Project Mazdaspeed3: Building a Stock Class Cone Killer- Introduction and Installing Koni Shocks

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Struts

Another autocross-oriented mod the original owner installed was a set of Koni yellow struts. We found out at our first Solo event that these were actually prototypes! See, Koni’s American office is based in Kentucky, and one of their engineers spotted the 3 dodging cones way back in 2008. Koni wanted to sell MS3 struts and offered a set to the owner for testing. Pretty neat, huh? What is less neat is that at that same autocross, we found that 6 years and 60,000 miles will cause Koni strut body seals to fail and cause the shocks to weep, which explained a lot of the odd handling we experienced the first time we autocrossed the car. Normally on MotoIQ, we would go with coilovers, but to keep the car in Street Class, we have to use the original spring and mount. So, we went with another set of Konis. Koni is one of the few companies that make performance struts that are not coilovers. Koni struts are adjustable in the front for our 3, helping us to dial in handling. Plus, if we ever choose to bump the 3 into Street Touring, we can pick up a set of Ground Control coilover sleeves.  

It should be noted that Koni can rebuild old dampers. However this is a 3-4 week process, and with no OEM struts to slap in, this would take the “driver” part out of our daily driven car. Without the stock dampers to substitute, it was simpler and easier to just buy new Konis. Also, our fronts were so bad that there was a good chance Koni would decline to rebuild them.  

The 3 uses a MacPherson strut front suspension and multi-link rear end. We decided to start with the rears for two reasons. First, they are the easiest to replace. Second, we ordered our dampers from Summit Racing, who had to order them from Koni. Koni sent Summit two left side front dampers instead of a left and right (the rears are symmetrical, so there were no issues there). Summit then told us the right front was backordered, constantly pushing the shipping date back. After the third delay we called Summit, only to find out it was Koni’s error and they needed to confirm with me that I did indeed already have a left front. To say I was upset with Summit for failing to contact me for this information, and Koni for screwing up a simple order, would be putting it mildly. Anyway, between Summit’s and Koni’s screw-ups, we had to spread out the install over a month and a half.

You can see that the piston shaft seal has failed and has caused our dampers to weep. You could really feel them lose their effectiveness as the oil seeped out, and our dampers eventually became useless. The oil also seems to have prematurely damaged our bumpstops as well. In the rear, the 3’s spring is housed in the control arm, separately from the damper. This is quite useful, as it means we don’t need a spring compressor to replace our dampers.