Where's the snatchy handling thread gone ?

[teebee]

Remember ?
Reared its head when tyres were changed ? ESP cutting in ?

It's just that mine's at the dealers Friday (aircon's packed up ) and I wanted to get their view.

[182_blue]

i guess it was lost in the recent issues (2 months worth of posts have been lost)

[RedRobin]

....It was me who started that thread - I gotta dash out now but will update this thread here when I come back this afternoon.

Meanwhile, here's something nice to look at while I do my write-up : -


 

[RedRobin]

....Okay, following 'snatching' problems when enjoying driving enthusiastically, I had a long and very helpful phone conversation with Goodyear's UK tyretech support.

Firstly, the tyre industry as a whole recommends that on FWD cars where it's safe to mix tyre treads (but always matched on axles and never at all on AWD vehicles) that you run your deeper treads on the rear rather than the front. This of course assumes that your front treads are not threadbare! The basic reason is (as I understand it) that as you approach the limits of your front wheels you don't want your rear wheels to be heading off as too much oversteer - The rear needs stability. Anyroadup, it's the tyre industry recommendation.

On the subject of this thread and a 'snatching' or 'tugging' problem : - The Goodyear F1 Assymetrics have a special insert on the inside designed to reduce leaning and to keep more tread on the road. The internal structure of the F1 Assyms is also designed to reduce G-forces. The GSD3 F1's don't have this same structure and therefore when 'normal' F1's and Assyms are on the same car (but of course axle matched), there will be a differential in shoulder flexing when driving more enthusiastically.

What's happening with the 'snatch' (Hello, boys!!) is that the GTI's ESP reads an apparent difference in tyre behaviour which it assumes momentarily to be the beginning of a skid and it compensates accordingly by kicking in with a 'tug' on the system.

Swopping wheels so that the new Assyms are on the front and worn GSD3's on the rear will reduce instances of snatching but not when you are driving much closer to the limits - In which case you could potentially be more easily saying hello to your rear end overtaking you. Fun to watch that happening on the track perhaps, but not in your own car on a public road with many obstacles!

It's safer not to run too high a difference of tread between axles and it's ideal to run all the same treads on all wheels, but in the real world good tyres cost money and why throw away perfectly legal tyres?

Recently I have found less instances of the 'snatching' and still have the worn F1's on the front and new Assyms on the rear axle with about 500 miles driven. I did an enthusiastic 170 mile drive to and from Castle Combe last weekend in hot and dry conditions without any snatching at all.

If you've got any further questions on Goodyear/Dunlop tyre tech subjects, you'll find them extremely helpful (unlike Vredestein!!) 01902 453097, being a service for the public as well as dealers.

Also : -

Goodyear - Goodyear-Contact

Dunlop - Dunlop Tyre Center | Support | Tyre Clinic | Tyre Doctor


[/end of tyre lecture]

[joesgti]

errrrr.........1 question?!!!? and im going to sound DUMB so take this p!ss if you all like, but what the hell is snatching???  :embarassed: :embarassed:

[RedRobin]

....Not dumb at all, Joe - I forgot to explain it this second time around.

Going into a fast bend it feels as if the brake is suddenly applied on one front wheel - A sudden 'snatch' or 'tug' as ESP kicks in only for a slit second and the car continues. But it's random and very disconcerting until you know what's going on - Especially the first time it happened on a country B-road while 'making progress'.

HTH (Hope This Helps)

[topher]

So with ESP off, no snatching?

[RedRobin]

....I never drive on public roads with ESP off.

[topher]

ok but health and safety aside.. that's the plan?

[RedRobin]

....Sorry but I never put my safety aside on public roads.

Plans are:

1 - It's not 'snatching' at the moment, so carry on until it does - If it works, don't mend it.

2 - If it starts 'snatching' again, swop F1's to rear and Assyms to front axle and see what happens.

3 - My F1's will need replacing soon so I'll have Assyms on both axles - Problem solved or Goodyear will get more involved.

4 - Quaiffe diff in a few weeks may override the whole problem.

I always drive on public roads with ESP On, so that's why it needs solving for those circumstances. Yes, I know that ESP Off might establish something but the snatching has happened so randomly and infrequently I don't want ESP Off for so long to find out.