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      06-13-2008, 04:36 PM   #45
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Originally Posted by enigma View Post
In theory, yes.

In practice I cannot say yet. I am guessing for a place like Laguna or the autocross site I showed you woudl want sport mode. For reno I would bet on normal. The other, I have no idea.
Thanks for all the feedback you two have been posting...it's interesting to read some of your comments, think back on recent track days, and visualize what's going on under the body.
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      06-13-2008, 04:49 PM   #46
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Thanks for all the feedback you two have been posting...it's interesting to read some of your comments, think back on recent track days, and visualize what's going on under the body.
No problem. I think normal is going to help in places like the brake zone on the back straight at Reno. In my lotus with the stiff shocks/springs I was litterally skippy across the top of the bumps. The ABS was going nuts as the wheels wanted to stop each time they lost contact with the surface. I needed more suspension travel.

The wild card here is what does BMW do when they adjust the shocks. Do they stiffen the front and rear at the same rate? Is it biased to one end or the other? Or in normal is it truely dynamic? I don't think anyone (here) knows yet.

My first planned event in the car is the July 20 autocross. I have some thunderhill dates that I am tempted by but have not signed up yet. Really want to get some more information about how the brakes hold up. I really don't want a repeat of my laguna trip in the E46. (new rotors/pads on friday for the event. New pads on Sat, wore the fronts out in 1 day, New rotors and pads Monday) That was a bit too expensive for my taste and led me to retire the old car from track use.
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      06-13-2008, 06:32 PM   #47
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Or it could be that BMW is correct and honest and that EDC in its normal/active mode is good enough to offer better track performance with better comfort. Purists would likely never believe this even if "proven".
if so then why would BMW waste all our time with this button? just for marketing? they should have had just soft and normal.

I suspect tho that on some smooth tracks or AX the sport may be faster.
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      06-13-2008, 06:39 PM   #48
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if so then why would BMW waste all our time with this button? just for marketing? they should have had just soft and normal.

I suspect tho that on some smooth tracks or AX the sport may be faster.
Why did they put the sport button on the E46? It didn't do anything but make the car harder to drive on the track.

However, if you read the forums people think it makes the car faster so it had value to them.

Summary, most people are easily deceived and prone to group think.
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      06-13-2008, 07:16 PM   #49
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Here is how BMW defines the EDC system.

Electronic Damper Control (EDC).
Electronic Damper Control (EDC) reduces variations in wheel load, ensures tyres have excellent traction and counteracts bodyshell movement regardless of the weight your automobile may be carrying - and regardless of the state of the road's surface. EDC can even help shorten braking distances, meaning you enjoy outstanding comfort along with the best in BMW on-road safety.

Sensitive sensors constantly monitor all factors influencing the vehicle's behaviour and occupants’ comfort, including road conditions, load changes and vehicle speed. In a fraction of a second, the signals are analysed by the EDC microprocessor and orders are sent to the actuators on the shock absorbers, which, with the help of magnetic valves, are variably adjusted to provide optimal suspension.
Thanks to Electronic Damper Control, the tendency for the nose to dip when braking is practically eliminated. The influence of potholes and unevenness on the road surface are reduced to minimum. Whether you're behind the wheel or relaxing in the rear of the cabin, EDC delivers a remarkably smooth and comfortable ride.
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      06-13-2008, 07:18 PM   #50
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Quote:
Originally Posted by enigma View Post
Why did they put the sport button on the E46? It didn't do anything but make the car harder to drive on the track.

However, if you read the forums people think it makes the car faster so it had value to them.

Summary, most people are easily deceived and prone to group think.
LOL - I hated the sport button - never used it (except to impress the new buyer!)

It still remains to be determined which is faster normal or sport - and of course that may depend on track, driver, conditions etc.
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      06-13-2008, 08:46 PM   #51
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Quote:
Originally Posted by Gearhead999s View Post
Here is how BMW defines the EDC system.
...
Good information. Have not seen that particular verbage before. What was the source. The "Aftersales Training" document has other good information:

-Both dampers in one axis are always adjusted simultaneously
-Three acceleration sensors: FL, FR and Rear
-Steering wheel angle used in EDC calculation
-Rebound is adjusted dramatically at least double sometimes at low piston speeds as much as 4x
-Compression is adjusted in a much narrower range
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      06-13-2008, 08:48 PM   #52
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Originally Posted by enigma View Post
Really want to get some more information about how the brakes hold up. I really don't want a repeat of my laguna trip in the E46. (new rotors/pads on friday for the event. New pads on Sat, wore the fronts out in 1 day, New rotors and pads Monday) That was a bit too expensive for my taste and led me to retire the old car from track use.
During my Laguna Seca event with TMR, i was pushing the car very hard; not to mention this was my first time at that particular track; so hard braking was inevitable at times. If you know Laguna Seca, a few turns(besides the corkscrew) really call for some hard braking if you are hitting high speeds.

Anyhow, my assessment, (keep in mind i'm thinking of my e46m3 as a comparison) the brakes held up very very well on the track and of course brake fad did occur, however they did cool down quickly. Brake fad was not as bad(IMO), as some have stated..and I was braking very late and hard at times during the first few sessions, as I was learning turn 11, 8, 5, etc etc.

After the track day, I thought i warped my rotors and shot my brakes as my steering did vibrate upon braking and my pedal lost some bite (never had this happen in my e46). Over the next few days, i had my rotors/pads inspected, bedded the brakes, had my brake fluid flushed, and alignment performed. Everything checked out, rotors were fine, and no vibrations what so ever. Brake pedal is back to normal, and the bite is back...basically, OEM fuild boiling point is way to low as usual....used Super blue etc on my last M3 and the loss in pedal feel never occurred. Brake pads had a ton of pad remaining...no worries at all.

Another positive is, brakes and rotors are covered under factory warranty. Obviously it depends on your dealer, however with myself and my CA, who is also tracks his car, as long as i'm under the factory warranty....brakes aren't a worry.

In summary, IMO, of course there are BBK's that will be better; but for the weekend track guy, M brakes are more than enough for me and are nothing to be concerned with.

All the best,
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      06-15-2008, 01:51 PM   #53
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you can use the ATE clear fluid - same specs as the blue and the dealer cant tell you have it in.
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      06-15-2008, 09:54 PM   #54
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I guess shocks could help your braking

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      06-16-2008, 01:11 PM   #55
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Super Gold (the clear-ish stuff) works VERY well.......I use it in my 928 on the track, running otherwise stock brakes & never have a problem....towards the end of sessions the pedal does drop a tiny bit, but still has power.... The 928 weighs just slightly less than the M3 & has about 80hp less with slightly more torque...but only has 12" 4 piston Brembos all the way around....
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      06-20-2008, 12:51 PM   #56
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Quote:
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you can use the ATE clear fluid - same specs as the blue and the dealer cant tell you have it in.
Yep. I don't think they would give you much grief if you had the blue in there though....It is only brake fluid and although it may imply that you track the car, that is how they advertise it anyway, right? As long as you are not in a "competative" event, I would think they would still cover the pads? Maybe not, but they are relatively cheap anyways, and aftermarket pads would be a better bet anyways for the track.

I use Super Blue and the Clear all the time. I alternate fluids as you can clearly see the color change when bleeding...so you know all the old fluid is out when you flush.

For me, I aint gonna worry about taking in my car with blue in it.
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      06-20-2008, 04:07 PM   #57
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one dealer denied me a fluid flush at inspection and noted on the invoice "racing fluid installed"
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      06-23-2008, 10:58 AM   #58
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one dealer denied me a fluid flush at inspection and noted on the invoice "racing fluid installed"
LOL. What a crock of sh!t. I would have their asses over a barrel for that.

If you are going to change any fluid in your car (oil, coolant, etc), they must meet or EXCEED the mfgs specs. Super Blue meets or exceeds the specs. I don't see why there is an issue. Also, even IF Super Blue was called "Racing Fluid 10,000", it doesn't mean that one raced his car.

I would so destroy that dealership for phucking with me...it would be epic.
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      06-23-2008, 11:17 AM   #59
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yeah but not a big deal for me as I do my own flushes.
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      06-26-2008, 01:07 AM   #60
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Quote:
Originally Posted by GT3 Tim View Post
Yep. I don't think they would give you much grief if you had the blue in there though....It is only brake fluid and although it may imply that you track the car, that is how they advertise it anyway, right? As long as you are not in a "competative" event, I would think they would still cover the pads? Maybe not, but they are relatively cheap anyways, and aftermarket pads would be a better bet anyways for the track.

I use Super Blue and the Clear all the time. I alternate fluids as you can clearly see the color change when bleeding...so you know all the old fluid is out when you flush.

For me, I aint gonna worry about taking in my car with blue in it.
I was at one time denied a brake fluid flush by the tech assigned to my old e46M3;so my CA had to push it through a different channel.

The standard practice is to indeed inspect all fluid in the vehicle to comply with OEM products; and unfortunately blue fluid doesn't cut it. The good part is, if you do not perform our request an early brake fluid flush; they would not check this until your 2 year interval anways, so you can still bring your vehcile in w/o any hassles.
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      08-04-2008, 02:07 PM   #61
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EDC

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Normal should yield better performance than Sport although Sport will most likely "feel" faster as you will bounce around more. Also, I use MDM, which seems to be a good trade-off for me at this point.
I hate to ask the obvious, but if normal is better than sport, why have the sport setting? Seems odd, though general consenus seems to be normal is the way to go.
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      08-04-2008, 02:52 PM   #62
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I hate to ask the obvious, but if normal is better than sport, why have the sport setting? Seems odd, though general consenus seems to be normal is the way to go.
Sport mode is passive, meaning, the computer sets a damping ratio when you put it into sport mode and then leaves it alone. Normal mode is active, in which the computer continuously adjusts the damping ratio. Some people do not want the computer to be adjusting the damping ratio as they are driving, and as an option, BMW has provided them with a passive setting. We know for a fact that in normal mode, depending on the driving conditions, the damping ratio can actually be more aggressive than it will be in Sport mode. Also, I didn't say that Normal is just "better". Better is a subjective term without qualification. I said "better performance" in the sense that normal mode should be "faster". You can't beat a well optimized computer system. Then the question becomes, "Is the Normal setting in EDC optimized for turning fastest possible laps on a race track?" Probably not, but I still don't know that one can easily beat it in Sport on a race track. I've read in several places that BMW has obtained its fastest Ring times during testing in Normal, which brings up the other question of "fastest possible lap around which race track?" since the system would probably need to be optimized further for a specific track for best results at that track.
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      08-04-2008, 03:16 PM   #63
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For me, I feel more comfortable in Sport mode, both in turn and at high speeds on long bends or stretches of road. I'm not saying that i am faster, but I do feel more planted and stable in the overall body movement of the vehicle....less sway.

I have 3 track days coming up this week, and have had considerable more knowledge of the car now; since my last track event back in May. I'll post my feedback from the events.
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      08-04-2008, 03:25 PM   #64
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Quote:
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Take a picture of the car in a sustained sweeping turn and both the hard and soft shock car will be leaning the same. They will have the same wheel travel.
This is only true to the extent that you are only considering the steady-state response (and I realize you used the term "sustained"). It is not true if you are considering the transient response, which I believe, is what Gearhead999s has been saying. Meaning, if you are measuring the "maximum" displacement of the system, there will be differences as in the transient case the displacement response is not only a function of spring stiffness but also of damping ratio. Although I am clearly not as experienced as you or Gearhead999s on the track, I can only assume that will have implications for the handling of the of the car in general. The extra travel of a so-called "less-stiff" suspension must have implications. Imagine hitting a series of bumps in close succession, which is probably constantly happening, or back to back quick steering inputs where the suspension never really has enough time to settle. What happens then?

Here is a piece of information that seems to be missing in this discussion. While I was speaking with Larry Koch, I asked him about this. He told me that, in Normal, the suspension can actually be "stiffer" than Sport depending on the inputs. He obviously was not referrring to the spring rate or the steady-state behaviour. He was referring to what Gearhead999s was referring to as "dynamic stiffness" of the system that is a result of the computer adjusting the damping ratio in real-time in the Normal setting.
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      08-04-2008, 03:43 PM   #65
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For me, I feel more comfortable in Sport mode, both in turn and at high speeds on long bends or stretches of road. I'm not saying that i am faster, but I do feel more planted and stable in the overall body movement of the vehicle....less sway.
It is entirely possible that "predictability" is a variable here, and that the Sport mode might feel more predictable somehow. However, I bet that with enough time in the Normal mode, one can learn how to predict its behavior to some extent as well.
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      08-04-2008, 09:23 PM   #66
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Quote:
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Take a picture of the car in a sustained sweeping turn and both the hard and soft shock car will be leaning the same. They will have the same wheel travel.
I think you are right they would be the same - but I think thats cuase springs and anti-sway bars have more to do with ultimate lean than the shock damping. shocks may affect how quick a lot transfers but ultimate lean will be spings and sways.
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