BUILD & LOGBOOK THREAD: E90 BMW RACE CAR

Introduction

Hi all, my name is Simon, and I am a racing addict. I wanted to share with you all my build which is an E90 BMW (325I) that we are preparing for club racing here in the U.S.

Before I begin, I wanted to briefly go over my resume. My racing background stretches back to karts, autocross, track days, and then club racing. I ran SCCA in numerous classes including T4, H Production, ITA, T3, IT7, and probably a few others. My biggest break came when I began racing in the FIA sanctioned 24H Series in a BMW M240I Racing Cup car before moving into GT4 in the 24H Series where we started the season finishing second in the Dubai 24 Hours on the final lap, which motivated us to chase the championship. We won the international title (in a BMW M4 GT4) which was a lot of fun. Lately, I have been racing at the Nürburgring Nordschleife in the NLS Series (formally VLN) once again in a BMW. I am also racing with the same team out of Germany that I began racing with in the 24H Series.

The plan for the E90 is to race endurance races with the World Racing League where I have raced many times before for another team. While I’ll still be racing overseas and other pro-am type events, the WRL series and other smaller endurance races offer me the chance to get seat time and have fun. It would be really cool to get some of my European teammates over here eventually to possibly do a race together on my side of the ocean. I’ll also be doing other club races with the car. All in the name of seat time.

The car:

I bought the car for $1,600 (6 speed manual) with a clean title. The car was a younger girl’s daily, but it had some issues, and her family just didn’t want to go down the BMW rabbit hole. The issue was simply an ELV malfunction (anti-theft steering lock system) and a very dead battery. Voltage issues and BMWs don’t get along. So, I plugged the laptop in, got juice, reset everything, and it fired up beautifully!
 
The goal here is to keep is very lightly modified in the engine department. Really just a better intake element and exhaust is what I am going for right now. We want to keep the car in the GP3 class where it could be a competitor. I’m also trying to stay on a strict budget.

Starting out, we did what we do best, rip stuff out:

We have the safety gear on hand and ready to go in thanks to RaceQuip. We will be using their FIA seat and FIA harness. This is the best bang for your buck FIA rated seat on the market. I refused to go with anything without a halo (the head protection) and this stole the show. We are also using their window net, right side net, and tow straps.

We also will be installing a Lifeline fire system which I recommend for any car that sees a race track. It’s far more effective than a handheld unit and most series require a real system these days. It’s a cheap price to pay for a peace of mind.

The first goal is to get the car track worthy to start developing it by running it on track. The E90 platform is of course a widely used race car especially in Europe so information is plentiful but since the purpose of this build is seat time, then what better way to develop it than being at the track.

Stages of the Build:

Stage 1: Gutting and preparing
Stage 2: Safety equipment (minus roll cage)
Stage 3: Suspension and Engine
Stage 4: Roll cage
Stage 5: Event Prep

Wow that is a killer deal!   Where did you find it?? (Facebook marketplace, Craigslist?)

tuning in for updates.  
 

hms Motorsport in massachusetts and North Carolina are great places for safety gear, too. 
 

Following with interest.

Who are your co-drivers?

yes...following

trumant said:

Following with interest.

Who are your co-drivers?

Right now some friends and a sponsor who I have also coached. I'll probably try to fill seats on occasion but my goal isn't to make money on it, just sort of break even and get to race more.

jfryjfry said:

Wow that is a killer deal!   Where did you find it?? (Facebook marketplace, Craigslist?)

tuning in for updates.  
 

hms Motorsport in massachusetts and North Carolina are great places for safety gear, too. 
 

 

On Craigslist which I hardly ever use anymore. It was a very vague ad, no pictures, but the car was local. Ended up being a very straight-up seller who even knew I may be able to get it running on the spot with a laptop. He just didn't want to deal with it.

SMALL UPDATE

So we've gotten into some more work now on the car. I installed the rain light that is required, we did a test fit of the seat, started routing wiring for our switch panel, and also started the suspension work.

For the seat I originally had gone with a Planted base and Recaro double-locking sliders since it's an endurance car. However, I could not get the seat to fit right with the sliders with this base as the tabs for I assume seatbelts were in the way.

I was able to get it mounted to the Planted base with just side mounts but since I need sliders I ordered a base from Bimmerworld. I'll get pics of that when I get to work installing it.

The seat installed via side mounts without sliders:

As I said it is an FIA rated seat from our partner RaceQuip. I was insistent we go with an FIA seat but also one with the halo. This seat is comfortable and very comparable to other entry-mid range halo FIA rated seats on the market. 

Pro tip: when you have a one-year-old kid and need to work on the car outside during nap time:

Anyway, onto some wiring stuff which is still very much being done. The rain light is done which is simple and I just ran a cable from the deck lid where it is mounted, to a switch on my radio delete panel. It's getting power from a fuse jumper which I would normally hesitate using but for something like this and something not always used I don't see any problems.

The car had some aftermarket radio gear when I got it, I found this when getting into some of the harness...nice!

Holes drilled on the trunk for the light, there's just two wires off of it that go through my grommet there. 

Here is what I decided on for a switch panel. It's really aluminum I just had some carbon fiber vinyl laying around and thought it looked nicer. It will have the main power button, rain light, driving lights, and the fire system pull cable if I can ensure it's mounted strong enough to not risk ripping out in an emergency. 

So for suspension we will be using Bilstein coilovers. We also went with E9X M3 front control arms. 

Unfortunately, Bilstein is having supply delays so we are testing with another brand's coilovers for the time being. However, we hope to have the Bilstein on for our first race in June.

Brakes are just blank rotors and for now, we are running Hawk DT60 pads. However, we are going to test some different options. In my experience, Hawk is typically pretty hard on rotors. We also have gotten steel lines from Bimmerworld. 

So that's all for now, I need more pics. We hope to test the car next week at Road Atlanta and our first race will be at Daytona with WRL in June. Tire wise we decided to go with Hankook, they have a WRL team deal. 

More soon and more technical pics as we dig in deeper!

Awesome thread. I have a 2008 328xi that I'm slowly building for autocross and daily driving, so I'll be keeping an eye on this! It'll eventually be a weekend track car once scope creep takes over.

UPDATE!

OK, so we finally got the E90 out for some testing at Road Atlanta a few weeks ago. This was just a Chin track day so no racing. To get ready I still needed to finish up installing our RaceQuip seat and belts along with a roll bar. I have a full cage from Kirk Racing which is a pre-fab but I am not using it, just this rear half for these track days until we can have a window to get the car into a fab shop. It’s obviously been a huge delay in the build. 

One thing I also said I was going to do was to install the BimmerWorld floor seat mounts which I did. They are so nice, loads of mounting options, threaded, it makes my life so much easier. For this event I just mounted the seat directly to this with the side brackets but for endurance races we will use the Recaro double locking sliders I have. Luckily my co-driver and I are similar build and height so this worked for the weekend.

Once that was all done, we put the other wheels on with new Hankooks and hit the alignment rack. We went with a very conservative setup, didn’t mess with rear toe, just the front which is out just slightly. The camber is very much on the conservative side as well.

Then it was off to the track!

I took the car out for the first warmup session to make sure nothing was falling off as I was sharing the car. After some cutting and adjusting the undertray panels we were good. 

I decided to just run a handful of laps to see what we had. I accidentally forgot to turn the traction and stability control all the way off so kept it short and easy to avoid cooking the brakes. The car out of the box was quite surprisingly good. We had the shocks all set in the middle and tire pressures were square to start. Weird I know but I like a good base to start at then adjust from there. Handling the car was loose in the high-speed stuff on entry but would develop a little mid-corner understeer. This quite possibly could have been the DTC but also like I said it was a totally neutral set setup. Either way it was doing quite well. I did a high 1:49 I think or low 1:50 after a couple of laps. There’s an easy two seconds at LEAST from turning DTC off and then quite a bit with setup work.

Engine wise it is bone stock. It runs strong, it’s of course slow, and the gearing is TERRIBLE. Which I kind of expected as we are still using the stock 325I diff, I have read the auto one is what you want for better gearing. Then we’ll add an LSD.

When my co-driver got in he had a 30-minute session, I told him to take it easy and just feel the car out. He was looking good and stayed out for almost the entire session which surprised me! Unfortunately, as the checkered flag came out, so did his call that the car was stuck on the side of the track, there was smoke, and that’s about all I got.

It turned out the right front caliper seemed to have seized. I am not sure why. Either the brakes got way too hot or there was a faulty part in there. Anyway, it managed to light a small fire which was enough to burn the new bushings there as well as the wheel speed sensor wiring. It also burnt the inside of the wheel pretty good and destroyed the tire. The body is fine. He told me the pedal started feeling soft so he backed down for a few laps but then it was too late. 

Looking at the tire it was obviously locked up massively for a moment to do that much damage! 

Needless to say, our weekend was over. So, the next plan is of course to replace the damaged items. Then we will take it back out for a track day to do a little more testing before we race it.

I am quite busy in August and in September I’ll be in Germany the entire month racing three back-to-back weekends at the Nordschleife! I’ll post some pictures and updates from that. By the way if anyone is interested in running there, hit me up! I can help every step or even help ship your own car there and store it by the circuit.

[B][U]UPDATE 12/7/2023[/U][/B]

So first off I'll briefly tell you all about our recent races in Germany. I raced in the NLS 12H which was a double six-hour weekend (two separate NLS races). It was awesome, day one was also the Red Bull show with Vettel among others. Tons of cool F1 cars, old DTM, V12 LMR, etc.

This go around I was in a FWD BMW! The 128TI which is quite a fun car. On Friday, we did have some handling issues that we sorted for Saturday. It can be a handful but it's no slouch. Hopefully, we can continue to develop it. We finished fourth on Sunday and a few times I had us in the podium spots. The Hyundais are super fast in that class though and even the VWs.

*Looks nasty but the bumper just kept coming loose. We tried duct tape. lol 

The following weekend I was entered in the 1000km which is a historic race. This time driving the team's E30 M3. Qualifying went well but unfortunately, my co-driver hit oil and the car was heavily damaged so we did not start. What a joy to drive though even at lower speeds as I learned the car.

[B][U]Video:[/U][/B] https://youtu.be/oy3Uu_HzclQ?si=H7AhkM4HWGfqbNhc

We cheated on BMW with our rental car though:

When I got back we slowly got the E90 back driving-worthy. We went with stock replacement calipers for now and of course new lines. I also replaced the tie rod on the passenger side which melted in the small fire from the summer track day.

We bled the brakes and replaced the fluid with more Motul. I have driven it a few times around to bed the brakes in and just make sure things are good. It feels really good so I'm happy. The car is actually listed for sale but we'll continue with it until it sells if it does. Main reason being I have so much else going on buying a race ready car would have made more sense but the E90 just isn't popular here for race cars like overseas it seems. But E36 and E46 keep popping up for cheap so...

I love this thing though. 

Nice! May I ask if you decided to remove the key and went to a hardwired ignition and starter switch? I heard this model have allot of computers for those keyfobs and the immobilizer can make it more complicated.

Bought a base e90 with a clean title, but not sure what I want to do yet. Sell it for cost and find an e46, fix and drive, or build a race car. Subscribed nonetheless