Mazda Rotary Club

General => General Technical => Topic started by: m1tch on December 24, 2009, 09:03:02 PM

Title: FD vs FC Diffs
Post by: m1tch on December 24, 2009, 09:03:02 PM
Hi all,

After seeing a few FD diffs being sold on here over the last few week - they are torsion rather than the FC\'s Viscous ones, I was just wondering which would be stronger.

I am thinking that the FC one is as the oil cooler, gearbox, propshaft, diff and drive shafts can take up to 500bhp, whereas the FD drive shafts just snap like toothpicks lol (they don\'t make them like they used to!)

Just wondering how much power a stock FD diff can take as they are a direct fit into the casing of the FC :)

Thanks in advance :D
Title: FD vs FC Diffs
Post by: memski on December 24, 2009, 09:31:14 PM
I read somewhere the fc diff is stronger, Better for drag, whereas fd diff better for track.
Title: FD vs FC Diffs
Post by: ad4m1 on December 24, 2009, 10:23:23 PM
Only some fcs have a viscous diff. Most I\'ve seen are open diff so about as much fun as spilling a boiling kettle on your lap.
Title: FD vs FC Diffs
Post by: dthebuk on December 25, 2009, 03:02:39 PM
i think its pretty rare for the FC to have a VLSD, most are open.

when you say how much power it can take, am i right in assuming its being used for proper drag launches? TBH if youre going for a propper drag car id run an uprated one thats made for it.

as for the fc vs fd diff. The fd would probably be better as it wont suffer as much from heat. And if you\'re planning to use one id get an fd one purely as they are no where near as rare. Or you could stop beeing a sissy and just weld the fc one :D
Title: FD vs FC Diffs
Post by: L18M on December 25, 2009, 05:58:00 PM
Quote from: dthebuk;661504Or you could stop beeing a sissy and just weld the fc one :D

not everyone is sleep drift, eat drift, work drift.. driftmas.. :p
Title: FD vs FC Diffs
Post by: dthebuk on December 25, 2009, 06:51:23 PM
pretty certain hayward ran a locked diff in their fb drag car.

so ha!!!

you have a point though
Title: FD vs FC Diffs
Post by: bin liner on December 25, 2009, 11:06:25 PM
FDs have Torsen LSDs and the S5 TIIs have viscous LSDs.  The S4 TIIs have Clutch LSDs. The Clutch LSDs from the S4 are the strongest if you want to drag race and are a direct fit into an fd casing. For road racing, the Torsen diff are better and will improve your cornering ability.  I have one in mine....cheaper than kazz etc
Title: FD vs FC Diffs
Post by: Bucko on December 25, 2009, 11:27:03 PM
on that subject i just had an plated lsd made up from elite engineering !!!!  why ..... i can easily get bits in the uk to rebiuld it unlike some !!
 
http://www.eliteracingtransmissions.com/