Bloody understeer and strange handling.

[CJ B]

Hi,
I'm new to mr2's and cannot belive how happy my car is to go straight on instead of going round the bend like i tell it. When I bought the car it had aftermarket 16" wheels with crazy size tyres (205/55/16 all round!) which I replaced with standard 15's with Yoko a-022's.
The car now sits a little lower but the handling didn't change as much as I had hoped for.
Also every once in a while when I go over a bump the steering seems to get upset and pull to one side briefly.

There are no strange noises from anywhere (except the stereo maybe ) and the brakes dont bind.

Anyone got any ideas?

Cheers,
Chris.

[Baker]

thats understeer.

[CJ B]

thats understeer.

Thanks for spotting that one - I edited the title.
How was my speeling?

[pizza boy]

Understeer? Strange handling? That must be an mr2 you have there

Maybe its the tire choice...Goodyear F1s are well rated with mr2s. Do you have the correct stock 15" size ? F=195/55 + R=225/50. Also ya got it re-aligned since the change in wheel size?
Im running "master bates"kangs up front..understeer central...
Is it in the wet where your gettin problems? I never had understeer probs in the dry..only wet.

[raptor95GTS]

to be fair the roads are pretty rubbish so you have to be real careful out there otherwise you are heading to the nearest ditch.

this time of year is not the time to be setting your best lapshowever check the obvious

get a 4 wheel laser alignment done
check your tyre pressures I tend to run 30 at the fronts and 32 rears

try not to hit the brake and throttle at the same time ( don't laugh heard it done and have done it myself)

[pizza boy]

Big feet eh?..nightmare

[jonno]

What tyre size did you change to? And did you get the alignment checked?

http://www.mr2mania.com/page.php?28

I use those settings on mine and they are fantastic.

Neil.

[raptor95GTS]

Big feet eh?..nightmare

yeah but dead easy to do when you are trying to blip the throttle for the downchange. Turns out I'm realy xxxx at that too

But if you wear any kind of boot you'll likely catch both pedals

[pizza boy]

Heh I have mastered the good ol shift blip ..altho to heel and toe it is nigh on impossible for me..

[raptor95GTS]

What tyre size did you change to? And did you get the alignment checked?

http://www.mr2mania.com/page.php?28

I use those settings on mine and they are fantastic.

Neil.

i assume you used dino's settings?

[BenF]

Hi,
I'm new to mr2's and cannot belive how happy my car is to go straight on instead of going round the bend like i tell it. When I bought the car it had aftermarket 16" wheels with crazy size tyres (205/55/16 all round!) which I replaced with standard 15's with Yoko a-022's.

<snip>

Anyone got any ideas?

Cheers,
Chris.

Chris, in a word - tyres. A-022s are fine in the dry, but they're an early 90s OEM spec tyre for the MR2, and in the damp and wet weather they're no match for F1s or S03s in terms of wet grip.

I'd check tyre pressures and also get an alignment somewhere I trust to do it properly - eg. Elite in Dagenham, London

[CJ B]

Thanks all for the pointers, to answer some of your questions -

The tyres are standard sizes with correct tyre pressures.
The car is a rev1 turbo which would of originally been fitted with 14" wheels.
Yes the weather whilst I'm cornering is wet, bloody horrible cold and wet - one of the 'perk's of living in England!
I read the tyre reviews on the old site and I think I will try the Bridgestone SO3's next - I didn't read about the F1's and the site is no more , with all the sliding around I'm doing it shouldnt take long to finish off the Yoko's.
I havn't had the alignment checked at all since owning the car so I think that will be my starting point.

I understand that the whole suspension was revised around '92, what are the differences and is it worth upgrading to later spec? Also what is the best (cost effective) aftermarket suspension set up i.e. lowered springs / new shocks / nicking a roadroller and re-surfacing the roads.
Also what wheels / tyres will fit the car? Can I put 285/35/19 & 225/40/19 on and have more rubber touching tarmac than a car park full of clio's? (I guess it would still be pretty crap in the wet / snow but would climb walls in the summer )


Cheers,
Chris.

[Patrick Gray]

it would be a good idea to give the suspension the once over aswell,check drop-links and balljoints etc.

[jonno]

i assume you used dino's settings?

Yes!

[SimonPearse]

the idea that bigger wider wheels = more rubber on the road is a common myth. The amount of rubber on the road is affected by the cars weight and the tyre pressure. e.g. a tyre inflated to 30 psi and carrying a load of 450 lb will have a contact patch of 450/30 =15 sq in.
If you don't believe me do a web search.

[jonno]

the idea that bigger wider wheels = more rubber on the road is a common myth. The amount of rubber on the road is affected by the cars weight and the tyre pressure. e.g. a tyre inflated to 30 psi and carrying a load of 450 lb will have a contact patch of 450/30 =15 sq in.
If you don't believe me do a web search.

Dont believe everything you read on the web...

If what your saying is true why do Lamborgini's run 325 wide rears? and why does my girlfriends Vauxhall corsa run 165's? Why do F1 cars run wider rears than fronts?

Tyre width makes a *huge* difference. We all know that pressures and the weight of the car affect the contact patch but the biggest single factor are the tyre dimensions.

Neil.

[Lauren]

[quote="try not to hit the brake and throttle at the same time ( don't laugh heard it done and have done it myself)[/quote]


Unless you are heel and toeing of course when it is essential to have your foot over both pedals.

[raptor95GTS]

the idea that bigger wider wheels = more rubber on the road is a common myth. The amount of rubber on the road is affected by the cars weight and the tyre pressure. e.g. a tyre inflated to 30 psi and carrying a load of 450 lb will have a contact patch of 450/30 =15 sq in.
If you don't believe me do a web search.

Dont believe everything you read on the web...

If what your saying is true why do Lamborgini's run 325 wide rears? and why does my girlfriends Vauxhall corsa run 165's? Why do F1 cars run wider rears than fronts?

Tyre width makes a *huge* difference. We all know that pressures and the weight of the car affect the contact patch but the biggest single factor are the tyre dimensions.

Neil.

if you spread the same weight over a wider area the pressure per square inch goes down but this is offset by having a gripper rubber and more of it.

But remember on ice the rally cars use narrower tyres as do f1 cars in the wet

ALso the fronts only steer whereas on f1 cars they also transfer the engine load to the ground hence doing more work.

Think how easy it is to drive ford ka in snow in comparision to an mr2? The Ka is lighter and has skinny tyres that dig in and grip.

[raptor95GTS]

try not to hit the brake and throttle at the same time ( don't laugh heard it done and have done it myself)

Unless you are heel and toeing of course when it is essential to have your foot over both pedals.

aye true. I find when I try to blip the throttle to match the revs I either

stop pressing the brake pedal as hard and xxxx up the braking zone
or
when I blip the throttle the revs go too high and the car lunges forward under the brakes and I xxxx up the braking zone

ho hum

[Lauren]

practice, practice...

It took me about 3 months of practicing before i could do it and a bit more honing of it to get it nice and quick rather than just for show.

I find i can do it in any car pretty much these days as i find i tend to drive heel and toeing normally so like anything with driving if you do it enough it becomes second nature eventually.