500-Mile Notes

[FTS]

I am definitely in learning mode of this car, it is certainly different than what I have experienced in the past, so I am not sure I am understanding 'Lenny" correctly yet. With hopes to not bore you or repeat all that has been said, I write the following with the intention of seeking opinions on whether what I am observing is common or am I misinterpreting the new car? So here it goes:

I have been driving mostly city and back roads to keep varying the RPM, moving between 2K and 5K. The RPMs build up quite fast in second and third gears even with partial throttle, 4th gear is a little slower than I expected, but the power comes in quite smoothly. I have to say that 2nd gear is quite addictive.

I haven't used the Sport+ settings, nor DCT's 3rd level yet. I want to make sure the active differential and the transmission components do not get overburdened too early. The DCT has been truly great; I am sure a driver following me cannot tell if I am using a manual or an automatic just be observing in traffic. However, interestingly enough I have been using my brakes more often during spirited driving than in my manual cars. I find myself down shifting very late into corners and staying longer on the throttle going into a corner than before, and because I am not taking the time to manually down shift, heel/toe, I am actually getting on the brakes much later, consequently putting more pressure on the brakes than previously, which also means I am not as smooth as I'd like yet.

Speaking of the drivetrain, the active differential is interesting. When exiting a corner with a healthy dose of throttle, there is this sensation that the backend settles down and finds the grip just a split second later than I am intuitively expecting. It is very similar to pre-997.2 911 Porsche without the Dynamic Engine Mounts, which with high lateral G loads, the engine would slightly move sideways due to its weight and the backend would take a split second to settle and become predictable. First time a driver experiences this it is very unsettling, but once you know it will happen you just slightly adjust your expectations and all is fine. Since the M4 has the engine in the front, I suspect it is the active M differential taking a short amount of time to decide the level of lock up. I am not sure I like it yet, but at least I know what to look for next time around to figure out what is happening.

Another not so pleasant sensation is with the Adaptive Dampers in Comfort setting. In normal city driving they are very compliant and feel taut, which I like a lot. However, when going into bends or corners that have slight camber or elevation changes, the shocks seem to have difficulty in controlling the chassis in those types of transitions. When this happens, the chassis feels as if it is floating on air and certainly gives the sensation that control may be lost momentarily, not a pleasant one, but manageable. I suspect this is due to nominal rebound rates of the shocks in comfort mode, because in Sport mode the chassis control feels right on the mark through the same bends and corners given street driving speeds. I am not sure how this will translate to the track, we'll find out.

Gas mileage is at 22.3 mpg, much better than I expected thus far. Interior is superb (I purposefully I am avoiding looking at the headliner), and I am certainly enjoying the electronics quite a bit, listening to music is really not my preferred method yet as the car is too new and I am learning its sounds. Exhaust sounds mighty fine to me, but what do I know, everyone else in the know says it is awful.

Finally the CCBs: first 300 miles they were very grabby, just the touch on the pedal was enough to brake actually. After few determined stops and past 300 miles, there is now a nice travel on the pedal. As it is said about all CCBs, the initial 1/8" of pedal travel lacks feel applying the brakes first time after cruising for a while. After this initial bite-less part, the pedal feel is superb and effective, actually very effective. So far there isn't any dust nor there is rust on rotors as expected of CCBs, wheels still look like new. Additionally, the usual CCB noise when approaching a stop is there, it is a more annoying noise than usual high-performance brake pads make, and interestingly there is an accompanying gentle shudder felt through the steering wheel.

That is it thus far, fire away please.

[fun2drv]

My CCBs do not make any noise whatsoever. I have 1600 mile on my car. There is no shudder either.

[FTS]

^ good to know, thanks for the feedback fun2drv

[JoeFromPA]

Agree on the active diff. Once engaged, it's awesome. The moment of engagement takes some getting used too.

Comfort mode on struts: Remember that the car's spring rates are fixed. So comfort mode in essence almost under-damps the car (in my opinion) resulting in a smoother and less bouncy ride and less harshness too.

As a result, you get floatiness in hard driving. While I enjoy driving it aggressively in comfort, I get body lean and "airiness" before it sets. I have greater confidence in sport and sport+.

[Brady1984]

If you are getting 22 MPG and have not yet used the Sport+ settings I don't think you are feeling the diff you are hitting the traction control (lightly).

This statement is what interests me though "the chassis feels as if it is floating on air and certainly gives the sensation that control may be lost momentarily" HUH? What car are you driving a 95 Buick Roadmaster? Is it possible you are jumping off a cliff in the car, I would check that before I checked the damper settings.

As for the CCB shudder and squeal, have you tried to bed-in the pads?
http://www.stoptech.com/technical-su...ake-pad-bed-in

[FTS]

Originally Posted by JoeFromPA

Agree on the active diff. Once engaged, it's awesome. The moment of engagement takes some getting used too.

Comfort mode on struts: Remember that the car's spring rates are fixed. So comfort mode in essence almost under-damps the car (in my opinion) resulting in a smoother and less bouncy ride and less harshness too.

As a result, you get floatiness in hard driving. While I enjoy driving it aggressively in comfort, I get body lean and "airiness" before it sets. I have greater confidence in sport and sport+.

I am glad I am not imagining things, thanks for the feedback.

Originally Posted by Brady1984

If you are getting 22 MPG and have not yet used the Sport+ settings I don't think you are feeling the diff you are hitting the traction control (lightly).

I have not hit the Sport+ settings yet. You may be right about the MDM interfering, but it feels different than that, and I don't see flashing lights on the dash, regardless you may be right.

Originally Posted by Brady1984

This statement is what interests me though "the chassis feels as if it is floating on air and certainly gives the sensation that control may be lost momentarily" HUH? What car are you driving a 95 Buick Roadmaster? Is it possible you are jumping off a cliff in the car, I would check that before I checked the damper settings.

I haven't yet jumped off the cliff, haha, but yes, the comparison is certainly not a huge exaggeration with the 95 Buick, an exaggeration nevertheless. I only feel it during such transitions that I described in Comfort setting of the EDC.

[Hawaii i8]

Sport Plus on everything man, just let her rip ... you know thats what she wants you too do!

[FTS]

Haha, yes, time will come

[onatuesday]

Originally Posted by FTS

Haha, yes, time will come

Don't forget the dampers will loosen up over time and that will change the feel of the car. I'm 4000 miles in and freeway stretches which had me bouncing off the roof in the very early days are now quite compliant.

[FTS]

Originally Posted by FTS

Speaking of the drivetrain, the active differential is interesting. When exiting a corner with a healthy dose of throttle, there is this sensation that the backend settles down and finds the grip just a split second later than I am intuitively expecting.

In an effort to learn more about the active M differential and how it behaves, I came across this very informative thread on the M1 boards, worth the read (particularly on pages 2 and 3):

http://www.1addicts.com/forums/showt...1003523&page=1

[dmk08]

You can definitely tell the difference in a manual vs dct from outside the car. Not saying either is better just saying.

[myzmak]

Originally Posted by dmk08

You can definitely tell the difference in a manual vs dct from outside the car. Not saying either is better just saying.

Please elaborate....

(What differences? Sound? Sexiness? Prowess of the driver? )

[dmk08]

Originally Posted by myzmak

Please elaborate....

(What differences? Sound? Sexiness? Prowess of the driver? )

Sound, lack of sexiness, and video game like prowess.