Koni Sport shock and bumpstop set (NB chassis)

I recently installed the new Koni sport shocks with FM bump stops, FM sway bars, and FM end links. My 2003 Miata with 30,000 miles did not feel that secure in curves before the change. It still had the original shocks. After the upgrade, my first thought after going through a pretty severe curve was “What curve?”. Even with the low mileage, the original shocks were gone - almost no rebound on the one I tested. I also replaced both shock bushings, both spring seats, and the dust boots with new Mazda parts. Ride height is still settling but is now about 1/4” higher than stock. I did not replace springs because car will be almost all road use and we do have some bumpy roads in my area. I tried the shocks at 1/4 turn off softest setting and it felt great. I then tried 3/4 turns off softest setting and it definitely got a little bouncy. 1/2 turn off softest setting was pretty good but I put it back on 1/4 off softest setting and will keep it there as long as I run the stock springs. An install issue I had was how much to tighten the new Koni 12 mm top nut? I ended up with about 1/4” of thread above the nut which compressed the new top bushing to about 11 mm (tightened while shock out of car). Overall, I am very happy with the new shocks and sway bars as my handling as greatly improved!

I ended up buying the FM springs separately while the Koni's were still shipping to me because I found out that the stock springs are too soft and I would end up on my bump stops too often. This went on my 70,000 mile 2002 NB with 15 inch rims and 205/50 tires on it. The setup is relatively stiff when it comes to cornering and stopping (almost no nose dive or lean), but somehow manages to handle bumps and cracks in the road very softly. It hits the perfect point where I only feel what I want to feel in the road. For context, my friend has a 2002 nb with close to a 160k on his factory bistien suspension setup and I found that his car handles a little flatter, but you will feel everything on the road. It was a bit too rough to daily drive in my opinion (and I'm 19). His suspension is 18 years old so it could have stiffened over the years. Note that this package does not come with upper and lower shock bushings as well as a rubber isolator so those will have to be reused from your current suspension or purchased new. This suspension is amazing so far and the team at FM really knows how to give quality customer service.

I have an NB with 150k miles, original shocks I believe. Well until I put these bad boys in. Install took me about 6 hours. Drilling the washers out was simple enough and I used a jack to slowly lower the stock coils so a spring compressor was unnecessary. Once everything was in and I got an alignment, I cranked them to full stiffness and took them for a spin. On the freeway bumps were more pronounced but nothing I couldn't live with. Then I took it through the canyons. To say my car was transformed is no overstatement. Where I used to have to baby it through the corners to not upset the chassis, I was carrying 10-15 mph more than before. The grip was very confidence inspiring, the front end had more bite than I could explore on a public road and the back was very controllable.

These shocks made more of a difference than I had hoped for. My favorite mod so far and easy to do yourself. Be aware that at least in my case they seemed to raise my ride height just a bit.