[Brett_C_F30_G42]

Hey guys!

So this is a part 2 to the track day post I made a few months ago. I recently tracked my G42 again and I’ve got a few updates:

1. I beat my previous track times by a whole 5 seconds (see original track times below in photo). My fastest track time was 1:48.1 around the circuit on Homestead-Miami Speedway. This is thanks to the brand new rear seat delete that I did. I got a Rear Sear Delete V1 from Stern Performance Parts over in Germany (first in the US!) and they are working on the V2 with Carbon strut bars for me (which will also be the first in the US). Photos are below.

2. Track Notes: the G42 is pretty well-rounded except for two main problems that I noticed:
(a) it threw its weight around a lot despite taking weight out and being lighter than others.
(b) I experienced what I believe is oil starvation. During my tracking, I noticed the oil temperature went extremely down which means that the sensor is not reading any oil. This is due to the extreme g-force conditions of the turns. So we will need a solution to this in the future…

3. Photos from the track day are posted below (more photos to come soon). I ran with Performance Driving Group, which also runs Sebring, and it was a great experience. I rose from Beginner to Intermediate! Highly recommend going to these if you can.

If you have any questions let me know! The G42 continues to rise beyond my expectations dispute only being a “M-lite” car.
——————————————————

[MrPickles]

Where did you get the cargo net... I like it!

[Brett_C_F30_G42]

Originally Posted by MrPickles

Where did you get the cargo net... I like it!

The red net? It’s part of the rear seat delete from Stern Performance Parts.

[ryo-]

is the rear seat delete the only mod you have done since your last track day? 5 seconds is a lot to shave off with just that

[Brett_C_F30_G42]

Originally Posted by ryo-

is the rear seat delete the only mod you have done since your last track day? 5 seconds is a lot to shave off with just that

It’s a combo from the rear seat delete and just getting better at tracking I guess. I also got brand new Michelin PS4S tires and before I had but worn down P Zeros. So a combo from those things. I haven’t done any other Performance mod since my last track day other than that

[Coconut]

Very nice! How much weight do you think the rear seat delete yield?

[apez]

Originally Posted by Brett_C_F30_G42

It’s a combo from the rear seat delete and just getting better at tracking I guess. I also got brand new Michelin PS4S tires and before I had but worn down P Zeros. So a combo from those things. I haven’t done any other Performance mod since my last track day other than that

I bet the tires and driver skill has the biggest impact. Weight savings is great and that backseat is pretty useless anyway, but I don't think you can give it that much credit - give it to yourself!


How did your tires, breaks, and temps hold up? Are you running camber plates or anything?

[Brett_C_F30_G42]

Originally Posted by Coconut

Very nice! How much weight do you think the rear seat delete yield?

It’s a net weight savings of 55kg

[Brett_C_F30_G42]

Originally Posted by apez

I bet the tires and driver skill has the biggest impact. Weight savings is great and that backseat is pretty useless anyway, but I don't think you can give it that much credit - give it to yourself!


How did your tires, breaks, and temps hold up? Are you running camber plates or anything?

I will say though the rear seat delete did make a difference in cornering when it came to throwing its weight around in the rear.
Tires were great. PS4S tires performed wonderfully and had grip for days.
Brakes were a bit okay because I’m running standard M Sport brakes with OEM brake fluid. So I couldn’t stop really hard over and over again but it held up great and I’m surprised they performed that well.
Temps held up really well as well.
I’m not running camber plates but I should

[Baldilocks73]

So you did fine even without the ZTK larger brakes, tires and cooling system?

[Brett_C_F30_G42]

Originally Posted by Baldilocks73

So you did fine even without the ZTK larger brakes, tires and cooling system?

Yup I did just fine without it

[Baldilocks73]

Originally Posted by Brett_C_F30_G42

Yup I did just fine without it

I've been going back and forth on ordering mine with the ZTK package. Not sure the extra cost is worth it, at least for me.

[Brett_C_F30_G42]

Originally Posted by Baldilocks73

I've been going back and forth on ordering mine with the ZTK package. Not sure the extra cost is worth it, at least for me.

I mean I didn’t really need it but I’m sure it helps in some capacity. The biggest thing would be the increased tire sizes but other than that nah. You should be fine without it.

[danallxt]

Thank you for posting
Could you elaborate what you mean by

(a) it threw its weight around a lot despite taking weight out and being lighter than others.

??
Oversteer/understeer?, weight pitch rear to front under heavy braking?, or just side to side weight transfer that you felt in the cabin?
(note: for me the car feels fairly light on its feet with normal driving, but when i tracked it i became very aware that it basically is a heavy car and you can really feel it when making transitions).

What tire pressures did you run front/rear cold or prior to a track run? Tire pressure at end of track run (hot).

How many successive laps would you do before cool down and pit?

Surprised you didn't change to high temp fluid at least, simple to do, i would highly recommend doing so especially since you mentioned not braking as hard as you could have. If interested i have a chart showing boiling temps of various brake fluids including BMWs so you can have a reference...email me and i will send it.

As others have mentioned i would guess most of the reduction in track times are due to your increased experience, especially if this is a return to this track, and of course better tires.

The oil starvation suspicion is very troubling.

[oldbmwtech]

Originally Posted by danallxt

Thank you for posting
Could you elaborate what you mean by ??
Oversteer/understeer?, weight pitch rear to front under heavy braking?, or just side to side weight transfer that you felt in the cabin?
(note: for me the car feels fairly light on its feet with normal driving, but when i tracked it i became very aware that it basically is a heavy car and you can really feel it when making transitions).

What tire pressures did you run front/rear cold or prior to a track run? Tire pressure at end of track run (hot).

How many successive laps would you do before cool down and pit?

Surprised you didn't change to high temp fluid at least, simple to do, i would highly recommend doing so especially since you mentioned not braking as hard as you could have. If interested i have a chart showing boiling temps of various brake fluids including BMWs so you can have a reference...email me and i will send it.

As others have mentioned i would guess most of the reduction in track times are due to your increased experience, especially if this is a return to this track, and of course better tires.

The oil starvation suspicion is very troubling.

I have tracked my M240 5 times and have not noticed any oil starvation. i bought the ZTK package mainly due to extra cooling and larger rotors/brakes. I do have camber kits, track pads and brake fluid, these are my only mods so far and would recommend this if you are going to track this car. Just remember tracking a car is not a race, just go out, have fun, keep the shiny side up, and be able to drive it home. There is no money or trophy's. Of course you want to get better and reduce your track time. This comes with knowing the car and skill. Have fun

[Brett_C_F30_G42]

Originally Posted by danallxt

Thank you for posting
Could you elaborate what you mean by ??
Oversteer/understeer?, weight pitch rear to front under heavy braking?, or just side to side weight transfer that you felt in the cabin?
(note: for me the car feels fairly light on its feet with normal driving, but when i tracked it i became very aware that it basically is a heavy car and you can really feel it when making transitions).

What tire pressures did you run front/rear cold or prior to a track run? Tire pressure at end of track run (hot).

How many successive laps would you do before cool down and pit?

Surprised you didn't change to high temp fluid at least, simple to do, i would highly recommend doing so especially since you mentioned not braking as hard as you could have. If interested i have a chart showing boiling temps of various brake fluids including BMWs so you can have a reference...email me and i will send it.

As others have mentioned i would guess most of the reduction in track times are due to your increased experience, especially if this is a return to this track, and of course better tires.

The oil starvation suspicion is very troubling.

Got a lot to cover…😂

What I meant about it’s weight was that while cornering it threw its weight around a lot, though it’s a light car. You could feel it wanted to slip in the rear but the LSD, xDrive, and tires never let it do so.

For tire pressures, I ran 28psi cold and it went up a lot from there. Tire temps climbed to 181°F.

For the brake fluid, I didn’t have time to change it out hence why I ran stock brake fluid. However, it worked super super well. I am very surprised about how well the OEM brake fluid held up (for OEM, that is).

Each track session included: Warm-Up Laps (2), Normal Laps (~9-13), and a Cool-Down Lap (1).

The improved overall lap time was a result of both the loss in weight and just getting better at tracking. The more I track, the more I test the car, push its limits, and the more confident I get.

Hope that helps!

[danallxt]

thanks,
BMWs dot 4 is rated 347 wet/509 dry

lot of folks like Motul 600 it is 401 wet/594 dry.
Motul 660 is 401/617
and 700 is 401/637

I see that track has a couple of real heavy braking zones at the end of longish straights.

[Brett_C_F30_G42]

Originally Posted by danallxt

thanks,
BMWs dot 4 is rated 347 wet/509 dry

lot of folks like Motul 600 it is 401 wet/594 dry.
Motul 660 is 401/617
and 700 is 401/637

I see that track has a couple of real heavy braking zones at the end of longish straights.

Yup. Turns 1, 3, and 10 are the most dangerous. 10 being the most dangerous; lots of people spin out there. If you don’t brake correctly and accelerate through the corner correctly then you’ll end up in the grass.

Photo of Track:

[danallxt]

this is a map of a PNW track i love and have run, know as "The Ridge". Not a long track or a real high speed track but quite complex. What i love is the almost constant elevation changes, ya got blind corners, definite elevation changes, with change of 300 feet from start to finish. A real fun track. Great rural/natural setting. (north of Portland Or, and south of Seattle). (2.47 miles long)