the standard diff on my FC is weak...

[James H]

James H do the solid diff mounts really make a difference? I was running a welder and silly suspensions and dtss eliminators and i just couldn\'t take it anymore! Infact it almost made the car impossible to sell!!

Solid diff mounts & a snubber def made a difference, it just made parking & slow turning alot more pleasent! The back end feels so solid & perdictable

[cr33ch]

Can someone show/tell me what the "DTSS" is from the sounds of it its just bushes? Its nothing like the Nissan\'s hicas system is it (i hope)?

[Prof]

Can someone show/tell me what the "DTSS" is from the sounds of it its just bushes? Its nothing like the Nissan\'s hicas system is it (i hope)?

No - it\'s far simpler - just bushes, with a bevelled edge that are designed to lock up at a certain load.  It effectively gives you a bit of passive toe steer so you can carry a bit more speed into a corner.
 
The Jury seems to be out on whether it\'s good or not - personally - I like it now I\'ve got used to it.

[dthebuk]

I think there ok when in good condition and stiff. But when they\'re kanckered they\'re ridiculous. When you turn in at high speed you find yourself turning in more than you realised and then have to make adjustments. I found mine to be similar to a leaking shock on the front of the car.

[cr33ch]

done a little research and from the sounds of it for drifting id better knock it out. where can i get the replacement bushes?

[dthebuk]

Give mazdarotaryparts.com a call. They\'re a UK dealer for racing beat who make the bushes

[jono395]

i prefered mine with them in, ive took them out now, makes a whole world of difference..

[cr33ch]

id say wanna swap with me but your quite a distance from me

[jono395]

swap what, diffs? ..yeah ill do that ha

[infernal]

Yeah, S4/[N/A] diffs are different than S5.

S4 stock diffs can be open or clutch type. S5 stock diffs can be open or viscous.

S5 diffs have different housings, different half shafts and propeller shafts than S4 models.

An FC can fit both S4 or S5 diffs, provided that you change the rest of the gear that differs.

Also S5 viscous diffs have different half shafts than S5 open diffs.

If you have the S5 open diff, you can swap the FD Torsen right in.

Hope this helps a bit...

Marios

:wave

[NeilSR]

Ok, I know nowt about diffs so take it easy

How can I tell what diff i have, mine a 1990 turbo II with what I assume is a standard diff?

What do you guys mean by it having \'good lock\'?

Im getting mine out on track, but need to make sure its gonna go sideways and Im not wasting my time

[infernal]

Go to a non-slippery parking lot with no cops around. Stand in the  middle, steer all the way to one side, rev up and dump the clutch with  first in gearbox. If the car pivots around one of the front wheels or  near it, then you have a limited slip diff. If you start making circles  and burn the inside wheel, you have an open diff, or a clutch pack diff  with worn disks, or a malfunctioning viscous probably with wrong gear  oil.
Viscous is not quite ideal for donuts though, but still...

[infernal]

Delayed addition:

A "good lock" refers mainly to torsen type diffs and it actually means how  many times the torque of the wheel that tends to spin will be  transferred to the wheel that grips better. How much is defined by the  TBR fraction (Torque Bias Ratio). For instance, a Torsen diff that has a  2.5:1 TBR means that 2.5 times the torque of the spinning wheel is  transferred to the wheel that grips. That\'s why torsen acts as an open  diff should a wheel lift off the ground [as 2.5 times 0 equals 0] lol. The higher the TBR, the "better" the lock.

A clutch pack type diff can be 1way [locks 100% during acceleration],  1.5way [locks 100% during acceleration and 50% during braking] and 2way  [locks 100% during both acceleration and braking]. Clutch type LSDs  basically act as on/off half-shaft couplers.

[dthebuk]

A clutch pack type diff can be 1way [locks 100% during acceleration],  1.5way [locks 100% during acceleration and 50% during braking] and 2way  [locks 100% during both acceleration and braking]. Clutch type LSDs  basically act as on/off half-shaft couplers.

I don\'t believe this is correct


I\'m under the impression that good aftermarket/race/drift diffs (kazz etc) will lock to about 80% (hence limited slip diff). i.e torque is split between the two wheels so the outside wheel has 80% of the torque that the inside wheel receives. A 1.5 way will lock up the full 80% on acceleration but only half of this on deceleration (say 40%) and a 2 way will lock up either way on acceleration or deceleration.

VLSD\'s in nissans lock up around 20-30% i think. the torsens in the fd\'s will lock up a similar amount, maybe a bit more, additionally they wont suffer as badly from heat.

Tbh best way to tell if its open is to drift it. If the car  keeps straightening up but doesn\'t bog down, chances are you have an open diff.

edit: also worth mentioning that LSD\'s are are loaded via the prop shaft and when the shaft produces a significant torque they lock up, you can add pre load so they lock up more easily. This means dropping the clutch will return you\'re diff to an open state. TBH this is what scares me most about using 2way\'s on the road instead of welders. They could lock up mid turn and catch you offguard. Where as a welder is always locked!

[infernal]

Well, they could possibly let the half-shafts slip a little, though especially when new, they should lock up pretty good. Don\'t know if there are versions that let slipping occour on purpose. I\'m not much into clutch type diffs. Sorry about that...

Sure thing is that clutch type LSDs don\'t act via torque multiplications, so lifting a wheel is not a problem. Therefore, the torque applied to one wheel is irrelevant to the others grip.

Torsens don\'t lock up, cause they constantly "check" the torque bias and distribute appropriately...