16" Wheels follow dips in the road. UPDATE: NOW WITH GEO SETTINGS.

[malcster]

Hi folks,

I have a set of 16" Super Advans, and the car seems to tramline - following any dips in the road etc.

If I was to drive it along an average side-road with the odd dip and pot hole, then let go of the steering wheel, it would be all over the place.
It's been the same ever since I've owned the car.

When driving along you can feel the wheel wanting to turn to the right or left as you go over minor dips etc.

I drove a civic once with 17" wheels and the same was happening with that.
But it all went away again when the guy changed back to the standard 15" wheels.

Is it the same reason here?

Also, before anyone recommends it, I have had a 4 wheel laser geometry setup done twice in the last year, second time was less than 1 month ago.

Cheers,

Malc

[dazzz]

What tyre pressures do you run?

I'd find a nice flat car park and test it under accel and decel.

[malcster]

28PSI at the fron 34PSI at the rear.
They're checked monthly too.

Also, I have ran it over a flat long surface and found no issues.
It's the same on the motorway for example, totally fine.

[Marf]

It'll be down to the wheel size/tyre combination.

Generally won't happen on a 15" wheel because you have enogh profile to soak up the little variations on the road, not so with larger wheels/lower profile tyres.

[malcster]

So is there any way to combat this? (other than going to the hassle of selling the 16" wheels, and droping to 15")?
Is there any way to modify the geo settings of the front wheels to stop it happening?

More or less Camber / Caster / Toe in / Toe out etc?
Or is it just something everyone with 16" wheels has to live with in order to have a little more grip at the rear?

The amount of times I've read "16 inch wheels are the optimum size for the MR2" I'm starting to wonder now...

[dazzz]

I run 32 front and 36 rear. I have 16s.

I would guess your problem is simply poo roads.

[riot68]

I have the same issue on my other car a Honda Accord, 17" wheels are standard on the car and low profile tyres, I am told it's just the price you pay for nice wheels that are better on good roads, just a bit worse on crap roads, although mine don't sound as bad as yours...

[jon_st205]

Have a look at your steering system too - the bottom UJ of the column, the track rods & the tie rod ends. Usually the track rod ends wear on all Toyota's, though less so on the MR2 without the weight up front. However it's not impossible, only a little bit of play can cause a lot of trouble.

Cheers,
Jon

[vishpish]

what suspension you running mate and what tyre sizes?

i went from a very low coilover setup to a standard ride height shocks and springs setup on my 205/45/16 front and 225/45/16 rear wheels.

noticed that the car seemed to bump steer like what your suffering, with the far lower suspension but not now at all!

[Blackmr2gltd]

Feel free to sell me your super advans! I'll p/ex my 15's

[malcster]

what suspension you running mate and what tyre sizes?

I had all the suspension compnants refreshed last year, so I am now Running brand new Black Bilstiens, with new Eibach -30mm springs.

Replaced droplinks and ball joints all for new items.
Also added Cusco adjustable Top Mounts (Set to standard at the mo).

Tyres were also new last year, Falken FK452s
Rears = 225 / 45 / 16, front = 205 / 50 / 16

[dazzz]

What geo settings did you have dialled in?

[jon_st205]

So you changed steering components or not? /invisible mode off

[GaryJ]

I also get the same problems described in the OP, my car came with 17" low profile aftermarket alloys and sometimes i can't relax when driving because some dips in the road kinda jolts the steering and the feels like its going to change direction for a second.

I'm having the alignment done as the tyres have abit of wear on the insides of the tyres, when i got the car 6 weeks ago the pressures was 20 on the front and 23 on the rear which was way too low. So i put it up to 30 on the front and 32 on the back.

[malcster]

So you changed steering components or not?

I have refreshed the suspension components listed above.

Not changed steering componants specifically, haven't track rod ends as yet - they seem to be fine, not much play in them.

Anything else you could recommend checking?

What geo settings did you have dialled in?

I've had 2 Geo settings done, first time was after replacing the dampers and top mounts.
This first one it was interesting to see how it'd been set up in the past - the initial values show a pretty tail-happy toe'd in rear.
Anyway, I had them re-set to Toyota's standard values that the garage had:




Second Geo Settings were applied after I changed the Droplinks and Ball joints.
Here I had Dino's settings (found on this site somewhere) added at this point:




...and that's where it's stayed.

[Moo]

Your toe settings are ok but front and rear camber values look a bit out, especially the right rear. The left rear is only just within spec too.

http://www.imoc.co.uk/forums/viewtopic. ... 19&start=0

I'm on 17" rims and don't get any tramlining at all. My camber settings are all at the preferred value of Dino's figures.

Not saying your camber is the cause of your tramlining, but if you've ruled out all other possibilties it might be worth getting the camber dialled in a bit closer. It might not fix the tramlining issue but given you have a fairly high camber variance between each wheel on the same axle you'd probably find it would improve your handling anyway.