Trackday yesterday (Donington Park)

[droid42]

Here's the trackday write-up I just posted on bimmer.org ...

Hi all,

My M3 endured its 2nd trackday yesterday at Donington Park in Leicestershire.

The morning started off wet so I drove around carefully, constantly worried that the DSC light would fail due to overuse :-) It didn't take long before a prat in a Ferrari 355 took a spin and ended up smashing the back of the car into a barrier. The track was closed for 20mins because the idiot forgot to bring his towing eye and the recovery man had to figure out how to pull the car off. Cheers mate.

Anyway, the wet start gave me a chance to get a feel for the circuit and I knew it fairly well before everything dried out and I could switch the DSC off.

Doninton Park is quite different from Bruntingthorpe, in that it isn't flat, is quite technical and is much, much harder on the brakes. I therefore came away with slightly different impressions of the car than a few weeks ago ...

Chassis: a work of genius. Many of my passengers during the day commented on how balanced the car was. Truly amazing (this is exactly what I thought after Bruntingthorpe but the non-flat nature of Donington reinforced this view).

Tyres: Distinctly average. I had to use the original Michelin Pilots because my brand new P-Zero Rossos developed a serious fault that required me to get a full refund last week. The smoother surface of Donington allowed me to notice how so-so the stock tyres really are. I really miss my S02s :-(

Engine: The best. No more to say.

Brakes: Rubbish. Very, very strong while cold but serious fade after around 4 laps (even with the brake vent covers out). I'm sure the discs and callipers are fine and it's the pads that are badly defective. One of the rear pads was so bad it was clearly white through through about 1mm of its surface. For my next track outing I'll definitely get some new pads and might think about DOT5.1 fluid and braided hoses.

I went to the trackday with a chap who has just spent a fortune to have someone modify his Mitsubishi Lancer Evo 6 RSX as the ultimate track car. They succeeded. It weighs around 1200kg, has about 387bhp and is easily the quickest point-to-point car I've ever had a ride in (and probably ever will). Even more balanced than mine, unbelievable grip (his AP-22 said a peak of 1.4g ... that's one-point-four!!!) and it was quicker than the Porsche GT3 (which was also very well driven).

There were some idiots on the track but, overall, I had a good time. It was good to get a few instruction laps from Ed Moore ... a very nice chap and currently 3rd in the Formula Ford championship (meaning he's somewhat of an expert at the driving game).

Ian.

[johann]

Ian,

I have virtually the same experience except my car has ContiSportContact which are really good for 4 laps or so, after that they get to warm and the grip is not tip-top.

I also think the cars sways a bit to much for my taste.

I agree that the problem is the brake pads, they seem to be way too soft. I had no big problems with fading my problems were with wear. They seem to melt like butter when used on a track.
I still had 15-20 laps before experiencing any fade at all.

The track, Lausizt EuroSpeedway's Gran Prix circuit, included several +200km/h straights followed by braking to 80-100km/h.

Maybe your pads were glazed from some high-speed braking. That may affect them so they get too warm too quick.

Did you have any problems with boling brake fluid?

1.4G? Was that with street tires?

Cheers,
/Johan

[droid42]

Johann,

No, I didn't have any problems with the brake fluid. However, as with all tuning activities, once you remove one component's limitation, you'll find another one somewhere else. I suspect the limits will be found in this order:

- stock pads
- fluid
- hoses
- discs
- callipers

I haven't yet found anyone to supply me with just replacement pads for the E46. Strange ... it's been available in Europe for nearly a year now.

Donington has a couple of straights where I needed to brake down from 200km/h and 160km/h regularly. I suspect if I had been gentler on the brakes (as I was later in the day) and had started to brake a little earlier, I would have been OK and not glazed them. That would have meant me being slower though

The 1.4g was indeed with road-legal tyres (Dunlop semi-slicks). Tony (owner) and Steve (Power Engineering) have created something really special ... a virtually no-compromise trackcar that can still be driven to the event. With slicks it would be a little quicker but, I suspect, not by much.

Ian.

[johann]

Ian,

No, I didn't have any problems with the brake fluid. However, as with all tuning activities, once you remove one component's limitation, you'll find another one somewhere else. I suspect the limits will be found in this order:

- stock pads
- fluid
- hoses
- discs
- callipers


You may very well be right. The discs seems to cope very well with heat. Unfortunately they didn't cope as well with my "steel pads".

I haven't yet found anyone to supply me with just replacement pads for the E46. Strange ... it's been available in Europe for nearly a year now.

I am trying to track down Pagid pads, I'll let you know how that turns out.


Donington has a couple of straights where I needed to brake down from 200km/h and 160km/h regularly. I suspect if I had been gentler on the brakes (as I was later in the day) and had started to brake a little earlier, I would have been OK and not glazed them. That would have meant me being slower though


Maybe we have to resort to Movit brakes, I was hoping not.

The 1.4g was indeed with road-legal tyres (Dunlop semi-slicks). Tony (owner) and Steve (Power Engineering) have created something really special ... a virtually no-compromise trackcar that can still be driven to the event. With slicks it would be a little quicker but, I suspect, not by much.

1.4g with R tires are pretty good. As good as the Lotus Exige on normal street tires. The Exige is the car that pulls highest Gs that Sport Auto has tested. I think it would be considerable faster with real slicks, don't know for sure though.

Cheers,
/Johan

[JohnH]

Ian,

Sounds as though you got your moneys worth. Makes you wonder how the brakes would have been if you had left your covers on. The pads seem to be a common theme as it appears they are the biggest problem on the M5 as well. What was wrongwith the new tyres you had to return? Didn't you decide to put a larger size than standard?

[droid42]

John,

One of the new Pirellis at the front started to leak badly. I took my car to Cooper BMW and asked them to investigate. They took the two front tyres off and noticed one of the beads was broken (hence the leak). When I checked the other tyre, it was damaged in a similar way but not quite as bad.

I then had the rear tyres removed at Bracknell Tyre & Battery (excellent and cheap) and saw similar damage to these too!

When I took them all back for a refund, it was granted immediately with absolutely no argument. Shame ... I was looking forward to trying them out at Donington. I'm sure they would have been much better than the Michelins.

Ian.

[MichaelJP]

That's a real disappointment about the brakes - I'm trading my M5 in for an M3 early next year and the brake fade on the M5 is by far the biggest barrier to enjoyment on trackdays.

Hopefully it will be fixable with just brake pad or fluid changes.

Is it only Porsche that can make trackday friendly brake systems? I used to be able to circulate until I got bored in my 993 Carrera.

- Michael

[johann]

MichaelJP,

The brakes are far superior than the stock M5 brakes.
With open cooling air chanells, new pads and perhaps other brake fluid. There should be no problem.

Cheers,
/Johan