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    a site dedicated to
     Scatha, a 2007 BMW Z4 ///M Coupe

Z4 M Coupe, Z4M, Z4MC, Z4MR, BMW MC
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Chassis Mods

     There are several companies that make good suspension components for BMWs. Few of them make products for the Z4, fewer still for the Z4 M. BMS put together a system for my M Coupe that uses the best possible individual components from various manufacturers to create a fully balanced and tunable end product. They include TC Kline, Ground Control, Turner Motorsports, Dinan and BMW.

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Mod # 57, Removed Headlight Washers

     While my M Coupe's front bumper was off the car during the CFR500 installation I removed the headlight washers and related hoses. I have never used them, I don't expect to ever use them, and removing them took 1.5lbs off the nose of the car.
M$RP:
Install Time:
Mass effect:
Vendor: 		$0
0:30
-1.5lbs
Na		 My M Coupe's front bumper, with the headlight washers installed.    A closeup of the washer cover, strapped down after the washer was removed.    My M Coupe's front bumper, with the headlight washers removed.    The washer reservoir bumg, plugged.
     

Mod # 38, Ground Control Sway Bars

     The Z4 M is not only badly under-dampened from BMW, but its factory sway bars are also inadequate for hard track driving. BMS modified and pair of GC E46 sway bars to fit the Z4 M, then developed the production version with Ground Control. They make a huge difference in the responsiveness and handling of the Z4 M, but you must have at least single adjustable (S/A) shocks to compensate for the added sprung tension of the sway bars. Sorry I don't have any good pictures of the sway bars installed. Here are two that show how flat the M Coupe corners now.
M$RP:
Install Time:
Mass effect:
Vendor: 		$1000
1:30
-12lbs
 BMS		 My Z4 M Coupe at California Speedway going through the infield chicane.    My Z4 M Coupe at full load in California Speedway's ROVAL hairpin.
     

Mod # 37, Dinan Supplemental Strut Bars

     I primarily bought these to visually compliment my BMW strut bar, but they also increase from end chassis rigidity. The Dinan supplemental strut bars are a particularly good choice because they are back cut to break in case of a collision - so kinetic energy won't be transferred through the engine bay.
M$RP:
Install Time:
Mass effect:
Vendor: 		$199
0:10
0.84lbs
Dinan		 Front view of my Z4 M Coupe's engine bay, highlighting the BMW strut bar and Dinan supplemental strut bars.    Side view of my Z4 M Coupe's engine bay, highlighting the BMW strut bar and Dinan supplemental strut bars.
     

Mod # 25, BMS Suspension

     What I call "BMS Suspension" is a deliberately selective arrangement of high quality aftermarket components sourced from the best BMW tuning companies. The Koni struts and shocks, and VVT springs, come from TC Kline. So do the camber plates, although they had to be modified with BMW E46 xi bushings to protect the strut tower and their studs had to be lengthened too. The trailing arms came from Ground Control. The rear bushing limiters came from TMS, although BMS now makes their own version that is supposed to be an improvement. The BMW strut bar was chosen by me because it is elegant, light, stiff, and relatively inexpensive.
     All together the BMS suspension is simply outstanding. Every component works great with the others. My minimum speed went up 8mph through Willow Spring's long constant radius Turn 2, and that was before the Ground Control sway bars! My Z4 M Coupe runs easy sub-2 minute laps at California Speedway's ROVAL (and that's with me driving, not a pro), which is comparable to many BMWCCA IP race cars.
M$RP:
Install Time:
Mass effect:
Vendor: 		$0
4:30
-3.7lbs
 BMS		 The TCKline front Koni shocks on my Z4 M Coupe.    The TCKline rear Koni shocks and VVT Springs on my Z4 M Coupe.    The engine bay of my Z4 M Coupe, showing the BMW strut brace and Dinan supplemental strut bars.    My Z4 M Coupe on the computer alignment rack at BMS after suspension installation.    My Z4 M Coupe on BMS's computerized 4-wheel alignment rack, ride height, camber and toe adjustments are finished.My Z4 M Coupe on BMS's computer alignment rack again, note ride height.   
     

Mod # 21, Front Camber Mod

     This is a freebie mod, and a good choice for casual trackers who don't want to invest in camber plates. You just loosen the top strut nuts and remove the BMW pin. This allows an alignment shop to adjust the front camber out to at least -1.5 degrees. I have BMS do all my alignments in-house.
M$RP:
Install Time:
Mass effect:
Vendor: 		$0
1:30
-0.02lbs
 BMS		 My Z4 M Coupe's driver-side strut tower showing that the BMW camber pin has been removed and studs moved inward.    Front view of my Z4 M Coupe, with stock camber.    Front view of my Z4 M Coupe with -1.5 degrees of camber.