BMW M2 Build - Fixing Track Failures

Contrary to what a Porsche owner says…..the BMW M2 is a great track car platform. Sure a GT3 or GT4 is more capable than any of BMW’s M line. But those Porsches cost significantly more (like 3-5 times more) than a stock M2/3/4. Even after you spend a ton of money turning an M2/3/4 into a track beast you are still in the hole less than a stock GT3 or GT4. Yes a Porsche will be faster, but speed and lap times are not always the main point of a car build. For some of us the main point is to simply have FUN and to create a one of a kind car. So if you are like me and you want a project car, but also want a great platform to work on, and you are on a budget, then the M2 might be a great option…..at least until you have a Porsche budget to play with :)

With that said, there are a couple things you will need to address on the M2 to make it a great track car that frankly are annoying oversights by BMW. The first, which is very well documented throughout the web, is the tendency for the M2 to go into limp mode on the track due to fuel starvation. While that is bad enough as is, what is worse is that you don’t know it is due to fuel starvation unless you have a code reader. This happens when you are pushing the car on the track under G load and the fuel tank is 1/2 full or less. What happens is the car will signal a drivetrain malfunction and immediately put you into a 35 mph limp mode…..not awesome. Fortunately the fix is easy and cheap. All you need is Dinan’s Fuel Upgrade Kit.

Another annoying mod you need to make on the M2 for the track is to either turn off all the nannies or code in new settings for the nannies so you have more control of the car. The US MDM settings are a joke. The Euro MDM settings are better, but the best for the track are the M4 GTS MDM settings. You can also use the M4 GTS settings for steering, the differential, and the transmission (DCT). To learn more about how I coded these into the SVMC M2 check out this post.

Other than those obnoxious, yet required, mods you enter the normal mods like wider wheels and tires, better brakes, better suspension, and more power. In case you are wondering what order of mods you should do I would suggest tires, brakes, suspension, codes/tunes, and then power. No need to have more power if you can’t do anything with it. If you are wondering what the priority is for the safety mods (cage, seats, belts, fire suppression, etc) my philosophy is that once you get out of the “A” run group and are driving solo then you should begin creating a plan for your car and start increasing safety along the way. Safety mods should never be overlooked and as you get faster your budget should shift from fun stuff to safe stuff.

One last comment about BMW’s for the track. If you are working with a modern BMW (anything after the e46 M3) weight is an issue. There is only so much weight you can strip out of a modern BMW, but you can say that about most modern cars due to safety standards.

UPDATE 11/12:

I took out the SVMC M2 to test out the Dinan upgraded fuel pump kit and it worked perfect. Before this upgrade I would go into limp mode if I let the fuel get to 1/2 a tank due to fuel starvation. With the upgrade kit I am able to take my tank all the way to empty without going into fuel starvation. I know this because yesterday at Sonoma after lunch I forgot to refuel and in my 4th session out I drained my tank to near empty without ever going into limp mode. The Dinan fuel pump kit is a must buy for any M2 that is going to see track duty.

BMW M2 Build - Custom Laguna Pipes

The last time I was at Laguna Seca I blew sound enough times that it almost ended my day. I ended up having to literally coast through turn 5 to pass sound (not fun). I started thinking about what kind of Laguna pipes I wanted. The issue is that I wanted them easily removable and I didn’t want them to scratch up the finish of my Dinan exhaust. So I came up with the design of putting the pipe extensions inside the Dinan tips and securing them with some simple bolts. I asked Edge Motorworks in Mountain View if they could fab them up and as always they were up for the challenge. They took it to the next level with some trick welding, stenciling their logo, and painting the pipes with matte black high temp paint. They simply redirect the sound away from the mic at Laguna but its enough to pass the strict 90 dB sound limit without having to lift or shift early. To be fair I do need to engage my electronic exhaust baffle as well but without a doubt these one of a kind pipes did the trick.

BMW M2 Build - Dinan Exhaust

For this build I tried to focus first and foremost on performance mods….but every now and then you need to do a mod simply to do a mod. I have had a few of those on this build but the most recent one is getting a Dinan free flow exhaust added to my Dinan resonator delete. While Dinan claims some performance enhancements for their exhaust system they are not material in my eyes. They are simply enhancements to make the car more enjoyable. Here is a great video highlighting the different options Dinan provides for the M2.

There are other systems that are louder or more exotic but the Dinan system is loud enough, 50 state legal, well fabricated, looks great, and reasonably priced. For all of those reasons I felt it was the right choice for the SVMC M2. Now I just hope I pass sound at Laguna Seca!!!!

BMW M2 Build - Power

The M2 comes with decent power from the factory without any modifications, but in the spirit of building my vision of an M2 GTS, I wanted to do a few things.  Before I get flame mail from those that want huge horsepower cars....I acknowledge that the M2 is not the most powerful thing out there.  But the power it does have is very balanced with the chassis.  I am in the camp that believes you don't need 500+ hp to have a fast track car.  With the right driver I have seen a Miata make a fool out of a Porsche or Corvette on the track.  I believe that a good driver and a balanced car will likely lay down the fastest lap times.  Stock the M2 has an inline 6 cylinder single turbo putting out 365 hp and 343 lbs torque pushing 3,450 lbs.  Not bad for a short wheelbase car that is priced reasonably.  The turbo has some lag but not much and often it is unnoticeable.  On the track under hard pushing you can notice the turbo lag a bit, but you can compensate for it by spooling up the turbo a bit early.

At the time I modified for power there were not many options.  No one had bigger turbos or bigger intercoolers available for the M2, so I opted for a cold air intake and a tune.  For these kinds of mods I always go with Dinan as they are a trusted brand that make reliable products.  I did not want to push the power too high as that often leads to other parts breaking or wearing out early due to the added stress or heat from the power mods.  I wanted a bit more power but mostly more responsive feel in the power delivery that would not stress the drivetrain or cause maintenance issues down the road.  I also live in CA and thus I wanted power mods that would pass CA's strict smog requirements.  Thus Dinan was the first place I looked as they are one of the few that go through the trouble of getting CARB certified (at the time of this post they are still pending CARB approval for some of their power mods).  

I got their cold air intake kit finished in carbon fiber as well as their stage 1 tune.  The cold air intake adds some engine bay jewelry but also gives the engine a nice note when you rev it up.  The stage 1 tune changes the signals going to the ECU that then "tricks" the ECU to make adjustments which results in more power and more responsiveness.  That is an overly simplified explanation, but for more details check out their product pages.

The claimed gains for these mods are as follows, but I will be doing a dyno after the build is done to record actual power and weight changes.  These gains are likely under ideal circumstances and thus I am a bit skeptical of how real they are, but what I can say is the car does have more power and responsiveness than a stock M2 and thus I am satisfied.

• Cold Air Intake: 10 hp peak gain, 15 lbs torque peak gain
• Stage 1 tune: 15 hp peak gain, 7 lbs torque peak gain

About a year ago Dinan did come out with a bigger turbo and intercooler package which would more dramatically increase power.  The reason I have not gone this far with the power mods is that the balance of the car (the best part of the car in my opinion) might suffer.  With gains of 101 hp and 86 lbs torque for Dinan's P2 Power Package I am not sure the car's chassis can properly utilize that much power.  Even on the track there are very few times I tell myself "I wish I had more power".  Usually I am wanting a bit more grip or more brakes as the power seems fine 95% of the time with the Dinan power mods I have already done.  

Those that follow BMW rumors know about the M2 Competition (M2 CS) coming out.  I have already been asked why I based this build on the original M2 and not wait for the M2 CS?  There are a few reasons.  The first is that when I bought this M2 and thought about the build the M2 CS was only a whisper.  The second is that the M2 CS will have a new engine (a detuned version of the S55 from the M3/4) yet the M2 CS will cost an estimated $10k more.  For $10k I could always tune up my M2's power to match or surpass the M2 CS's power if I really wanted to.  If I was to do that I would certainly go with Dinan's P2 Power Package.  But the biggest reason I did this build on the original M2 is that I am not sure I need more power given this is a track oriented car versus a street or drag car.  I want the best stopping power possible so I can dive into turns and I want power I can confidently lay down coming out of turns.  For that I don't need the M2 CS but rather I need big brakes, great suspension, and a balanced setup.  And from what I have heard, the M2 CS will not upgrade the brakes or suspension over the original M2 as the M2 CS upgrades are focused on the engine and cosmetics.  And even if they did upgrade the brakes they still would not match the Sparta Evolution brakes I am about to put on.  So I have decided not to fall into the age old trap of simply wanting more power.  I am focused mostly on getting power I can lay down and having a great suspension that compliments the balanced M2 chassis.  Plus I happen to have an M2 laying around :)