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Discussion Starter #1
As I mentioned in an earlier post (http://www.bmwm5.com/ubb/Forum1/HTML/000990.html), attached is a link to a video of a lap in my M5 @ Thunderhill Raceway. I have very little experience in recording and editing videos, so this is the best I can do for now. The windows were down on the car and the camera was mounted off the rear deck, so unfortunately there is not much engine/exhaust sound to be heard. You will however hear plenty of tire squeal (Dunlops). The Porsche in the video is a 1996 C4S.
http://www.benefitsinfo.org/baby/arlen/M5_Thunderhill.mpg
 

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Sweet!! I don't want to give it away for anyone who hasn't seen it, but I was hoping the footage wouldn't end. Nice driving.. you could definitely hear the nice engine roar near the end of the video.
 

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NICE DRIVING !!!!!!!!!!!!!!!!!!
 

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What a great ride. We enjoyed it a lot. Wish we were there. How long was that straight where you topped 125MPH.

Thanks for the post and your hard driving.

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Jim
07/00 M5 Titanium over Red
 

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Way cool driving and way cool video!

Now, I have visited http://www.thunderhill.com. They say they are 1 hour north of Sacramento. The website also has track map, too. Looks like part of it was an old airfield.

I got a couple of questions, and would appreciate it if you could help me answer them:

1. What else is required besides a helmet and a decent driving skill? Do they require you to have a harness, or taking their class before entering it?

2. I looked at the track calendar. Which day did you go? For "open test"?

Given that I live about 2 hrs. southwest of Sacramento (in the bay area), I think the optimal way to have fun is actually to drive up there on Thursday night and spend a night there and get up early for Friday session. :)
 

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Roger,

Great job on the video! It allowed me to re-live the track experience. You were doing some great driving.

By the way, I'm pretty sure that I warped one of my rotors during the day on the track - I am checking it out today.

The whole day was a blast, but it might be the only day that my beast see's the big track.

John
 

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This was very cool!
Your video really shows the M5's ability.
But boy, do the Dunlops scream!

I have done several track days with my Michelins and they did almost not scream at all. Was it very hot outside?

At one of the tracks, Anderstorp an old F1 track, in the fastest corners, I managed to drive 125 km/h with four people in the car. In the same corners STCC Cars (same as BTCC or DTM) drive 135-136 km/h. They have race tires, race suspension and much lighter cars.
I had standard tires, standard suspension,
is the M5 a great car or what? One of my friends filmed a lot and I will post a "little movie" once I've had it edited.

/Johan
 

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For anyone so inclined as to want to take their M5 to the track:

It's looking more and more like I'll be taking the M5 to the Shelby Club Fall Classic up at Thunderhill (10/14-15.)

There are a number of clubs that run track events in the Bay Area and if you've never been on a track before you want to hook up with an instructor (either through the club, or otherwise.)

I don't expect the M5 to be an ideal track car by any means - while fast, it's just too bloody heavy and it will be hard on its brakes and tires.
 

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johann,

I was running my M5 with Michelins the same day with Roger. They screamed every bit as loud as the Dunlop's. The Michelin's may have had a little better grip, but they both make a lot of noise.

It was 80-90 deg F on the track. I don't think it was a temperature related issue. I have run mine at autocrosses during cooler weather and they screamed then as well. I really don't think the noise is unusual for a street tire being pushed hard through a power drift.

John
 

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Originally posted by jlvink:
johann,

I was running my M5 with Michelins the same day with Roger. They screamed every bit as loud as the Dunlop's. The Michelin's may have had a little better grip, but they both make a lot of noise.

It was 80-90 deg F on the track. I don't think it was a temperature related issue. I have run mine at autocrosses during cooler weather and they screamed then as well. I really don't think the noise is unusual for a street tire being pushed hard through a power drift.

John
Well my tyres have been pretty quiet, they did occasionally scream?
It has been in the range 70-80 F air temp.

Can it be related to the surface? Or differences btw US and Europe tires?
I know that there are big differences btw tires sold in Europe and Asia even though it is the same brand and type.

I have really been pushing the car to it's (and my) limit on the tracks (Hockenheim, Anderstorp, Kinnekulle).

/Johan
 

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Marlin and I will be at Sebring Nov 11 for the "Track Days" sponsored by Panoz. I thing were in the kiddie or senior division


I'll be checking for track damage on other cars before I'll commit my beast.

Spartanburg was fun but not extreme enough for me.

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Jim
07/00 M5 Titanium over Red
 

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I guess it's possible that they have a different compound for the Michelin Pilot's in Europe vs. US; but I have never heard this before.

We were running our tire pressures in both cars in the mid-40psi range;could this be the difference?

John
 

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Mid 40 PSI, what is that in the metric system? And when will you start using it)


On track I have the recomended (by BMW) maximum pressure, 3.2 front and 3.5 rear. I checked this with Michelin and this were their recommendation as well.

/Johan
 

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Discussion Starter #18
Thanks for the great feedback on the video. I'll try to respond to a few of the questions raised.


Camera Mount: I have a great mechanic in SF (Aldo's Perf Motors) who rigged me up a simple but very effective set up. I already had a racing camera mount ($90 I/O Port from www.ogracing.com) that he used as the core mounting piece. The way the system worked was we removed the center headrest; anchored a 1.5" aluminum rod at the top the rear seat by using the other two headrests to hold it in place; fashioned a steel bracket with an eyelet in one end and a single 4-5" prong about 2/3 of the way along; used the existing center car seat mounting bolt on the rear deck and one of the two holes from the removed center headrest as the mounting points for the whole assembly. We put a slight indentation in the aluminum pole where the bracket made contact for better stability. The whole think takes 3 minutes to install and remove and leaves no marks whatsover. In this case a picture is truly worth a thousand words:

http://photos.yahoo.com/bc/rarlen?e&.intl=us&.flabel=fld10&.from=d&.pindex=1&start=1&.src=bc&.done=http%3a//photos.yahoo.com/bc/rarlen%3fd%26.flabel=fld10%26.intl=us%26.src=bc

http://photos.yahoo.com/bc/rarlen?d&.flabel=fld10&.intl=us&.src=bc&start=1


Thunderhill: That main straight is 1/4 mile long. Thunderhill is the best of three Bay Area tacks to start out on because it is a challenging track but there is massive amounts of run off areas such that it is very unlikley (but not impossible) that you would damage yourself or your car. There are $50/night motels right by the track and most people stay over before a track event to be sure they are well rested.


Track Events/Equipment: Different events require different equipment, but the minimum standard is a Snell 95 helmet. Some clubs and schools require roll bars and extinguishers, but this is more the exception than the rule. I don't know about specific Thill test days because i've only done club events where our club has rented the facility.

I couldn't agree more with JEM that you should have an instructor or mentor when you first start out as it could be the difference between never going to the track again and getting absolutely hooked. If anyone is interested, I can share the names of several instructors who I know that will travel to Thill.

Tires: I was running the stock Dunlops. In case you missed my prior post, please check out
http://www.bmwm5.com/ubb/Forum1/HTML/000990.html


Rotors: John indicated that he may have warped a rotor and the other M5 driver thinks he could have warped his front two, if not all four. Dealer cost to replace all pads/rotors is $2,200 (ouch). I did not have any warping problems. I don't know if our braking techniques were the same, but I tried to avoid diving on the brakes as I was concerned about changing the balance of the car too abruptly given it's mass. This may have saved my rotors, or it may have been blind luck.

Please let me know if I can answer any other questions.
 

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Johann,

The tire pressures could very well be the difference. Roger started the day with lower pressures and worked his way up to 44/48psi on his Dunlops. They were still squealing, but apparently not as bad. I also adusted my Michelins up, but only to 42/44psi.
As for the conversions(I admit the US are metric lagards);
42psi = 290kPa
44psi = 300kPa
46psi = 320kPa
48psi = 330kPa
51psi = 350kPa

If my conversions are right, you were told by BMW to run 46/51psi on the track. This is consistent with a previous thread that I found; it mentioned that BMW Spartanburg ran their tires near the max tire rating of 51psi on the track. (They also recommended the door jam pressure of 44/48psi for the street). I definitely ended up with some outside "cupping" on my tires running the lower pressures of 42/44psi.

There is a definite possibility that we could have reduced tire squealing by running higher tire pressures.

John
 

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Roger,

Since the Thunderhill event I can feel a slight "shudder" during firm braking. I just checked out all four rotors; the rears look OK but the fronts have shiny "high spots" indicating warped rotors. They don't look real severe and I am hoping that resurfacing them is all that I need to do.

Did the other Roger confirm that he warped his as well? The tremendous straight-away speeds that you can get with the M5 put a lot of demand on the brakes under track conditions. Your driving technique was apparently a lot kinder to the brakes than mine, although I did notice each time you pitted they were smelling very strong.

John
 
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