I had the pleasure to work on the Secure Wealth Advisers’ BMW F20 M135i race car for the Bathurst 6 Hour. Australia’s biggest production car race.
The Bathurst Motor Festival is an annual motor racing event held at the Mount Panorama Circuit in Bathurst, New South Wales, Australia during the Easter long weekend. The motor festival includes GT-1 Australia, Improved Production racing categories, and of course production car racing which I was involved in. There were also some other support racing groups, like Porsche racing club, and historic car racing.
Improved Production and Production Cars are two different categories, in Improved Production there are no limits to modifications, you can do anything you want to the car as long as it fits on the body of the car. The production car racing that I raced in has limitations on tyre size (only allowed two sizes up up from factory), limitations on boost (only allowed to run the maximum boost that that specific motor left the factory with in any variation or form, in our case that was 1bar/14.5psi which is found on the N55 in the BMW M2), and a few others, like limitations on intake manifold and intake piping, type fuel to run... etc.
I am not going to bore you with all the details on the limitations to modifications, but I'll just say that I enjoy Production Car racing the most out of any racing category atm. Due to the limitations to modifications, this means that you need to start with a decent base before converting it to a race car, and that makes it more challenging. In my opinion, modern turbo BMW's make a fantastic starting point to build a race upon
. Conversely the Improved Production series has not limits to modifications, it becomes a game of who has the deepest pockets to dump endless funds on the car and build a 1,000hp racer
At the race, all three drivers put a fantastic show driving the car across the famous Bathurst Mount Panorama Circuit. We fluctuated between 2nd and 3rd outright positions throughout the 6 hour long race, and eventually finished at 7th position (out of 44) due to an issue with the rear brakes and a swollen tyre wall.
Earlier this year, I flew to Sydney and coded out all the DSC nannies on the race car, and I got very positive feedback from all the racing drivers. Since all the nannies got turned off the car didn't participate in any endurance races, but instead was driven multiple short stints around different circuits to test out the suspension and the overall setup. Unexpectedly, we found ourselves chewing through rear brake pads during the race, still not sure if that's related to coding out all the DSC nannies or not. We are using ENDLESS Competition brake pads, which we were told they will last the full 6 hour duration of the race easily (they're proven to last on the EVO's for the same duration on the same track driven just as hard), but unfortunately the rears were completely worn down to the backplates after only 3 hours through the race. By the end of the 6 hour race, the second set of rear brake pads that we installed in the pits during the race were down to 1mm, and the front pads which have lasted throughout the whole race were also down to ~2mm (front right pad looked slightly thicker than front left, this variation in wear between front left and front right could have been due to the EBD, Electronic Brake-force Distribution, I could have switched it off by coding, but I thought it wouldn't hurt to just keep it on as it would help with braking in the wet).
The team did a phenomenal job to minimise the impact of the brakes issue we had, by replacing the sizzling hot brake pads in the pits during the race, and got it done in under 4 mins!! The gloves were smoking when I held the pads, but we had no option but to replace them while hot. The AP Racing calipers made this very easy too, just needed to pull out two pins and the pads could be taken out. The race car has AP Racing Radi-CAL forged calipers installed, absolute state of the art race caliper technology. You can enjoy reading about them in
this article, engineers will be drooling as they read through hahah.
The car was in great mechanical condition after the 6 hour race, just shows how well-built those German cars are
. Can’t wait long enough for our next racing event! (most likely Phillip Island 600km endurance race).
I drove from Melbourne to Sydney, then Sydney to Bathurst, and on the way back I took the same route, Bathurst to Sydney, then Sydney to Melbourne. I thoroughly enjoyed the drive through the Blue Mountains on the way to Bathurst, breathtaking views and very windy mountain roads
All up it was around 2,600km of driving until I got back home, touch wood no dramas for my car throughout the whole trip.
Filling up at 4:30am, before jumping on the motorway
Prior to the trip, I did the following preparations to my car to reduce the wear and tear on the tyres, and reduce driver fatigue.
1- Raised the ride height to reduce -ve camber at the front and rear, for better hwy stability, and less tyre wear.
2- Pumped tyres up to 39 psi to reduce the rolling resistance for better fuel economy on the hwy.
3- Eye-balled my wheel alignment to make sure I got even toe on the left and right sides of the car.
4- Backed down the dampening on the Öhlins coilovers for better hwy comfort (and reduced driver fatigue). Getting ready for Sydney’s beautiful roads too haha
5- Torqued down all wheel bolts, all front and rear control arms bolts, front and rear subframes' bolts and steering rack, steering column... etc. to make sure nothing is loose.
6- General check up on all fluids, and confirm there are no leaks... etc.
7- Take a spare wheel and a jack with me.
Hume hwy is such a monotonous boring road, doesn’t matter what car you’re in, it’s boring as hell, I would have definitely flew up if I didn’t have to lug so much tools, computers and cables with me to Bathurst. These cars seem to be very well suited for hwy cruiser duties though.
There’s also a drastic change in asphalt quality once you cross the NSW borders. It’s much harsher, there’s a lot more tyre noise in the cabin, and it feels more abrasive on the tyres. But it’s probably a lot more durable on the long run so they don’t have to keep resurfacing the road every few years.
I didn’t notice any sizable additional fuel consumption due to the 12% shorter final drive gearing (3.46 current, up from 3.08). Still did a bit over 800km per tank, there might be a 5-8% fuel consumption increase, which is negligible. Manual F8x cars M2/3/4 have the same 3.46 final drive ratio and also same transmission gear ratios. So my car is still sort of within factory specs.
As you can see in the below photo, the engine will sit at ~2,750rpm at 110km/h, not a challenge for the N54 to constantly sit at near 3,000rpm for 11 hours, these German cars are designed to sit at 250km/h on the Autobahn for prolonged durations. So there was no worries there. Turbos were barely spinning either as it's a low load situation (open wastegates).
I stopped at Gundagai in NSW for food, coffee and fuel, couldn't help but take a couple of photos of the striking beauty of the classic E92 body shape, I do like the Sparkling Graphite Metallic colour too
Some footage and photos that I captured during the week I spent camping in the pitlane garage:
6 nights before the race. we had to replace the transmission, because it started crunching badly when downshifting to 2nd gear, and occasionally in 3rd too. Those ZF GS6-45BZ are very weak compared to the older GS6-53BZ/DZ manual gearbox found in the old school N54 cars and E9x M3. In theory the GS6-45BZ is more advanced (has Synchromeshes with carbon friction linings which provides more precise shifting, and lowers the drag losses in the geartrain, also has shorter gear travel which results in shorter gearstick travel without having to use a ssk), but it's just so weak! Plenty of 1M owners and N55 powered 135i/M135i/M235i/335i/435i owners have broken theirs, there was even one here on the forums that broke reverse gear hahah, how does that even happen?! It's not like anyone shifts aggressively into reverse
.
Even though I would have loved to convert the race car to use the older and stronger GS6-53BZ/DZ N54 box from the E8x/9x 135i/335i, there was no time for that conversion. The boxes are a different length, so it'll need a custom prop-shaft made up or swap the output flange across which requires a special puller tool to remove, and in the case of the N54 gearbox, the female end of the pilot bearing is on the transmission input shaft instead of the flywheel. So we would have had to find an old N54 flywheel, and press the male end of the pilot bearing out of it and press it into our flywheel. Cool project, and we'll definitely do it in the future, but for the sake of this race, there was no time and we just wanted to get it running. After failing to locate a F series N55 transmission to fit the M135i race car
, we had to settle for a manual gearbox from the E82 1M. Both are identical GS6-45BZ and similarly weak, but the 1M box doesn't have a gear position sensor.
We bit the bullet and fitted it to the car, and cable tied the connector for the gear position sensor under the car, and hoped for the best. Lucky the lack of the gear position sensor didn't throw the engine in limp mode. It just had an error stored about the gear position sensor signal missing, but everything else worked perfectly.
5 nights before the race, we corner balanced the car, and set the wheel alignment using threads:
With 4 nights to go to the race, we arrived at the pitlane garage and camped there with the car, countless hours of work on the car, and staying up till 1am to finalise things, 6am starts every morning... Motorsport is definitely a lot more hard work than what it appears to be from the outside.
Over the following 3 days leading to the race, we had 4 practice sessions to perfect our car setup, and for the drivers to get a good chance to adjust to the car and track, and provide feedback on how the car feels. After the practice sessions finished, we had a qualifying session, this dictated our starting position on the grid.
In between our practice sessions, GT-1 Australia were also conducting a practice session. It was awesome seeing GT3 racing cars close up, and hearing them going full throttle down pitlane straight from couple of metres away
GT3 race cars full throttle flyby down the straight (VOLUME UP):
Pics from race day, 6 hours endurance race
Pic of the brake pads (ENDLESS Competition pads) after 3 hours into the race, we have ordered a different brand competition pads made of harder material and we'll see how those go. The j-hook AP Racing rotors had very little wear on them, so we're assuming that they're probably very hard material, and the pads ended up copping all the wear instead.
Also, we had a tyre failure about about 3 hours through the race too, the driver felt vigorous vibrations through the steering wheel, asked him to pit ASAP and we got it replaced in 1min and 28secs.
Close Up shots of the car mid-corner shows that the front right tyre was getting tormented through corners.
Media coverage:
I uploaded the whole 6 hour race to my YouTube channel, it was originally broadcasted on FOX Sport, enjoy!
I thought this was very funny haha
This has to be the most awkward moment in Australian Motorsport! I had to cut it out and uploaded separately.
