EXXEL Distributions
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Wheels | Tires -- Sponsored by The Tire Rack

Post Reply
 
Thread Tools Search this Thread
      04-15-2020, 09:30 PM   #45
CanAutM3
Lieutenant General
CanAutM3's Avatar
Canada
11423
Rep
17,070
Posts

Drives: 2019 M4cs
Join Date: Jan 2012
Location: Montreal

iTrader: (0)

Garage List
2019 BMW M4cs  [0.00]
2018 Audi RS3  [0.00]
Quote:
Originally Posted by aboulfad View Post
Coming from you that’s shocking, I expected some equations if it ain’t broke don’t fix it, it’s set to 32psi and ok. Once our climate warms up, I’ll experiment a bit.
Don't forget, I am a test engineer by profession (at least I was for a long time), so I do believe in empirical data .
__________________
///M4cs 2019 F82 Lime Rock Grey
MPE / CF Mirror caps / MP-HAS / GC Camber plates
Appreciate 1
aboulfad1478.50

      04-15-2020, 09:33 PM   #46
CanAutM3
Lieutenant General
CanAutM3's Avatar
Canada
11423
Rep
17,070
Posts

Drives: 2019 M4cs
Join Date: Jan 2012
Location: Montreal

iTrader: (0)

Garage List
2019 BMW M4cs  [0.00]
2018 Audi RS3  [0.00]
Quote:
Originally Posted by aboulfad View Post
Coming from you that’s shocking, I expected some equations if it ain’t broke don’t fix it, it’s set to 32psi and ok. Once our climate warms up, I’ll experiment a bit.
Note that the recommended pressures for my M4cs are 35psi front a rear.

I run 37 front and 35 rear.
__________________
///M4cs 2019 F82 Lime Rock Grey
MPE / CF Mirror caps / MP-HAS / GC Camber plates
Appreciate 0
      04-15-2020, 09:56 PM   #47
aboulfad
Brigadier General
aboulfad's Avatar
Canada
1479
Rep
3,871
Posts

Drives: 2015 M4 MG/SO
Join Date: Mar 2014
Location: MTL, QC

iTrader: (0)

Garage List
2015 BMW M4  [5.00]
Quote:
Originally Posted by CanAutM3 View Post
Note that the recommended pressures for my M4cs are 35psi front a rear.

I run 37 front and 35 rear.
I recall seeing this config - higher front than rear: decrease understeer ?
Appreciate 0
      04-15-2020, 09:57 PM   #48
CanAutM3
Lieutenant General
CanAutM3's Avatar
Canada
11423
Rep
17,070
Posts

Drives: 2019 M4cs
Join Date: Jan 2012
Location: Montreal

iTrader: (0)

Garage List
2019 BMW M4cs  [0.00]
2018 Audi RS3  [0.00]
Quote:
Originally Posted by aboulfad View Post
I recall seeing this config - higher front than rear: decrease understeer ?
Nope. Optimize tire wear due to high camber on front axle .

I am far from the limit when driving on the street
__________________
///M4cs 2019 F82 Lime Rock Grey
MPE / CF Mirror caps / MP-HAS / GC Camber plates
Appreciate 0
      05-03-2020, 02:24 AM   #49
anurak
Private
anurak's Avatar
Thailand
17
Rep
55
Posts

Drives: M4 CS
Join Date: Nov 2015
Location: Thailand

iTrader: (0)

Quote:
Originally Posted by Billy_BMW View Post
Try higher pressures, 45psi front and rear and see if there’s a difference.
OMG it works! I try today with Front: 38 psi Rear: 40 psi the car feels more direct and under WOT the rear doesn't feel wobbling anymore. Using the same road the oversteer in mid cornering is improved as well. It seems that PS4S side wall is much softer like you mention, using high pressure will fixed this problem.
Appreciate 0
      05-30-2020, 02:57 AM   #50
Steveo
Lieutenant
Steveo's Avatar
Scotland
48
Rep
581
Posts

Drives: M4
Join Date: May 2009
Location: Scotland

iTrader: (0)

I’m getting slight rubbing on new PSS 295 30 20 on the rear on my M4CS, stock wheels.
Wasn’t expecting that to be honest with most comments saying 295s would be fine on the forum.
Stock suspension, no change in ride height.
Any ideas?
Appreciate 0
      05-30-2020, 07:34 AM   #51
CanAutM3
Lieutenant General
CanAutM3's Avatar
Canada
11423
Rep
17,070
Posts

Drives: 2019 M4cs
Join Date: Jan 2012
Location: Montreal

iTrader: (0)

Garage List
2019 BMW M4cs  [0.00]
2018 Audi RS3  [0.00]
Quote:
Originally Posted by Steveo View Post
I’m getting slight rubbing on new PSS 295 30 20 on the rear on my M4CS, stock wheels.
Wasn’t expecting that to be honest with most comments saying 295s would be fine on the forum.
Stock suspension, no change in ride height.
Any ideas?
Spacers?
__________________
///M4cs 2019 F82 Lime Rock Grey
MPE / CF Mirror caps / MP-HAS / GC Camber plates
Appreciate 0
      05-30-2020, 08:33 AM   #52
Steveo
Lieutenant
Steveo's Avatar
Scotland
48
Rep
581
Posts

Drives: M4
Join Date: May 2009
Location: Scotland

iTrader: (0)

Did think about putting some on, maybe 5 or 7mm?
Appreciate 0
      05-30-2020, 11:20 AM   #53
RevNev
Lieutenant
225
Rep
422
Posts

Drives: X3 M40i
Join Date: Oct 2018
Location: Australia

iTrader: (0)

Quote:
Originally Posted by Steveo View Post
I’m getting slight rubbing on new PSS 295 30 20 on the rear on my M4CS, stock wheels.
Wasn’t expecting that to be honest with most comments saying 295s would be fine on the forum.
Stock suspension, no change in ride height.
Any ideas?
295's are getting tall, but I wouldn't think they'd scrape at ET40. 285 Cup2's and Bridgestone S007A's don't scrape with 10mm spacers.

I couldn't get any 285 PS4S, nil stock in Australia and fitted Bridgestone S007A's on my 763M street wheels. My ZCP's in CS suspension spec with Eibach springs and the Bridgestone's have better lateral grip than the Cup2's on the street.

Cup2's need some heat that's hard to attain and maintain on the street and they're lousy when cold and I've found the Bridgestone's better to blast around a few favourite corners faster when the Cup2's weren't up to optimum temperature for maximum grip. The Bridgestone's don't throw as many rocks down the side of my car as the Cup2's and minimising stone chip potential's a bonus and they're quieter.

The Cup2's are better grip wise on a long spirited drive and I use them on my 19" track wheels, but as an overall street tyre, the Bridgestone's are pretty impressive and definitely don't degrade the car's transient handling on the street, quite the contrary. They're quite stiff in the sidewall where perhaps the PS4S aren't so much, but I can definitely say they didn't mess my car up on the street after familiarisation with Cup2's.

Last edited by RevNev; 05-30-2020 at 11:29 AM..
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:32 AM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST