[oldbmwtech]

Originally Posted by XC3LLR8

What are you considering a "track event"? Changing pads after a weekend event (20 min sessions) seems excessive. We didn't even do that for the SS 1LE and it's much more of a track car than the 240.

Changing to street pads after a track weekend. Not hard to do.

[XC3LLR8]

Originally Posted by oldbmwtech

Changing to street pads after a track weekend. Not hard to do.

So you're talking about swapping the street pads to track pads, and then back after the event? I thought you were suggesting swapping out new track pads for each event.

[oldbmwtech]

That would cost to much, new track pads for each weekend

[Thundernight]

Most track pads can be daily driven as well, so if you don’t want to jack up the car, you can leave them on. Hawk DTC-70 is about as hardcore as you can go while maintaining streetability, since many high end track pads need to be at a high temperature to work properly. Higher heat = more friction. It’s important to look at friction vs. temperature graphs to see which compounds will work well in both low and high temperature environments.

The challenge I am running into is finding a good track pad for the G42. Someone mentioned that Ferodo has an option, available to us, but they are back ordered with no availability timeline. I’d love to use Hawk pads, but they do not appear to have the right pad plate for our cars..

[Thundernight]

Originally Posted by bmwloverm2

Hi Thundernight

I cannot express enough how I enjoyed your detailed post. THANK YOU.

I'm almost a newbie in track days, so I'm wondering two things that I hope you help me understand few things:

1. Would it make sense to inflate tires with Nitrogen instead of air because it is supposed to minimize effects due to temperature?

2. Assuming i am going to enter a track day with my M240i "daily", and assuming everything is in good conditions:

- neither tires are in its last days +
- pads/rotors are in their mid-life
- oil, brake fluids are also in their mid-life

What would be your suggestion that i should change BEFORE AND/OR AFTER a track day?

From what you mentioned, makes lots of sense to change BEFORE at least:

BRAKE FLUID

- Change Brake fluid to a good one with higher boiling point like: Motul RBF660 Dot 4.

- I guess I should change brake fluid again after the track day?


ENGINE OIL

- Should i change it before? Or before + after?


PADS

- Keep an eye to break pads during the track day + also after to see if I have to change them.

- I guess it's not a super idea to change pads to new ones just right before track day because pads will need some time to find it's perfect fit to the rotors. But also probably not a good idea to go into the track day with "just" a mid-life pads or i risk to finish while tracking...or coming back home?

What else am I missing?

PLEASE NOTE THAT EVERYTHING ON MY CAR IS OEM, nothing has been replaced for any performance liquid, etc.

Thanks for the kind words! If your fluids, brakes and tires are in their mid life, than I personally wouldn’t change anything. Especially since you are new to track days, you likely aren’t going to be pushing the car as hard. As long as you are driving within 70-80% of the cars capability, you probably will not overheat the brakes. That said, if you feel more comfortable with the idea of Dot 4 fluid, it is definitely a good upgrade to do.

Nitrogen is not very practical for track days because you will be letting some air out throughout the day. Unless you bring a nitrogen tank, I wouldn’t bother.

After your first track day, inspect the pads and see how much material you have left. Mine were worn by about 10-15% from when I started the day, so not too bad..

An oil change after the track day would be wise, but not completely necessary. The benefit of doing an oil change afterwards is that you can tear open your oil filter and inspect for metallic deposits. If you see shiny sediment in the filter, chances are that you have a bigger issue..

Keep us posted how your track day goes!!

[oldbmwtech]

Originally Posted by Thundernight

Last night, I was able to take my G42 to a SCCA track night at Thompson Speedway. For those who are also interested in getting track experience with their cars, I figured it would be helpful to share my notes.

Car - 2022 BMW M240xi with ZTK package (893M wheels, Michelin PS4S tires), completely stock with DSC OFF
Conditions - 92F, mostly sunny with scattered storms
Track Layout - 1.7mi/2.7km road course, clockwise

Session 1:

Initial Tire Pressure (psi): 41
Ending Tire Pressure (psi): 47.5 left side, 46.5 right side
Session Notes:

• Initial laps felt really good. Second gear was extremely low for the road course and only used it for the hairpin at turn 4. The car is well balanced with initial, low speed understeer that can be turned into oversteer/powerslide with minor throttle manipulation and brake steer at corner entry. At medium speed turns (3rd gear), the car was more neutrally balanced and felt extremely stable. The high speed stability also felt good at turn 10. The final corner is a double apex with the final apex positioned right at a crest. I pushed the car hard a couple times to get a good exit and the rear got extremely light and twitchy. It's also very high speed, so that was to be expected. Keeping the wheel straight while over the crest was key for maintaining stability and getting a clean line. It is important to get all your steering done and have the wheel pointed straight before the crest.
  
• The Michelin Pilot Sport 4S tires started to overheat and become greasy very quickly due to the summer heat and high starting pressures. The edge of the front left tire also started to chunk, which was a clear indicator that the pressures needed to be adjusted.
  
• Brakes felt good for half the session (approx 10 minutes), then started to feel spongy towards the end. Specifically, the braking zones at turn 1 and 4 were the hardest on the car. As a result, I started to do cooldown laps to let the brakes cool down and get some airflow through the car. The brakes still felt soft coming off the track and drove around the infield for a few minutes to help cool the brake rotors. The car sat parked for 40 minutes between sessions and it was enough time for the brakes to cool down sufficiently to drive on the track again.
  
• Surprisingly, the water and oil temperatures were running perfect, with no indication that they were running hotter than usual. The water temperature gauge needle was perfectly centered in the middle and the oil temperature was hovering around 210F. I think the extra cooling capacity the ZTK package offers made a huge difference.

Session 2:

Initial Tire Pressure (psi): 34
Ending Tire Pressure (psi): 41 left side, 40 right side
Session Notes:

• Reducing tire pressure made an improvement with lap time and led to more consistent performance throughout the session. The car felt more planted in all corners and was able to carry more speed.
• Brakes started to drop off around the same time as the previous session. As before, I started to do cool down laps early to ensure that I had enough brakes to drive 2.5 hours back home. The stock brake pads did not degrade as fast as I expected, but they definitely started to glaze and lose friction/stopping power. Lots of pad material was transferred to the rotor, but the rotor is still in good shape with no signs of excessive wear or glazing.
• Turn 6 is off camber (going into the banked oval) and difficult to carry speed. The rear end wanted to step out where the pavement transitions. This made it fun, but not very fast..

Session 3:

Tire Pressure: No Data
Session Notes:

• Brakes felt the same as the last session. Good in the first few laps, but gradually lost stopping power. The brakes simply couldn't handle the heat. To preserve the car, I lifted off the throttle between the start/finish line and the #6 brake marker. This seemed to help as the car did not need to dissipate as much heat as previous laps. I also noticed that there was a bit of knockback with the brake pads heading into braking zones. For those that are unaware, knockback happens when the lateral load of the car pushes the brake pad and pistons back into the caliper. The brake rotor applies a lateral force into the caliper, which creates dead space between the rotor, pad and caliper. Before heading into the braking zone, I tapped the brakes to set the pistons and pads which firmed up the brake pedal dramatically. In doing so, the brake pedal travel was reduced and the brakes were much quicker to respond to inputs.
• The tires felt good with a lot of front end grip. I wish I checked the pressures but ran out of time to do so. After the session, I noticed that the front left tire sidewall was making contact with the road, which is not good. The pressures must have dropped between the sessions and was lower than expected. about 30 minutes after the third session, the front left tires cooled down to 32psi, which confirmed that they were too low. Interestingly, I did not notice any performance difference with this lower psi setting.

Final Summary:

• Suspension - Good in sport plus. No excessive body roll.
• Front Alignment - Could use more camber. I believe that the factory spec is 0.5 degrees of positive camber and toe (in). Additional positive camber and a negative toe (out) angle would have been beneficial. I will be looking to see what aftermarket options will be available for camber adjustment, and if the camber plates for the G80/82 M3/M4 will be compatible with the G42.
• Tires - The Michelin Pilot Sport 4S tires did a really good job, but were no match for cars running Nitto NT01, Bridgestone RE-71R or Pilot Sport Cup 2 tires. Next year, I will be swapping to Cup 2 tires and will report back. Tire pressures seemed to be happy between 38-42psi (hot). Front pressures lower than 38psi resulted in rolling of the sidewall. Any higher than 42psi and the tires overheated.
• Braking System - The 374mm brakes from the ZTK package is the minimum requirement that I'd want for the M240. This track day took place during a heat wave with temperatures exceeding 90F and the brakes struggled with heat soak early in the session. If any smaller brakes were equipped, I likely would have boiled the fluid. My recommendation is to use Motul RBF660 Dot 4 fluid, which has a much higher boiling point and will withstand the heat. I use this in a few other performance cars and it is the gold standard. The factory brake pads have a lot of bite in the first few laps, but drop off once they exceed their operating temperature. Unfortunately, Hawk, Brembo, Ferodo, PFC and Wilwood do not appear to offer a racing pad for the G42 yet, but once an aftermarket option becomes available, it would be a major performance increase. Along with the DOT4 fluid, Hawk DTC-70 (or equivalent) brake pads would be the single best performance upgrade on this car.
• Engine - The B58 is a complete animal. Plenty of power and torque. No oil consumption whatsoever. I was even able to hang out with the corvettes and Cayman GT4's in the straights without much trouble. It is a truly amazing engine.
• X-Drive - Incredibly well developed. I thought that this was going to be the weakness of the car, but it turned out to be one of the most amazing aspects of the driving experience. It managed the power incredibly well, kicking in where needed, but maintaining the rear wheel bias we all love. I was able to break the rear end loose and powerslide at any corner on demand. At no point did I miss RWD.
• DSC - Never used it. Not needed either. DSC will actually make your brakes overheat faster.. Hold the button down for 3 seconds and thank me later
• M Laptimer - Amazing App. It did a great job tracking lap times and other useful data.
• Fuel - I started the event with a full tank. After three 20 minute sessions, I burned through 11.5 gallons which triggered the reserve fuel warning.

Thundernight

I just tracked my M240 at MSRHouston. Everything is stock on this car. I have many years of track experience and I put this car to the test. I ended up needed 2 front tires due to not enough NEGATIVE camber. The front tires rolled on the sidewall. Tire pressures were 40 and after laps 47 lowering the tire pressures caused more roll so I had to bump up pressures. Camber plates are available for this car Vorshlag makes them and yes they also fit the G20/G80. I ordered a set but have not received them yet. For track pads I ordered Pagid however they did not fit correctly the caliper pins did not line up with the holes in the pads. I ended up with Endless ME20, have not installed them yet but will in a few weeks. They look correct. Stock pads worked ok but like you said they faded after several laps. I have plenty of pad material left which is amazing. This car keep up with most 911s I even passes quite a few and there was a 2022 M3 that had no chance with me in the turns, down the straights we were even. This car is an amazing track car and with a few modes it will be a great track car especially for the price. We will see how they hold up in a few years.

[inc235]

Has anyone considered sizing down to 18" wheels/tires with ZTK for tracking? I've seen that 18" will fit, but clearance seems small. (rough estimate is 1-1.5" gap between wheel and brake rotor?).

My logic in trying to size down is it will be cheaper to source 100-200TW tires. Also I'll be daily driving as well, so it can be a dedicated track tire set.

Any thoughts?

[oldbmwtech]

Originally Posted by inc235

Has anyone considered sizing down to 18" wheels/tires with ZTK for tracking? I've seen that 18" will fit, but clearance seems small. (rough estimate is 1-1.5" gap between wheel and brake rotor?).

My logic in trying to size down is it will be cheaper to source 100TW tires. Also I'll be daily driving as well, so it can be a dedicated track tire set.

Any thoughts?

I agree with you. I have been looking myself but not found any 18s. I hope someone makes them that would be sweet.

[Economatic]

Good thread! I recently started looking at the M240i as an all season DD (including snow) and something I can do a few track days with each year. It sounds promising a set of camber plates is all it will need, aside from the typical consumables.

I'm looking forward to read more on-track reviews and hopefully some 18'' wheel options will be available soon.

[danallxt]

Oldbmwtech

I just tracked my M240 at MSRHouston. Everything is stock on this car. I have many years of track experience and I put this car to the test. I ended up needed 2 front tires due to not enough NEGATIVE camber.

Do you know what the stock camber setting is? Also what are you going to try to dial in for negative camber with the new camber plates to make a difference?

[oldbmwtech]

Originally Posted by danallxt

Oldbmwtech



Do you know what the stock camber setting is? Also what are you going to try to dial in for negative camber with the new camber plates to make a difference?

Stock camber is -.5 once I install these plates I will go with -2.5 to -3 for track use and stick with the -.5 for street. By the way Bimmerworld has the Vorshlag camber plates as well as Vorshlag.

[inc235]

Originally Posted by oldbmwtech

I agree with you. I have been looking myself but not found any 18s. I hope someone makes them that would be sweet.

Yea I hope so too. I'm thinking that the wheels for m340i/ix (on tirerack) may be a good place to start, but still not too sure lol

[gp_solo2]

Originally Posted by danallxt

Oldbmwtech

Do you know what the stock camber setting is? Also what are you going to try to dial in for negative camber with the new camber plates to make a difference?

Mine is -0.85 up front front and -1.3 in the rear.