Hi guys, is there any difference between the 2 differentials or they are exactly the same ? The reason i ask is i am building the said 2.5 tdi quattro as a track car so if the b5 rs4 is a stronger/better unit then i would look for one to swap... Any more details from the peoples in the know ?
Rs4 rear diff different than the 2.5 tdi quattro/s4 diff ?
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Hmm looking at the part numbers gives us this:
RS4:
01H500040L rear axle differential 37:9 / DQA
A4:
01H500040G rear axle differential 41:9 / DQA,DRL CKK
01H500040L rear axle differential 37:9 / DQA
So the RS4 diff is available on the A4, but oddly enough, DQA is listed with two different final drive ratios...
Anyone shed any light on that?
RS4:
01H500040L rear axle differential 37:9 / DQA
A4:
01H500040G rear axle differential 41:9 / DQA,DRL CKK
01H500040L rear axle differential 37:9 / DQA
So the RS4 diff is available on the A4, but oddly enough, DQA is listed with two different final drive ratios...
Anyone shed any light on that?
The diff thats on the car now is a DQT, gearbox is DAK... Thats on a '98 b5 2.5 tdi quattro. I believe that being a 6 speed box, the final ratio would be similar to the s4/rs4 wich is also a 6 speed ?!
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Hmm
DQT isnt listed but DAK is...
01H500040K rear axle differential 37:9 / DAK
Seems that DAK is the same ratio as the RS4 diff though at 37:9 (or 4.11:1)
I wouldnt think there is any advantage changing it. If your going to start messing with diffs then install something like a quaife ATB.
DQT isnt listed but DAK is...
01H500040K rear axle differential 37:9 / DAK
Seems that DAK is the same ratio as the RS4 diff though at 37:9 (or 4.11:1)
I wouldnt think there is any advantage changing it. If your going to start messing with diffs then install something like a quaife ATB.
Sorry, meant DAK... DQT is the gearbox code(only fitted on quattros). I was thinking at a Stasis centre diff wich would give a 4 in 1 diff ! I cannot find any details of Quaife rear diffs, how much it will cost to get one and what benefits they will give ? Reason i asked if the rs4 diff is compatible is 'cause i wanna build the v6 tdi as a track car (half way there !), i know they dont have s4 power but if you fit a BMW x5 turbo(Garrett GTV2260), Iveco nozzles and a decent remap/tuning chip, you will easily see 250Bhp with 500+ Nm of torque while still returning 30Mpg average ! Thats enough to embarass many petrol cars and i love the torque ! Trow a Cummins VP44 injector pump(wich can fuel up to 1000Bhp!) and a big front mounted intercooler and you looking into serious power. The bottom end is strong enough to cope with 500Bhp(it does have strong end bearings and a girder) so it does not need strengtening as yet, then throw a sintered/paddle racing clutch from Sachs and an uprated pressure plate and you'll be able to put all that power on the floor... would be a pig to drive in traffic though...been there done that !
Quaife ATB's are around £900. I have one for the 1.8tqs. they are different from teh S4/RS4 ones (reason I got mine is the guy bought the wrong one)
advatages are simple. no pwer loss through either one of the rear wheels..
Off camber corner or bumps where one wheel lifts more and loses a bit of traction ATB will maintain split of power instead of power drain to one with least grip.
advatages are simple. no pwer loss through either one of the rear wheels..
Off camber corner or bumps where one wheel lifts more and loses a bit of traction ATB will maintain split of power instead of power drain to one with least grip.
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^^ To be picky, a Torsen (like an ATB) needs a bit of traction on both wheels to function properly. If you lift a wheel completely, it will act just like a normal open diff.
The EDL should take take of things should that happen anyway though, so its not THAT relevant in this particular case!
The EDL should take take of things should that happen anyway though, so its not THAT relevant in this particular case!
Having had an ATB fitted to my rallycar, an ATB doesnt act like an open diff all a bit or none.
Read here:
http://www.quaife.co.uk/What-is-a-Quaife-ATB-differential
Hope this clears thing oup.......
Read here:
http://www.quaife.co.uk/What-is-a-Quaife-ATB-differential
Hope this clears thing oup.......
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seems to indicate it will lock and maintain power to the gripping wheel.....
"it automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree."
you saying this doesn't work or are you refering to the ""cross axled" effect when you lose grip on two opposite corner on a landrover
"it automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree."
you saying this doesn't work or are you refering to the ""cross axled" effect when you lose grip on two opposite corner on a landrover
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a Torsen (like an ATB) requires SOME traction for the biasing effect to work. A spinning wheel thats on contact with the tarmac will provide this.
a quote from wikipedia:
If you completely lift a wheel (or are stuck in some really slippy mud) the diff will act like an open diff.
Cross-axling on landrover happens becuase even with the centre diff locked the front and rear diffs are open. So if one wheel on each corner loses grip you stop.
Quaife ATB's in Landrovers arent very good, because they dont work when one wheel is off the ground, and you still end up cross axled. A proper locker or plate/clutch LSD doesnt do that. The only exception to this is landrovers that are fitted with traction control. Once the ECU realises the wheel is spinngin and applies the brake, the torsen kicks in properly, just as described above.
Similar thing would happen on a quattro right enough, because it has "electronic diff lock" which is designed to act across each axle to stop one wheel spinning up, and would be much more effective with a ATB than without!
a quote from wikipedia:
If you completely lift a wheel (or are stuck in some really slippy mud) the diff will act like an open diff.
Cross-axling on landrover happens becuase even with the centre diff locked the front and rear diffs are open. So if one wheel on each corner loses grip you stop.
Quaife ATB's in Landrovers arent very good, because they dont work when one wheel is off the ground, and you still end up cross axled. A proper locker or plate/clutch LSD doesnt do that. The only exception to this is landrovers that are fitted with traction control. Once the ECU realises the wheel is spinngin and applies the brake, the torsen kicks in properly, just as described above.
Similar thing would happen on a quattro right enough, because it has "electronic diff lock" which is designed to act across each axle to stop one wheel spinning up, and would be much more effective with a ATB than without!
well I am trying to get a rear subframe so I can fit the poly mounts off the car as it will be a bitch of a job with lots of down time if i pull the frame then have to remove teh old ones (quite like to blast and clean a spare one as well.
diff seals have gone as well so I will just do them all at once.
what is teh centre mod? washers? probably not TBH
kind of got my hands full as it is. one week old baby, in laws in residence, engine build will be finshed in a week or so requiringa swap, got a landscaping job in progress that needs to be finished this week and I am meant to be working as well,,,,,,, do want this turbo in before 2011 though!! been in a box far too long!!
diff seals have gone as well so I will just do them all at once.
what is teh centre mod? washers? probably not TBH
kind of got my hands full as it is. one week old baby, in laws in residence, engine build will be finshed in a week or so requiringa swap, got a landscaping job in progress that needs to be finished this week and I am meant to be working as well,,,,,,, do want this turbo in before 2011 though!! been in a box far too long!!
Yeah I fancy doing the washer mod, just not 100% sure what size of washers I require.
Looked into it a couple of years ago but then forgot about it.
Looked into it a couple of years ago but then forgot about it.
sounds like a bodge and one that is stressing something more than it should be which would worry me.
it shifts a %age rearwards does it?
it shifts a %age rearwards does it?
Yeah perhaps.
It allows an 80:20 split instead of 66.6:33.3 apparently.
A few people have been running it on their cars for over 2 years with no reported issues.
It allows an 80:20 split instead of 66.6:33.3 apparently.
A few people have been running it on their cars for over 2 years with no reported issues.
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rallyman: i know the EDL uses the cars brake, its just a primitive traction control system, however with an ATB it will do a better job.
Soupie: You do realise it wont change the power distribution? It will still be 50-50 front-rear. All the 66/33 split refers to is the maximum amount of torque the diff can shift one way under loss of grip, and i really cant see that tiny change being worth it, unless your running really big power, and having trouble putting it down when launching hard.
Soupie: You do realise it wont change the power distribution? It will still be 50-50 front-rear. All the 66/33 split refers to is the maximum amount of torque the diff can shift one way under loss of grip, and i really cant see that tiny change being worth it, unless your running really big power, and having trouble putting it down when launching hard.
Yeah I understand it would be more beneficial to big power cars I just fancied doing it to see what it was like really.
I am not sure of the power the chaps have that made the change but they found it worthwhile.
I am not sure of the power the chaps have that made the change but they found it worthwhile.
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man, I didn't know that.
been trying to get hold of AdamS4 for his.
how much for the frame? sounds like another road trip!
been trying to get hold of AdamS4 for his.
how much for the frame? sounds like another road trip!
What ratio is the Diff Dave, sonicdeathmonkey want an rs4/s4 diff. Or is it the one from the TQS
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I just checked the speel wheel tag (Cardiff Audi lost my service book, with sticker) and my transmission code is DQA, but someone someone mentioned that there are two final drive ratios specified against DQA?
Or am I just confusing myself? Hope to have a rear diff lined up off RS246.
Or am I just confusing myself? Hope to have a rear diff lined up off RS246.
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A DQA diff for sale? PM me with the details:where is it, how much, how many miles it done etc!
Cheers,
Steve
