SRP Pedals Installed

The M Coupe, as well as many of its “M” contemporaries, came with a very odd clutch pedal and hydraulic setup.  BMW fitted a Clutch Delay Valve inline with the flexible clutch line.  The CDV acts as a flow control valve, limiting the amount of brake fluid released back to master cylinder when you depress the clutch pedal.  It basically slips the clutch, whether you intend to or not, every time.  Theories abound as to why they would do this; but in essence it does nothing but shorten clutch life and make it difficult to shift properly and quickly.  The “CDV delete” as it has come to be know, is a very common upgrade to these cars.  On the M Coupe it just requires replacing the stock flex line, which I did with a RE stainless steel line.  The path to shifting nirvana doesn’t end there though.  BMW also installed a “spring over center” or “helper spring” to the clutch pedal.  This spring helps reduce the amount of force required to press in the clutch pedal.  After an initial hard push, it becomes noticeably lighter and can be held against the stop without much effort.  Again, BMW only used these on a few cars, the M Coupe being one.  Like the CDV, it’s probably great if you have weak legs or are new to manual transmissions, but I found it rather frustrating.  After driving the M3 and Spyder around, a drive in the Coupe had me stalling out and difficulty finding the engagement point.  Fortunately this can be solved easily by removing the helper spring and installing a simple return spring (PN: 35 21 1 158 489) like found on most clutch pedals.  While doing all these upgrades, it’s also advisable to ditch the ill-fitting pedal bushings for solid Delrin units.  This reduces the side to side play of the pedals, giving them a much more solid feel and straight back and forth travel.  To top it all off, a set of SRP aluminum pedals replaces the spongy rubber covers for better pedal feel.

Stock Pedal Setup with Helper Spring

This is the stock setup. You can see the helper spring in the center.

Stock Pedal Bushings vs Delrin Bushings

The OE plastic bushings are loose fitting, you can see the split in the plastic. The Delrin bushings fit much tighter.

Modified Pedals

Here you can see the new setup with the return spring.

SRP Pedals

SRP Aluminum pedals installed.

More information on this upgrade can be found here: http://www.bimmerfest.com/forums/showthread.php?t=79181

 

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