[gp_solo2]

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Thought I would share some feedbacks from my first autocross with my new G42.

Let's start with my Autoslalom background: I started in the late 90´s running in a local club here in Canada for a period of about 10 years. I ran a Neon ACR in street and street touring and then a Miata in street then stop for about 10 years and started again in 2015 for about 2 years in my 2015 M235. I won several provincial and national championships down the road. My M235 was a rwd, automatic (no diff) and square setup running RE71r 235 all around. It was competitive locally but would likely have required a bit more « goodies » to be competitive at a US National level.

My current car: I have a G42 with the optional M pro pack and adaptive suspension which mean I have the Pilot sport 4S (245 front 255 rear). I have a set of Yoko A052 on order but they are BO for now

The course was pretty tight with a few tight hair pins…not necessarily the type of course for a 3800lbs car and not a lot of places to exploit the power of the B58 but it is what it is. On top of that it was a sweltering 31 degrees Celsius (95 Fahrenheit).

First of all I am not used to run on street tires so I had to figure out the right tire pressure. Started at around 38psi ( iDrive was suggesting in the 42-43 area) but had to increase for my afternoon runs as I was rolling over the shoulder a bit on the front. May not be the optimal pressure I would need more testing to figure it out.

I found the car to be very well balanced with a ton of traction. I started my first two runs in traction mode and quickly switch to DSC Off. Even with all aids off it felt well planted and stable even when heavily thrown at higher speed. For sure you can feel the weight and size of the car but it is not as bad as I thought. On tighter corner you need to slow down enough to avoid understeer but once it start to rotate you can slam on the accelerator and the car will rotate and get you out the corner fast and without drama.

I don't think I was able to fully reach out the limit. Still need to get use to the dimension of the car, etc. My first 3 runs were not clean. I clipped cones with my rear tires every time but got used to it after that.

The results: We were 31 in the street category. I was able to finish 2nd (raw time)/3rd (pax time) in street. Quite happy with the result considering I was on PS4S and most of other top drivers were on dedicated 200tw tires.

Interesting fact: my brother came with his M2CS. He has similar experience and was running the stock sport cup and I did run a faster time by 0.816 sec but he did a « dirty » run with 2 cones that would have been good for a .901 sec lead which would have ended very close once the pax index applied.

Will definitely do more events during the summer but I believe this car, being in FS, will be competitive and I can't wait to see how much more I can get out of her.

Random facts:

- The HUD shift light is very useful and well done
- Tried the BMW Laptimer app…for some reason there seem to be less features compared to last time I used it in 2016. Missing the wheel input and gear info
- Got a max lat. G force of 1.16g which is way more then my old M235

[jbazz]

Originally Posted by gp_solo2

For sure you can feel the weight and size of the car but it is not as bad as I thought. On tighter corner you need to slow down enough to avoid understeer but once it start to rotate you can slam on the accelerator and the car will rotate and get you out the corner fast and without drama.

I 100% agree with this! Nice write up and thanks for sharing. Love to try an autox event One day. My Miata has 200tw tires and also takes corners much differently.

[HardBoiled]

Awesome man, I feel like feedback from people with real skill is rare on internet forums.

Looking to return to autocross myself after a 5y absence, distracted by tracking motorcycles.

My car is still in break in period. How was steering feedback when oversteering? My last car was e92 m3 w hydraulic steering. It would weight up beautifully when countersteering and easily fall back to center when straightening up—do the electric racks do the same to some degree?

[gp_solo2]

Originally Posted by HardBoiled

Awesome man, I feel like feedback from people with real skill is rare on internet forums.

Looking to return to autocross myself after a 5y absence, distracted by tracking motorcycles.

My car is still in break in period. How was steering feedback when oversteering? My last car was e92 m3 w hydraulic steering. It would weight up beautifully when countersteering and easily fall back to center when straightening up—do the electric racks do the same to some degree?

I won't lie to you there was not much feedback in the steering. I felt more with my but then through my hands but that being said the steering is quite fast and precise. I did not find it a big handicap although you have to guess a bit what's going on with the front end and rely on other cues.

If I can add; I did a run as a passenger in a wonderful Alfa 4C to coach a first timer. This is the total opposite in term of feedback having a non assisted rack and he was struggling in the very tight sections as he was limited by how fast he could turn the wheel and it is de-multiplied quite a lot.

My brother in is M2CS said he had great feedback and incredible front end bite but he was limited by its rear traction while I was much more stable and having no traction issues at all. Different beast and very interesting to compare how they behave but kudos to BMW engineers these are great cars.

[conradb58]

Impressive ! I will be at the Nurburgring during Touristenfahrten the 31st May - 2 June. I hope we share similar experiences with the car. Amazing feedback for the tire pressures btw , I will start with those as I have the Pro Pack as well. Now it's time for the car to go on a diet!

[Remonster]

The outer shoulder of the PS4S is very soft rubber which rolls over and melts very easily in autocross conditions. There isn't much you can do about it and it'll be a non-issue when you get your A052s or other future sets of 200tw tires that are designed to manage the heat and G forces of autocross or track use better.

[gp_solo2]

Originally Posted by Remonster

The outer shoulder of the PS4S is very soft rubber which rolls over and melts very easily in autocross conditions. There isn't much you can do about it and it'll be a non-issue when you get your A052s or other future sets of 200tw tires that are designed to manage the heat and G forces of autocross or track use better.

Thanks for the info this is good to know. First time I run these tires. They were not too bad considering what they are. Wondering how much I will shave with proper 200tw tires.

[mabrahams]

I just don’t know if SCCA will still class the 240 in FS or another class… do you think it’s competitive still or would the 230i be better option in DS (more than likely) with MPack.

[gp_solo2]

Originally Posted by mabrahams

I just don’t know if SCCA will still class the 240 in FS or another class… do you think it’s competitive still or would the 230i be better option in DS (more than likely) with MPack.

This is a good question. The 230 is lighter on the nose which should make it more agile but I don't believe you can get the M pro pack with larger wheels. The index advantage will be a nice plus though. Only time will tell and with so low number coming out we may not know this year unfortunately

[khoa@x-ph.com]

Nice write up!! Thank you for sharing buddy.

[stefan]

Interesting. It's a big car for autox but I feel this way about all my modern M cars. Is the steering rack pretty quick? Usually BMWs are on the slower slide making autox a bit of an arm stretching exercise.

[oldbmwtech]

Anyone here upgraded to SS Brake Lines and Upgraded Pads? If so what did you use with part #'s

[gp_solo2]

Originally Posted by stefan

Interesting. It's a big car for autox but I feel this way about all my modern M cars. Is the steering rack pretty quick? Usually BMWs are on the slower slide making autox a bit of an arm stretching exercise.

The steering is quick and precise…no feedback but perfectly fine for autocross and I was on a tight course. I have another event this weekend with forecasted rain. Looking forward to put the xDrive to good use.

[conradb58]

Originally Posted by oldbmwtech

Anyone here upgraded to SS Brake Lines and Upgraded Pads? If so what did you use with part #'s

Yes. Lines from the M340 are direct fit.

[oldbmwtech]

Originally Posted by conradb58

Yes. Lines from the M340 are direct fit.

Thanks for the info

[Beware-of-the-Phoggy]

Anyone have a recommendation for starting tire pressure using the P-Zero Performance Non-RFT tires? (225 front, 255 rear)

I'm planning to give it a go next weekend, and don't want a repeat of my first autocross day with my GTI when I completely melted my front tires.

[gp_solo2]

Originally Posted by Beware-of-the-Phoggy

Anyone have a recommendation for starting tire pressure using the P-Zero Performance Non-RFT tires? (225 front, 255 rear)

I'm planning to give it a go next weekend, and don't want a repeat of my first autocross day with my GTI when I completely melted my front tires.

I don't have experience with the 225/255 P-Zero but I do have some with the 245/255 PS4S and RE71RS. They like to run generally high. I found that anything under 39psi in the front (hot) would roll over the shoulder so I was running generally between 39 and 41psi upfront. At the rear I found out that running higher PSI help rotate the car a lot and achieved a better balance. On grippy surface I was running +4 psi at the rear compared to the front and on slippery surfaces closer to front pressure.

Since you have the narrow 225 your car will understeer more so not sure what the right ratio will be but same principle should apply.

Good luck and enjoy and take time to learn the car. It took several events before I became comfortable with the car but once you do it is a beast. Last weekend event I finished 1st overall against 96 participants including a formula SAE at a local event. Definitely a lot of potential but the weight need to be managed and will make you pay if you bring too much speed in slow corners or if you do your input at the wrong time.

[Thundernight]

Originally Posted by gp_solo2

I don't have experience with the 225/255 P-Zero but I do have some with the 245/255 PS4S and RE71RS. They like to run generally high. I found that anything under 39psi in the front (hot) would roll over the shoulder so I was running generally between 39 and 41psi upfront. At the rear I found out that running higher PSI help rotate the car a lot and achieved a better balance. On grippy surface I was running +4 psi at the rear compared to the front and on slippery surfaces closer to front pressure.

Since you have the narrow 225 your car will understeer more so not sure what the right ratio will be but same principle should apply.

Good luck and enjoy and take time to learn the car. It took several events before I became comfortable with the car but once you do it is a beast. Last weekend event I finished 1st overall against 96 participants including a formula SAE at a local event. Definitely a lot of potential but the weight need to be managed and will make you pay if you bring too much speed in slow corners or if you do your input at the wrong time.

Have you played around with camber setups at all? From my experience, the G42 could use some adjustment.

[gp_solo2]

Originally Posted by Thundernight

Have you played around with camber setups at all? From my experience, the G42 could use some adjustment.

I went to my local alignement shop but they did not have the specs yet for the G42 so decided to leave it as is for now.

Camber is not adjustable up front and this is what I wanted to increase unfortunately. It is sitting at around -0.85 degree front and -1.3 degree rear with a bit of toe in front and rear.

I instead adjusted my driving and tire pressure and got very good results.

[tubingchamp]

The 225's understeer quite a bit on AutoX.. Still fun though, because you can just power thru a bit and the X-drive helps push you around the corner.

Not as fun when you're trying to drive sort of spiritedly in the rain. Looking forward to upgrading the tires/wheels

[Beware-of-the-Phoggy]

Originally Posted by tubingchamp

The 225's understeer quite a bit on AutoX.. Still fun though, because you can just power thru a bit and the X-drive helps push you around the corner.

Not as fun when you're trying to drive sort of spiritedly in the rain. Looking forward to upgrading the tires/wheels

Understeered quite a bit more than I expected, my first time out. Wouldn't have mattered nearly as much if I'd arrived early enough to learn the course.

Going again next weekend, going to try gp_solo2's recommendation to run the rears at higher PSI than the front.