dowser

Some months back I started investigating a way to improve front end response to aggressive direction changes.

I've a my00 with Koni's & Eibach's plus Prodrive style geometry - the handling is very good on known roads (ie; must be very exact with entry to ensure the balance is right). However, on roads I don't know I'm more likely to enter a corner too fast - I usually lift off and use the oversteer to correct me in the dry, but am a bit too wimpy to do this in the wet , meaning I use steady state throttle to manage the understeer induced.

I'd like to be able to boot the throttle in the wet and have it affect the rear, but at the moment it only washes out the front.

How can I correct this behaviour - I want the front to have a much sharper turn in (dare I say it, just like an Evo!)? Should I fit an upgraded rear ARB, or a Quaife ATB front differential....or both?! I also have steel ARB links ready to fit at front and rear, but don't imagine these are going to do too much for this specific problem?

The Quaife is expensive at ~£500 plus fitting (it's in the gearbox) - how much is a rear ARB? And how much will the ARB change the ride quality?

Moray - I think you fitted the Quaife? Were you running standard (STi) ARB's at the time?

Many Thanks, all opinions appreciated
Richard

Sigmund

I'd like to know what difference the Quafie ATB diff does too. I've considered putting it on both front and rear end of my car. Mostly needed at the front though as the Rear have lsd already.

dowser

There was a post a few months back where I started asking questions (but search is down ) - I think only a couple have gone the new diff. route. I'd pretty much set myself to do it, when I got an email suggesting rear anti-roll bar will have the same effect...at less cost, obviously

Problem is, I guess with the rear ARB the ride quality will suffer (?).....and the clutch is going to be changed soon anyway....very undecided at the mo'

Richard

EvilBevel

Hey dowser

OK, what I'm gonna say is my personal opinion, and that of someone who can *really* drive who drove my car (he is in rallying) and knows what an Impreza or EVO normally feels like:

The ATB works wonders for me in slower tight corners where typically the inside front wheel would spin (and the front open diff would allow that) under load. The ATB locks in this case (a bit of a funny feeling the first few times, you really have to hold your steering wheel).

Same goes for faster corners where with applying just a touch more throttle, you can "chuck in" the front wheels (best I can describe it). Mind you, you are then "commited" to the corner, and best not back off mid bend ...

My car feels pretty balanced now in a lot of departments (ATB, uprated rollbars/endlinks/ALK, DMS gold), and if I would certainly get the ATB over & over again given the choice.

You don't feel the ATB at all during normal driving (it needs to see torque differences before it can operate, otherwise it just acts as an open diff).

So far so good

However !

It does not do away with the power on "pushing yourself to the outside of the bend". Yes you loose the clumsy "oops, inside wheel gone" feeling, but you still (I'm talking dry surface here) have a case of power on understeer, not the "let's flick the rear a bit" power oversteer, say EVO V style.

It is my understanding that this can only be changed by changing the centre diff (at least I hope so) from 50/50 (or 55/45, I'm still not clear on that one) to something like 65/35 (rear biased).

Mind you, I could be WRONG, I haven't tested this. Yet

So is it worth it ? Yes. Will it make your car into a power oversteer car ? No.

HTH, and again, only my personal opinion

Theo

PS: what is the distribution (front/rear) on an STi type RA ?

Adam B

I've heard that the torque split of (all) the RAs is 35/65 (f/r). Although I can't comment as to whether the exact numbers are correct my RA certainly is 'rear biased' and was a real handfull in the wet with OEM tyres and geom !! ... a totally different car now with ALK/geom/bump.
Interesting to note that a friend of mine, who also has an RA, warned me about this well in advance (so it's not just me !! )


Cheers

Adam

dowser

Thanks Theo - just ordered one

Richard

Stelios

Dowser where did u order it from mate? I want one!
Evilb where can i get a dms gold? AVO dont do them anymore

A lot of thanks guys

dowser

Quaife direct - arrived yesterday and will be fitted next week

They're at www.quaife.co.uk - but I think I had the last one in stock.

Richard

AJbaseBloke

Dowser, if it is not a secret, how much was it pls?

EvilBevel

Stelios, I got them at AVO, so ...

Do TSL or Scoobymania do them ?

AJBase, IIRC, it was something like 550 UKP. No secret, price is on their website.

Stelios

Yes I know I phoned Nigel as per your instructions and a secretary politely told me they dont do them anymore...

dowser

I think list is £525 plus vat - so much money for something so small and unsexy looking

Richard

dowser

Picked up the car last night

Initial impressions very good.....I can now instantly tighten the cars line through the corner by using a big dab of throttle; the front end claws for grip, whereas before you'd get a 4 wheel drift followed by the back slowly coming out.

As Theo mentioned, first time is a bit disconcerting

Not been brave enough to see what happens if I leave the boot in yet

There's a bit of torque steer, most noticeable when over-taking on a bumpy road, but not bad.

Thanks for the advice Theo - see, I don't always argue
Richard