strange thing with torsen

[maRS2]

when i wot the car about 5 second after i get a big kick from the back with a clonck noise or two like if the if the center dif or rear torsen was locking and giving all the power to the back.
If I accelerate to 3/4 nothing hapened.

what could it be?

[Ski]

rear diff mount(s).

HTH

[maRS2]

they are brand new

[Ski]

sorry didnt read properly. Did you say all the power slips to the rear wheels only after 5 seconds of WOT?

No ideas

[maRS2]

after 5 second I get one or two good kick in the *** with clonk noise and it seams like if the back torsen is locking
maybe it's locking because to much torque?

[~Delta]

Torsen diff engages with an audible noise / feel, akin to a shunt under hard accelleration, perfectly normal.

[maRS2]

Delta thank you it's exactly what you describe that I get.

but why does ir engage when i'm going WOT to pass car on straight line doing already 60 mph?
Do you think that one wheel start to sleep with the torque ( huge torque with RS2 at 30 PSI) in the straight line at this speed on cold day -3°

[S2central.net]

Torsen diff engages with an audible noise / feel, akin to a shunt under hard accelleration, perfectly normal.

Torsen is ALWAYS engaged - you cannot disengage it... In my view any severe shunting must be down to worn gearbox or differential mounts... COuld also be knackered propshaft joint - or heavily worn differential internals.

Paul

[maRS2]

I think what delta want to say with engage is start to lock automaticaly to avoid one wheel to spin

[S2central.net]

Torsen doesn't lock either... It is a limited slip device... Max torque split is approx 70/30 or 30/70 by nature of its internal gearing. Nominally it runs about 50/50 of course.

Paul

[maRS2]

I can tell you it lock as for the MOT brake test here in france they put first the front wheel on some kind of roller to test braking power and then the back.

the guy could spin the front wheel untill a certain speed above what the center torsen lock and made the back wheel sitting on the floor turn and the car jump out of the roller.

so it seems to me that under a certain speed difference in between both side it work like an open diff and then above it's lock and can split up to 30/70 or 70/30.

[maRS2]

Your right may be I shcould check my tranny mount as my diff mount are brand new.

but noise come from the back

[S2central.net]

I can tell you it lock as for the MOT brake test here in france they put first the front wheel on some kind of roller to test braking power and then the back.

the guy could spin the front wheel untill a certain speed above what the center torsen lock and made the back wheel sitting on the floor turn and the car jump out of the roller.

so it seems to me that under a certain speed difference in between both side it work like an open diff and then above it's lock and can split up to 30/70 or 70/30.

Maybe he feckin BROKE your Torsen (or rear) diff during this test!!!!!!!!

The workshop manual states that such 2-wheel brake tests should be done at no more than the equivalent of 15 km/h. The Torsen's ability to facilitate limited slip are not infinite - if you physically lock one axle (like on that test) you are asking for trouble ... something has to give.

For MOT tests in the UK, garages without 4-wheel brake test rollers actually take the car for a test drive in the car park using a brake force g-meter to test brakes are ok.

Brake tests in NI all use a proper 4-wheel tester in government run test centres.

Paul

[Ski]

Maybe he feckin BROKE your Torsen (or rear) diff during this test!!!!!!!!

Paul

My thoughts exactly

[maRS2]

thank's Paul that make me worry!!!

in France they mostly test braking power differences between right and left.

If you car have no brake but right and left same power you will get your MOT
Crazy!!!!!

PS I have TT (twin torsen, center and back)