Is there any reason why we cannot use a fmu like form jackson racing. I rarely hear anyone talk about anything other than the cartech and the sfmu. And what is the difference between the sfmu and their fmu? they are both rising rate aren't they?

As far as I understand the sfmu is a lot more adjustable than an fmu. Although you can use a fmu it will still work just fine, you just cant fine tune it as well as with the sfmu. I have an sfmu and would recomend it for all lower boost applications like under 15psi.
Patrick
96 GS
14.14 @ 96.5 mph on 8psi 8 Nov.02
HRC kit, S20G, FMIC, Howell bottom end 8.6 pistons, S-FMU, Blitz BOV, P&P head, SS valves, lots more little goodies

so an fmu uses discs like the sfmu, what about the fmu from jackson racing and the other companies?

I dont know anything about what jackson racing uses sorry.
Patrick
96 GS
14.14 @ 96.5 mph on 8psi 8 Nov.02
HRC kit, S20G, FMIC, Howell bottom end 8.6 pistons, S-FMU, Blitz BOV, P&P head, SS valves, lots more little goodies