Need some advice with braking/turning issue

[ka-mai]

I have a question...

Ive been tweaking the tune settings on my fave cars and there's an attribute which keeps raising its head and I'm curious how I should go about "tuning it out"... i will try to explain...

The attribute is evident when I'm hitting a corner hard and ill brake round the bend (usually setting the brake bias more on the rear - say 5 and 8 front / rear) to get a slide going. The car will steer nicely into the corner but as soon as I put power on fully to maintain the slide and back off the brakes, the nose swings out again, instead of pushing the back out and turning in as I would expect, and I have to brake and steer hard back into the corner again.

Its quite a regular occurence - i mean visible on many cars.

Generally im lowering the front spring rates, raising the rear, increasing the front tow in and reducing the rear. Ie generally going for more oversteer rather than understeer.

Any ideas what's causing this? I'm a bit lost and its ruining the fun driving otherwise great cars :-)

Thanks alot!

 

[dr_slump]

You should do exactly the opposite with the spring rate: front hard, rear soft!
Raising the rear is also in the most cases the wrong way. Try a higher front than rear!

Sometimes, a negative rear toe has the opposite effect and reduces oversteer. Weird I know.


Try this:
Front stiffness max. (springs, dampers, bars)
Rear stiffness min. (springs, dampers, bars)
A higher front than rear ride height.

=MASSIVE OVERSTEER!

 

[ka-mai]

You should do exactly the opposite with the spring rate: front hard, rear soft!
Raising the rear is also in the most cases the wrong way. Try a higher front than rear!

Sometimes, a negative rear toe has the opposite effect and reduces oversteer. Weird I know.


Try this:
Front stiffness max. (springs, dampers, bars)
Rear stiffness min. (springs, dampers, bars)
A higher front than rear ride height.

=MASSIVE OVERSTEER!

Thanks, Im a bit of a nube to tuning, does that mean I should raise the values (for want of a better word) for the all the front items, and lower the values of the rear items, ie Spring rate, shocks, and bars? ie the opposite of what Ive been doing?!

Will work with default toe-in until i sort out the above, i think.

Can't try it right now... kids, bed, wife watching news, cooking, etc. But later... :-)

Its tricky to know what to do with all the variables to adjust.

 

[praiano63]

I have a question...

Ive been tweaking the tune settings on my fave cars and there's an attribute which keeps raising its head and I'm curious how I should go about "tuning it out"... i will try to explain...

The attribute is evident when I'm hitting a corner hard and ill brake round the bend (usually setting the brake bias more on the rear - say 5 and 8 front / rear) to get a slide going. The car will steer nicely into the corner but as soon as I put power on fully to maintain the slide and back off the brakes, the nose swings out again, instead of pushing the back out and turning in as I would expect, and I have to brake and steer hard back into the corner again.

Its quite a regular occurence - i mean visible on many cars.

Generally im lowering the front spring rates, raising the rear, increasing the front tow in and reducing the rear. Ie generally going for more oversteer rather than understeer.

Any ideas what's causing this? I'm a bit lost and its ruining the fun driving otherwise great cars :-)

Thanks alot!

Understeer out of a corner mean:

- front swaybar to hard
- Excess of front toe (+ ou - )
- Rear swaybar to soft
- Rear suspension (compression) too soft.
- Front suspension (rebound) too stiff.
- too much downforce (if you use wing)
- Front springs too stiffs
- Rear springs too soft

Set each point one by one ,after if not resolve try combinations, take note to come back on your old setting if necessary.

 

[ka-mai]

Understeer out of a corner mean:

- front swaybar to hard
- Excess of front toe (+ ou - )
- Rear swaybar to soft
- Rear suspension (compression) too soft.
- Front suspension (rebound) too stiff.
- too much downforce (if you use wing)
- Front springs too stiffs
- Rear springs too soft

Set each point one by one ,after if not resolve try combinations, take note to come back on your old setting if necessary.

thanks a lot, will dabble! But just one thing, what does too stiff/soft mean in terms of the values ? Is the higher number stiffer/harder and lower softer? Sorry if Im being stupid here. Just Im having difficulty correlating the numbers to the "realworld"!

 

[praiano63]

thanks a lot, will dabble! But just one thing, what does too stiff/soft mean in terms of the values ? Is the higher number stiffer/harder and lower softer? Sorry if Im being stupid here. Just Im having difficulty correlating the numbers to the "realworld"!

Yes ,value = number.There a specific value for each tune. In your case the problem is that you're above and under this value. Take your actual number and increase or decrease 1 point by 1 point ,till you find the good balance.
No problem, it's a pleasure to help you.

 

[shifty1]

thanks a lot, will dabble! But just one thing, what does too stiff/soft mean in terms of the values ? Is the higher number stiffer/harder and lower softer? Sorry if Im being stupid here. Just Im having difficulty correlating the numbers to the "realworld"!

Stiff = High value
Soft = Low value

Springs for example {2.8 - 15.0} 3.4 = soft, 14.5 = stiff

Check out Scaff's tuning guide (PDF links). It's heavy on weight balance theory and the three parts to cornering/turning.. You have to read it, but it will raise your GT I.Q. by a ton. He also explains the proper(IMO) method and sequence to balancing the weight of the car first. You'll realize your driving style may be more aggressive than needed to be, or you can adjust based on aggressive style. Good stuff

 

[Taunto_Svt]

Why not set up your lsd to run a more open style diff. Maybe you have it locked. Try bribing your acceleration numbers on the LSD settings down and see how that works for you

 

[Wintermute.]

May I ask which cars you're attempting to tune?

 

[georgiebest]

You should do exactly the opposite with the spring rate: front hard, rear soft!
Raising the rear is also in the most cases the wrong way. Try a higher front than rear!

Sometimes, a negative rear toe has the opposite effect and reduces oversteer. Weird I know.


Try this:
Front stiffness max. (springs, dampers, bars)
Rear stiffness min. (springs, dampers, bars)
A higher front than rear ride height.

=MASSIVE OVERSTEER!

Those settings are completely wrong? That would cause massive understeer?

Oversteer occurs when the weight of the car is transferred to the front. To do this you need to have soft front springs, stiff rear springs or a lower ride height at the front than rear.

To the original poster. If this is only occuring when you apply throttle then I would suggest altering the rear springs. When you apply throttle you are accelerating the car, and therefore the rear springs will be doing the work, the front springs will have very little to do.

You are trying to achieve oversteer, so stiffening the rear springs will mean that when you apply the throttle, the car will transfer less weight to the rear, and keep more at the front end of the car which will give you over-steer.

You could also lower the front end of the car to give more general oversteer effects that will be apparent even when you are not throttling the car.