Was wondering, is the center diff in a non-dccd classic v4 sti locked? I.e. perm awd? or is it open? or is it limited slip, just not adjustable like the dccd?

 

It should be a limited slip viscous centre diff I think, not capable of 100% lock and reacts to slip progressively, as you say just not adjustable

 

Ok thanks.

Im sure this next question has been asked before. Is there a difference in the power split between a DCCD and a non-dccd diff? Are they both 40/60% in a v4 sti vs sti type R for example.

 

perm awd drive usually assumes an open diff -- part time 4 wheel drive as used in some SUV's is usually locked -- i.e. should only be used on slippery surfaces not on tarmac etc

 

Anyone got a definitive answer for the STI v4/ v4 sti type R power split front/rear?

 

I've had a look around and found a transmission chart than had some useful stuff in it. According to this:

STI V3 / V4 transmission code "TY752VBCAA" has viscous LSD rated at 4kgf with open front diff
STI V3 / V4 Type R/RA with trans code "TY752VB5CA" has DCCD rated as 35:65 front/rear with open front diff
STI V4 V-Limited Type R/RA trans code "TY752VB6EA" has DCCD rated at 35:65 front / rear with a helical front LSD

I presume from that, where the LSD is rated at 4kgf that is the torque differential between the two sides before the diff starts to do something about it, and the two DCCD diffs on the Type R's listed above are 36:65 on fully open setting then variable through the DCCD to 50:50 locked at a guess. The helical front diff on the V-Limited is interesting tho... not sure what that does / how it works...

Hope that helps a bit

Cheers

Pete

 

Cool.

Was there no mention of the f:r ratio for the TY752VBCAA then?

 

Unfortunately not, tbh I'd like to know myself as thats the one I've got in my car. I'm guessing its because being a viscous LSD it may not have a 'default' setting as such, more like a reaction rate to detected slip. My guess here is that it operates more open than a DCCD unit when driving normally, then gradually tightens up as slip is detected... until you start to smell burning

 

I guess the viscous unit should produce the same torque split pre wheel spin. So there should be a stat of what that split is somewhere. Ive heard previously 50:50, 40:60. But no definte answer.

more googling required lol.

 

if its a viscous I would have though that pre slip it would act in the same way as an open diff --- i.e. a 50/50 split

 

lets forget the Center LSD. And lets rule out any wheel slip. So with full grip. what is the torque split?

 

Dont know if this helps......i know thr helical front diff is standard on the v4/5/6 limited sti type ra...

The SPDA - Transmission Chart