit a conventional tower bar, additional bracing has been fitted around the front struts.


A 1-minute-flat lap is still a big deal at Tsukuba, and I find it impressive how a lightly tuned M235i can achieve these sort of numbers. That said, I would love to see a properly tuned M4 attempt a time at Tsukuba. Maybe Assist can built one as their next demo car…

Dino Dalle Carbonare
Instagram: speedhunters_dino



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I'd like to see what time the Assist M3 touge car would do at Tsukuba. It is/was at the pointy end of the field in the HV touge segments from a year or 2 ago.

Dino Dalle Carbonare

Yeah haven't seen it in a while


Looking into getting an M235i myself, what kinda put me off was the lack of a factory equipped LSD . Is this one running an an aftermarket LSD or is it open diff?


There are quite a few choices for LSD for this car. The factory M Performance LSD which is a whole new diff center section and quite affordable through your local dealer or online as well as many other options from Quaife etc. From other M235i owners I've met online or at the track, a popular upgrade is the Quaife with custom gearing. I run mine on track with no LSD but with all the traction controls off the car utilizes the e-LSD, which is actually pretty good.


Yeah I've looked into the Quaife and from what I've read its a little better for my budget than the M Performance LSD since it doesn't have any actual clutch packs. Its good to know that there are aftermarket options out there and that the F22 is still a hoot around the track with the e-LSD! I'm probably gonna push the LSD upgrade down the line and get a nice set of track wheels and tires first.

Dino Dalle Carbonare

Not too sure on that but surely there are aftermarket choices out there


Now you done did it and mentioned project drop top Dino, has there not been any development as of '15?

Dino Dalle Carbonare

Not much, it gets driven every day, needs a good detail in & out but I'll get an update up soon! I promise

Mohamad daneshmand

fantastic handling

Dino Dalle Carbonare



My 2nd best BMW platform after the 1M/1series coupe even if 2 series is considered the upgrade or 2nd generation of the 1 series coupe.
But how cool is that you can find a factory wide body kit for the car.

Dino Dalle Carbonare

Yeah and it's carbon fiber and comes with fender liners. Would be cool if more of this type of stuff is offered by other manufacturers


Well, long time ago A/C, power steering, power windows,.... were option and because of market demand are now starter package (in most cases). Maybe wide body kit will face the same future, at least we hope, even if the aftermarket shops are showing a good stuff.

Dino Dalle Carbonare

Yeah but what you say makes life easier in cars, wider fenders allows you to run bigger rubber, can't see your average housewife ticking that option when choosing her new grocery-getter lol


I've a huge soft spot for the 2 Series, with the M2 being one of the best cars that I've ever driven.

Interesting about the ZF gearbox instead of DCT. Read (or maybe heard) recently that manufacturers are leaning towards the ZF auto-boxes now over dual clutches because they're continuing to improve and their low speed performance is so much smoother. Apparently a weight saving too?

Dino Dalle Carbonare

I had the 335i before the 435i and that had a dual clutch. Loved it but the ZF is almost as good in any gear BUT the first to second gear shift which for some reason feels and sounds very torque-converter-ish (love making up new words). Aside from that it's easier to live with, smoother when in auto mode/ECO pro and has 8 speeds which is marginally better for long drives & fuel consumption


Haven't experienced any low speed discomforts with modern PDKs. They're flawless. I would imagine a ZF box is done more for cost than anything. Would make sense due to the complexity of a twin clutch gear box.


Love it!

I've got a 135i that has recently been demoted to a second car. I'm in the process of upgrading it now I don't have to do it every day and articles like this only fuel the fire.

First on the list will be a proper LSD from Birds followed by a map and possibly suspension upgrades. This article answers the question of what wheels. Shame mine is blue!

Dino Dalle Carbonare

We like feeding fires haha


Damn that's perfect. BMW killed the blistered fender game imho; the M2 and M4 are truly menacing in stock form.


295 tires all-around, this is like mini grip machine!

Dino Dalle Carbonare

It's all about the 295 section tires these days lol


Because that's currently the widest tires, no?
I honestly want to see 315mm tires & interest to see how would these car managed to house it.

Dino Dalle Carbonare

No there are far wider tyres out there, it's just the biggest size you can fit on GT-Rs and Evos without serious mods


I feel like the 2 series doesn't get too much attention and is defiantly underrated. I am in love with BMW and after seeing the HGK M2 I was in heaven. I want one so bad and seeing this one I am more into it!! this one isn't as crazy looking at HGK but it still beautiful car!!

Dino Dalle Carbonare

Yeah the M3/M4 steal all the limelight but these smaller models actually make more sense if you want to build a fun track car


Nice looking car and a minute flat is pretty quick. I've always wondered why Suzuka isn't used as more of a bench mark over Tsukuba. Tsukuba seems kind of "rinky dink" and doesn't seem like a particularly challenging track to drive. Any thoughts Dino?

Dino Dalle Carbonare

Proximity to Tokyo is everything in Japan, hence why Tsukuba & Tsukuba remain the most popular ones. If you are down south Okayama is a popular one for time attack. It's a pity we don't see Suzuka & Sugo used more in time attack as they are both amazing in their own way. Just too far for a lot of shops I guess


Thanks for the info. That makes perfect sense. Tokyo is where the money is! I find Tsukuba to be incredibly boring...basically a few hair pins and incredibly low average speed for a circuit. 130R is a proper corner!

Dino Dalle Carbonare

It's a fun track, boring it is not. It's challenging and scary at the same time, one mistake and you are on the wall


Tsukuba or Suzuka? God I love how in Japanese pretty much 80% of everything rhymes.


the car - driver combination is too good, that was easily the most boring lap i've ever seen around there lol no excitement at all, not even the hint of a slide or correction lol

Dino Dalle Carbonare

haha you know what, you have a point. Too much grip, just enough power. Need less of one and more of the other to make it more visually fun I guess...


If you gona take your M235i to the track, first on the list must be suction pump and oil pan from M3/M4. Otherwise you'll kill the engine after 1-2 track days if you really drive it hard(not cruising). This lubrication system is used on M235R BMW racing car.