F82 M4 light weight measurement and Road Atlanta review observations

[M3 Adjuster]

Originally Posted by gthal

Great review... your pics are HUGE!! I can't see all of them without scrolling. Maybe just my computer.

I had to switch to my iPhone :-(

[M3 Adjuster]

Originally Posted by karussell

daily traction of course there is no issue unless you want to have police lights and neighbors shaking their fists at you. 255 i agree are good size. 275 better. the e9x could heat up 275 fronts quite well. actually its most preferred spec is 275's squared. on the e46 it was 265 square. this car i think 275/295 would be very nice indeed. and also i think going up on the fronts will keep it proportionally neutral. just it will launch harder on late apex low speed turns. look at road atlanta's track map. turn 7. if you can get just 1mph faster on exit of that turn you can carry that faster speed for that entire damn straight. thats seconds off a lap time. and i think this change alone will net more than a 1mph gain. more likely 5-10mph using same tire compound.

Enjoyed your review. .

I've been saying that these turbo cars need more rubber than what BMW is putting on them for a long time. Agree with you on the tire sizes for e46m3 as 265 square, e9x m3 as 275/35 square. While the e9x setup works pretty well, My 1M does even better with 285/30 square actually!

Keep in mind that your car has another 50-60 ft lbs of torque!

I threw a set of 315/30 meatballs on 11 " wheels in the rear of my 1M for autocross she really did well, and that's when I realized I finally wasn't spinning the rears!


Exiting Turn 7 you want as much mechanical grip as possible in order to get off the corner without wheelspin and to be able to put all the available power to the road, as soon as possible, I agree a 275/295 is a good start for the M4 but I bet 285/315 would be delicious on a set of apex or forgelines if you like.

As far as MDM, yes the American version is dumbed down , or at least it has been in the e9x and e8x. Hopefully some of the coders will have a euro version available. The euro MDM is what we should have gotten as well.

Enjoyed hearing about the adaptive suspension and where/Why it works best as I know the track well!

[F82speed]

Originally Posted by M3 Adjuster

...As far as MDM, yes the American version is dumbed down , or at least it has been in the e9x and e8x. Hopefully some of the coders will have a euro version available. The euro MDM is what we should have gotten as well.

Not sure of any specifics but EAS has the Euro MDM as a choice in their a la carte 'Coding Personalization' offering now...

There's also a related DIY thread here http://f80.bimmerpost.com/forums/sho....php?t=1061243

[heckyeahbro69]

flat out motorsports is having a de at roebling road Jan 31-Feb 1. there's plenty of open slots, you should sign up. I'll be out there.

[nicknaz]

OP thanks for sharing! Any lap times for the adaptive vs passive cars? Sounds like you drove both on the same day on the same track so this would be a great data point to have.

[Accel Junky]

For whatever it is worth I picked up a set of Intercomp scales that I've been wanting for years and got some more data for you:

This is bone stock, everything that came in the car is still in it and nothing else. Manual, cargo net, floor mats. F80 6MT with only options 19s and extended leather. This is COMPLETELY empty of fuel. I literally let it run out on the scales.



This is the same scenario but with COMPLETELY full tank of 93oct gas. So exactly 100lbs of fuel.

[CanAutM3]

Originally Posted by karussell

The HAS system is working well.
I will provide an in depth review once i have another track day on Road Atlanta. Its the only new item on the car and I want to review it purely on its merits while keeping all other conditions as near the same as possible.

Driving on street I will say the adaptive suspension works well with them in sport and sport-plus. I think they are a tad too much for the comfort setting making the car feel like it rebounds off uneven pavement a little too aggressively versus fully absorbing the bump. I have been driving on sport plus now almost exclusively as its my M1 setting anyways and I feel the car takes a set much more readily. feels very direct and responsive not that stock it did not, but it is noticeable. bumps don't seem to be much concern either. I figure I paid for the fancy shocks I will make them earn their keep.

Any additional insight on the K&W HAS on both street and track?

Since my M4 is my 4 season DD, I am a bit concerned about ground clearance for winter driving, so I am hesitant at installing pure lowering springs. But the HAS do offer an interesting option. Do you think it would be easy to raise the car for the winter and then lower it back in spring?

Further, another benefit I see in the K&W HAS is be the possibility to corner balance the car. Have you done so? If yes, what is difficult to achieve?

Thanks in advance, I value your insight

[karussell]

Originally Posted by M3 Adjuster

Enjoyed your review. .

I've been saying that these turbo cars need more rubber than what BMW is putting on them for a long time. Agree with you on the tire sizes for e46m3 as 265 square, e9x m3 as 275/35 square. While the e9x setup works pretty well, My 1M does even better with 285/30 square actually!

Keep in mind that your car has another 50-60 ft lbs of torque!

I threw a set of 315/30 meatballs on 11 " wheels in the rear of my 1M for autocross she really did well, and that's when I realized I finally wasn't spinning the rears!


Exiting Turn 7 you want as much mechanical grip as possible in order to get off the corner without wheelspin and to be able to put all the available power to the road, as soon as possible, I agree a 275/295 is a good start for the M4 but I bet 285/315 would be delicious on a set of apex or forgelines if you like.

As far as MDM, yes the American version is dumbed down , or at least it has been in the e9x and e8x. Hopefully some of the coders will have a euro version available. The euro MDM is what we should have gotten as well.

Enjoyed hearing about the adaptive suspension and where/Why it works best as I know the track well!

cool. love the 1M. hope to see you at Road Atlanta sometime. would love some rides. she is a tricky and challenging course. one of my all time favorites stateside.

I think 315 would be rubbing all over on a lowered car but maybe there is room with just the correct ammount of offset. I think 305 would be good but will try 295 first. too much tire can't get them to optimal temps on such a fast course.

[bigdog1250]

Really great read, thanks for taking the time to post this. Can't wait to get my car and of course track it down the line.

Cheers!

[karussell]

Originally Posted by CanAutM3

Any additional insight on the K&W HAS on both street and track?

Since my M4 is my 4 season DD, I am a bit concerned about ground clearance for winter driving, so I am hesitant at installing pure lowering springs. But the HAS do offer an interesting option. Do you think it would be easy to raise the car for the winter and then lower it back in spring?

Further, another benefit I see in the K&W HAS is be the possibility to corner balance the car. Have you done so? If yes, what is difficult to achieve?

Thanks in advance, I value your insight

Ah the height adjustment is pretty standard for any coilover. It doesn't take long to adjust. Front just raise one side pop off the wheel and use the included wrench. The rears its quicker to just undo the one bolt on lower trailing arm and pop out the spring perch adjust and place back. takes 10 minutes.

Yes I have corner balanced it. Its a breeze and feels solid!

I have used coilovers in winter with snow salt and ice. All I can say is after the first year things get a little crusty and harder to adjust. Maybe would be good idea to have some corrosion protection applied to the aftermarket parts.

[m4 java green]

Quick question. Do you keep the 12.5mm spacers front, 10mm spacers rear for street driving? I have 19 stock setup, will this work for me?

[karussell]

Originally Posted by m4 java green

Quick question. Do you keep the 12.5mm spacers front, 10mm spacers rear for street driving? I have 19 stock setup, will this work for me?

actually its other way around. 12.5 in back. yes will work on 19 stock wheels. street is fine.

[turbo8765]

Originally Posted by heckyeahbro69

flat out motorsports is having a de at roebling road Jan 31-Feb 1. there's plenty of open slots, you should sign up. I'll be out there.

Please post lap times when you get back. I've been dying to see what an f8x will run at RRR.

[Brindle101]

Nice write up, agree with most of it. One question, what GT3 are you referring to? If it is the 991 you are wrong about the straight away speed. I have an M4 and 991 GT3. I love the M4, but not in the same league as GT3, even in the straights, the GT3 is considerably faster and pulls much harder. The 991 engine is in a league of its own and a masterpiece as it screams to 9000 rpm. Also the throttle response is much sharper, but the driver is able to put the power down with much more control.

[karussell]

Originally Posted by Brindle101

Nice write up, agree with most of it. One question, what GT3 are you referring to? If it is the 991 you are wrong about the straight away speed. I have an M4 and 991 GT3. I love the M4, but not in the same league as GT3, even in the straights, the GT3 is considerably faster and pulls much harder. The 991 engine is in a league of its own and a masterpiece as it screams to 9000 rpm. Also the throttle response is much sharper, but the driver is able to put the power down with much more control.

The 991 certainly screams however my only data point was one driver at that event who was clearly being very gentle with the throttle. I was referring to the 997.2 GT3 RS at the track that day and I was able to gain on them significantly leading onto the back straight. of course once we got to 10a they started pulling away and its done by the time were on the front straight.

from a roll I suspect the 991 GT3 would be slightly faster than a stock M4 but not by much.

[m3bs]

Originally Posted by heckyeahbro69

flat out motorsports is having a de at roebling road Jan 31-Feb 1. there's plenty of open slots, you should sign up. I'll be out there.

I'll be there with my E36 trying not to get run over. Impressive roster for the event, including a Pagani Zonda R!

[SMURFDADDY]

Nice to see somebody using this car as the red headed track slut that it was intended to be

[cbdoc]

That big head in that ugly M3 reminds of Jim... Jim is that you?