BMW M3 Forum (E90 E92)

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


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Track / Autocross / Dragstrip / Driving Techniques
 
Post Reply
 
Thread Tools Search this Thread
      09-01-2020, 08:52 PM   #1
nicksm3
Lieutenant Colonel
nicksm3's Avatar
467
Rep
1,779
Posts

Drives: e92 m3 Competition
Join Date: Jun 2014
Location: Westchester NY

iTrader: (5)

Track only Alignment specs...

Finally going to full SPL Kinematics, took helper spring out on my MCS 2ways to raise Spring Perch. Will be running 18x10.5 wheels square with 305/645/18.

Looking for some specs/ideas for optimal performance, what are the hardcore track only guys running?

Thank you
Appreciate 0
      09-01-2020, 09:37 PM   #2
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Will vary depending on driver, track, spring rates, ride heights, tires etc etc.

But roughly you'll want to be looking at:
Front Camber: ~-3.5 to -4*
Rear Camber: ~-2 to -2.5*
Front Toe: 0 toe up front is the most common, but depending on preference and other setup settings anywhere between an 1/8in toe in and an 1/8in toe out (per side) is reasonable
Rear Toe: I'd run at least a 1/8in toe in (per side) for the rear, up to 1/4in

I can't remember the caster angle of the top of my head, I know I contacted BW and went off of their recommendation and haven't touched it since.

1/8in to 1/4in negative rake is the typical recommendation for 'track use'. This is a very simple and effective way to shift the handling balance of the car.

Tire temps and tire wear should be used to determine 'optimal' camber settings. Front toe will be used to adjust turn in response and front end straight line stability and rear end stability using rear toe. Ride heights should be adjusted to alter handling balance.

If you frequent numerous tracks, there will be no settings that will work optimally at more then 1 track, so keep that in mind. It will always be a compromise, so set the car up optimally for the track you visit most often and have small adjustments noted for alternative tracks.

Again, this is all rough settings and it will vary per car, track and so on.

Last edited by tsk94; 09-01-2020 at 11:47 PM..
Appreciate 1
nicksm3467.00

      09-02-2020, 01:12 PM   #3
Samo6556
Private First Class
89
Rep
185
Posts

Drives: 09 BMW M3
Join Date: Oct 2012
Location: Barrington, il

iTrader: (0)

I am doing

-3.6 front
-0.02 toe out each side
-2.4 Rear
Standard toe in. Would go more aggressive but I drive to and from the track

I feel if I was going full slicks I would want -4 camber up front. Id need to slot the strut tower to do that with my current set up. I'd imagine with the SPL arms you would not need to.
Appreciate 2
elim11379.50
nicksm3467.00

      09-02-2020, 01:23 PM   #4
dparm
Stop the hate, get a V8
dparm's Avatar
United_States
2983
Rep
8,054
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Frisco, TX

iTrader: (1)

Are you planning to run scrubs full-time? I would check on what those need versus a Hoosier.
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 1
nicksm3467.00

      09-02-2020, 02:27 PM   #5
Kelse92
Major
United_States
650
Rep
1,009
Posts

Drives: 2013 e92 M3 & e46 330ci
Join Date: Aug 2018
Location: Dallas, TX

iTrader: (0)

Max camber I can get out of the KW Camber plates and strut tower up front is -3.6 rear is -2.4/2.5. 0 toe up front tiny bit of toe-in on the rear. I run 265/645 scrubs mostly, and get pretty even wear out of that setup. But I'm jealous you're running the 305/645's...that's the unobtanium size lol the only 305's I can get local are 660 or 680.
Biggest clearance issue will be up front, but should be able to make do with -3.5 or greater camber if your ride height's not crazy low or something.
__________________

#ladydriven Heavy-spec M3 // KW Clubsports // AA x-pipe // Gintani muffler // Macht-Schnell intake // Gintani tune // OMP Seats // Too Many Apex Wheels // Stoptech ST-60 // Cobalt Friction brake pads
Appreciate 1
nicksm3467.00

      09-02-2020, 09:15 PM   #6
nicksm3
Lieutenant Colonel
nicksm3's Avatar
467
Rep
1,779
Posts

Drives: e92 m3 Competition
Join Date: Jun 2014
Location: Westchester NY

iTrader: (5)

Thanks for the info for those who chimed in.
I normally run 285 square Hoosier R7.
Recently I made the change to 900lb front springs (now shorter 5") from the 6"
And rear 1200lbs.
Full front and rear aero. Last fall I ran 2:04 at the Glen on 275 square and slicks were shot pretty much chorded.
July Ran 2:03 on 285 square but had a blow out front drivers tire. Lots of heat/scrubbing into the boot...luckily it happened into the braking zone going uphill.
So now planning on going back in Oct on fresh 305 Pirelli full slicks, raised spring perch/collar, full SPL Kinematics, more camber ....and hoping Sub 2...I'll be happy with 2:01 but I know i can achieve Sub 2.
Appreciate 0
      09-03-2020, 10:05 PM   #7
P1zzaboy
Private
11
Rep
66
Posts

Drives: E93 M3 '08
Join Date: Dec 2017
Location: Quebec, Canada

iTrader: (0)

I canít understand how you guys can run higher than 2deg camber rear. I run at 1.8 and still eat through inside of the tires Very fast. Approx .10deg toe in each side.
Appreciate 0
      09-03-2020, 11:04 PM   #8
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
Quote:
Originally Posted by P1zzaboy View Post
I canít understand how you guys can run higher than 2deg camber rear. I run at 1.8 and still eat through inside of the tires Very fast. Approx .10deg toe in each side.
You sliding a lot?
__________________
E90M 6MT Slicktop Single Humper in need of a diet
Appreciate 0
      09-03-2020, 11:24 PM   #9
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Quote:
Originally Posted by P1zzaboy View Post
I canít understand how you guys can run higher than 2deg camber rear. I run at 1.8 and still eat through inside of the tires Very fast. Approx .10deg toe in each side.
Because every car, driver and track combination requires a different alignment to optimize tire wear.

If you're consistently wearing inside rears, then go to less camber. You also are running quite aggressive toe which will certainly contribute and accentuate to the inside wear.
Appreciate 0
      09-03-2020, 11:29 PM   #10
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Quote:
Originally Posted by Bartledoo View Post
You sliding a lot?
This too.
Appreciate 0
      09-03-2020, 11:39 PM   #11
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
.2 degrees total toe-in is ~3/32" with 275/35 tires. Not super aggressive.

Reason I asked about sliding - if you're sliding around a lot with the inside tire only partially on the ground (because it is effectively at a massive positive camber in relation to the lateral motion) it will destroy it pretty quickly if you're on an abrasive track. I had to stop having so much powersliding fun when I moved to softer tires. Otherwise, the rears would get destroyed in a tapered fashion within a few sessions at my primary tire eating track. Same thing with wheel spin, particularly inside wheel spin in slower corners.
__________________
E90M 6MT Slicktop Single Humper in need of a diet
Appreciate 0
      09-03-2020, 11:58 PM   #12
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Quote:
Originally Posted by Bartledoo View Post
.2 degrees total toe-in is ~3/32" with 275/35 tires. Not super aggressive.

Reason I asked about sliding - if you're sliding around a lot with the inside tire only partially on the ground (because it is effectively at a massive positive camber in relation to the lateral motion) it will destroy it pretty quickly if you're on an abrasive track. I had to stop having so much powersliding fun when I moved to softer tires. Otherwise, the rears would get destroyed in a tapered fashion within a few sessions at my primary tire eating track. Same thing with wheel spin, particularly inside wheel spin in slower corners.
Hmm, the calculator I used (which likely would be wrong), said it was 1/4in per side (0.1degree per side). I've always worked in inches for toes angles, so the degrees mean absolutely nothing to me.

If that's the case though, then yeah, that's not much.
Appreciate 0
      09-04-2020, 12:28 AM   #13
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
Quote:
Originally Posted by tsk94 View Post
Hmm, the calculator I used (which likely would be wrong), said it was 1/4in per side (0.1degree per side). I've always worked in inches for toes angles, so the degrees mean absolutely nothing to me.

If that's the case though, then yeah, that's not much.
The shops around here are all over the place. Inches, degrees, one even uses mm.
__________________
E90M 6MT Slicktop Single Humper in need of a diet
Appreciate 1
tsk94679.00

      09-04-2020, 12:35 AM   #14
fsmtnbiker
Second Lieutenant
300
Rep
222
Posts

Drives: E92 M3, E36 M3, TM3
Join Date: Jul 2013
Location: Bay Area, CA

iTrader: (0)

I prefer working in degrees but if you donít have an alignment rack itís not very practical.

0.2 degrees of total toe in will measure:
3/32Ē with toe plates (25Ē toe plate span)
1/16Ē on strings (18Ē wheel lip span)
Appreciate 1
tsk94679.00

      09-04-2020, 07:39 AM   #15
P1zzaboy
Private
11
Rep
66
Posts

Drives: E93 M3 '08
Join Date: Dec 2017
Location: Quebec, Canada

iTrader: (0)

Quote:
Originally Posted by Bartledoo View Post
.2 degrees total toe-in is ~3/32" with 275/35 tires. Not super aggressive.

Reason I asked about sliding - if you're sliding around a lot with the inside tire only partially on the ground (because it is effectively at a massive positive camber in relation to the lateral motion) it will destroy it pretty quickly if you're on an abrasive track. I had to stop having so much powersliding fun when I moved to softer tires. Otherwise, the rears would get destroyed in a tapered fashion within a few sessions at my primary tire eating track. Same thing with wheel spin, particularly inside wheel spin in slower corners.
Your explanation makes a lot of sense, thanks! I run small tracks where traction in second gear is hard to get, and may have an heavy foot and tendency to enjoy slides 😅
Appreciate 0
      09-22-2020, 11:38 AM   #16
nicksm3
Lieutenant Colonel
nicksm3's Avatar
467
Rep
1,779
Posts

Drives: e92 m3 Competition
Join Date: Jun 2014
Location: Westchester NY

iTrader: (5)

All SPL parts are installed and alignment thank you to ACM in Fairlawn NJ🙌🏻
Here are the current alignment specs....
Attached Images
 
Appreciate 4
tsk94679.00
Kelse92650.00
rhyary537.50

      10-15-2020, 06:30 PM   #17
LS3Series
Private
LS3Series's Avatar
19
Rep
66
Posts

Drives: BMW 330i
Join Date: Aug 2019
Location: Richmond, VA

iTrader: (0)

Quote:
Originally Posted by nicksm3 View Post
All SPL parts are installed and alignment thank you to ACM in Fairlawn NJ🙌🏻
Here are the current alignment specs....

I think that is a lot of rear toe isn't it? I don't know your exact tire size, but my 275/35/18 are .12 degree per side, .24 Total toe

Everything else looks awesome to me! -4.1 front camber
__________________
LS3/TR6060 E90 Daily Driver Track Build
Appreciate 0
      10-15-2020, 11:14 PM   #18
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
Yea I run .21 deg rear toe total. I ran about 0 for 6 track days and it felt fine but the inner rears got blasted, probably from rear compression causing toe out, especially with the wang.
__________________
E90M 6MT Slicktop Single Humper in need of a diet
Appreciate 0
      10-15-2020, 11:44 PM   #19
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Quote:
Originally Posted by Bartledoo View Post
Yea I run .21 deg rear toe total. I ran about 0 for 6 track days and it felt fine but the inner rears got blasted, probably from rear compression causing toe out, especially with the wang.
Are you running spherical rear arms or still stock?

I believe with stock arms and bushings the rear toes-in quite a bit under compression. This is eliminated, or largely mitigated, with spherical rear arms and bushings.

I have no idea what these degrees translates to in terms of mm or inches of toe-in (as that's what I've always used). But I run ~4mm (just over an 1/8") toe-in per side (going to less next season, but not due to tire wear) and have very uniform tire wear with ~-2.5* of camber.
Appreciate 0
      10-16-2020, 01:05 AM   #20
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
Quote:
Originally Posted by tsk94 View Post
Are you running spherical rear arms or still stock?

I believe with stock arms and bushings the rear toes-in quite a bit under compression. This is eliminated, or largely mitigated, with spherical rear arms and bushings.

I have no idea what these degrees translates to in terms of mm or inches of toe-in (as that's what I've always used). But I run ~4mm (just over an 1/8") toe-in per side (going to less next season, but not due to tire wear) and have very uniform tire wear with ~-2.5* of camber.
I'm running stock. Most of the rear suspension arms are spherically mounted no? Are real trailing arms not? Honestly only looked at the stuff around the spindle.

Also, the toe actually changes in the outward direction under squat. Somebody kept posting the opposite many times in various threads, and Malek finally confirmed that it was not true. His post is below.

"The suspension is designed to reduce toe in during squat and will increase toe in when weight is transferred off the back end.

Meaning if you have 3/32nd inch static toe in, during squat the toe will decrease to lets say arbitrarily 1/32nd-1/16th. It will NOT increase toe while squatting.

Malek"

I've also seen it first hand when I lowered the rear and then got a fresh alignment. The toe was actually out slightly in the rear, after lowering the rear. One one side it was lowered enough to gain -.3 degrees of camber and the toe changed outward over a mm on that side.

As for the conversion, I'm running 2.4-2.5mm total toe-in in the rear currently which is ~.21-.22 degrees with my tire size.
__________________
E90M 6MT Slicktop Single Humper in need of a diet

Last edited by Bartledoo; 10-16-2020 at 01:14 AM..
Appreciate 0
      10-16-2020, 01:10 AM   #21
tsk94
Captain
tsk94's Avatar
Canada
679
Rep
854
Posts

Drives: E92 M3
Join Date: May 2017
Location: Calgary

iTrader: (1)

Quote:
Originally Posted by Bartledoo View Post
I'm running stock. Most of the rear suspension arms are spherically mounted no? Are real trailing arms not? Honestly only looked at the stuff around the spindle.

Also, the toe actually changes in the outward direction under squat. Somebody kept posting the opposite many times in various threads, and Malek finally confirmed that it was not true. His post is below.

"The suspension is designed to reduce toe in during squat and will increase toe in when weight is transferred off the back end.

Meaning if you have 3/32nd inch static toe in, during squat the toe will decrease to lets say arbitrarily 1/32nd-1/16th. It will NOT increase toe while squatting.

Malek"

I've also seen it first hand when I lowered the rear and then got a fresh alignment. The toe was actually out slightly in the rear, after lowering the rear. One one side it was lowered enough to gain -.3 degrees of camber and the toe changed outward over a mm on that side.
Interesting, thanks for clarifying the toe change.

I don't believe any of the rear suspension arms are 'spherically mounted' as the stock rear arms are still a rubberized bushing with a steel insert. I suspect any toe change that happens with the stock arms is eliminated when the rear arms are changed to a true spherical/ball-joint arm. And no the trailing arms are not - it's a rubber bushing (a fairly stiff one) that can be upgraded to solid as well where it mounts to the spindle and where it mounts to the subframe.
Appreciate 0
      10-16-2020, 01:16 AM   #22
Bartledoo
Just Some F****** Guy
Bartledoo's Avatar
United_States
1567
Rep
2,047
Posts

Drives: 2011 E90 M3 6MT
Join Date: Aug 2015
Location: Seattle, WA

iTrader: (0)

Garage List
2011 E90 M3  [0.00]
2021 Tesla Model Y  [0.00]
2003 VW Eurovan  [0.00]
Quote:
Originally Posted by tsk94 View Post
Interesting, thanks for clarifying the toe change.

I don't believe any of the rear suspension arms are 'spherically mounted' as the stock rear arms are still a rubberized bushing with a steel insert. I suspect any toe change that happens with the stock arms is eliminated when the rear arms are changed to a true spherical/ball-joint arm. And no the trailing arms are not - it's a rubber bushing (a fairly stiff one) that can be upgraded to solid as well where it mounts to the spindle and where it mounts to the subframe.
I can definitely confirm several of the rear arms are spherically mounted. Just not sure which aren't as I haven't removed those yet at any point. The rear main control arm is spherically mounted to the wheel carrier. Ask me how I know! Okay I'll tell you. I accidentally rotated it and got it jammed into the control arm and got extremely pissed at the extra trouble I caused haha.
__________________
E90M 6MT Slicktop Single Humper in need of a diet
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 09:43 PM.




m3post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, 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