BimmerPost Supporting Vendor
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, AP, Brembo, GIAC, Koni, Ohlins, Performance Friction, Stoptech, Vorshlag
BMW JRZ RS1 Installed
2011 BMW 1M(shares most of the suspension with the E9x M3)
• 22 mm rod strut, 16 mm rod damper
• 24 clicks of rebound
• Adjustable gas pressure, mono tube
• Piston designed for high performance
• Large adjustment range
No other relevant suspension mods.
Installation is straight forward using OE upper mounts front(camber plates are optional) and rear. Spring rates used on the BMW 1M JRZ RS1's are Swift 336 lb/in (6kg) front and 672 lb/in (12kg) rear, more than doubling the front rate and with a 40% increase in rear rate. With some tweaks in rates this same system will work great on the E9x M3 as well. Helpers are used front to prevent the main springs from unloading and in the rear to allow quick change of the rear springs. Swift thrust sheets are also used to prevent spring rate spikes and to dampen any noise with the coilover springs. Harsh rides generally result from dampers that are not properly valved for the spring rates, but that is not the case with the RS1's, they are valved for a wide range of spring rates and are a perfect match for the rates above. The ride is comfortable, even more comfortable than OE. YES, you read it right! Yet, the entire suspension is well controlled and have much better performance than OE.
JRZ RS1 kept things simple for the users with one damper adjustment, offering just one-way, 24 clicks of damping force adjustments. For the spring rates above we settled on 6 clicks on the front and 5 clicks in the rear for street use. Going up to 10+ front and rear Dr. Jekyll instantly turns to Mr. Hyde, with confident inspiring turn-in at high speeds along with stiffer, but not harsh ride.