This info is going to be relevant for anyone wanting to race SCCA Street class autocross. Otherwise there are probably better solutions out there for you.
For those who don't know, SCCA street class allows you to change the suspension damper, but springs must still be the OE spring. There are a few other requirements, like the overall length can't vary by more than 1" in either direction, and the spring perch must be in the same location relative to the lower mounting point.
Normally the standard for this would be a Koni sport shocks (Koni yellow). These however are discontinued, and while there still seem to be some inventory for the rear's, the fronts are all gone new, and very hard to find used.
The next option would often be a custom shock from the likes of Penske, but now you're talking thousands of dollars for a set of shocks. Out of the budget for me, and would cost more than half of what I paid for the car itself!
After talking to some other racer's about the dilemma, I was pointed to Chris at Redshift Motorsports, who has made a name for himself in the community custom valving BC BR coilovers. After discussing my needs with him, he agreed to put together a kit which would be valved to match the OE spring rates, and meet the other requirements.
I finally received the parts this last Friday, installed over the weekend, and raced on Sunday.
There were a couple caveats to fitting the parts. The first (and I think this applied to Koni's also) is the OE top spring perches and washers needed to have the mounting hole enlarged. The OE damper rod is 10mm, and the BC BR is 12.5mm. After seeing if a black oxide bit I had on hand would work (it did not) I used a 1/2" cobalt drill bit, my drill press, and lots of cutting oil to get through the metal. I would not try to do this with a hand drill, as you need to go through a couple inches of hard steel, and especially near the end of the cut it was very easy to get the drill bit caught.
The second caveat was something we overlooked when considering dimensions, but happily worked out, if barely. On the rear shocks, I originally was not able to adjust the spring perch low enough - with the lower locking ring, the perch locking ring, and the perch in place - due to how tall the lower mount hardware which the shock body threads into is. Fortunately by removing the perch locking ring, and tightening the perch all the way down against the lower locking ring, the spring perch ended up almost exactly where it needed to be (about 1/16" high when using the plastic spring isolator, about perfect without it. I opted to keep the isolator on for now). (see picture)
The third was really minor but when setting the overall length, the damper rod on the BC's is shorter than the OE Bilstein. You need to measure to the shoulder where the upper perch will rest. I overlooked this the first time I put one together, and had to go back and redo it.
Race day came, and after my first run all I could say was, "holy ****! Car felt amazing!". Night and day difference vs the 15 year old FE3 Bilstein's. The car felt so much more put together and responsive for both turning and braking. This was 100% worth the cost and headache (and dehydration in this KY heat/humidity) to install. I haven't fiddled with any damping adjustments yet, and just ran with where Redshift shipped them (23 clicks from full soft). Comparing my times vs other driver's I consider to be consistent for past events vs this last event I'd estimate I picked up a second to a second and a half in my times. Hopefully that trend continues.
For those who don't know, SCCA street class allows you to change the suspension damper, but springs must still be the OE spring. There are a few other requirements, like the overall length can't vary by more than 1" in either direction, and the spring perch must be in the same location relative to the lower mounting point.
Normally the standard for this would be a Koni sport shocks (Koni yellow). These however are discontinued, and while there still seem to be some inventory for the rear's, the fronts are all gone new, and very hard to find used.
The next option would often be a custom shock from the likes of Penske, but now you're talking thousands of dollars for a set of shocks. Out of the budget for me, and would cost more than half of what I paid for the car itself!
After talking to some other racer's about the dilemma, I was pointed to Chris at Redshift Motorsports, who has made a name for himself in the community custom valving BC BR coilovers. After discussing my needs with him, he agreed to put together a kit which would be valved to match the OE spring rates, and meet the other requirements.
I finally received the parts this last Friday, installed over the weekend, and raced on Sunday.
There were a couple caveats to fitting the parts. The first (and I think this applied to Koni's also) is the OE top spring perches and washers needed to have the mounting hole enlarged. The OE damper rod is 10mm, and the BC BR is 12.5mm. After seeing if a black oxide bit I had on hand would work (it did not) I used a 1/2" cobalt drill bit, my drill press, and lots of cutting oil to get through the metal. I would not try to do this with a hand drill, as you need to go through a couple inches of hard steel, and especially near the end of the cut it was very easy to get the drill bit caught.
The second caveat was something we overlooked when considering dimensions, but happily worked out, if barely. On the rear shocks, I originally was not able to adjust the spring perch low enough - with the lower locking ring, the perch locking ring, and the perch in place - due to how tall the lower mount hardware which the shock body threads into is. Fortunately by removing the perch locking ring, and tightening the perch all the way down against the lower locking ring, the spring perch ended up almost exactly where it needed to be (about 1/16" high when using the plastic spring isolator, about perfect without it. I opted to keep the isolator on for now). (see picture)
The third was really minor but when setting the overall length, the damper rod on the BC's is shorter than the OE Bilstein. You need to measure to the shoulder where the upper perch will rest. I overlooked this the first time I put one together, and had to go back and redo it.
Race day came, and after my first run all I could say was, "holy ****! Car felt amazing!". Night and day difference vs the 15 year old FE3 Bilstein's. The car felt so much more put together and responsive for both turning and braking. This was 100% worth the cost and headache (and dehydration in this KY heat/humidity) to install. I haven't fiddled with any damping adjustments yet, and just ran with where Redshift shipped them (23 clicks from full soft). Comparing my times vs other driver's I consider to be consistent for past events vs this last event I'd estimate I picked up a second to a second and a half in my times. Hopefully that trend continues.
