3002 tii’s Track Day Journal

Been hustling last 2 weeks to knock out my mod list. Truthfully, none of these were needed but where’s the fun in keeping things stock!? First up is lighting…

I already upgraded my xenon projectors a while back, but I can’t stand the lack of visibility during fog. And no low beam is going to cut through that unless you source 3K bulbs, which would be a nuisance to everyone on the road. I did consider retrofitting oe fogs but decided it wasn’t worth the trouble (i.e., mess with the LCM, source a new light switch and open up the brake ducts). Then I recalled seeing a race car at my local track with a light bar that looked surprisingly good.

IMG_5214.jpeg

However, I wanted something a little more stealth. So after taking some measurements, I determined there should be enough space to mount it behind the bumper while sitting above the oil cooler.

IMG_5195.jpeg

It’s visible if you’re specifically looking down there. Else, I find that itactually blends in quite well with the lower honeycomb.

IMG_5235.jpeg

Interesting note, this light by Diode Dynamixs is SAE / DOT approved, so it’s legal for street. You can see how the beam pattern widens out without blinding anyone.

IMG_5249.jpeg

I know it’s not everyone’s cup of tea but I dig it, and more importantly it’s functional. Now onto aero changes…
 
Last edited:
Despite my best attempts to convince APR to release a swan neck, they apparently have no interest developing products for cars 20+ years old haha. So the moment I saw a used GTC-250 pop up, I jumped on the deal.

IMG_5330.jpeg

This wing is huge, sitting 6 inches wider and 1 inch higher over my GTC-200. If I’m not careful, the end plates will catch my arm when I walk around the hatch. Despite its larger dimensions though, it does not exceed the width of the car nor sit above the roofline. However, it does hang off the rear deck which is one of my favorite aspects.

IMG_5253.jpeg

To balance out the rear, I shifted my front splitter forward by +1.0 inch. This will undoubtedly scrape, so I added some titanium skid pucks by the leading edge to take the brunt of any impact.

IMG_5298.jpeg

I also incorporated side spats to help deflect air off my tires. Using 1/8” ABS plastic, I cut and molded the spats to follow the curvature of the fender. Side note, the M finally looks like it has wide fenders lol.

IMG_5215.jpeg

The spat is held in by the factory fender rivets along with an L bracket attached to my splitter. At some point I may need to trim the inboard side as I noticed slight rubbing. But I’m also experimenting with the smaller tire sizes. If there’s no noticeable loss in handling with a 245mm front, then trimming may not be required after all.

IMG_5288.jpeg
 
Last edited:
My calipers have been running hotter ever since I switched to DTC-70s up front. Even with titanium shims, I managed to cook my caliper boots last fall. So over the winter, I rebuilt both front calipers with hi-temp boots and seals from OPS. Feedback from M3 owners seem to suggest these are up to the task, but with very little data out there, I figured it wouldn’t hurt if I looked into some cooling solutions.

On my old 3.0si, I installed brake cooling ducts by the factory fog lights. For the M, I had to get a little more creative if I didn’t want to hack any of the plastic trim behind the bumper. My options were then limited to:

Option 1 - Illustrative Scoop off Control Arm
IMG_8827.jpeg

Option 2 - Illustrative Ducts in the Lower Tray
IMG_8853.jpeg

I decided Option 2 was better since the ducts are more secure. On the other hand, the volume of air fed through would be less, but a shorter and more direct path for the hoses should counter some of that.

So I began tracing the oe tray on a 3mm aluminum composite sheet.

IMG_4442.jpeg

After trimming to shape, I cut out the inlet hole with my rotary tool. Then I attached the ducts with some low profile fasteners before sealing the edges with black silicone.

IMG_5408.jpeg

So how will the air be directed to the rotors? Simple… I picked up Westerlund’s brake cooling kit. Install is straightforward. Remove the caliper, use tin snips to remove the dust shield. Use provided hardware to mount the new backing plates.

IMG_4371.jpeg

I have to say these things are absolutely beautiful. The backing plate bolts up to the spindle perfectly and provides the same coverage as the factory dust shields. Best of all, he was even able to customize the inlet to accept a smaller 2.5 inch hose.

IMG_4375.jpeg

IMG_5404.jpeg

The attention to detail is quite obvious. For example, he includes a C-shaped piece to cover the tiniest of exposed area on the hub that forms when you remove the factory pressed dust shield. Other features include a protective cap for the wheel sensor. Basically a Z4 kit offered by a Z4 enthusiast.

IMG_4372.jpeg
 
Last edited:
Well this is irritating, that looks amazing and I've gone and bought a 2nd hand previous iteration westersund kit without all the clever bits like the abs shroud 🤦🏼‍♂️

Looks fantastic nice write up!
 
Well this is irritating, that looks amazing and I've gone and bought a 2nd hand previous iteration westersund kit without all the clever bits like the abs shroud 🤦🏼‍♂️

Looks fantastic nice write up!
You are not alone. I had a pair of v1’s as well but can’t fault the guy for continuing R&D to offer a better product!
 
You are not alone. I had a pair of v1’s as well but can’t fault the guy for continuing R&D to offer a better product!
Oh for sure, the latest ones look fantastic! Have you any before data on brake temps to compare with after data?
 
Oh for sure, the latest ones look fantastic! Have you any before data on brake temps to compare with after data?
Unfortunately not. I ran out of caliper temperature strips a while back. Though I suppose I can still run a before vs after just by doing a session with and without the hoses connected.
 
Last edited:
After 26 heat cycles my RT660 began cording so I went back to the RE-71RS (not the latest RZ compound ). This time around though I decided to downsize the fronts from 255 to 245. Rubbing wheel liners is semi annoying but I don’t want to have to mold new tire spats after each weekend.

IMG_5282.jpeg

As expected, the 245 on 9.5 et35 clears strut side without any spacers (vs before I had to run 7-10mm).

IMG_5412.jpeg

Outboard side is a different story though, there’s maybe 2 pubic hairs worth clearance with my 996 caliper 🤣 but all that matters is the rim spins freely. Track day tomorrow so excited to test all the latest upgrades

IMG_5420.jpeg
 
Last edited:
Back
Top Bottom