F82 M4 light weight measurement and Road Atlanta review observations

[stressdoc]

Racing front seats, akra, BBS-FI, stereo delete and we might be down to 3200 lbs.

[von_zoom]

Past week end I got to experience the M4, albeit in the rain, but seemed the car will do a fair job in the dry. Currently, I drive a Z06 and the power, torque, and speed is quite a bit more than what I observed in the M4. Now, I did not drive, so may not be a fair comparison. I did visit my BMW store yesterday, and to get a M3 or M4 configured like I want will require some doing. Probably after the first of the year, so I have some time to give it some thought, plus a BMW event at VIR next week end.
Enjoyed your report.
vz

ps Will this be the thread that replaces the M3 forum? If there is another, will someone post a link. Thanks.

[/// M sa]

Love reading Reviews from the experts that know their shit great review man!

[Powaup]

Good read, I've been working on the stuff you thought me at Spa and I can feel my driving skills are improving as long as my confidence in my M4.

I agree about what you said in regards to tire width, I sometimes feel like there's too much power for the rear tires going from 1-2 and 2-3 and wow the weight savings gained by removing the back seats are impressive, I'm curious as to what my car weighs with leather and exec pckg stuff but next autocross I'm for sure removing the rear seats

[X2Board]

Originally Posted by Needsdecaf

\

Arena Red. My friend had a '99 Boxster in same color. We had some fun in that car.

That's one of the cars I wish I had kept.

[CanAutM3]

Great review and insight . Thanks for sharing

What are your thoughts on alignment? You mention good wear on the front tires. Are you running stock alignment?

[kitesurfer]

Originally Posted by gthal

I think the OP would be considered a little bit more experienced than an "amateur"... just my take

P.S. We can debate how much better the active suspension is versus passive but the debate is based on how much and not whether it is better.

Amateur = forum member reviews = not paid as a profession to review cars ,
It was not meant to question his ability to hot shoe around a track.

With that being said I also take some professional reviews with a grain of salt

[SakhirM4]

Originally Posted by kitesurfer

Amateur = forum member reviews = not paid as a profession to review cars ,
It was not meant to question his ability to hot shoe around a track.

I would take OP's opinion over most professional reviewers. He lives with the car - they don't. He is much more intimate with it than they are and appears to be mostly unbiased .

[dawgdog]

Another great review! Based on the previous review I changed my order to active suspension and I am glad I did. This car is planted, stable, has gobs of torque and with dct is easier to drive fast than my RS.

[solstice]

I don't see any reason to doubt the OP's claim that the adaptive suspension is faster around a track. It should be since it's designed to keep more average friction by adjusting damping to conditions. I'd get it if I was a professional racer or even a track rat where I want any advantage I can. Does that make me want want it in my street car, no since I prefer the feel of the passive suspension just as I selected the MT for feel and not ultimate speed.

[MaynardZed]

Most paid car "professional" reviews aren't worth the paper they're written on. That being said, any review (professional or not) can be put in better context if we have objective data like lap times, g-forces, terminal speed, etc. to go along with the subjective portion of the review.

[FTS]

Such a positive review, quite encouraging, fun to read, thank you Karussell.

At the same time you are confusing the hell out of me I just don't know the platform at all, no question, and I am having difficulty even conceptualizing few things, particularly tire/wheel sizes, spacers and the overall balance of the car.

I have the impression that the M4 is quite lively at the back from the factory due to it being slightly noise heavy, the multi-link suspension, torque, direct bolt of the subframe to chassis probably being the major reasons for it. And I also have the impression that the factory did not put a wide enough wheel and rubber in the back comparatively to the fronts, which contributes significantly to its loose nature.

If all this is in fact correct, I have few questions and am asking for guidance from all that are willing to enlighten an ///M newbie:

• Would a square wheel/tire setup make things worse with stock springs and A/R bars?
• Wouldn't putting wider spacers in the front comparative to the rears effectively reduce wheel rate more in the front and imbalance the rear further?
• I believe that wheel width is more important that tire width; if one uses 275/295 combination with same wheel widths or same width increase (let's say 1" front and rear) do you think it would actually help balancing against the oversteery tendencies? Wouldn't a 265/305 (or even 325) tires on 9.5"f and 11"r setup arguably yield a more neutral setup?

TIA

[karussell]

Originally Posted by dsm918

Great thread So based off your review on the adaptive suspension, is that option really needed on a car that will primarily only see the street and never the track? What setting on the adaptive does the passive most feel like? Sport?

Let me put it this way, If your drive involves a road then I recommend the adaptives. On track they perform better especially when having to deal with rapid bump rebound like jumping on and off a berm. On the street you can run it in sport or sport plus even if its fairly rough and it will adapt to the conditions maximizing contact patch while still soaking up bumps.

I can't tell you where the passive's fixed damping falls relative to the adaptives as the adaptives are always adjusting. i will tell you that before the entry to the esses at Road Atlanta on turn 3 is a fast right hander you can absolutely nail right over the berm and continue accelerating through turn 4 and the esses. By the end i need 2 braking zones just to bleed off the speed for turn 5. The passive shocks can't handle that berm and you have to ease off the throttle. In this case the adaptives have made that entire complex of turns into a straight with possibly a full second lead over the same car with passive shocks. Alternatively if you were to run adjustable coilovers with a high rate of rebound and damping for such a fast course and with an aggressive sway bar setting you also can't use full throttle over the berm. I catch several cars from this corner alone. In this case and its common on many tracks the adaptives are simply superior.

[karussell]

Originally Posted by Needsdecaf

Karussel:

What made you choose the MT over the DCT? For someone who is going to track the car often, I would have thought it would be opposite.

I prefer a manual transmission. Originally we were going to prepare and enter this car in this years 24 Hour race at the Nurburgring. The team director and I decided on only two options at the time. DCT and Adaptive Shocks.

DCT simply because there is no possibility of a mis-shift when you are tired and racing at 3am. We have lost a few engines this way over the last few years.

does it shift faster? no doubt. does it improve a lap time? I don't think so as long as the driver doesn't make a mistake. Given humans make mistakes and especially when fatigued the choice of DCT was for improving the odds of finishing the race rather than performance improvement.

purpose built race cars such as the 911 Cup and M3 GT4 don't use DCT's either because they are heavy and complex. instead a race car will have a sequential single clutch transmission that needs to be completely rebuilt on a regular basis.

personally I find DCT in this car way too smooth. Its too much like an automatic and I like the manuals gearing. It makes the car feel like it accelerates faster. Plus with the power band from the motor you can simply choose a higher gear and shift less altogether improving your lap time. I do not think DCT alone will improve a lap time.

I am probably a little crazy to most though as I preferred a manual E30 with steel subframe bushings and 800lb springs for my daily commute in Orange County/LA traffic. I'm sure normal folks are happy to have an automatic when stuck on the 405.

[karussell]

Originally Posted by RocketBoots

Thanks for the follow-up reviews. Would you say there was a noticeable difference, for YOU, after shedding the ~40lbs of rear seat?

Not a damn thing. lol

By the time we finished the brakes and bedding them in we were too tired to put the seats back in it.

I did notice the car is louder with them out. That was cool. Practically just like in the E46 you can place your track wheels back there in the circular area it creates.

Seats are now back in for kid duty. Took me 10 minutes yesterday.

[karussell]

Originally Posted by stressdoc

Racing front seats, akra, BBS-FI, stereo delete and we might be down to 3200 lbs.

I think its entirely plausible. We shall see.

[karussell]

A Z06 is quite a car but just like the GT3 the problem I have with them is my two boys have to fight over who gets a ride. In the M4 everyone can enjoy it. If i get a 3rd pit crew member then might have to get an M3 again. lol

Originally Posted by von_zoom

Past week end I got to experience the M4, albeit in the rain, but seemed the car will do a fair job in the dry. Currently, I drive a Z06 and the power, torque, and speed is quite a bit more than what I observed in the M4. Now, I did not drive, so may not be a fair comparison. I did visit my BMW store yesterday, and to get a M3 or M4 configured like I want will require some doing. Probably after the first of the year, so I have some time to give it some thought, plus a BMW event at VIR next week end.
Enjoyed your report.
vz

ps Will this be the thread that replaces the M3 forum? If there is another, will someone post a link. Thanks.

[///MCFC]

really wish this site would automatically resize pix. hate having to constantly scroll or zoom out/zoom in.

[karussell]

Originally Posted by CanAutM3

Great review and insight . Thanks for sharing

What are your thoughts on alignment? You mention good wear on the front tires. Are you running stock alignment?

The alignment is untouched so far. We are getting in the KW height adjustable coil system for adaptive shocks and will corner balance along with adjust toe settings. I think we will just stick to factory settings on toe for now. one variable at a time if at all possible.

[CanAutM3]

Originally Posted by karussell

The alignment is untouched so far. We are getting in the KW height adjustable coil system for adaptive shocks and will corner balance along with adjust toe settings. I think we will just stick to factory settings on toe for now. one variable at a time if at all possible.

If I understand correctly, the stock camber setting, especially at the front, is adequate for the track? That would be an M3(4) first.

[karussell]

Originally Posted by CanAutM3

If I understand correctly, the stock camber setting, especially at the front, is adequate for the track? That would be an M3(4) first.

currently I have no inclination that it needs more camber. the tires seem to be fully engaged. I plan to go to a wider tire so I will keep the current settings and see the difference before adjusting. I imagine slightly more negative camber in front would help but the car is already so neutral and the cost is increased tire wear.

This M3(4) is doing many things as a first since the original. First M car to be capable on a track direct from the factory floor. That says a lot. I'm thinking based on how it behaves the camber has been carefully considered. I want to keep this car perfectly usable for both day-to-day and track use. Some compromises will have to be made.

[karussell]

Originally Posted by kitesurfer

I take these amateur reviews with a grain of salt, especially when comparing a hotly debated option such as adaptive vs passive, and here is why:

One of us has driven both systems on 3 very different race tracks. One has not.

The topic is not hotly debated except by yourself. News flash this isn't a religion. Adaptive suspension is adaptive. fixed suspension is fixed. race tracks and the road are not all one continuous smooth pavement. one of these is designed for real world conditions. one is not.

I look forward to your definitive review and your shock dyno tests. Until then I would take your opinion with a heaping dose of salt lined on my Margarita.