[chrispy28_xd]

I've recently been seeing more folks taking their M340i to track days, so I figured I'd share my journey here since maybe people are warming up to the idea of tracking this boat. I upload full sessions (minus in/out laps) to youtube if you're curious. On the tracks I frequent, I'm in the open passing group, and in orgs where OP groups are split, I'm usually in the faster group. The car isn't particularly fast, and I'm of average driver skill, so my lap times are generally on the slower end on most days. Regardless, the car has held up very well to the abuse, and it has been an excellent tool to learn high performance driving, cars, and mods in general.

Most recent track event (Labor Day 2024):

YT playlist: https://www.youtube.com/playlist?lis...nX-Jhi1uosn5h5 (I don't recommend watching my older videos lol)


Mod list (as of September 2024):

Tires and Brakes
255/35-19 Bridgestone RE-71RS
19x9.5 ET25 Apex VS-5RS
CSG C21/C11
CSG carbon weave brake lines
Castrol SRF

Suspension Setup
JRZ RS Pro
Eibach springs (Shaftworks USA spec kinda)
Vorshlag camber plates
H&R front sway bar
Eibach A90 rear sway bar
SPL front and rear sway bar endlinks
Dinan thrust arm monoballs
Turner/SPL FLCA
Verkline rear arms and bushings (knuckle/spring perch)
3.4/2.1 camber, 0 front toe, .22deg total rear toe in

Engine Stuff
Factory tune
CSF intake manifold
CSF front and aux radiators
Armaspeed intake
AA catted downpipe
AWE non-resonated touring exhaust
Motul 8100 x-max 0w-40

Interior
Sparco Pro 2000 QRT (driver side only)

Exterior
RaceLouvers hood vents
Some trunk lip I forget
Some rear diffuser I forget

Upcoming
None...

[peelerec]

Originally Posted by chrispy28_xd

I've recently been seeing more folks taking their M340i to track days, so I figured I'd share my journey here since maybe people are warming up to the idea of tracking this boat. I upload full sessions (minus in/out laps) to youtube if you're curious. On the tracks I frequent, I'm in the open passing group, and in orgs where OP groups are split, I'm usually in the faster group. The car isn't particularly fast, and I'm of average driver skill, so my lap times are generally on the slower end on most days. Regardless, the car has held up very well to the abuse, and it has been an excellent tool to learn high performance driving, cars, and mods in general.

Most recent track day (5/27/24):
https://www.youtube.com/watch?v=wuaFeMXlCng

YT playlist: https://www.youtube.com/playlist?lis...nX-Jhi1uosn5h5 (I don't recommend watching my older videos lol)


Mod list (as of June 2024):

Tires and Brakes
255/35-19 Bridgestone RE-71RS
19x9.5 ET25 Apex VS-5RS
CSG C21/C11
CSG carbon weave brake lines
Castrol SRF

Suspension Setup
Ohlins Road & Track
Eibach springs (575 lb-in front / 900 lb-in rear)
Vorshlag camber plates
H&R front sway bar
Eibach A90 rear sway bar
SPL front and rear sway bar endlinks
Dinan thrust arm monoballs
Megan Racing rear trailing arm, rear toe links, upper bent arm
3.2/2.0 camber, +.14 total front toe, +.3 total rear toe

Engine Stuff
Factory tune
CSF intake manifold
CSF front [...]

Glad to see you finally post your build, Chris. You probably hold the most track experience in the country for the G20 platform

How is the recent addition of heat vents helping with cooling? Significant IAT drop? It’s going to start heating up here soon so looking forward to seeing more data and your new suspension!

[Big_red015]

Following!!!

[chrispy28_xd]

I don't have enough data to determine if the vents help with IAT, but that was never the goal; it was to give me more hot laps before having to do a cooldown lap. So far it's helped I think.

[RCKYMTN M34OI]

Awesome! Love to see someone using the platform this way!
You've got a pretty expansive suspension mod list
I've got questions:
Am I correct in assuming this isn't your daily driver then?
How is the ride comfort with the coilovers/monoballs?
How was install on the sway bars? DIY install or shop? (i'm really considering these but would want to install myself)

Thanks for sharing! Make sure to post more from your track experience in the future

[prostcfc]

Sway bars are a big job, however kern417 posted a video on YouTube a while back where he didn't fully remove the front subframe to do the front. He has a F30, but I imagine the install would be similar on our cars.

[chrispy28_xd]

Originally Posted by RCKYMTN M34OI

Awesome! Love to see someone using the platform this way!
You've got a pretty expansive suspension mod list
I've got questions:
Am I correct in assuming this isn't your daily driver then?
How is the ride comfort with the coilovers/monoballs?
How was install on the sway bars? DIY install or shop? (i'm really considering these but would want to install myself)

Thanks for sharing! Make sure to post more from your track experience in the future

• It's my daily.
• Monoballs are always worth it if you care about the driving experience. I can still remember how different the car felt after having them installed. It's like I can feel the road.
• The Ohlins on stock springs rode better and were more comfortable than stock suspension. However, with the stiffer springs I have on, it's rough but I don't mind. I've had relatives in my car, and they have commented that it's bouncy. I think they're underdamped, but this is my first foray into performance cars so I'm 100% sure. I've also had it on for 20k+ miles and way too many track days, so they've probably lost some performance.
• Both front and rear sway bars require lowering subframes. I don't do much DIY besides brakes, so I had my shop do it.

[RCKYMTN M34OI]

Originally Posted by chrispy28_xd

• It's my daily.
• Monoballs are always worth it if you care about the driving experience. I can still remember how different the car felt after having them installed. It's like I can feel the road.
• The Ohlins on stock springs rode better and were more comfortable than stock suspension. However, with the stiffer springs I have on, it's rough but I don't mind. I've had relatives in my car, and they have commented that it's bouncy. I think they're underdamped, but this is my first foray into performance cars so I'm 100% sure. I've also had it on for 20k+ miles and way too many track days, so they've probably lost some performance.
• Both front and rear sway bars require lowering subframes. I don't do much DIY besides brakes, so I had my shop do it.

Any drawback in daily driving with the monoballs? increase in noise/vibration/roughness etc.?

[chrispy28_xd]

I honestly can't tell you if it added any NVH. I've had it on for like a year and a half now, and my car is hardly quiet with all the random squeaks and creaks.

[peelerec]

Originally Posted by RCKYMTN M34OI

Any drawback in daily driving with the monoballs? increase in noise/vibration/roughness etc.?

Definitely notice increase in NVH, but that’s the point with monoballs. I think it’s all positives and no negatives if you’re looking for more road feel/steering feel.

[prostcfc]

Awesome, thanks for sharing. Stuff like this is inspiring to stick with the platform. I'm super conflicted. I can either dump a lot of money into mine and continue with it, or go down the traditional path and get a track prepped e36 or e46 M3. Actually took a track prepped e36 m3 for a test drive today and almost pulled the trigger, but passed on it.

[chrispy28_xd]

The JRZs finally arrived this week. It somehow missed the production line back in May, and the Dutch went on vacation or something, so it was delayed a full month. No pics of the rear, but they are still divorced. I didn't go true coilover because I was told it's not necessary unless I need even higher spring rates (aero). I worked with Shaftworks USA to figure out spring rates for my application, and they also tested the dampers. I don't expect the spring rates to be perfect, but they should be a good starting point at this level.

New spring perches from Vorshlag are arriving soon, but I'm still waiting on reservoir mounts. A few friends say I can just use zip ties to secure them, but real mounts will ease my mind. Hoping to have these on the car by November since there's an open test day at Thunderhill that month. Perfect for a shakedown since I'll likely have to adjust the rear sway bar to get the balance I want.

Comparing the front struts to OEM, the profile on these JRZs is much smaller. The Ohlins that I currently have already reduces clearance even compared to OEM, so it's possible that the JRZs will give me a lot of clearance up front. This opens up the possibility of running square 10" ET38 wheels. I plan on getting new wheels next year anyway since a few in my current set are fairly bent and require a lot of weights to balance. It might be perfect timing.

[Garf117]

Why did you end us going 3.3 camber up front? Was adding front camber noticeable on track? I'm considering my first real move beyond stock + wheels/tires/pads/fluid. Sway bars seem too involved for now.

[chrispy28_xd]

Originally Posted by Garf117

Why did you end us going 3.3 camber up front? Was adding front camber noticeable on track? I'm considering my first real move beyond stock + wheels/tires/pads/fluid. Sway bars seem too involved for now.

If you're asking why negative camber is needed for track cars, then I recommend reading up on suspension geometry and how load affects it. I'm not an expert by any means, but basically as your suspension is loaded, you gain camber. If you're running 0 camber (which is what G2X cars come from the factory I believe), that means when you take a corner, you now have positive camber, reducing tire contact patch and therefore grip. To counteract this, you add static negative camber. There are several downsides to negative camber, like reduced straight line braking performance, but if you do it right, then you'll still be faster.

As for how I ended up at -3.3, I just felt like I needed more. I'm probably going to bump it up to -3.4 when the JRZs are installed as well. As for it being noticeable on track... yep it is. I remember going from around -2.5 to -3.0 for the first time, and despite it being the only change, I still noticed way better turn-in since the front tires just had more grip.

[RCKYMTN M34OI]

I just reviewed your suspension mod list . . . A90 rear sway bar!?
You have x drive correct?
I've been trying to confirm if the supra sway bars are compatible with the M340 or not. I'm assuming the eibach front sway bar for A90 doesn't work with the M340 and thats why you went with the H&R front sway bar?

[chrispy28_xd]

The G20's rear multilink suspension is basically the same as the A90/G29, which is why the SPL/Verkline rear arms are the same SKUs. And no, it's RWD but xDrive and RWD rear suspension are the same, though the xDrive OEM rear sway bar is thinner. The front sway bar is not the same as the A90 unfortunately.

[peelerec]

Originally Posted by chrispy28_xd

The JRZs finally arrived this week. It somehow missed the production line back in May, and the Dutch went on vacation or something, so it was delayed a full month. No pics of the rear, but they are still divorced. I didn't go true coilover because I was told it's not necessary unless I need even higher spring rates (aero). I worked with Shaftworks USA to figure out spring rates for my application, and they also tested the dampers. I don't expect the spring rates to be perfect, but they should be a good starting point at this level.

New spring perches from Vorshlag are arriving soon, but I'm still waiting on reservoir mounts. A few friends say I can just use zip ties to secure them, but real mounts will ease my mind. Hoping to have these on the car by November since there's an open test day at Thunderhill that month. Perfect for a shakedown since I'll likely have to adjust the rear sway bar to get the balance I want.

Comparing the front struts to OEM, the profile on these JRZs is much smaller. The Ohlins that I currently have already reduces clearance even compared to OEM, so it's possible that the JRZs will give me a lot of clearance up front. This opens up the possibility of running square 10" ET38 wheels. I plan on getting new wheels next year anyway since a few in my current set are fairly bent and require a lot of weights to balance. It might be perfect timing.

Running a square 10” wheel setup would be awesome.
How many hours are the JRZ’s rated for? I don’t think I’d ever be able to do this beautiful of a setup with the amount of mileage I daily drive + track.

[Garf117]

Originally Posted by chrispy28_xd

If you're asking why negative camber is needed for track cars, then I recommend reading up on suspension geometry and how load affects it. I'm not an expert by any means, but basically as your suspension is loaded, you gain camber. If you're running 0 camber (which is what G2X cars come from the factory I believe), that means when you take a corner, you now have positive camber, reducing tire contact patch and therefore grip. To counteract this, you add static negative camber. There are several downsides to negative camber, like reduced straight line braking performance, but if you do it right, then you'll still be faster.

As for how I ended up at -3.3, I just felt like I needed more. I'm probably going to bump it up to -3.4 when the JRZs are installed as well. As for it being noticeable on track... yep it is. I remember going from around -2.5 to -3.0 for the first time, and despite it being the only change, I still noticed way better turn-in since the front tires just had more grip.

I was curious why you chose -3.3 specifically. idk if that was the max you could get from those camber plates or if you felt more would cause instability at higher speeds. Good to know they made notice. Road Atlanta is my main track and turn 12 is a fast sweeper. I'm sure a bigger tire patch on the outside would make a difference. Thanks!

[chrispy28_xd]

Originally Posted by peelerec

Running a square 10” wheel setup would be awesome.
How many hours are the JRZ’s rated for? I don’t think I’d ever be able to do this beautiful of a setup with the amount of mileage I daily drive + track.

Shaftworks recommends every ~2 years or ~25 track days, so I'll probably do my rebuilds every summer.

[chrispy28_xd]

Originally Posted by Garf117

I was curious why you chose -3.3 specifically. idk if that was the max you could get from those camber plates or if you felt more would cause instability at higher speeds. Good to know they made notice. Road Atlanta is my main track and turn 12 is a fast sweeper. I'm sure a bigger tire patch on the outside would make a difference. Thanks!

I was at -3.2ish with maxed out plates. Now that I have adjustable arms, I can go much higher.

[chrispy28_xd]

Updated recent track event. No changes since the last so it was just a fun outing.

[chrispy28_xd]

JRZs are on. The 6" springs that they came with were too long and raised the car too much even at the max preload, but fortunately my shop had shorter 5" springs that we put on instead. They're a bit softer, but oh well. I attached some pics for how the reservoirs are mounted.