How I solved my ibiza understeer cheaply

[Ibizainjection]

Hello everyone, I'm new here, just bought my first 2002 mk3 ibiza 20vt half a year ago.
I read so much about suspension parts, coil-overs and stuff, but looks like the cure is realy simple and cheap!

My car is completely stock.
I never liked the handling of the car, nor the ride quality and "jumpiness".
Playing with air pressure (higher front, lower rear) did only a small change but made the ride terrible on bad roads.
Yesterday I went to do wheel alignment for the car, asking for a 1.75 negative camber on front which is outside the manufacturer limits (limits are 0 to minus 1 degrees front, and -1 to -2 rear).
the guy really was afraid to tune it that way, since he was never asked to exceed the manufacturer recommendations.
finally the guy set it to -2.6 degrees front, and actually it could be pushed even more.

The change in the handling of the car is so noticeable.
when I enter a slow turn, increasing more and more the steering input, the cars just increase more and more its turning, without reaching a point where I increase steering but hardly increas turning. The handling is very neutral.

On quick turn-in, if a very gentle brake is applied, the rear end just step immedietly outside. It is also hapening almost "on demand" when I lift off, gets the car quickly turn its face where I want it, and then hit the gas to stop the rear slide and accelerate.

It cost so little, and now actually I feel like I am driving a peugeot, not a seat.

Nevertheless I am considering fitting a rear ARB to make turn in really crisp.

 

[m0rk]

watch your shoulders on the tyres with that much camber, you'll see them gone in about 6k.

check the rear shocks for leaks too, they're the first to go & are pretty much useless by 9000miles from new.

 

[Ibizainjection]

watch your shoulders on the tyres with that much camber, you'll see them gone in about 6k.

I guess you are right about the INNER sholders taking most of the weight now and wearing off quickly. theoretically.

The situation with my car is, The tires drove about 15,000 km, yet there is no visible wear on them (they are the medicore Falken 512).
But after only 40km of track driving (slow track with almost no straits), the front tires got realy realy bad on the OUTSIDE shoulder, and this has happened with a high air pressure, I guess it would be worse with lower pressure.
So, when I will replace tires it will be due to the wear on the OUTSIDE shoulder.
I am hoping that more negative camber will even the pressure on the front tires during track driving, therefore lessen the wear of the outside and actully prolong the front tires life.

check the rear shocks for leaks too, they're the first to go & are pretty much useless by 9000miles from new.

I bought the car after about 105,000km, they checked on that machine that shakes the car, and it showed all 4 shocks are ok, meaning have very slight diffrences between them, in terms of force and efficiency.

 

[Nautilus]

Hello

Just found out your other thread on the same matter and asked a few questions:

Elimination of understeer - cheaply

Thank you,

~Nautilus

 

[Ibizainjection]

Hello

Just found out your other thread on the same matter and asked a few questions:

Elimination of understeer - cheaply

Thank you,

~Nautilus

What is your question? The other thread was deleted.

 

[DPJ]

Does it work for the MkI Leon too?...

I've been pretty content with the car handling as long as I ran the crappy P6000 tyres - they gave up far before suspension could do the same now as I run Goodyear F1 Asymmetric, they grip like motor oil on someone's new silk shirt but suspension now had found its limit, understeer is easily felt in hard turns. Increased tyre pressure to 2.7bar front and 2.4bar rear, this improved handling and ride too (higher pressure Goodyears act better on potholes and speed bumps!)

I try to find a way to increase handling precision, and at the same time to allow some ability to drift (I'll buy some crappy discarded tyres for that!)

Considered rear anti-roll bar for some time, still an option. Heard that VAG rear axle incorporates an anti-roll bar as well. If there is a thicker bar from another similar model which can be made to fit the Cupra/FR it would be even better since it's invisible and doesn't catch on speed bumps like ARBs with links can do.

Thank you,

~Nautilus

.......

 

[andycupra]

am i the only ones whos worried that if you are rounding a corner and are required to slow in a hurry you may arrive at your destination going backwards? although i guess this depends how much of a difference there is.
I thought that the rear end coming out was an issue already on the ibizas?

i particularly like the fact the mechanic was hesitant to set it to -1.75 and then after some persuation set it to -2.6...

 

[Ibizainjection]

Nautilus, sorry about your new silk shirt.
If the new F1 tires grip great, why dont they grip great in the front as well as in the rear? I dont know if it is right to say something like "the suspension gave up, and when suspension gives up it means understeer."

Andycupra, I like the rear coming out since it is fun to induce and control, and it means I am closer now to the real potential of the car since it is balanced (sometimes understeers, but sometimes oversteers).

I guess it is more dangerous now to brake unexpectedly in the middle of realy tight turn, but the rear side steps out and the car immedietly loose some speed which alows it to quickly stop sliding, especially if the driver knew it was coming, and made immediat steering correction (it is enough to move the steering wheel a little bit towards the middle to stop the little slide, you dont realy have to make opposite lock, unless you realy late to react.

 

[ibizacupra]

thats a mad amount of camber for road use...

do you encounter road works in your part of the world?
steering must pull like a mofo

 

[rich.h44]

I might try a bit of negitve camber!sometimes. My front end is glued 2 to road,otha time it understears like its on ice

 

[Ibizainjection]

thats a mad amount of camber for road use...

do you encounter road works in your part of the world?
steering must pull like a mofo

I encounter alot of bad roads and potholes, actually the good grip in the front alowes me to reduce air pressure in the front and still get decent grip, so ride quality improves noticably.

I do feel a momentary pull aside when I drive over a pothole with only one side of the car, but eventually the car stays in the original direction. This annoying little "shake" might be due to toe setting, which I know I have about 5mm total toe in the front and in the rear, just dont know if it is toe out or toe-in. toe-in usually improves stability in strait line.

 

[Nautilus]

Nautilus, sorry about your new silk shirt.

It was a metaphor. I never got so pathetically unlucky in my life (yet)

If the new F1 tires grip great, why dont they grip great in the front as well as in the rear? I dont know if it is right to say something like "the suspension gave up, and when suspension gives up it means understeer."

Tires do grip great. Suspension, alignment are not up to the task. That is, on crappy P6000s I lost grip plenty of times, got skidding (usually outwards wheel) like on ice, before understeer could be felt, and on standard cars, when speed slows by any means including skidding, understeer reduces itself. Now F1s do no longer skid, but in high-speed turns nose still appear to point "outwards" from the curve and speed has to be slowed - what is this if not understeer?...

~Nautilus

 

[Nautilus]

Tested the car a bit ago, on some deserted highways, mostly to see if the new coil pack fires well. Got up to 180km/h on some stretches.

Tires: Goodyear F1 Asymmetric
Tire pressure ~2.7bar front, ~2.3bar rear.
Suspension: FR factory sport suspension
Alignment: never checked, supposedly in factory parameters
Gear change: Forge Adjustable Quick Shifter set to (about) middle position

Conclusions:

- lane changes: almost neutral;
- wide high-speed curves: almost neutral with a barely perceptible hint of understeer
- tight curves, up to 90 degrees: almost neutral, slight oversteer when braking gently or releasing the throttle

Future prospects: should I increase negative camber front - decrease negative camber rear, in 0.25-degree steps?...

~Nautilus

 

[Ibizainjection]

Future prospects: should I increase negative camber front - decrease negative camber rear, in 0.25-degree steps?...

~Nautilus

If you ment asking me- I am not an expert.
I know that in my car, the rear beam suspension is not adjustable. You need to torturedly stretch it with a body jack to change toe, I guess rear camber can also be changed the same way, but stretching is expensive, inaccurate and why bother? dont reduce the traction of the rear, its better to improve the front.
If you like the handling of your car as it is, keep it.
If you want less understeer more oversteer- use more negative camber in the front, but I think you will not notice any change if you change it only by 0.25 degrees.

 

[Nautilus]

Thank you

I've asked about the rear setting because in the sport-suspension equipped Leon rear negative camber is visible, one can see the rear wheels slanted inside like this / --- \ (and factory advice for tyre pressure is aimed towards understeer as well, they recommend to increase rear pressure up to 3bar when car is loaded in the rear)

I wouldn't risk to jump to -1, -1.5, -1.75 degrees front without testing, that's why I would try in 0.25-degree steps (and I know, each step of adjustment is costly )

~Nautilus

 

[Ibizainjection]

The front negative camber in my car is visible too.

 

[rich.h44]

Got any pics mate?

 

[Ibizainjection]

Got any pics mate?

Yes,
one picture shows the negative camber in the front,
the other shows the new goodyear F1 GS-D3 with the wheel turned, and you can still notice the wheel is cambered.

Actually now with the grippy goodyear on the front wheels only, the car is so much fun! I can slide gently the rear even at 25 km/h ...
I have excellent turn-in when doing so with a bit of brake applied.
when on the limit you can feel the rear on the verge of sliding, and if it does its really gentle and controllable (and self diminishing as well).

link to pictures

 

[George K]

if it is any help the Clio 182 with the cup packs run 0.10' to 0.20' minutes toe-out.