Track day at Nürburgring - PeachParts Mercedes-Benz Forum

#1 10-01-2002, 05:07 AM

Hi guys

Last night I paticipated in a track day on the Nürburgring, not the nordschleife, but the F1 track. This track is usually not open for track days. But a racing club in Germany had arranged this special event. I usually take my Honda S2000 to track days, but since it's rear tires was all worn down I took the my MB E500 instead, which just had brand new Dunlop SP9000 tires installed.

The track was really nice, but the car was really a lot different from the S2000, rolling and steering input was really minimal in comparasion. And with the automatic gearbox, you could almost read a book, before the shift that you wanted actually happended.

I was also amazed to see a Honda S2000 follow me on the straight, but of cause he had the benefit of manual gear and much higer exit speed of the corner before the straight.

But real funny anyway, just be able to toss the car around, and having a laugh.

But this soon ended, after 4 laps my brake light came on, first only blinking a bit. But after another half lap, then it was permanently on. I was almost going for another lap, but in the last minute decided to head for the pits. Just to check out was could be wrong, at the turn at the end of the pit entry lane I could fell that the brake pedal felt a bit strange, and when I came to the speed limit sign before pit entry, the brake pedal went straight to the floor of the car

!!!!

I got the car stopped and went out to see, what was going on, and my discs was burning red, just like lava. After 30 secs, the brakes was of cause smoking, so I went out for slow lap, with almost no brakeing power, to cool the brakes.

After all this I checked the brake fluid, and the level was OK. I understand that the heat of the brakes can totally disable the brakes totally. But will this make the pedal go to floor ???

The car was OK again after the brakes had cooled, and this morning I tried the car in several hard brakings. And everything felt really OK.

Or was there something else wrong with my car ? I mean could I also have experienced a boiling brake fluid, and is there someway I can verify this ? And if so, should I imediately get the fluid changed ?

Have some of you guys experienced this situation after just 4-5 laps ? Of cause this was a high speed track, at the end of the straigh we hit 190 km/h, before braking for entering a 180 degree turn.

MB had changed my brake discs around a year ago, could it be that they have put 250D brake discs on the car ? Or are there no difference between E500 brake discs and the discs from the smaller E class cars ?

Hope some of you guys that have had your car at the track can give me some answers.

Best regards
SUN

Michael · #2 10-01-2002, 05:48 PM

You have either 300mm or 320 mm front brakes - can you tell if the internal venting is directional or not?

In either case, sounds like your brakes faded very early...how old is your fluid? I change my fluid before every track event, sometimes 2-3 times/year. Brake fluid LOVES water, so your boiling point drops quickly.

Also, try acquiring 1994 SL600 front brake pads - they are pretty close to an endurance racing compound, and are pretty stout. Or you could go with a race pad. But Change That Fluid!

Glad you kept it on the track - I've been there, and it's a horrible feeling

Also, which brake light came on, the "Brake" light or the worn pad light? It's quite easy to melt the pad sensors on the track (I'm quite certain yours are cooked) and have them falsely indicate low pad material.

Let us know

amg kodiak · #3 10-01-2002, 06:08 PM

Agreed,

My C36 (SL600 brakes) used to fade early as well. Flushing the fluid solved the problem.

~dnm

#4 10-01-2002, 11:10 PM

Michael may be on the right track- are the rotors directional and on the correct side of the car? if not, no venting and very hot rotors will result.

Michael · #5 10-01-2002, 11:27 PM

Alan is right (don't get all weepy, Trackman), but my point was, more specifically because I failed to highlight this in my earlier post, that the directional rotors are 320mm, and the non-d's are 300mm. Just trying to help you know what you have - frankly, Trackman's point hadn't occurred to me (can you believe I'm gonna do the One Lap with this guy? Geez, I think he's just using me to get some sleep

...lucky he's fast on-track!)

#6 10-02-2002, 05:38 PM

Hi,

Thanks for the comments, but one thing stay un answered, can burning hot brakes make the pedal go to the floor or was something else wrong ?

I just checked the service papers, and my brake fluid was last changed 5th of May 2001, so at the next service I'll ask them to change it again. I'll also ask them to check up on the sensors.

Also thanks for the tip about SL600 brake discs, I will think about such discs on next time they need changing. Are there any requirements regarding wheels sizes, because my current winter tires are only 17" ?

What about brake pads, are there also special pads for the SL600 model ?

Best regards
SUN

Michael · #7 10-02-2002, 06:16 PM

Burning hot rotors are consistent with a very hot braking system, so if your rotors were that hot, your calipers were likely pretty darn hot too...this can indeed lead to the symptoms you experienced.

Frankly, though, I just don't understand why they got so hot so fast - isn't the F1 track only 7-8kms long? Were you trail braking a lot, or (no offense intended) riding the brake? Did you brake over long distances and less aggressively, or were you really getting on them then coming off? Please describe better if you can.

In a moist climate, a year and a half is a long time for brake fluid - what's your climate like? Also, what kind/brand/type of fluid is in there?

As to SL600 brake discs, I use that reference since both the rotors and calipers of a later-500E and any 600SL are identical (320mm rotors, directional). I believe all Euro-market 500s had the larger brakes, but I guess you'll be able to answer that question for us. And they fit under 16" OE wheels, so 17s will work great.

As to 600SL pads, I just know that those particular pads are suitable for light-moderate track use; they are the same shape and thickness as the 300mm brakes use.

#8 10-02-2002, 08:12 PM

Hi Michael

Well nice to know that theat itself can make these symptoms, because when you experience things like this one is really looking for explainations.

Well it could be that I was riding the brake, but really I don't think so. But on that evening I was not wearing trainers, or racing shoes, so the posibility exist. But the braking patern was really to brake as hard and late as possible. It was actually not the full track we were racing on, they have made it a bit shorter, but there were 2 parts of the track were you braked from 180 to 40 km/h and the other part was around 190 to 30 km/.

Next Monday they actually have a track day again, and this time it should be the full length grand prix track, which is open. But this time I think I take the Honda instead :LOL:, then I can also finish off my already worn out rear tires :-)

Is there an easy way to tell if I got the 320 mm rotors ?

I have no clue what fluid MB have put in there, I normally leave the service fully in the hands of the MB garage. But the car have only done 17.000 km in this period, but that really doesn't matter I guess. Since it's the time which is factor here.

Well I ask the garage to change the brake fluid, anyway when the car goes in for pre winter service in about 2000-3000 km time.

Michael · #9 10-02-2002, 08:25 PM

Soren,

I'm pretty sure you have the 320s; look for a part number on either rotor & post it here (it's scribed into the rotor on the hub, or hat, part). If it starts with 129, they're 320mm.

Have you driven the nordschleife? What a track. Can't wait to get back there.

And have ein biere at the grun holle (sp? translates to "Green Hell") bar for me!

#10 10-03-2002, 01:16 PM

Hi Michael

Well sure I've done around 25-30 laps on the nordschleife over the last year or two. A really funny and scary track to drive on. And it's just so beatifull as well. But the casuality figures over there really gives you some respect for that track. As far as I remember it kills 8-10 people a year, and injures hundreds every month. Mainly bikers, but in some cases also people in cars.

Since it's such a narrow track, I've never dared to take the Mercedes over there. But this sommer I tried a trip in the ring taxi, that was the most awesome thing I ever tried. 4 wheel drifting in this new model M5, with 120 km/h around the corners. There was nothing on the track, that the driver did not over take, including bikes

And in one corner, the side of the M5 was around 20 cm from the boot of a biker trying to take the same corner. After such a trip, you just relize that you are not fast and can't really drive a car :LOL:

Well its really nice to live so close (only 130 km) to such a nice play ground :p

I guess you have been there, was you driving. If yes in what kind of car ?

Regarding the rortors, then I'll have a look tomorrow.

Michael · #11 10-03-2002, 05:10 PM

Soren,

I had a rental CLK Cabrio with a 6 speed and 2.3 litre Kompressor motor. Drove it so hard around the Nordschliefe I deployed the rollbar! Amazing how loud that deployment is.... The car was quite neutral, and fairly easy to hustle around the track.

Since the car didn't have all that much power (200-220 HP is my guess), I almost couldn't get into trouble. #1 most fun thing about lapping that track was the carousel...on one lap I dove under 2 VW Golfs that seemed to be racing each other (I'd been following them for awhile), but since neither was particularly fast (I can say this because I'M not that fast!) when they stayed up in the carousel, I dove down into the concrete heavily-banked section and got them both. What a rush!

Of course, about 100 meters later a RUF Porsche blew by me like I'd put it into Reverse! And then a bike blew by doing a wheelie, with a passenger! Unbelievable, everyone should do laps on that track at least once in their lifetime just to see how short all other tracks are by comparison. How can a person EVER memorize that track??!?

I actually went back again last year, but it was late in the year and that day the track was closed!! Oh well, I'll try again soon I suppose

BTW, was Sabine Schmitt the driver that took you around in the 'ring taxi? I hear she's the fastest driver...probably wants to get off the track quickly and back up the street, where she owns a bar!!

130k, eh? YOU'RE KILLING ME!!!

#12 10-04-2002, 05:00 PM

Hi Michael

Cool car, I find it extra cool to be driving up there in a cabrio, for some strange reason.

I thought that the car had to be on it's side for these roll bars to deploy, aparently not

Yeah the carousel, is really a funny part of the track, and actually very hard to drive fast. Because it's so natural to brake, but it's possible to take this part a quite high speeds, since you are simply sucked in there, and trown out at the other side. But I've never dared to take this part in really high speed though. But the bottom part of my front spoiler is actually hitting the ground when driving in the carousel in my Honda

Yeah these 911's over there are really awesome, most of them in full racing trim. I only managed to pass one 911, but he was also driving like an old man (very slow indeed) :p

Well after these laps I have quite a picture of the track in the mind, but sure every time the first laps are taking very carefull. I have come way too fast into a corner, when you expected it to turn left, and suddenly found out that it actually went right !!!!! As far as I remember around 60 out of the 74 corners are blind !

Other parts I like, is the two "straights", were it's possible to drive full throttle if you dare. Because the road is fairly straight, but you can't se this, because of all the corners, but these are just small bends.

But sure it's atrack of dreams, well that's also why it's so legendary. btw. in the spring this year I was passenger in a Friends Honda S2000, and he was driving like a mad man. I thought we would crash at least three times. Then we come around a corner, and we see this 80 passenger bus roling around the track !!!!!!! Full of japanese turists, absolutely crazy !!!!

If you go there again, it could be fun to meet up for a beer at the "Grünne hölle" bar

Nope the car we took was not the official ring taxi, but one arranged by a German motor sports magazine. They are actually the only one's together with the official ring taxi, allowed to go there with paying customers. This is enforced these days, after some problems with people who took paying customers in on the track, but did not have the propper skills to drive at the limit. But Sabine is sure driving there very often, our driver had doen 24 hours at both Spa Francho-champs and the ring, as well as Porsche cup and formel 3000. So he knew what he was doing

.

Nope 80 miles nothing more, around one to one and half hours of driving on the autobahn. And maybe an hour longer, if one goes along route 257, with it's beatifull twisty country roads leading up to the Eifel mountains.

Another cool thiong about the ring, is the whole atmosphere, and all the cool cars up there. Last time I saw both a Viper, a BMW M1, and a brand new BMW Z8, Lotus 340R, Lotus Elises, loads of 911's as well as a SL55 AMG, with a Luxemburgish plate saying "SL 055"