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Disadvantages of Q2?

I've just been informed that Alfa do not recommend fitting the Q2 to non Q2 cars as the Q2 unit interacts with the VDC and ABS and that this would not happen with a Q2 diff fitted to an older alfa.

What are the effects of this? As anybody noticed any advirse effects of fitting Q2?

Cheers Stuart
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Re: Disadvantages of Q2?

That's BS as Alfa dealers will do it for you (Mango's for example).

No issues at all and it intervenes as usual once traction is lost, which only happens in extreme circumstances or if you're really heavy footed in the wet

It really is an excellent system & Alfa missed a big trick by not having it when the 147/156 GTA & 3.2 166/GT were on sale
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Re: Disadvantages of Q2?

if AR will fit one for you, is that not a bit like admitting they screwed up in the first place?

on the other hand, by offering to fit one, its a bit like an optional extra i suppose.

i dont know anyway cos im yet to get one
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Re: Disadvantages of Q2?

well i'm sure i must have one of the oldest cars to have one fitted as mines a r plate jan. 98. don't know what vdc is but i must be without.

as for does it work. i now love s bends and roundabouts.
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Re: Disadvantages of Q2?

you have to pay for it
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Re: Disadvantages of Q2?

I agree with squadrone rosso......... tremendous system, would have one in a 147 definitely, makes it a blast to drive
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Re: Disadvantages of Q2?

Its 97% borrocks.

The 3% that isn't borrocks is that the ABS, ASR and VDC are tuned slightly differently if a Q2 is fitted as standard.
It seems reasonable that they might work very slightly better as a result.

The Q2 still works fine as a retrofit, and far far far better than the car as standard!

In reality the only thing that you may notice is that when you are at fuill throttle the ASR will sometimes behgave more abruptly on a car that had it retro-fitted.

The Q2 diff has minimal impact on the ABS as far as I could feel, I couldn't notice any difference in braking over a car that didn't have the Q2 fitted as standard.
In fact Torsen maintain the Mechanical Q2 diff (Torsen T2) is fully compatible with any ABS system.

However I do reckon it is theoretically possible that braking into a corner with a car that was equipped with Q2 from the factory could have very marginally better balance..
The reason being, that the Q2 diff, like many LSDs, works slightly under braking as well, so a truely optimized ABS system might be able to take account of that and bias the brake effort slightly differently accross left and right wheels.

I would guess that the VDC/ASR tuning would be about allowing the driver more aggressive use of the throttle before starting to brake wheels or cut fuel.

IMHO Its no big deal though - these systems are setup to have a wide operating range. Once you change to stickier tyres and to upgraded pads - much of the originals car balance will have changed.

Many people have retro-fitted the Q2, all have raved about it.


Originally Posted by stu_the_flat View Post
I've just been informed that Alfa do not recommend fitting the Q2 to non Q2 cars as the Q2 unit interacts with the VDC and ABS and that this would not happen with a Q2 diff fitted to an older alfa.

What are the effects of this? As anybody noticed any advirse effects of fitting Q2?

Cheers Stuart

I'm not a doctor - but I really do recommend braking later
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Re: Disadvantages of Q2?

what i have found is that with the traction control on it cuts in and put the car into understeer to correct a little bit of what would have been controllable oversteer.

I spoke to alfa about mine when the diff went. essentially they said this: they cannot endorse it because it hasnt been tested in the GTA so I assume they dont want to recommend it incase it goes wrong and they are liable.

But they also said it would improve the way the car drives. In essense they wouldnt pay for mine directly after the standard one broke but gave me a voucher to the value of one to spend as i pleased

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Re: Disadvantages of Q2?

While it may slightly compromise the operation of the ABS/ASR/TC, the reality is you're less likely to use the electronic systems thanks to the improved traction provided by the LSD.
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