Alfa Romeo Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
Hi

First time posting here. I got myself a GT 1.9 JTD last week
I would just like to know how can I easily check if it is the Q2 Diff? Is there a difference in gear placement or Reverse or something like that?
and also where can I find a nice Gear knob?

THanks
 

·
Registered
Joined
·
6,004 Posts
Hi Mopkop, welcome to AO.

The factory fitted Q2 has a Q2 badge at the back. The best way to test is to park on your friend's grass, switch off ASR, rev it up and drop the clutch - see if both or only one wheel spins
 

·
Registered
Joined
·
80 Posts
Models after 2006 had the Q2 option, in all other cases a Q2 diff could have been retrofitted.

The factory fitted Q2 has a Q2 badge at the back.
Theoretically yes, but reality is often a lot different...
 

·
Registered
Joined
·
4,196 Posts
If it's a pre-2006 car (probably also still if it was first registered in 2006) then it very probably doesn't have a Q2, as it would have to have been specifically retrofitted.

If it is a post-2006 car, it could possibly have a Q2. I assume there is no badge on the back.
If there is no badge, there's a few ways to "check". Like Gertie said, the "test if both wheels or just one wheel spins on wet grass" test - make sure there's open space in front of you when you do this!
The other "check" is to find a nice bit of curved road (quiet, wide road with safe runoff areas) and go into the bend at speed and then apply a lot more power in the corner. If you find it just running wider understeer, it doesn't have a Q2. If you find that when you apply more power, it "pulls into" the corner and feels like it's just taking the line tighter and tighter the more power you apply, then you have a Q2.

Of course, the absolute foolproof way to check is to physically inspect the diff. To do this, you'd have to remove one of the side-shafts and look into the diff casing. If you can look straight through the diff, it's a Q2 diff and if there is a shaft inside the diff blocking the view, it's a normal open diff. Someone could correct me if this is wrong, but as far as I know, this is the visual difference without physically removing the diff.
 

·
Registered
Joined
·
2,694 Posts
If it's a pre-2006 car (probably also still if it was first registered in 2006) then it very probably doesn't have a Q2, as it would have to have been specifically retrofitted.

If it is a post-2006 car, it could possibly have a Q2. I assume there is no badge on the back.
If there is no badge, there's a few ways to "check". Like Gertie said, the "test if both wheels or just one wheel spins on wet grass" test - make sure there's open space in front of you when you do this!
The other "check" is to find a nice bit of curved road (quiet, wide road with safe runoff areas) and go into the bend at speed and then apply a lot more power in the corner. If you find it just running wider understeer, it doesn't have a Q2. If you find that when you apply more power, it "pulls into" the corner and feels like it's just taking the line tighter and tighter the more power you apply, then you have a Q2.

Of course, the absolute foolproof way to check is to physically inspect the diff. To do this, you'd have to remove one of the side-shafts and look into the diff casing. If you can look straight through the diff, it's a Q2 diff and if there is a shaft inside the diff blocking the view, it's a normal open diff. Someone could correct me if this is wrong, but as far as I know, this is the visual difference without physically removing the diff.
yes this is essentially correct. you need to strip out the side shaft and look through to be sure to be sure.

but that said, someone who is familiar with a Q2 diff would be able to tell by driving it a relatively short distance.

what you could also do which might make it more obvious is wet the grass next to your driveway then put one wheel on the wet grass and the other on the hard surface and pull away hard (assuming you have the space to do this). if its and open diff it will just spin the one wheel on the wet grass and go no where. try it with some hand brake applied - like 50% pressure.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #6
Thanks for all the replies. Awesome Community . Alfa is amazing.

It is post 2006 so chances are good then... Ill have a look sometime during the week to try the options
 

·
Registered
Joined
·
4,196 Posts
Well, it's not like "chances are good" necessarily, but yes, better chance than if it was from before 2006.

It was an option offered, not a standard thing on all or most of the cars in South Africa.
If you know South Africans, you'll know that they generally like to fit all of the look-faster cosmetic options possible, but few of the options that actually make the car go faster to match the look.
 

·
Registered
Joined
·
2,514 Posts
The other "check" is to find a nice bit of curved road (quiet, wide road with safe runoff areas) and go into the bend at speed and then apply a lot more power in the corner. If you find it just running wider understeer, it doesn't have a Q2.
I beg to differ. On a wet corner, if I floor the GTV, the Q2 diff lock up and the car go straight. Two wheels turning at the same speed doesn't turn, irrespective where the the steering is turned. But Gerrit will now tell me I drive like a doos, the throttle is not a on/off switch, and he is probably correct.
 

·
Registered
Joined
·
2,694 Posts
I beg to differ. On a wet corner, if I floor the GTV, the Q2 diff lock up and the car go straight. Two wheels turning at the same speed doesn't turn, irrespective where the the steering is turned. But Gerrit will now tell me I drive like a doos, the throttle is not a on/off switch, and he is probably correct.
:biglaugh::biglaugh::biglaugh::biglaugh::biglaugh::biglaugh:

I must say that the Q2 with the ASC turned off just allows you to have a bigger faster accident.

With ASC on you can plant the power in a corner and let the electronics and the Q2 sort it out - they work together VERY well. The ASC just modulates the power - it doesn't shut it down completely. You can feel the torque shifting between the wheels.

I think the GT has a much updated ASC by comparison to a 916?
 

·
Registered
Joined
·
6,004 Posts
I think the GT has a much updated ASC by comparison to a 916?
Pre-facelift 916.... VERY much worlds apart in electronic stability control. The 916 has a mechanical anti-dive brake bias control and pure Antilock Brake System. The GT has full EBD built into the ABS ECU. The GT applies brakes for ASC combined with reducing power to get rid of wheel spin (the true killer of diffs). The GT has yaw control as well - brakes the inside back wheel when the back steps out
 

·
Registered
Joined
·
2,757 Posts
mopkop, where are you based mate? I have a quaife in mine and can tell you the drive is night and day...happy to take you for a spin in mine or drive yours ..I will know in seconds as I had it fitted after owning the car for a few months.

both torque and understeer are hugely reduced by the Q2 , in fact all but eliminated and i have around 240 BHP going through mine, if you don't have it do it the next time you have the clutch out , spend the extra £100 or so over a stock clutch and flywheel and go for the GTA and SMF deal, this will allow you to re-map the car safely to just over 200 BHP on the stock turbo without issues (if there are not any underlying) and if you decide to go further at a later date and hybrid the turbo you will already have a clutch in place that will handle the extra power it will unleash...

I mention all of this because if i had known st the start where my modding could go i would have made sightly different choices along the way that would have saved me quite literally thousands..

good luck whatever you decide.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #12
mopkop, where are you based mate? I have a quaife in mine and can tell you the drive is night and day...happy to take you for a spin in mine or drive yours ..I will know in seconds as I had it fitted after owning the car for a few months.

both torque and understeer are hugely reduced by the Q2 , in fact all but eliminated and i have around 240 BHP going through mine, if you don't have it do it the next time you have the clutch out , spend the extra £100 or so over a stock clutch and flywheel and go for the GTA and SMF deal, this will allow you to re-map the car safely to just over 200 BHP on the stock turbo without issues (if there are not any underlying) and if you decide to go further at a later date and hybrid the turbo you will already have a clutch in place that will handle the extra power it will unleash...

I mention all of this because if i had known st the start where my modding could go i would have made sightly different choices along the way that would have saved me quite literally thousands..

good luck whatever you decide.
Im from Joburg SA. From your ither post i presume you are in UK?
 

·
Vendor
Joined
·
46,352 Posts
Unless you've driven a few of these cars with & without a Q2 diff, you won't be able to tell by driving it.

You can get the N/S driveshaft out of the gearbox without taking it out of the hub, you could inspect the diff and get it all back together again in 30 minutes or so on a ramp with luck on your side.
 
1 - 13 of 13 Posts
Top