Retrofitting a Q2 to an existing Alfa

Originally Posted by sandys

Sounds a lot more positive that my experience so far, still get a fair bit of wheelspin and VDC action, to be fair theres bugger all traction to be had on the roads around my way, salt, mud, water < 3 degrees so I am holding off proper judgement until my trackday end of the month, think I need 4wd

Well, this guy has a stock 2.5 V6 with considerably less torque than a modified JTD like yours, and certainly more "linear" power output as a N/A engine. The roads where he tested the diff are very slippery, i can assure you of that, but there wasn't any ice because the outside temp is still well above 5 degrees in Athens. IMO nothing can save you from an ice patch if BOTH tractive wheels hit it, apart from tires with spikes of course.

Deleted

Interesting I could see that there was a post by alfasud.ti but couldn't read it for at least 30mins, the forum just would show the page, hence my dodgy reply above.

Originally Posted by alfasud.ti

Well, this guy has a stock 2.5 V6 with considerably less torque than a modified JTD like yours, and certainly more "linear" power output as a N/A engine. The roads where he tested the diff are very slippery, i can assure you of that, but there wasn't any ice because the outside temp is still well above 5 degrees in Athens. IMO nothing can save you from an ice patch if BOTH tractive wheels hit it, apart from tires with spikes of course.

Yes, Fear the all powerful JTD

Its not particularly ice its the type of roads they are thats the issue, guaranteed at least once every few months even more around this time of year I will see a car on its roof, in a field etc. nearly always a hot hatch though end of last year an STi was off so 4wd is not infallable, Thursday on a less difficult section of a pretty slow A road just out of the exit of a roundabout a 993 was at the otherside of the road on its roof, very mangled so when I say conditions are sketchy its not just hard for the FWD Alfa diff or no diff.

The method of road construction used in Greece makes them fine in the dry but UNBELIEVABLY slippery in the wet. If the diff is still holding and giving traction in those conditions it is doing well.

Originally Posted by David C

fine in the dry

Sorry, couldn't help it.

Let me explain my last post a little, wouldn't want David to get offended.

With the occasion of the 2004 olympic games many main roads in and around Athens were completely rebuilt with decent rainwater drainage. However most secondary roads/avenues that would not carry any "olympic" traffic were not touched, therefore they are still slippery as hell to this day.

About road construction, unfortunately during the past decades they used cheap asbestolithic tarmac instead of the most expensive but by far better vulcanic one. As a result newly paved roads are OK for a year or two but become very slippery with time because asbestolithic tarmac loses its grained surface because of wear and becomes smooth and slippery.

Does anyone know what the warranty on the T2 diff is which is used (for the Q2 system) ?
This as Quaife has lite time warranty...

The Q2 is a torsen differential so it has 2 clutches inside and its oil has to be changed periodically, so I wouldn't expect nothing like a lifetime warranty.

a Torsen diff has no clutches, read the first post and look at the links, its lifespan should be no different to a Quaife.

Quaife diffs are a torsen style diff as are the Q2 diffs, not a clutch type.

Mmmmmm....sounds to me as though sandys you might not have the LSD working as well as you could as you sound a little doubtful as to its operation. When the moto journo's drove the factory Q2's they banged on at how immediate the difference was. Now if they think its good it really must be good so I am a little sceptical as to whther its working quite right??

Its working, its just the expectations of what it can do need to be adjusted in my case, if theres no grip to be had on the road then the diff is not going to chnage that, you'll just get two wheels slipping instead of one. The roads are perilous around my way, its not city driving, its a mixture of A nd B roads out in the country side that are in wide open space and so prone to frosting/icing as well as being covered by mud etc. from tractors.

Another 2 cars fell victim on my journey this morning, again on the slower roads, head on after a tight bend, my guess the ZX took it at 30/40mph which is reasoneable to do so (70+ in my case normally ) but had to deal with frost/ice understeered onto the other side of the road taking out a Clio, nice. What annoys me is that this will add to the statistics for speed cameras but nothing will be done to teach drivers how to deal with and assess road conditions

Long and the short of it, the diff does its job, with the ASR off on cold damp roads I can floor it and have grip to move (providing traction is there to be had) , very minor wheelspin, I can be fairly aggresive in a corner with the throttle and I don't get wild understeer, the odd side to side shake at the front where the car is going from grip to no grip with wheels trying to catch and teh car cuts in.

I think a few people will like myself expect this thing to suddenly make it so your front wheels will never slip again, thats not the case you have to drive to the point of slip and thats when the diff starts doing its work when theres a differential between the power transmitted to each side. I also thought it would work with ASR on and to a point it does but the action is much more pronounced with it off which when you think about what it needs to work,which is wheelspin it starts to make sense. Most of my issues have come from expectation and not knowing what to expect, the car is different now an I need to learn how to drive it.

My only other experience of diffs where on an Evo where the action is a lot more aggressive and you can really feel the torque shift, the Q2 is very refined.

Originally Posted by sandys

a Torsen diff has no clutches, read the first post and look at the links, its lifespan should be no different to a Quaife.

You're right, sorry for my mistake.

I couple of friends of mine fitted the Q2 diff. One on a 1.9 JTD GT, and on a 1.9 JTD 8V 156TI. It's getting fitted into a GT 3.2 V6 soon.

with the amount of people retro fitting Alfa won't be able to sell actual customers a Q2 car

Seems quite handy in the snow, quite decent acceleration shame about the stopping part with the over eager ABS.

Do you think on the Q2 cars that maybe the ABS ecu can be slightly reprogrammed to handle the diff, maybe an Alfa dealer maybe able to do this? In th write-ups they mention a load of additonal tweaks are made to the Q2 from the standard GT, suspension etc. maybe the ABS ecu is one of them

Great, do report back on how the V6 chap gets on

Originally Posted by charlee

I couple of friends of mine fitted the Q2 diff. One on a 1.9 JTD GT, and on a 1.9 JTD 8V 156TI. It's getting fitted into a GT 3.2 V6 soon.

The parts are quite cheap (420 euro's all together in the Netherlands), but not orderable at the moment over here

Originally Posted by AB156V6

The parts are quite cheap (420 euro's all together in the Netherlands), but not orderable at the moment over here

Same thing over here...

Here are some pics of the Q2 and the stock free diff side by side on a bench:

http://img100.imageshack.us/img100/1140/torsen2if1.jpg
http://img100.imageshack.us/img100/130/torsen1xy3.jpg

Indeed nearly the same as a Quaife diff.

Can you still buy these parts in the UK or in Greece? If so I'd like to know, as in the Netherlands they are no-go for the moment ! (will have some higher shipping costs, but better then nothing )

I'll find out on the weekend I am off to the dealer to get arse raped for an oil change, how lazy am I

Thanks Sandys !