Retrofitting a Q2 to an existing Alfa

Originally Posted by Chris155

I suspect that reliability comes on the basis of the gearbox oil being kept at the correct temperature range and given that GTA's seem to have an issue with diffs (sun gears) particularly in hotter climates, there may be some cause for concern.

I too think diff failure has a lot to do with temperature. All 3.2's and Q-system 156's f.ex have special cooling vents for the gearbox built into the original undertray. Of course all automatic transmissions runs hotter then a manual, we know this, but the 3.2's must also run a bit hotter then a 2.5 since the engineers put a vent there.

Was wondering if there's anything that could be done to keep the gearbox temps in check at least on a higher output engine, is cooling done via external ventilation at the moment?

Saying that, the torsen might have the advantage here producing less heat whereas the clutch type could be leading to its own destruction from the friction of the plates causing overheating, eventually failing, not to say the torsen type wouldn't fall apart if over stressed, but 600 horses on slicks sounds promising.

Originally Posted by 147owner

Not sure about the temperature issues, but the real issue with the GTA diff is it is not strong enough for the torque of the engine. An example of penny pinching I think. To quote my mechanic after fitting my new Quaife diff, the original diff is "rubbish". And to quote another engineer, "it's not a matter of if, but when it will break." Or to be very definite: "The problem is related to a stress concentration factor at the rear and front of the pinion bevel gear tooth. The von-misess stress at 50% throttle is around 900 MPa (about three times the yield strength of the material)".

Meanwhile, I'm happy to have the Quaife between my wheels....

What do you think of the Quaife? It could be the tyres I running and the pressure I run them at (38psi) but mine sniffs about a fair bit on uneven roads...

Originally Posted by Caldo Bollente

Was wondering if there's anything that could be done to keep the gearbox temps in check at least on a higher output engine, is cooling done via external ventilation at the moment?

You could add an oil cooler for the gearbox oil but as I don't fully understand the prinipals involved - Would it require a pump? for instance, I can't offer any more than that.

What about a heatsink and a fan ala a computer CPU only on a bigger scale?

Dude, you're the Master Transplanter, I have no idea... the fan sounds good to me!

For 17" tyres 38 psi seems very high to me, thats 2.62 bar, I run mine at 2.4 bar (approx 35 psi) for the road - the factory recommendation I think.

For track I start at 2.5 bar cold and cap it at 2.8 bar hot.

I have tried the quaife only on track and it seemed well behaved, too much so was my impression - but the fact you are experiencing some torque steer might mean that it was actually well enough judged for the road.
The standard dampers (poorish for the class of engine involved) do contribute to the squirming around a bit too.

Originally Posted by Chris155

What do you think of the Quaife? It could be the tyres I running and the pressure I run them at (38psi) but mine sniffs about a fair bit on uneven roads...

re tyre pressures, there was something in AROC where people had been complaining about uneven tyre wear to stealers (yeah I know neg camber causes it, perfectly normal) and the remommendation was to up the pressures to 38 / 34 f/r IIRC.

I've got FK coil overs on mine.....

Originally Posted by Chris155

re tyre pressures, there was something in AROC where people had been complaining about uneven tyre wear to stealers (yeah I know neg camber causes it, perfectly normal) and the remommendation was to up the pressures to 38 / 34 f/r IIRC.

I've got FK coil overs on mine.....

i think you will find that with the GTA uprights you get less inner tire wear compared to the 2.5 (when lowered)

I am on abut 40-45mm lower then stock and still manange to get nice and even wear on my street wheels. huge benefit if you ask me!

e b spares sell them...£265 plus vat.....thinking of one for myself but might wait a bit untill i have done a few more miles and do clutch at same time.

I got myQ2 today....will be going on the car within a week or so....together with Koni-FSD, PolyBushing for the strut bar (if that was the name for it) and Brembo brake discs with EBC pads.

The powerflex in the back wil be coming within a month.

I am still having problems with the BMC-CDA....that filter pumps too much air

Originally Posted by kgb

I am still having problems with the BMC-CDA....that filter pumps too much air

Could you explain more in detail? Ive got the CDA aswell, maybe you need a remap?

ciao

Originally Posted by kgb

I am still having problems with the BMC-CDA....that filter pumps too much air

dont you mean the fuel pump doesnt pump enough fuel?

Well, after fitting the BMC-CDA 70-150 the big one (for my car BMC recommends the small one 70-130 now I know why) the car started over boosting big time.

2.2Bar was easily achieved (with the atmospheric one it is around 3Bar). Factory setup maximum is 1.2Bar with my remap for a standard car the max is 1.41Bar...

With both catalytic converter removed and a free flow back box fitted, the car was probably already boosting more then 1.41Bar...BUT everything was still within controllable limits. As soon as I fitted the BMC-CDA the boost when sky high...car was entering safe mode every time I push it.

Playing with the location of the BMC intake pipe was also causing an effect...meaning direct from the bumper more boost, behind the bumper less boost.

We cut the boost pressure, so it was peaking at 1.7-1.8Bar we will reduce that further. I am thinking of 1.5-1.6Bar max.

The strange thing yesterday when I went all the way to Thessaloníki and back was that over there were I am at the Sea level (meaning hire atmospheric pressure, the car was over boosting a lot again, when I came back to Sofia some 630meters above sea level the car was getting back to "normal").

I have no idea yet from where the JTD takes it atmospheric pressure readings, but maybe somethings wrong there.

There is another thread about my problem but no one has written there...

The bottom line is that BMC-CDA really does it jobs, I hope that I bit more playing with the map of my car will cure it.

Take care

Originally Posted by Chris155

What do you think of the Quaife? It could be the tyres I running and the pressure I run them at (38psi) but mine sniffs about a fair bit on uneven roads...

To be honest, I don't notice much difference just driving on suburban roads. But I have noticed there is more grip where once there was power understeer if you give a bootful when exiting a 90 degree corner. Torque steer appears reduced too, but does depend on the road surface. I gave it squirt last night on uneven piece of up hill road and the car danced around a bit, darting left and then right again, not so much torque steer but just a bit of movement that was easy to control, if that makes sense.

Originally Posted by kgb

Let's keep the thread Q2 oriented....

Originally Posted by kgb

Well, after fitting the BMC-CDA 70-150 the big one (for my car BMC recommends the small one 70-130 now I know why) the car started over boosting big time.

2.2Bar was easily achieved (with the atmospheric one it is around 3Bar). Factory setup maximum is 1.2Bar with my remap for a standard car the max is 1.41Bar...

With both catalytic converter removed and a free flow back box fitted, the car was probably already boosting more then 1.41Bar...BUT everything was still within controllable limits. As soon as I fitted the BMC-CDA the boost when sky high...car was entering safe mode every time I push it.

Playing with the location of the BMC intake pipe was also causing an effect...meaning direct from the bumper more boost, behind the bumper less boost.

We cut the boost pressure, so it was peaking at 1.7-1.8Bar we will reduce that further. I am thinking of 1.5-1.6Bar max.

The strange thing yesterday when I went all the way to Thessaloníki and back was that over there were I am at the Sea level (meaning hire atmospheric pressure, the car was over boosting a lot again, when I came back to Sofia some 630meters above sea level the car was getting back to "normal").

I have no idea yet from where the JTD takes it atmospheric pressure readings, but maybe somethings wrong there.

There is another thread about my problem but no one has written there...

The bottom line is that BMC-CDA really does it jobs, I hope that I bit more playing with the map of my car will cure it.

Take care

Sorry , couldn't resist!!

Some pictures from today, fitting the Q2 and also the front set of Koni-FSD.... by the end of the week the rear Koni's should be fitted as well.

In the pictures you can see my powerflex bushes fitted....I am waiting for the once that go on the strut bar...as my one is 24mm and I ordered by mistake 22mm.

http://kgb.alfaromeo-bg.com/147tuning/stage10/

You can see the pictures at the above link...

Dont know if any one has mentioned this (cant be arsed to read 12 pages) but Autodelta are selling lsds that will fit most recent alfas including the TS models.

Link

Yes, everybody knows about the AD LSD, but it's a plate type.

Originally Posted by Alexandrus

Yes, everybody knows about the AD LSD, but it's a plate type.

and it is almost 1500euro compared to 300-400 the Q2 costs.

I will drive for couple of days, then write my review on the diff...as of now I am happy with it, but I need to do wheel alignment because my car polls to the right a bit...

But on some corners where before the ASR was kicking in, now it stays silent.