2003 UK M3 CSL

[Mike RT4]

Nothing much going on apart from still enjoying the car. I've switched to AO52s for track to gain some grip, but having done just one track day with them, I have yet to really lean on them, but initial impressions are that they are much better than Cup 2s, but have zero rim protection.












In my mission to keep dropping the weight down, I have subtracted another 1.6kg with a billet alluminium Y-brace, replacing the OEM steel item:

[Mike RT4]

Awesome! Does your car have full AC and stereo? Any other weight modifications?

Yes, it has every single option possible, including rear PDC and Xenons. You can see the full spec and the weight saving details on the first page

[Bry5on]

Corner weights with full tank of fuel (absolutely brimmed):

Awesome! Does your car have full AC and stereo? Any other weight modifications?

[Mike RT4]

I have recently been having some gearbox lag issues that felt like the clutch was being briefly dipped when getting back on the power after hard braking. It seemed to get worse the hotter the transmission / diff oil got, so at first I thought it might have been the diff (see video for symtoms - ignore the short-shifting on the back straight, this was because I could feel that there was some fuel surge (not the symptom)). The worst case of it was just after 8mins, where it pitched the car into a slide (like you get when clutch-kicking wjen drifting):

https://youtu.be/0yNjECR_YnI

I took it in for a check-up and to have my Radium catch-can fitted, where I discovered that the centre prop doughnut was completely shot:





I run an E36 M3 Evo plated diff, and checking the oil, it was perfect (I change it at every service). One of the dampers needed a service, so I did all four and took the opportunity to redo the geo to be a bit more aggressive, as I could see I still had more to go from the tyre wear. Now running 4° on the front and 2.5° on the rear.




Corner weights with full tank of fuel (absolutely brimmed):



I've added some weight back in the car with the Radium catch tank and Bry5on 's exhaust brackets (I also forgot I had a litre of top up oil in the boot, along with the first aid kit that I usually remove, which would account for a a couple of kilos ).

The Radium catch can - being designed for LHD cars only, I bought the universal fitting kit and installed it here:











I also fitted some titanium bleed nipples on the AP brakes, as I had a couple sieze on me last time, which actually cracked a caliper getting it out (excuse the state of them, picture was taken before the car was washed ).



The SMG software also was re-adapted in case that was a cause and it was discovered that one of the rear ABS sensors was intermittently losing it's signal (error logged, but no lights on the dash), so this was replaced, as allegedly it can cause strange issues with the SMG.

Hopefully this has fixed the issue, but I won't know until the next outing.

If anyone has had similar issue, I would be interested in knowing what the problem was?

[Gearhead55]

Hi there, yes that is correct. However, with the offset of the rear wheels, you have to take the front spacers off when running the OEM 9.5s on the front (they would poke and hit the arches with spacers - in fact you need at least 3° of camber to run them even without spacers). I actually found that the 265/30 square set-up gave too much grip on the front end for the standard CSL seats and seat belts on slow corners, where I found I was being lifted out of the seat with the g-force that this set-up gave and trying to brace myself to prevent this was uncomfortable. As it's just for fun, I prefer to run the OEM staggered set-up, where I just reduce my entry speed accordingly. The square set-up really requires proper seats with harnesses (the CSL seats don't have the same kind of support, and despite being fixed back, have no provision for harnesses).

gotcha. They look great. I run a 265 or 275 square set up with more than -3* camber up front already, so I think a square 9.5 CSL wheel would work too.

[Mike RT4]

Mike RT4 I'm not seeing specific mention of it in this thread other than the little (x4 for track use) note when describing the wheel/tire set up, could you give a little more info about that? Are you running the 9.5 rears with a 265/30 squared tire set up on the track? And is that with only a 12mm rear spacer or 12mm spacers all around? TIA

Hi there, yes that is correct. However, with the offset of the rear wheels, you have to take the front spacers off when running the OEM 9.5s on the front (they would poke and hit the arches with spacers - in fact you need at least 3° of camber to run them even without spacers). I actually found that the 265/30 square set-up gave too much grip on the front end for the standard CSL seats and seat belts on slow corners, where I found I was being lifted out of the seat with the g-force that this set-up gave and trying to brace myself to prevent this was uncomfortable. As it's just for fun, I prefer to run the OEM staggered set-up, where I just reduce my entry speed accordingly. The square set-up really requires proper seats with harnesses (the CSL seats don't have the same kind of support, and despite being fixed back, have no provision for harnesses).

[Gearhead55]

Mike RT4 I'm not seeing specific mention of it in this thread other than the little (x4 for track use) note when describing the wheel/tire set up, could you give a little more info about that? Are you running the 9.5 rears with a 265/30 squared tire set up on the track? And is that with only a 12mm rear spacer or 12mm spacers all around? TIA

[Arlen4369]

Good thread. Ordered a pair of the same rear arms

[Mike RT4]

Just some more pictures showing pictures of the different screens - still in the process of building one with all three screens on display at once, because as previously mentioned, scrolling between screens is not ideal.

These temps were achieved after a short forray up to an indicated 140mph (rev limiter in 4th):






The diff and gearbox never get into the green (above 80°C / 176°F) unless on track.

For reference on the CSL, the last oil light on the rev counter goes out when the oil is at 65°C (149°F), which is a smidge above 75°C on the gauge (165°F on the US gauge)

I forgot to post the track temperature data (too busy enjoying the day to take photos):

Some interesting temperature data figures from the above track day.

27°C (81°F) ambients
Longest session: 20mins
Number plate removed for max airflow.

Aircon on max all the time.

On track peak water temps 89°C (192°F)

Air intake: 32°C (90F) (spiked at 78°C (172°F) queueing for the noise test).

Transmission: 118°C (244°F)
Engine: 116C (241°F) (dash gauge showing just over 3/4 - 125C(257°F))
Diff: 114C (237°F)

[Obioban]

Thanks!

[Johnydesmo]

Hi, my first post, Mike sent me, I am the very lucky owner of a (faster SB ) CSL here in the UK - bought within weeks of Mikes in 2013 ...although his has seen much more proper track use!
I have uploaded a blank panel here: https://cults3d.com/en/3d-model/gadg...ay-blank-panel for anyone wishing to create a project that fits directly into your ashtray...
Feel free to contact me if you wish a different format

[Obioban]

Personally I'd like a solidworks part file, but a step file would probably make it the most universally useful.

I'll PM you my email.

[Mike RT4]

Would you be willing to upload the CAD file for the ash tray insert? Having something that fits plug and play into that area without cutting seems like it would be a good starting point for all sorts of projects.

Do you have a preference to a particular format (as I can email it to you, so you can upload / host here)?

[Obioban]

Would you be willing to upload the CAD file for the ash tray insert? Having something that fits plug and play into that area without cutting seems like it would be a good starting point for all sorts of projects.

[Mike RT4]

Oh! Android head unit, interesting...

I like the three gauge approach, but yeah you should definitely add a way to control the gauges in place. As accessible as that space is, removing the gauge from the car for a simple tweak gets old fast.

How about an app for the head unit? Bluetooth or I bus should both work fine. I bus would be cool cause you could feasibly control it with other things as well (e.g. BlueBus), but bluetooth means you could also control it from your phone.

Always here if you need more ideas for your project to go way, way out of scope

Yeah, as stated in my OP, I have the AVIN 4 with the IBUS and Appple Car Play.

Thats quite some mission creep LOL.

I just want to know what everything is doing temperature wise on track, so although nice, the above suggestions would extend the project time considerably.

The main reason for the interest in transmission temps is that when we were shown around the cars at Schirmer on the CSL 20th Anniversary trip, I was astounded at the size of the cooling arragement they had on the rear diff of Jangobipbip's CSL build and Tom explained that when lapping continuously at the Nordschliefe, without it, the diff oil cooks itself and then it looses all it's locking ability with such high temps.

Sadly, we weren't allowed to take pictures, Best images (sort of) showing the set-up are here:

https://www.instagram.com/reel/CprnQPeIhLS/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==