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      06-29-2010, 10:19 AM   #5
crfine88
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Drives: E86M
Join Date: Jan 2009
Location: Cave Creek AZ.

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Ground Control Track School Kit

#4

I was ready for a more track oriented suspension set-up, so I began searching for what was available for our cars. As it turned out, there was not much. I read through the development of TCK’s kit on another member’s car. I looked into KW, but found very little technical information. Then, I stumbled across www.ground-control.com .

At the time I was on the fence between KW and GC. GC provided an abundance of technical data, and their customer service was un-matched. GC was willing to develop a kit specifically for my needs. They came through with a complete coil-over kit with dual adj. koni struts, eibach springs, and camber plates for a deal that could not be matched. So, with the promise of 100% satisfaction, I jumped on the GC track school kit.

Installation:
Modifications had to be made. GC took care of all issues through overnight delivery, and their phone support was un-beatable.

First issue: The hardware holes for the front struts. They were too small and had to be drilled out. I was told that this was because of the powder coating; however, when I drilled I hit solid metal.

Second issue: The brake line bracket on the front struts was mounted too high. This was fixed with zip ties. It was painful to install zip ties on the M, but it worked.

Third issue: The rear bushings where the spring and body meet were the wrong size. GC shipped a new set out overnight.

Fourth issue: In the lowest setting, the rear springs raised the car a half inch. GC shipped a different set of springs to me overnight.

Fifth issue: Coil chatter. If you look at my installation photos, you can see that when the rear suspension is stretched out, there is play in-between the spring and body. The result is an annoying noise from the rear when you go over rough road. At the time there was no real fix for this. It had zero affect on performance. It was just very annoying. If I ran the taller rear spring, there was no coil chatter, but it lifted the car. If I ran the shorter spring, there was coil chatter, but I could lower the rear as much as .75 inch.

Performance:
After I installed and uninstalled different variations of the kit several times, the end result was…WOW!

The performance upgrade was remarkable. The turn-in had improved 100%. The coupe sat way flatter in the turns. This was definitely a track worthy kit. The kit completely changed the driving characteristics of the M for me. It was so stable @ high speed in turns, that it really boosted my driving confidence. I was able to brake much later and exit turns much faster. The ride wash much more harsh, but the performance gain was worth it. The only downside for me was the damn coil chatter, which would eventually put me over the edge into a different kit.
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Last edited by crfine88; 06-29-2010 at 02:11 PM..
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