my M3 CSL

[mattCSLnut]

Originally Posted by alexk

Yes Matt. I miss the Ohlins especially when I go to the track.
The Ohlins as a race suspension was dead easy to adjust. Just crawl under. Job done.

The Kw needs a jack, lift the car etc etc.

It's exactly for that reason I've disliked KW set up in the past. Whiles my Bilstein PSS10 isn't as RACEY as KW CS or Ohlins, it's as simple and convenient to adjust as the Ohlins (no jack required) with only 10 clicks from soft to hard. Simples

Originally Posted by alexk

Swiss MOT. Its the way it is.

They sure know how to spoil car guys having fan with their cars

[alexk]

So here is a photo of the rear KW clubsport dampers (version of 2014).
As you can see with the OEM calipers there is no chance to remove the calipers (change pads) without having to remove the rear damper and moving it out of the way.

Annoying is the word that describes it.

[alexk]

Here are the pads after Monza.
The rear ones were Mintex M1144.
Very good pad and never let me down on the CSL and the Z3 coupe.
They also do not make any stupid noises

The front pads boiled as expected

[alexk]

I am very happy with my CSL but when you meet cars at the track with more horsepower, it is annoying to see them being faster on the straights.
BHP increase in the CSL is a painful road so I started running out of ideas.
Then Mr Gorilla reminded me about the importance of weight saving.

I think I can relative easy remove another 50kgs from my CSL, but what would this mean ?

I did some tests and now I will bore you with numbers.
The tests happened in a controlled environment, with exact same conditions and on the same test track.
I did two runs with less weight and then I added 32kgs to the car and repeated the same runs.
All runs were done with 3rd gear so as I don't shift gear.

Run with 32kgs less
70 -> 145 km/h
time: 6.3 secs
distance: 0.19km

60 -> 150 km/h
time: 8.0 secs
distance: 0.23km

Run with 32kgs more
70->145 km/h
time: 6.5 secs
distance: 0.20 km

60 -> 150 km/h
time: 8.1 secs
distance: 0.24 km

So we see here that when the car has 32kg added, it's consistently ~200ms slower in this type of acceleration and that in a virtual race it would be 100m behind compared to the lighter car.
That is a shocking difference.
Reducing 50-60kg from the weight of the already light CSL would have a significant difference.

I decided to start a CSL diet.

And here is a photo of the CSL yesterday, after I cleaned and polished it

[shimmy]

and heres today after the work

[glendog74]

Originally Posted by shimmy

and heres today after the work

Lol!

[Clubber]

Originally Posted by alexk

I am very happy with my CSL but when you meet cars at the track with more horsepower, it is annoying to see them being faster on the straights.
BHP increase in the CSL is a painful road so I started running out of ideas.
Then Mr Gorilla reminded me about the importance of weight saving.

I think I can relative easy remove another 50kgs from my CSL, but what would this mean ?

I did some tests and now I will bore you with numbers.
The tests happened in a controlled environment, with exact same conditions and on the same test track.
I did two runs with less weight and then I added 32kgs to the car and repeated the same runs.
All runs were done with 3rd gear so as I don't shift gear.

Run with 32kgs less
70 -> 145 km/h
time: 6.3 secs
distance: 0.19km

60 -> 150 km/h
time: 8.0 secs
distance: 0.23km

Run with 32kgs more
70->145 km/h
time: 6.5 secs
distance: 0.20 km

60 -> 150 km/h
time: 8.1 secs
distance: 0.24 km

So we see here that when the car has 32kg added, it's consistently ~200ms slower in this type of acceleration and that in a virtual race it would be 100m behind compared to the lighter car.
That is a shocking difference.
Reducing 50-60kg from the weight of the already light CSL would have a significant difference.

I decided to start a CSL diet.

And here is a photo of the CSL yesterday, after I cleaned and polished it

I also decided to take the same route, power increase is almost impossible as CSL engine is stressed as it is. I am not willing to stress it even further for MAYBE +10hp which I can hardly feel.
Less weight is the key. 18" Ultraleggera's saved 3kg per wheel including tires. Which made a huge difference.
On my next outing I will install JIC Magic Cross Titanium backbox and Braille battery to cut down a further estimated 25kg. And AP setup for a few kg's more. Let's see if it will make any difference.

[Mike R]

Hi Alex,
Can you list everything you did to take out the weight? How do you think this will affect the handling balance of the car, as BMW went to great lengths to get a 50/50 weight distribution?

Will you then corner weight the car to put it back to where it should be by adjusting the coilovers?
Cheers

[alexk]

Originally Posted by Mike R

Hi Alex,
Can you list everything you did to take out the weight? How do you think this will affect the handling balance of the car, as BMW went to great lengths to get a 50/50 weight distribution?

Will you then corner weight the car to put it back to where it should be by adjusting the coilovers?
Cheers

Hi Mike

That was just a test to see what effect it would have.
I just put a spare diff from an M3 E30 in the trunk...

In terms of weight savings, I now plan to do the following:
- Braille battery
- Remove rear seats
- Change front seats to Recaro pole position
- Bin the secondary air pump

As each axle weights ~675kg, removing a bit of weight from here and there is not affecting so much the weight distribution (especially seats are between the axles and in the middle).
I am not too bothered about corner weighting. I personally find this over the top with no real results as the weight on each wheel is dynamic when we drive the car.
You accelerate in a straight line, more weight on the rear wheels.
You accelerate while turning left, more weight on the rear right wheel.
Et cetera.
Pointless in my opinion.

[Loaded]

You have a nice plan ahead of you Alex!