dowser

Hi All

I attended a Drift Training day in Germany a week or so back - this is a German style competion type thing, where the goal is to get sideways as long as possible around a set corner (do you have these in the UK?).

It wasn't a natural environemnt for the Scoob - the day was packed with BMW's

The only way I could get the back end out was with the handbrake - a quick dab of this and then wait (...and wait) for the back end to almost overtake the front before applying throttle. But even with this I found it very hard to modulate the throttle to keep the car balanced in a drift (the steering was next-to-useless - I just left it pretty much straight ahead once I'd applied power again).

On the road I use lift-off oversteer to position the car a bit (only in the dry ) before a corner - but was unable to do this on the day reliably.

If I ignored the "drift" bit, I could negotiate all the circles, corners and coned-chicanes much faster than the rear-wheelers. It just didn't look that exciting, with understeer being the natural state when pushing too hard.

So to questions - I guess using the handbrake at 80-100km/h is not going to be great news for my centre diff? Has anyone destroyed one doing this? What are the symptoms? I think mine's OK - all four wheels spin on a sprited launch.

What is the bias on the Scoob (my00)? I find it hard to believe it's 50/50 front/rear - or is bumpsteer coming in to play?

I *think* the OE diff is a viscous coupled one - are mechanical diffs available to suit, and what differences would I notice (Moray - didn't you fit a mechanical to yours)?

Thanks all - upholding Scooby fame, there were two of us in the finals (5 out of 50) of the Drift Challenge staged at the end of the day. I stuffed up in the finals - the track had dried out mid-corner by this time and I just straightened up and shot forward But another Scoob on skinny winter rims/tyres got 2nd place All other slots went to BMW - old generation M5 with 340ps driving the rear was optimum car for the day.

Cheers
Richard

dmel

Why use the handbrake when you can use the brakes? Approach the corner faster and brake harder when turning in. The maximum braking should occur at the maximum turning. Both braking and turning should be progressive. This techique makes the nose set in nicely minimizing understeer and destabilises the tail. Depending on how hard you push you can have anything from neutral cornering up to 4 wheel drifts.
You can also visit http://www.drivingtechniques.co.uk which explains this with more detail.

dowser

Tried it, and failed miserably I use lift off oversteer on the road to an extent - but couldn't get it in the wet on the track.

One of the instructors loaned me his Evo6 (RS, I think - certainly no active yaw) - I used the foot brake method to great success in the Evo, I found giving it a left/right (or right/left) flick before the entry also helped to unsettle things nicely.

Once sliding, the Evo is very easy to balance - with the Scoob the only time I got the foot brake method to work was by hooning it up to the corner with way too much entry speed.....I ended up spinning

Just practice I guess - but I'd like to know how to make the Scoob more like the Evo in the handling department. This experience was the first that led me to question the centre diff, previous to this I assumed bump-steer would correct a lot of the inherent understeer.

Thanks
Richard

dowser

I read this thread last night (yes, all of it );

http://www.scoobynet.co.uk/bbs/thread.asp?threadid=28498&Page=1

In it Moray comments that fitting a front Quaife ATB LSD to his RA put handling on the same level as that of an Evo5 or 6...sounds like what I'm after!

Does anyone know whether this can also be fitted to a Euro Scoob without upsetting the balance - I guess the rear diff on an RA is better than a normal Euro car's?

Anyone else replaced any of their diffs?

Many Thanks
Richard

EvilBevel

Richard,

Disclaimer: I'm not a gifted driver, so take this with a grain of salt, ok ?

Being the gear **** I am I fitted the ATB a few months ago to my MY99, to replace the open front diff.

Under normal driving, you don't notice it much, but in tight corners, at the exit, when you apply power again, you do feel quite a difference. (remember the diff only locks when a) there is torque and b) one of the wheels has less traction.

As best as I can describe it, it "removes" the power-on understeer quite a bit.

Downside: when driving normally (again applying throttle) and one of the wheels has less grip (bumps, mud), you do get a torque steer reaction, which can be a bit tricky if you are not used to it.

Other downside: the understeer balance of the car changes to a much more neutral one, so you really have to get used to it.

I'm happy with it, but that doesn't mean you would be happy. I feel the car is very balanced now (and I think so did SDB but I'm not sure). If you however would feel the rear diff is not up to it, Quaife also can sell you the matching rear diff (more upgrade money, goooood )

In my opinion however, it is the centre diff that is now the "weakest link" as it takes ages before it start to lock a bit.

HTH,

Theo

dowser

Cheers Theo

Yep - I've asked Quaife about the rear and centre too - the rear's listed, but not the centre...but I recall Adam mentioning it was supposed to be on it's way.

Where did you get it from/how much did you pay/how much hassle to fit?!

Thanks
Richard

EvilBevel

I bought it via Mark Verhoeven. I had found it myself via Moray and the Quaife website, but I prefer to have these things handled by someone who knows a bit more about cars, and I don't mind to pay for that I always fear questions like "do you want the X5zzRE version or the PT766 one sir ?"

Price was something like UKP 550 IIRC ?

Hassle ... well, they have to drop the gearbox & open it (front diff is in the gearbox, as is the centre diff), but it all fitted beautifully. Dealer had a small problem with leaking gearbox oil when they refitted the lot, some seals (?) where the front axle connects to the diff needed to be replaced. Took about 3 hours in total. Never had any problems with it afterwards.

If you are considering doing this, you *might* think about waiting (inquiring) for the centre diff, so you can replace both at once.

HTH,

Theo

dowser

Thanks for the info

I've asked about the centre as well...I feel major expense syndrome coming on.

Your downside's don't seem much like downside's to me - it's exactly what I want to cure

Cheers
Richard

dowser

Unfortunately Quaife do not make a centre diff - no mention of one in the future either

Can anyone recommend another manufacturer? It would be rude to remove the gearbox and not change both

Thanks
Richard

KJTomassini

Try viscous center LSD 20 kg/m from MRT or get yourself an electronic center diff (ask Prodrive if they can sell you this one for gr.N rally car), together with Quaife front and rear diffs should be very good combination.

Kristijan

dowser

Thanks Kristijan

Do you know what the difference between the 20KG/M centre LSD and the original euro one is?

MRT mention "as used on our rally car" when talking about the STi front & rear LSD's....but not the centre one.....

The STi front LSD is hideously expensive compared to the Quaife item!

Any other idea's on who might do an uprated centre diff?

Cheers
Richard

KJTomassini

Sorry, don't know the exact difference but I have driven two standard Imprezas, one fitted with 20 kg/m center diff,all I can say is that with 20 kg/m center diff car feels much more stable especially around looong fast 3rd gear corners, especially on loose surface. When you throw the back end out it just goes and goes sideways until you decide that's enough (but you have to be very quick!!), and that is without front LSD, which helps even more! With standard center diff car just floated around corners and I haven't got enough grip compared to 20kg/m center diff.

Hope this helps!

Kristijan

EvilBevel

Richard, why don't you ask Ben Taylor at MRT (mail: Ben@mrtrally.com.au ). He has been extremely helpful to me in the past and really takes his time to explain things. He seems to be pretty honest as well (no marketing BS).

Give it a whirl

Theo

Edit: one day I will learn to type

[Edited by EvilBevel - 10/19/2001 5:41:15 PM]

dowser

Thanks Theo - I've done so.

firefox

Stock STI centre VC's are 12Kg.

The Kg refers to the lock-up characteristic.

a 20Kg will be more suited to off road use.. IMHO

But chances are everyone will disagree

J.

dowser

Thanks J

Anyone know the difference between a euro car's centre and the STi one?

Cheers
Richard

EvilBevel

Kermit, I disagree

LOL, just kidding, thanks for the info. Can only echo Richard's question really about the diff (hum) between STi and Euro spec...

Theo