We currently have application guides for the Mazda Miata (from 1990 to 2016) and Mazda RX-8. For other vehicles, send us an Inquiry and be prepared to pay $75 for consulting on your application. This is our standard fee for bump stop questions and does not include any parts you may need to order from 5Xracing.com. Whether you want better durability and lower cost than factory bump stops or seek a performance upgrade, FCM bump stop kits are a must-have.
Application guide for all supported vehicles
FCM Bump Stop Selection Matrix for 1990-2005 Mazda Miata
FCM Bump Stop Selection Matrix for 2006+ Mazda Miata and 2004+ Mazda RX-8
Types of Fat Cat Motorsports bump stops currently available
FCM 36mm linear - for cars lowered 1/2" or more OR using front springs MORE THAN 250 lb/in. Recommended for low cars with stiff springs. Standard on FCM custom coil-over kits (300f/220r - 600f/375r), usually shortened depending upon spring rate used
FCM 36mm front/46mm rear - Recommended for moderately stiff lowering springs such as Tein S-tech, Eibach, Racing Beat, H&R or Flyin Miata
FCM 46mm linear - for cars at stock ride height/stock springs or slightly lowered. A good choice for street/mild sport applications.
(FCM 54mm) - not recommended, superceded by FCM 46mm or FCM 58mm red bump stops which we've found to be more durable.
FCM 58mm high-performance - available in red, white and blue (soft, medium, and hard) densities. For 1990-2008 Miatas used for aggressive driving (on stock springs) or Stock-class autocross to stiffen effective spring rate when stock springs must be retained. Mix densitities front/rear to achieve desired handling balance (usually one step stiffer rear vs. front when using a large front bar). May also be used on Penske/Koni 28-series shocks to prevent tire/fender contact and supplement primary spring rate ala NASCAR/Indycar
FCM 76mm high-performance - available in red, white and blue (soft, medium, and hard) densities. For 2006+ Miatas, 76 red may be used as a OE replacement bump stops. For custom applications stops may be cut to varying lengths
FCM 12mm bump rubber - very stiff engagement, >600 lb/in, only recommended as a suspension limiter on a trailered autocross car. For track or street use, a 36mm or trimmed 76mm Red/White/Blue are best.