Retrofitting a Q2 to an existing Alfa

The Q2 cannot be fitted onto Alfas with 5-speed gearboxes and that includes all TS/JTS models, as well a V6TB engined models with 5-speed gearboxes. This is because the "Fiat" transmission's ring gear is larger in dia. than the "Alfa" (V6/JTD) one, so they are not interchangeable.

An exception is the later V6TB engined models with 6-speed gearboxes, that have an "Alfa" transmission. Also in 5-speed models the 6-speed transmission can be retrofitted, along with the Q2 of course. It appears that the bellhousing pattern is the same in 5-speed and 6-speed models in V6TBs.

Anyone knows if the Q2 fits the 6-speed box of the 159 2.2JTS?

Probably not.

Originally Posted by Trailbraker

Very good KGB, hopefully new 159 2.4 JTD's will get this too..

Lets hope I can get it retro fitted at a reasonable cost.

Great thread BTW guys. Really opening my eyes.

Originally Posted by 156F1

Anyone knows if the Q2 fits the 6-speed box of the 159 2.2JTS?

The block & and 'box is GM sourced so no, sorry

I've asked my dealer to look for the parts numbers Sandy posted. Perhaps a nice option for the GTA (and ofcourse Arnoudt's 156) if the price is right.

The full Madeno diff option is just a bit to expensive for my "non-track" GTA. But I would like to have the Q2 fitted for a reasonable price and benefit for normal use and the occasional "damp" Ring visit.

Great find & thread.

Thanks guys.

Originally Posted by alfasud.ti

The Q2 cannot be fitted onto Alfas with 5-speed gearboxes and that includes all TS/JTS models, as well a V6TB engined models with 5-speed gearboxes. This is because the "Fiat" transmission's ring gear is larger in dia. than the "Alfa" (V6/JTD) one, so they are not interchangeable.

An exception is the later V6TB engined models with 6-speed gearboxes, that have an "Alfa" transmission. Also in 5-speed models the 6-speed transmission can be retrofitted, along with the Q2 of course. It appears that the bellhousing pattern is the same in 5-speed and 6-speed models in V6TBs.

BUT it will fit 5 speed JTDs Right???

You can play with that online ePer over here...to see what...where

http://91.92.0.122:7080/navi?KEY=STARTUP

Originally Posted by kgb

BUT it will fit 5 speed JTDs Right???

Best to check for yourself but looking at that Eper (great link thanks) as long as you don't have the really low power JTD (M14, 100CV 74kW) it will fit. (well its the same stock diff number as mine, whether it fits or not is another matter, I doubt Alfa would chnage the diff housing)

mine was 116 once upon a time...now no one knows....about 150-160hp...360-380NM....

Yep the diff is the same...did you need anything else other then the diff???...as you mentioned that you bought some other parts as well, but did you use them at all???

the bearings were used for sure as for the rest of the bits I got some backin a box with the old diff but I don't know what was used (it was a big bag of assorted spacers etc.) I couldn't get the new crown wheel bolts so my old ones were reused, can't really tell you much else I handed my car over to Adie the man from Delmont ....ummm... AHMotorsports and handed him a wad of cash and was on my way

Fair enough but Aide hapens to be some 4000kms away :-)

I need to know what to order (get) before I dismantle my Bella...

According to my mechanic there is an abundance of Q2 spare diffs in Italy. He's got 3 apart from his already and has ordered 4 more that will probably arrive next week. Apparently Alfa Romeo predicted that *this* would happen and ordered many spare Q2s from Zexel. Perhaps this is their way of atoning for not fitting a stock LSD to all their powerful versions in the first place.

Wow, Alfa does something unexpectedly thoughtful shock! (Well done chaps )

So the Q2 can't be fitted to a TS with a 5 speed box, but it will fit a 6-speed TS box. Can anyone see where I'm going with this.......

Will a 6 speed box from a 166TS will fit a 147TS? Is a straight swap possible or would it mean swapping the internals from one to the other?

If I'm talking rubbish just tell me to shut up and go away

Had that thought myself, long before the Q2 diff appeared.

I asked around and have been told that there are big differences in the mounts of the two gearboxes, so that 166 gearbox cannot be fitted to an 147, unless you do a hatchet job on the gearbox mounts. Not sure about this though because i didn't try it.

Also used 166 6-speed gearboxes are really hard to find.

Originally Posted by ode

So the Q2 can't be fitted to a TS with a 5 speed box, but it will fit a 6-speed TS box. Can anyone see where I'm going with this.......

Will a 6 speed box from a 166TS will fit a 147TS? Is a straight swap possible or would it mean swapping the internals from one to the other?

The 2.0TS 166 uses the 6-speed box used in the V6, but with a different bellhousing.
So to fit a 6-speed box to a 147/156 TS/JTS you need to use the 166 2.0TS bellhousing.

There are other options for the 5 speeder, Kaaz offered me there TS diff to try on my car on a return at no cost if it doesn't fit it was about 700 inc VAT. not as cheap as the Q2 but an option all the same, I think AHM can probably supply diffs to fit too in a similar price ball park.

Clutch type diffs do appear to offer some benefits over a torsen based on comments in this and many other threads, could be the easy option rather than sourcing gearbox bits etc.

There are more things to gain by installing a 6-speed box than just the ability to install a Q2 diff: Closer ratios and possibly a long 6th gear that reduces noise and fuel consumption at high speeds.

Is this the most exciting thread on AO at the moment?

I think it has to be

I don't have anything useful to add, so just carry on, as you were

I need the Q2 badly...

Today I changed my air filter...(which was extramlly dirty) and now the car spins the tires all the way on 2nd gear as well :-(

ps: raced a lexus gs300...up to 170km/h he was no more then a car ahead of me...He didn't look at me at the trafic lights as i was going to tell him that he is racing an 1.9 diesel 8v:-)

Here are the first "user experiences" from a greek alfista who has just installed a Q2 to his 156 2.5V6:

ΤΗΕ ΤHING No2:

Today the thingy has been fitted (hush-hush) and luckily we had some rain so i was able to give it a test and tell you my impressions.

I did a test drive around the repair shop with cold tires and very slippery roads because of the drizzle.

I was prepared for the worst but love (call me VDC/ASR) came ...a day late. Hehe!

Straight line: abrupt lifting off the clutch pedal (wet tarmac), the car leaps forward and builds rpm gaining speed, while you feel the torque shifting between the two driveshafts so that the car can get some decent grip till second gear. When you shift you haven't lost many rpm because the ASR has kicked in way later and hasn't cut the car's power from take-off. The result is that you gain several seconds and yards in take-off.

"Loaded" conclusion 1: What a dog this 2.5 V6 that can't spin the wheels on wet tarmac!!

"Loaded" conclusion 2: The chavs probably won't like this thingy because it won't let them burn rubber at traffic lights.

First right uphill turn (tarmac always wet) with a screaming 2nd gear and the VDC is silent, somewhere before the track-out point i saw the VDC light blink once with the corner of my eye, had i not noticed i would have thought that the VDC hadn't kicked in at all. The rpm were effortlessly climbing while the car maintained the course i had planned in my mind before the turn.

"Loaded" conclusion 3: Oh dear, the guys that fitted the Q2 must have damaged the VDC because it doesn't seem to work.

Downhill right turn with both directions empty and lots of visibility, nice opportunity. Abrupt turn-in with the accel. pedal all the way down so that the car would supposedly slip to the opposite direction. Traces of understeer for a split second before somehow the car magically tucked in and took the rest of the turn before going to the opposite lane. VDC kicked in a little after the apex. Phew, it seems that it works after all.

"Loaded" conclusion 4: The thing ...has a mind of its own, who gave it the right to mess with your laws Mr. Isaac Newton?

Some more observations after 20kms of fooling around:

Panic braking: You can feel the diff ping-pong the engine braking torque between driveshafts before the ABS kicks in, and when it does it's with way more pressure on the brake pedal.

Braking where one side of the car is on dry surface and the other on wet. The same behaviour with the torque transfer being more evident (steering wheel wobbles slightly) but the car keeps straight without the fear of destabilizing its rear-end. The thingy has done its work until finally the wheels try to lock and the ABS kicks in at the last yards of braking.

In general road handling and cornering is much better, especially on slippery road like today. The car gets its power to the road a lot better and makes it obvious that its limits have gone way up, but this needs more practice and faster "hands" because track-out speed is considerably higher than before. It's like driving a different car.

Nothing more to say so far, more after some weeks of experience.

Overall conclusion: It's well worth its money ...three times over!

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