under the skin of the Focus RS

under the skin of the Focus RS - by Autocar.co.uk

Рет қаралды 18,748

Күн бұрын

Пікірлер: 29

@EdgyNumber1 14 жыл бұрын

@kevrs2 Ah right, well all they've done is reduce the kingpin offset. Standard Macpherson struts allow the hub to turn about the strut. This system mounts a knuckle on the strut, and the hub turns about the knuckle- thus reducing the kingpin offset. The greater the KPO, the greater the feedback forces to create torque steer. Best analogy: The Standard set up represents a long spanner, the RevoKnuck represents a small spanner. It's easier to turn a longer spanner and this is what you don't want.

@EdgyNumber1 14 жыл бұрын

@kevrs2 Theoretically it's possible but the problem here is one of cost. It's not like shortening springs, shocks to lower the height of the vehicle. You have to fundamentally change the geometry of the front suspension and that takes a lot of R&D to get it right, so it'd be unlikely they'd come up with a kit for that specific car. It's not impossible. The struts would need to put in a fixed position, a new type of hub would need to be engineered and produced, and that's after thousands of miles

@EdgyNumber1 14 жыл бұрын

@TheSaintST1 of testing and different set-ups. In all honesty, the best thing you can do to minimise the torque steer is the use of an ATB diff (which you say you have), use poly-bushes on ALL mounting points, especially the Track Control Arms to reduce longitudinal movements against the road. Ensure the car is balanced laterally (no weight bias on either side), ensure all wheels are balanced. The key here is to make sure that everything is in balance and not loose.

@EdgyNumber1 14 жыл бұрын

@Rawr454 I have to partly agree with him on this, you cannot totally eliminate torque steer on an FWD car simply because of all the jobs the transaxle has to do. You can take certain counter measures, both passive and active in order to control it but you can never totally eliminate it.

@EdgyNumber1 14 жыл бұрын

@Deango2 The diff is an ATB type and not a clutch based LSD type diff. It features gearing rather than the usual clutch plate system used LSD's, therefore the torque biasing to the wheel with the most grip is far more progressive and doesn't snatch (reducing torque steer further) Quaife do aftermarket options for many, many cars, world wide and can even build them to order. They are direct replacement, 'fit-and-forget' (and as a result), come with a lifetime warranty.

@EdgyNumber1 14 жыл бұрын

@kevrs2 Renault use something similar in their current high power Megane. I'm not sure whether they use the same type of diff though. Ford uses an advanced ATB diff, and Quaife Engineering can supply these to almost ANY standard road car as a direct replacement to the old diff that's in there. Unlike LSD's, ATB type diffs need no maintenance, and because they use gearing instead of pre-load clutches, they are 'fit-and-forget'. Maintenance free, with a life time warranty. :)

@EdgyNumber1 14 жыл бұрын

@TheSaintST1 Double wishbone is still more effective, especially if optimised for weight and is more flexible to tune *but* it costs far too much to implement- a problem that Rover/Honda found with 400/Civic - interestingly it handles very well, especially in MG ZS form. RevoKnuckle is a high cost effective way of getting close to the benefit of having double wishbone for much less money. Personally I think it's a brilliant piece of engioneering!

@fusion01wp 15 жыл бұрын

Kudos to Ford. After owning many VW's and watching the way the GTI's / Scirroco's are going, the RS would surely be v. high up on my list for next hatch if only we got it in South Africa!

@EdgyNumber1 14 жыл бұрын

@syxxsyxxsyxx It does under very hard acceleration in a straight line. That's the physics of transaxle FWD i'm afraid, no matter what gizmos and gubbins you throw at it. Where this sytem really comes into it's own is cornering stability - it just grips, and grips - torque steer is seriously reduced when accelerating from the apex of a bend - this means more stability thus more speed.

@EdgyNumber1 14 жыл бұрын

@TheSaintST1 It's a cheaper alternative to double wishbone suspension: The Rover 400/MGZS has this and is highly effect - but expensive. I'm sure Lotus worked on something like this with Corus Steels a few years before..

@Mpayne 2 жыл бұрын

The superstrut on the ae111 corolla has a similar design which came a decade before this, the revo knuckle is much more robust tho.

@krepecish 15 жыл бұрын

Thanks for the quick insight. So there IS a way to make FWD car nice to drive with more than 230 bhp or so. I wonder if those double wishbones (is that correct?) work as good as revoknuckle does if presenter didn`t mentioned Audi and Peugeot.

@EdgyNumber1 14 жыл бұрын

Hmm. The problem is that you cannot get over the physics of FWD cars in general, in that the wheels up front *still* have to do all the work. However RevoKnuckle is very effective though in reducing the scrub radius which in turn reduces the leverage forces which result in torque steer(look at the diagram at wheel offset and kingpin geometry) , making, at least straight line acceleration more comfortable. the semi active diff and the electronic trickery controls the rest.

@dombou70 15 жыл бұрын

Considered buying a GTI and spending 3k on a stage1 upgrade of some kind? The chassis is a peach and can handle 320+ bhp with ease. Sure there'll be more torque steer then an RS with it's trick suspension, but it's also a VW, and to some... that's appealing.

@1001Hobbies 15 жыл бұрын

You have evidently been under a rock.

@sspope 15 жыл бұрын

Because the division that makes Mustangs is in America and the one that developped this is in Germany and they developped it for this car. It will take some time till Ammies start to use it.

@EdgyNumber1 14 жыл бұрын

@TheSaintST1 Hmmm.. given that the suspension system between Mk1 focus and Mk2 Focus has changed very little, I wonder if this could be retro fitted to Mk1 Focus.... has anyone tried this??

@woooster17 7 жыл бұрын

The only comment I can make is.. I own a Mk2 Focus ST and a Mk2 Focus RS, and there is truly a difference in feel between to the cars in the steering. That's without considering the rest of the chassis which is much better than the ST.

@xGiLL 7 жыл бұрын

Yeah, I've driven my mates ST and it doesn't compare to my RS

@draquine 15 жыл бұрын

I still don't get it but the FOrd Focus RS has great handling. Whatever it is...it works.

@JaySee5 15 жыл бұрын

What he says doesn't make sense. Honda used to make double wishbone FWD cars, but they still had torque steer. It can't be just the suspension, there's something in the LSD. Why's this a big deal? Didn't Honda already solve FWD torque steer years ago with the Prelude SH? Double Wishbone + Fancy LSD.