|
|
SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS! |
Post Reply |
|
Thread Tools | Search this Thread |
08-21-2019, 09:07 AM | #1 |
Captain
939
Rep 709
Posts
Drives: 06 Black Sapphire Z4MR
Join Date: Jul 2018
Location: Ontario
|
Fitment nightmare
I don't think I have ever had as much issues fitting a set of wheels on any car than the Z4M
Wheels in question: 18x9.5F, +28, 245/40-18 RS4, I needed a +3 spacer to clear the strut, -2.8 front camber, 0 toe 18x10.5R, +30, 275/35-18 RS4, needed +12 spacer to the back, -2.4 camber I will not change the wheels, its the numero uno wheel for me for about 15 years, so don't suggest me change better fitting wheels I have no issues in the rear, its the front On the track I rub on the bumper, to the point of popping off the sides of the bumper. There is also clear rub marks on the fender liner in the middle both in the front and the back of the fender liner. I'd like to see if i could eliminate the spacer so it fits slightly further inwards but I had issues with the tires rubbing against the strut, and was told the camber plates on the KW don't shift position of the coilovers i am SOL If anyone has insights on better fitment, especially for track use i'd like to hear it. To me ideally removing the front spacer Is the only viable solution go narrower tires?
__________________
Revolution of our Times
I will return to the track, one day. |
08-21-2019, 12:46 PM | #2 |
Get off my lawn
965
Rep 1,186
Posts
Drives: 6MT
Join Date: Sep 2015
Location: USA
|
Running 18x9.5 up front isn't unheard of, however it pushes the limits of the stock geometry and certainly requires alteration for a full-functional track setup. I rub slightly with a 18x9 245/35/18 front setup with a 10mm spacer and KW CS coilovers set up for it.
Folks running 9.5+ on the front usually roll the fender and a 245/35/18 tire. Even more serious track junkies seek out a roll-center correcting aftermarket control arm to allow better track adjustment. Last edited by 86Zed; 08-21-2019 at 12:52 PM.. |
Appreciate
0
|
08-21-2019, 01:07 PM | #3 |
Lieutenant General
2387
Rep 12,635
Posts
Drives: Z4 M, X5, GX460
Join Date: Apr 2008
Location: CT
iTrader: (100)
Garage List E86 Z4 M [10.00]
F15 X5 xDrive35i [9.17] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.53] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [8.93] |
What struts are you running?
Try dialing the caster back and adding a tad bit more camber. Post pics if u can, I get the issue but pics always help... |
Appreciate
0
|
08-23-2019, 07:15 AM | #4 |
Captain
939
Rep 709
Posts
Drives: 06 Black Sapphire Z4MR
Join Date: Jul 2018
Location: Ontario
|
I'll take a pic when I get a chance
It's likely the tire size is to blame, was hoping to keep the stock rolling diameter I have since raised the car a little and it seems to help, the more important thing for me is trying to eliminate the spacer
__________________
Revolution of our Times
I will return to the track, one day. |
Appreciate
0
|
08-23-2019, 10:55 AM | #5 |
Banned
0
Rep 10
Posts |
|
Appreciate
0
|
08-23-2019, 01:59 PM | #6 |
Second Lieutenant
75
Rep 264
Posts |
I had a rub issue as well in the front, towards the front bumper above the air duct (275/35/18 on a 18x9.5 et35 on -2.8* front camber). For me the solution was I needed to raise the ride height to prevent rub. Keep bumping it up and adjust the rear accordingly if/when you stop rubbing up there!
__________________
2017 M2 - Camber Hubs, MPE, and some other goodies 2006 Z4M - Epic Tune / Eventuri CAI / Euro Headers / Stromung / FA 500 / AS SSK / Arc 8s 2004 Z4 3.0i - Gone, but not forgotten! |
Appreciate
0
|
08-23-2019, 06:31 PM | #7 |
Lieutenant
287
Rep 431
Posts |
Like others have noted, 9.5" wide wheel should fit up front, especially with a 245 tire, but your offset seems just a tad low.
For reference, I'm running three setups with rolled fenders, -3.4* camber, linear spring (JRZ), 3mm spacer and 275/35/18 Hoosiers: 18X9.5 et35; 18X9 et40; 18x9 et42 Considering with the 3mm spacer I am effectively at a 32 offset, you're only poking out 4mm more. Perhaps roll your fenders and worst case add a little more camber. Not the best picture but hopefully gives you an idea of how much room there is with fenders rolled and this setup.
__________________
1995 E36 M3 | BMW CCA Club Racer - IP #34 | Gray / Blue / Orange | 261WHP | 2,700lbs
2013 E92 M3 Competition 6MT Slick Top | AW / Fox Red | 2006 E86 M Coupe | Silver Gray / Imola | JRZ RSTWO | APR Aero | Sparco Seats/Belts | Weichers Cage Gone: 2017 Audi Q7 | 2011 E93 328i 6MT | 2014 Audi A6 | 2010 VW CC 2.0T | 2011 G37 S Coupe 6MT | 2004 G35 Coupe | SW20 MR2 Widebody Turbo |
Appreciate
0
|
08-28-2019, 03:02 AM | #8 |
Dog Listener
711
Rep 7,850
Posts |
Which KWs are you running?
This is a bit perplexing to me as I've run 265/35 RS4s on 9.5 ET 35 wheels with 5mm spacers, Turner E36 camber washers, -2.7 neg camber, zero toe. I honestly don't recall if the camber washers increase or decrease the space between wheel and tire (I'll try to find that) but it think it helps. Granted, my setup was with stock suspension, possibly shorter non-linear springs, but 265s are way wider tires. I'm not the fastest person in the world on track but I'm not slow, running in the advanced group. Zero rubbing. Hmm... I think it buys space, as I couldn't run the same setup on the wife's Z4M with linear springs and no camber washers. Needed a 12mm spacer to clear the spring collar, effectively an being a 9.5 ET 23 with a 265 tire, and that pushed the tire well past the fender. Even a 245/40 on a 9" ET 30 rubbed the fender liner on her set-up on compression, even though it didn't hit the strut. If washers increase the space, and my data looks like they do, you could run less camber via plates and end up at the same alignment settings with better geometry and more space. For 15 bucks and and hour or two of time (if you diy) it might be worth a try. |
Appreciate
1
filtercoffee110.00 |
08-28-2019, 07:04 AM | #9 | |
Captain
939
Rep 709
Posts
Drives: 06 Black Sapphire Z4MR
Join Date: Jul 2018
Location: Ontario
|
Quote:
I have been looking at those camber washers as well. Note, the new alignment and raising the car 3 full turns seems to defenitely have helped but I really won't know until I hit the track again new setting: -2.8. Most likely I am just running too low, but the thing I want most to eliminate is defenitely the spacer
__________________
Revolution of our Times
I will return to the track, one day. |
|
Appreciate
0
|
08-28-2019, 08:39 AM | #10 |
Second Lieutenant
75
Rep 264
Posts |
Keep in mind camber washers pivot the wheel at their mounting point, pushing the wheel and tire closer to the suspension. I had to remove mine when going to 275s for this reason and lost about 20% of the camber I previously had (-3.3* to -2.8*)
__________________
2017 M2 - Camber Hubs, MPE, and some other goodies 2006 Z4M - Epic Tune / Eventuri CAI / Euro Headers / Stromung / FA 500 / AS SSK / Arc 8s 2004 Z4 3.0i - Gone, but not forgotten! |
Appreciate
0
|
08-28-2019, 04:30 PM | #11 |
Midlife Crises Racing Silent but Deadly Class
1827
Rep 5,337
Posts
Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day
|
Remove the helper springs.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
|
Appreciate
1
Finnegan711.00 |
08-29-2019, 01:10 AM | #12 |
Dog Listener
711
Rep 7,850
Posts |
That's what I thought happened with them. Thx.
|
Appreciate
0
|
08-29-2019, 11:06 AM | #13 |
Midlife Crises Racing Silent but Deadly Class
1827
Rep 5,337
Posts
Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day
|
I run the rear wheels up front with moderate negative camber on 245/40/18s, no spacers. Maybe the fender and the fasteners have already been worn away by the 275/35/18 on 9.5" wheels (the front offset of 43-18mm=25mm).
Here's what I see as the problem. At 30mm offset it's just in far enough not to rub the fenders. At 28-3 (effectively 25mm) and at 9.5" vs the 9" on my setup, you're effectively pushing the wheel 11mm closer towards the fender. With the amount of additional caster on the Z4 M front suspension due to the offset FCAB, when you turn the wheel full lock the outer radius increases and the tire comes in contact with the edge of the bumper and fender liner. You have 2 options. Ditch the spacer. If you need 3mm to clear the spring perch, remove the helper springs. That pushes the KW club sport base perch up by about 1-1.5", which should alleviate the need to use a spacer to clear (ask me how I know). Then run centered FCAB to decrease the caster angle so as the kingpin swings from one extreme to another, the edge of the wheel won't swing out and rub and damage the wheel well and bumper. You lose a little bit of the sharp steering that's inherent on this chassis, but you gain more clearance. Or run a shorter front tire. 265/35/18 is about 0.4" shorter than 245/40/18. The front end is spacious enough to accommodate up to 285 wide tires with minimum rubbing (again, ask me how I know). A 265 width tire is narrow enough to still be a good fit on 9.5" wide wheels, and being .4" shorter would alleviate that 11mm closer to the fender you're dealing with with this particular wheel/tire combination even though it's WIDER. Of course, neither combination is guaranteed to fully alleviate unless you try it. I just know that some here have had good experience (myself included) regarding front rub with either. I am 99.95% certain the combination of ditching the 3mm spacer (and removing the helper springs to clear wheels/tires inside) and going to a non-eccentric bushing will solve it (heck there's a pretty good chance just removing the spacer AND helper springs will 'help'). I'm 85% sure going to 265/35/18 will solve it despite the math about the tires being wider but shorter. You won't know until you try though. But MOST here are correct, your front offset for the size of wheel and tire is way WAY too low. You need about et 38 for that combination to work flawlessly inside the front wheel enclosure...But if you can't and won't change the wheels, those two options I outlined above is what you should try.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
|
Appreciate
0
|
08-30-2019, 07:00 AM | #14 | |
Captain
939
Rep 709
Posts
Drives: 06 Black Sapphire Z4MR
Join Date: Jul 2018
Location: Ontario
|
Quote:
I'll have to take the front end apart anyways as winter is approaching here, the hope is to do some bushings this winter, ill remove the helper then.
__________________
Revolution of our Times
I will return to the track, one day. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|