I would like to know what tyres are on the front Jabeo.
We have an old SW na which runs Toyo T1R all around and it handles fine. Can throw it through corners no problem. Being an na auto it's not a fast car in a straight line but it has led runs through twisties with those behind having fun trying to keep up. It works.
I had Potenzas on my AW and that car handled like a kart, it was epic. It's now mknz's AW and at the time had Isaac's hard low suspension. The rear tyres wore out so I replaced them with Toyo T1R as they had been great on that old grey SW and were a bit cheaper and have really deep tread so last for ages.
Went for a serious drive on the back road twisties past Lake Waikare. Oh hell WTF..? Back end of the car was all over the place scary as hell. At pace any steering input or any bump was down-right frightening. Got home, threw some Potenzas on the back instead. Sorted.
Why: Potenzas have a stiff sidewall designed for very precise steering response. T1R have much softer sidewall designed for a more comfortable ride.
If the only thing that changed was your tyres, then the Nankang must have softer sidewalls than the front tyres, in which case you'll be feeling the same wobbly arse end bizzo that freaked me out.
Solution: run the same make and model of tyres on both ends. That keeps the handling balanced, in the same way that T1R on both ends of an SW makes for slightly slower steering response but perfectly balanced handling, so you simply hit the steering wheel a split second earlier but the car responds predictably and feels fine.
Never run different makes and models of tyre front and rear or it may end up feeling like rubbish.
And absolutely never run differing stuff side to side (actually illegal if I remember rightly) or you may spin when hitting the brakes in an emergency due to one side sticking more than the other.
I will never understand why people want to save a few bucks on tyres. They are the only thing holding the car on the road, and therefore make ALL the difference regards handling, feel, cornering, traction, braking etc. Safety and driving confidence = decent tyres. End of story.
Also, run correct pressures. Not silly hard and not silly soft. Start with OEM and gently try 2 psi more or less at a time. Back end feels wobbly? Add 2 psi in the back, it may stiffen them a little and help stabilise, as if they had a stiffer sidewall. You let the pressure out. That's going to de-stabilise the rear end, make it even more wobbly.
Obviously you don't want them too hard or you'll lose grip especially in the wet. But not too soft or you'll have a floaty boaty, a wonky donkey.
Good book, that. Classic.
My red SW is not exactly standard. It has coil-overs (extra stiff ones) and wide tyres with low stiff sidewalls. Not cheap tyres either. They were developed for Ferrari and Aston. But despite the low sidewalls and 35 aspect ratio, I find that 2 psi less in the back makes all the difference in feel between being super planted and slightly iffy when pushed.
For that reason I run nitrogen as it has less variation with different temperatures (weather temperature, road warmth, wet road cooling the tyres etc) and therefore makes for more predictable handling.
To sum up: run the same make and model tyres front and back. Start with OEM pressures and carefully experiment from there, changing one end at a time by maybe 2 psi and see how it feels. Wobbly rear? More rear pressure. Or less front pressure.
I'm guessing you're not playing with adjustable shocks either mate. Like sway bars, they are another aspect of getting the balance right. Stiffer rear or softer front = more oversteer, stiffer front or softer rear = more understeer.
Regards wheel alignment specs, I've found that the OEM spec is pretty good, whether on a standard SW like our grey one or on a messed with one like my beastie bus. Basically it's more or less like this:
Front, about 0.5mm to 1.5mm total toe-in. About 1 to 1.5 degrees negative camber.
Rear, about 5mm total toe-in. About 2 to 2.5 degrees negative camber.
I don't know what those toe-in measurements are in degrees, the mm is the difference between the front and the rear of the tyres as measured between leading inner edges and trailing inner edges. See the BGB diagrams if you don't know what I mean. It's actually really simple.
The MR2 spec is around the other way compared to most cars regards camber. It's rear engined so the weight is on the back, hence more negative camber on the rear to stop the tyres rolling under the car during hard turn-in. In fact if you really want to set it up right, look at the weight distribution of an MR2 and thus run tyres that are about 10% wider on the back, about 10% more pressure on the back, and about 10% more negative camber on the back. Of course an SW being heavier and fatter in the arse than an AW means you might need a little better than 10% for an SW.
Anyway that balances the handling and makes it feel good cos the weight and the grip balance each other out. Simple really eh.
Also an MR2 is designed to have power added through-out a corner and not be under braking. If it were under braking in a corner you might want more negative camber on the front because the front end is loaded more than normal, but if you are under throttle in a corner you'll want more negative camber on the rear as the back end is loaded more than normal.
If you tend to brake through the first half of a corner and accelerate out of it you might think the car feels like understeer-oversteer (common SW complaint) but if that's the case re-train yourself. Think about it, the car can be set up for either braking in a corner (more negative camber up front) or acceleration in a corner (more negative camber at the rear). Choosing one option: Do all your braking before the corner then accelerate gently all the way though it. You might find the car feels a lot more planted and predictable. Sure as hell works for me.
You're a club member so you have search privileges. Use the Advanced Search feature and search posts by mickeyduck in Rides with the word "alignment" and see what you find. You'll get the OEM SW specs from the factory manual aka BGB, as well as specs from the Geddes brothers who race an SW in 2K cup, and the specs I run on my 500hp wants-to-kill-you-under-WOT-cos-of-that-grip-variation-from-a-bump-or-something SW.
I've outrun motorcycles on twisty back-roads many times in all my MR2's. I love playing with them and they never win. It's not because I have bigger cahoonas. I'm actually very sensitive to how a car feels and very seldom push it beyond the point where the rear or front tyres start to slide. In fact knowing how to keep it right at that limit and not go past it is the trick. That is the point at which you are extracting the maximum from the vehicle.
Confidence in the car makes all the difference and you'll only get that if the car is set up correctly. If your car is not on the right rubber it can never be set up correctly. Simple. Like walking on cheap sneakers on a polished concrete surface on a wet day. Dodgy as hell, likely to hurt yourself. Wear better sneakers with better tread, they stick, no worries.
Red soled sneakers = scary in the wet. Black soled sneakers = safe as houses. Cheap vs expensive. Sorry vs safe. Exactly like tyres. Case in point:
.
All things are NOT created equal.
Start by getting stuff worth getting. Go from there. Otherwise no amount of advice is going to help you.
I learnt that the hard way. Your turn.
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