understeer ?

[deg]

never really drive my car that hard but last night i was giving her a wee bit of petrol and the understeer was actually a bit scary was wondering if this was common with vectras or is there something im missing ?
the car is an sri with cheap 18" tyres although the tread is 80% could this be the reason ? just looking opinions please

[mark1319]

Can be sorted with some grippier tyres, firmer suspension, strut brace etc. Anything that stiffens the chassis will help, but tyres are the first thing to think about IMO, if you put some good quality rubber the difference will be night and day

[Big Sig]

Cheap tyres? One of those nice comedy Asian makes?

[BlueRob]

buy a decent tyre....makes the car feel like something else. You might also want to check the suspension itself

[boba]

Tyres aren't the biggest cause on dry roads but if it's wet it's a different matter. Also how often do you do this sort of thing? If you bottle things a bit you will lose the traction which is almost the only thing hauling you round the corner. But it will never be the same as a RWD, especially in the wet. Also big wheels with a hard ride should be matched into improved suspension otherwise you will just get more skittering around - a hard ride isn't the same thing at all as good roadholding although lots of people seem to think so.

[deg]

yeah the tyres are cheapie jap things, the car is also lowered with stock sri dampers. the conditions were a bit damp but even so, the car just basically wanted to go in straight lines, would i be better accelerating through corners ? i thought this would transfer weight to the back making the steering worse?

[mark1319]

Slow in, fast out. Enter a corner with reasonable speed and hold the throttle on gently then when exiting the corner feather the throttle to pull you out. Try going round a corner with no throttle then do as above and you'll feel the car gripping as you apply the throttle

[BlueRob]

Tyres aren't the biggest cause on dry roads but if it's wet it's a different matter. Also how often do you do this sort of thing? If you bottle things a bit you will lose the traction which is almost the only thing hauling you round the corner. But it will never be the same as a RWD, especially in the wet. Also big wheels with a hard ride should be matched into improved suspension otherwise you will just get more skittering around - a hard ride isn't the same thing at all as good roadholding although lots of people seem to think so.

Sorry to disagree...there are tyres on dry roads that are crap....some are good on dry a bad on wet (most) and some are good on wet an bad on dry....a good tyre handles well on both

[boba]

If you freewheel round the corner there's only the tyre friction to get you round and there's the whole of the car's momentum to carry you happily into the far field . In the wet there's not a lot of the friction but there's the same amount of momentum.

If you ease in the power the increased pull will more than compensate for any weight transfer. You just need the confidence to do it when it seems as though you will just go off the road a bit faster. . Just don't stamp your foot through the floor (and don't hit the brakes either).

[boba]

there are tyres on dry roads that are crap....some are good on dry a bad on wet (most) and some are good on wet an bad on dry....a good tyre handles well on both

True, but unless you're driving track tyres they're all better in the dry even the best ones aren't they. I've certainly never driven a road tyre which actually gripped better in the wet!