Car Question - Someone Should Be Able to Help

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 12:34

Hey all

After fitting oversized alloys because I had them lieing around in my garage and it was cheaper for me to fit them instead of buying 4 new tyres, my MK3 Astra is now experiencing alot of bump steer, its an annoying pain in the ass, as if the car is steering with a mind of its own! The increased size in wheel has obviously made the angle of the drag link steeper.

Will lowering the car help to solve this issue? Just to change the springs, not expensive full setups.

One of you mechanically minded guys or girls may know..

.. save me the hassle in talking to chavs on modified car forums...

Thanks

Lee

Maver-Nick · Post by **Maver-Nick** » Jan 26th, '06, 13:18

Gallon of petrol and a box of matches...

That'll sort it...

Stick to the bike...

1blue · Post by **1blue** » Jan 26th, '06, 13:30

SRAD-NICK wrote:Gallon of petrol and a box of matches...

That'll sort it...

Stick to the bike...

Lee wrote:The increased size in wheel has obviously made the angle of the drag link steeper.

Why do you say that? I don't think the wheel size will affect the drag link angle.

Dump steer is a comon problem when you change wheel dia or width. Often caused by the extra trail of a bigger wheel or the extra leverage of a wider wheel. Also the new tyres are often stiffer and translate more loads to the steering as well. Its not easy to sort out sometimes.

Maver-Nick · Post by **Maver-Nick** » Jan 26th, '06, 13:32

1blue wrote: Dump steer is a comon problem when you change wheel dia or width. Often caused by the extra trail of a bigger wheel or the extra leverage of a wider wheel. Also the new tyres are often stiffer and translate more loads to the steering as well. Its not easy to sort out sometimes.

Yeh...I agree...

Me and my mechanical skills that is...

chris_1127 · Post by **chris_1127** » Jan 26th, '06, 13:35

if you just change springs wont you get problems with the shocks bottoming out? plus, itll probably just mean that you feel every single bump that sends you into the kerb/on to the wrong side of the road more. silly q maybe but the wheels are the right offset for your car?

my old car didnt have massive wheels (195 15's) but was on konis with shorter springs (combined with pas), it used to be all over the place on bumpy roads. its worth getting tracking done too to make sure its spot on too to minimise it

sonic · Post by **sonic** » Jan 26th, '06, 13:38

might be worth checking the balance and the tracking before changing anything too drastic! also did the rims need spacers?

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 14:15

The standard offset is ET49, my wheels are ET42.. so 7mm out is fine and there is no rubbing. Had the tracking done yesterday as this was also 10mm out, dropped it into Kwitfit in my lunch break and took them hour and a half! Vauxhalls have there steering track rod ends at the top of the wheel arch.. stupid idea, gets covered in crap and seized up..

The wheels are wider as well.. and low profile tyres. How do the thousands of cars with aftermarket wheels overcome this?

The handling is vastly improved on nice smooth twisty roads, but through town or lanes.. steers into every bump, hole..

I thought that maybe a change in ride height could help to decrease this problem slightly. But I now know that I'm running correct tyre pressures, correctly balanced and now tracking is perfect.

Lee

Gingey · Post by **Gingey** » Jan 26th, '06, 15:28

sonic_gsxr wrote:might be worth checking the balance and the tracking before changing anything too drastic! also did the rims need spacers?

There you go, the guys hit the nail on the head, those are definately the first two things you want to check. Another chance is that the wheels dont fit around your 4/5 wheel axles......sounds stupid, but they are trying to make it illegal to put anything other than brand alloys on matching cars as these other makes simply dont fit, causing huge problems and possible danger all round. Is it a constent problem or does it only happen at a certain speed?

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 15:32

I said above the balance and tracking are spot on, and it doesnt require wheel spacers. Its a 1995 car, and the wheels fit the car exactly and perfectly, its not such a dangerous issue, just an annoyance to drive, its not like the car is going to drive off the road, I am holding the wheel, but you can feel it moving in your hands.. when I go throwing it about its fine and dandy.. but your average country road feels every single contour and wants to steer into them.
Lee

chris_1127 · Post by **chris_1127** » Jan 26th, '06, 15:53

all your wishbone bushes, balljoints and top mounts ok?

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 16:02

All as they should be, had everything checked over whilst it was on the ramp yesterday.

chris_1127 · Post by **chris_1127** » Jan 26th, '06, 16:05

you could try trading it in for a mk2 golf, thatd make it handle a lot better ;)

baskie · Post by **baskie** » Jan 26th, '06, 16:12

sonic_gsxr wrote:might be worth checking the balance and the tracking before changing anything too drastic! also did the rims need spacers?

lol exactaly what i was gonna say, taking typres on and off putting noew rims on and off bound to have an effect, get them aligned.

aslo if u fitted biger rims, they not hitting the wheel arch wen u go over bumps, might need a stiffer damper.

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 16:13

Funny you should say that, nearly traded the bike against one just before christmas. But he wanted too much for the car, £1650!! and only offered my £1000 for the bike.. the car will only be here till early summer anyhow, and then I can afford to upgrade.

Lee

ZXR400Lee · Post by **ZXR400Lee** » Jan 26th, '06, 16:15

I'll just put up with it.. I only drive 310 miles a week to work and back. Roll on summer time, just take the bike to work, but will have to fill the tank 3 times per week..