W205 C63..........hmmmmm
MBWorld Fanatic!
Joined: Feb 2008
Posts: 2,829
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'20 GLC300 SUV
Tires are even an issue for the M3/M4 because of the insane amount of torque that car makes. People that have tracked the new M3/M4 have reported that the Michelin PSS became very greasy and unstable after a few laps.
Dyno runs have shown that BMW severely underrated the M3/M4. On Dinan's engine dyno (a much more accurate dyno), the M4 made 484 horsepower and 446 lb-ft of torque.
Graph here:
http://f80.bimmerpost.com/forums/sho....php?t=1036115
But here's the thing - tires are not really an issue on the street. I've never had a problem running 255-section rears on the street with my W204 C63. I'm not sliding all over the place wherever I go. Even when I drive spiritedly in warm conditions, the vast majority of the time I am able to hook up without much drama. Yet, at the same time, spinning the wheels a bit occasionally makes the car fun to drive.
When I do HPDEs, I run a dedicated track tire - not the street tires that come with the car.
If you run proper cup tires at the track, you're going to have the grip you need. Especially if you jump up to the largest size that will fit on the car.
The vast majority of AMG owners will never track their W205 C63s. The AMG engineers have to come up with tires that are optimum for the car under street use conditions.
Last edited by zibby43; Sep 27, 2014 at 01:00 PM.
Banned
Joined: Jul 2013
Posts: 2,811
Likes: 7
C63 AMG
The M is not under-rated or under tired
If it had 480/445 like some claim why is it slower to 150 that a car with 480/440 that weighs 400 lbs more?
One dyno said it was 500/500 lol
The best it has run is 12.1/119
The same mag did 12.1/120 in a PP w204
400 lbs heavier
Smaller tires
Let's see what rototest comes up with
A third party certified testing agency
2008 C63 http://rototest-research.eu/popup/pe...p?ChartsID=795
400 wHP
they haven't done a new m yet
And here is why the m dyno numbers are bs
They are ramp runs
The only accepted method in industry is steady state
Run to an rpm and apply load til it bogs back off stabilize and record
Repeat every few hundred rpm
You can see the data points and times on the rototest tabs
Go to down load tab pull up the hp pdf
Test mode steady state
Sample time at each 4.8 sec
1 of the 12 points (500 rpm interval) is longer than a typical ramp test
http://rototest-research.eu/function...efinedStatus=0
If it had 480/445 like some claim why is it slower to 150 that a car with 480/440 that weighs 400 lbs more?
One dyno said it was 500/500 lol
The best it has run is 12.1/119
The same mag did 12.1/120 in a PP w204
400 lbs heavier
Smaller tires
Let's see what rototest comes up with
A third party certified testing agency
2008 C63 http://rototest-research.eu/popup/pe...p?ChartsID=795
400 wHP
they haven't done a new m yet
And here is why the m dyno numbers are bs
They are ramp runs
The only accepted method in industry is steady state
Run to an rpm and apply load til it bogs back off stabilize and record
Repeat every few hundred rpm
You can see the data points and times on the rototest tabs
Go to down load tab pull up the hp pdf
Test mode steady state
Sample time at each 4.8 sec
1 of the 12 points (500 rpm interval) is longer than a typical ramp test
http://rototest-research.eu/function...efinedStatus=0
Last edited by Ingenieur; Sep 27, 2014 at 07:56 PM.
Super Member
Joined: Jun 2013
Posts: 538
Likes: 1
From: Melbourne
C63 AMG 507 Edition
Reviews have been pretty universally good on the way the BMW handles. Maybe you weren't driving it right?
Perhaps, just perhaps, AMG made the wrong decision? I know its difficult to accept, but big companies (even great companies) make poor decisions all the time. Arrogance, laziness, profit calculations, someone's ego, incompetance - all these can factor into building a car that is less than optimal.
Or they had different priorities?
Engineering principle is one factor of many they use to make decisions.
I will, and I will also post on forums expressing my disappointment. Maybe if enough do, they will get the message for next time.
And how many might they have sold if the tyres were wider? Opportunity lost maybe.
Super Member
Joined: Jun 2013
Posts: 538
Likes: 1
From: Melbourne
C63 AMG 507 Edition
But here's the thing - tires are not really an issue on the street. I've never had a problem running 255-section rears on the street with my W204 C63. I'm not sliding all over the place wherever I go. Even when I drive spiritedly in warm conditions, the vast majority of the time I am able to hook up without much drama. Yet, at the same time, spinning the wheels a bit occasionally makes the car fun to drive.
I disagree with you on this. Of course you can drive the car without losing traction everywhere, but in lower gears you really can't get the power down to the road that the car is capable of. You need to baby it up to a higher speed before you really get into it.
I like that you can break traction whenever you want, I would just prefer the balance was tipped more in favour of a little more grip. Car would be more fun to drive if it didn't have to be babied so much.
And yet the BS has wider rears, and is perfectly fine to drive on the road.
Super Member
Joined: Apr 2014
Posts: 728
Likes: 6
From: Chicago, IL
2018 AMG E63s
Don't know if the car & driver pre-review was included here yet - a pretty decent read: http://www.caranddriver.com/news/201...-and-info-news
Super Member
Joined: Mar 2009
Posts: 911
Likes: 22
From: Ottawa, Canada
2014 C63 507, 2012 R350
[QUOTE=Bardman;6180831]
I understand the point you are trying to make and while I don't necessarily agree with you or Ingenieur, I'll throw this out...no matter what tire you put on there are going to be traction issues putting 500+bhp to the rear wheels. 450+ lb.ft torque. I don't think a 285 is going to change it much. I am sure different tire sizes were experimented and I suppose there certain tradeoffs that AMG, at the end of the day, didn't want to live with.
Going 245/265 must be after thousands of kms what they felt works best.
The rear rim, is it not .5" wider than the existing 507?
I understand the point you are trying to make and while I don't necessarily agree with you or Ingenieur, I'll throw this out...no matter what tire you put on there are going to be traction issues putting 500+bhp to the rear wheels. 450+ lb.ft torque. I don't think a 285 is going to change it much. I am sure different tire sizes were experimented and I suppose there certain tradeoffs that AMG, at the end of the day, didn't want to live with.
Going 245/265 must be after thousands of kms what they felt works best.
The rear rim, is it not .5" wider than the existing 507?
