Good question, I would like to know this too (just for peace of mind more than anything else!)

 

Hi

Just had a Q2 diff put in my 147 JTDm last week. To answer your questions, it is much better on the sharp bends and roundabouts - had one wheel slip once, but the difference is the traction control light doesn't come on as the power is trnasferred to the other wheel and you keep going where you point the car! before the diff was fitted it would 'skip' and break traction quicker - I notice the difference, but then I drove it before it was fitted.

And to the best of my knowledge, there is no way of telling from the outside or from the engine bay what diff is fitted - it's housed in the normal gearbox/diff casing.

hope this helps

J.

 

I don't think the Blackline came with the Q2 - it was a trim change only, built specifically for ARUK.

 

You can spec the Blackline with a Q2 as an option.

 

About £400 I think.........

 

I'm assuming the trick of trying to turn one jacked up wheel doesn't work with a torque biasing diff then, only with a plate type?

David C, Trailbraker and a few others will know for sure.

 

You are right this wont work, since the torsen diffs stop working when one wheel is unloaded.

The simplest way to tell is that
a) The ASR should be a LOT harder to provoke with a Q2 diffed car.
Even from take off, and way way way harder once you are moving.

b) When cornering with some cornering load under throttle, you can feel the torque split trying to help you into the corner, in a non-Q2 diffed car extra power always results in extra push understeer.

 

Hi Mo

Firstly....good choice mate.:thumbs:

I suppose the intriguing thing about the Q2 limited slip differential is that in some ways you kinda hope you never have to rely upon it bearing in mind it's a safety measure after all.

When I tried the 147 fitted with Q2 on the handling course at last year's Cloverleaf Club track day at Knockhill the instructor had me do the course with ASR on and then with ASR off.....and I have to say with it of you really do notice the difference - my kidneys were more likely to exit my body than the back end of that car stepping out. So go find an empty carpark, switch off the ASR and chuck it about a bit......but be safe mind.

Can I ask......does your Blackline have a Q2 badge on the rear? And does your V5 state clearly 'Q2'? Just another couple of obvious clues I think.

Enjoy it!:thumbs:

 

The Q2 mechanical diff isn't primarily a safety aid per-se, its designed to allow you get *more* speed out of the car by optimizing the total available traction.
It doesn't increase grip in any way, just mechanical traction (power transmitted to the road).

You could argue that it gives you more control over traction so helps safety a little in that sense, but more traction equals more speed.
Of course reducing understeer under heavy throttle could of course be construed as helping safety in a few situations, but this is probably not applicable to most accident avoidance scenarios.


Something like ESP is a safety aid since it can detect when things go haywire especially on the road and then intervenes

But the mechanical Q2 works ALL the time, continously transferring torque in a close to optimal fashion so you power gets to the most useful wheel to go fast or simply avoid wheel slip in wet conditions.

This is useful whether pulling off smoothly at the lights on a wet day, or haring around a track.

On a windy road you can feel the benefits without being a complete hooligan, you can just smoothly apply the power earlier out of corners than without a Q2 diff.

Cheers,
TB

I suppose the intriguing thing about the Q2 limited slip differential is that in some ways you kinda hope you never have to rely upon it bearing in mind it's a safety measure after all.
Enjoy it!:thumbs:

 

Find a quiet road with a grass verge & good surface. Position your car with one wheel on the grass verge, one on the tarmac... then floor it. Non-Q2 cars will struggle to transfer grip to the tarmac-planted wheel, the Q2 will be noticeably grippier.

Worth a try.

 

Oh and one other thing to check.

There should be a 'sticker' on the body which can be seen when you open the driver's side door stating 'JTDm 16v Q2'.......and maybe Q2 logo'd scuff plates too?

 

Thanks for all your comments. I see the some different ones on how to test it. As I've only ever driven a Q2 fitted car it's hard to make a comparison. I did make the wheels spin when accelerating from standstill (when I put the car into 2nd). I've not really played around with the ASR yet (6 days into owning the car).



I just checked it (quick dash to the carpark and back!) - it says "Alfa GT 1.9 JTDm 16v Blackline" - none of the trim indicates what type of GT it is (eg petrol, diesel etc) -it only has the word "Blackline" all around it.

About £400 I think.........

It's £480 (and can be retro-fitted) - it is only available on the diesel (as someone stated).

Surely the simplist way is to call alfa with your chassis number and get a price for a new diff, the system will know which one you have fitted to your car.

Easy.

I may well do that... seems to be the easiest option.

Blackline has a 'Blackline' badge where the Q2 badge normally is - was going to have the Q2 badge put on mine, but not sure where to put it now! Dunno about the V5, but online insurance quote systems don't list a Blackline Q2 as a separate model.

As above wrt no Q2 badge anywhere on it - not got my V5 yet as I've only just bought it. For insurance I went for Blackline instead of Q2...

 

Surely the simplist way is to call alfa with your chassis number and get a price for a new diff, the system will know which one you have fitted to your car.

Easy.

 

Can I ask......does your Blackline have a Q2 badge on the rear? And does your V5 state clearly 'Q2'? Just another couple of obvious clues I think.

Blackline has a 'Blackline' badge where the Q2 badge normally is - was going to have the Q2 badge put on mine, but not sure where to put it now! Dunno about the V5, but online insurance quote systems don't list a Blackline Q2 as a separate model.

 

If you are going anywhere near us, up the M1 from London or whatever you could call in and I can tell you if it has a Q2 fitted

Ned

 

I will do if I'm going back up north to visit home, thanks I also see you've got that saturday morning health-check - it might be a little premature as the car's all new...

I went through all the paperwork last night and noticed I have a digital print-out that has the Q2 option written on it. Will that be enough to cover it?

 

Can a Q2 be dealer fitted to a petrol GT or it restricted to 1.9JTdm?

 

Its restricted by which gearbox it will fit. It isn't compatible with a 2.0 JTS, but it will fit a 3.2 V6. Not sure if a dealer would fit it though, you could buy it from a dealer and get it fitted elsewhere.

 

Got my V5 today - no mention of Q2!

 

It wouldn’t be mentioned on the V5, anyway the DVAL get all sorts of information wrong on V5’s.

Ned

 

Oh and my V5 states quite clearly 1.9 JTDm 16V Q2.

It would be, because its part of the model name - as would a GT Q2 as well. I think the difference with the Blackline is that the Q2 is just an option and was never intended to form part of the model name - hence why no mention on the V5, or any online insurance quoting system.

My dealer is going to give me a 'SIGI' print (whatever that is!) that shows the Q2 diff option being included.

 

no and no.

its hidden in the case of the box.

you can tell by driving it, pull out of a junction sharpish - floor it in fact, it the inside wheel spins forever, you don't, if it spins just a little and traction is good then you have it.
Dry road of course.

In the wet the LSD will spin both front wheels in a straight line rather than just 1.

 

interesting like the halidex in the Audi