FWD oversteer!
Discussion
My Quantum 2+2 RST is basically a Fiesta XR2 with an Escort Turbo MK3 engine tuned to approx 180 bhp.
It has Spax adjustables with 1.4 springs on front and Spax adjustables with 1.1 springs on the rear. The car weighs 800kg.
My problem is it wants to oversteer and hence feels a bit strange for a FWD car as most understeer.
Because it was made from an XR2 it has a rear antiroll bar and I have considered removing it or adding one to the front.
Any one here know how to set up a safe Fiesta XR2 please?
It has Spax adjustables with 1.4 springs on front and Spax adjustables with 1.1 springs on the rear. The car weighs 800kg.
My problem is it wants to oversteer and hence feels a bit strange for a FWD car as most understeer.
Because it was made from an XR2 it has a rear antiroll bar and I have considered removing it or adding one to the front.
Any one here know how to set up a safe Fiesta XR2 please?
whats the geometry set up on it at the mo like?
if the rear end is toeing out, that will cause over steer issues as the rear wheels try to steer
usually, just the rear ARB is used to induce understeer, but as i'd imagine the Quantum weighs less than the car its based on it may be worth a try with the rear ARB disconnected
if the rear end is toeing out, that will cause over steer issues as the rear wheels try to steer
usually, just the rear ARB is used to induce understeer, but as i'd imagine the Quantum weighs less than the car its based on it may be worth a try with the rear ARB disconnected
trackerjack said:
My problem is it wants to oversteer and hence feels a bit strange for a FWD car as most understeer.
Because it was made from an XR2 it has a rear antiroll bar and I have considered removing it or adding one to the front.
Why would you want to increase understeer on a FWD? Is it really that bad to drive?Because it was made from an XR2 it has a rear antiroll bar and I have considered removing it or adding one to the front.
mk2 24v said:
Usually, just the rear ARB is used to induce understeer
Say what now? ARBs increase load transfer across the axle which reduces grip. A rear bar will induce oversteer.I think.. I think a rear ARB with some stiffness compared to a front ARB with none (because it's not there) will induce a bit of oversteer. I thought toe out would reduce oversteer?
Eitherway my advice would be to let it oversteer, it's a FWD, power out of it
http://www.youtube.com/watch?v=gPCGnkApnDU
Eitherway my advice would be to let it oversteer, it's a FWD, power out of it
http://www.youtube.com/watch?v=gPCGnkApnDU
I presume your talking about toe out on the front axle
Toe out will make the car turn slightly quicker into a corner
Toe in will turn in slower
You should really have it set to 0deg
However the change in feel isnt that much from in to out tbh I very much doubt this will cause your car to oversteer.
Have you checked the real alignment ? The rear wheels should toe in slightly. This will have more of affect how the car handles.
From what you have posted id think the problem will be somewhere else on the car possibly the springs. You have 2 different springs on but you havent said the spring rating of them. I presume you are thinking the ones off the higher engine car will be a harder ? Id would of thought springs from a 1.1 + 1.4 Fezza would be the same ( im guessing at that ) Are the springs off the same age car ? Possibly they changed the rating on different dates / years ? Worth a check.
The ARB will take away grip from the end of the car that its fitted to. So if you only have one on the back possibly thats your problem. Easy way to check this is just take it off and go for a drive see what it does.
Give me a shout if you want any more info
Toe out will make the car turn slightly quicker into a corner
Toe in will turn in slower
You should really have it set to 0deg
However the change in feel isnt that much from in to out tbh I very much doubt this will cause your car to oversteer.
Have you checked the real alignment ? The rear wheels should toe in slightly. This will have more of affect how the car handles.
From what you have posted id think the problem will be somewhere else on the car possibly the springs. You have 2 different springs on but you havent said the spring rating of them. I presume you are thinking the ones off the higher engine car will be a harder ? Id would of thought springs from a 1.1 + 1.4 Fezza would be the same ( im guessing at that ) Are the springs off the same age car ? Possibly they changed the rating on different dates / years ? Worth a check.
The ARB will take away grip from the end of the car that its fitted to. So if you only have one on the back possibly thats your problem. Easy way to check this is just take it off and go for a drive see what it does.
Give me a shout if you want any more info
theshrew said:
You would defo not want a FWD car to oversteer as you have a lot less chance to catch it than you have with RWD.
Absolute rubbish. Oversteer in a FWD, apply lock and nail the throttle. Slide aborted.What do you do in a RWD? Nail the throttle? More oversteer. Lift off? More oversteer.
theshrew said:
You would defo not want a FWD car to oversteer as you have a lot less chance to catch it than you have with RWD.
I'm sure this is just a type, you obviously meant RWD where you said FWD and vice-versa. The ease with which FWD oversteer is corrected is clearly displayed in the above youtubes link.Not sure about 2 deg of toe being normal either..
Kozy said:
Absolute rubbish. Oversteer in a FWD, apply lock and nail the throttle. Slide aborted.
What do you do in a RWD? Nail the throttle? More oversteer. Lift off? More oversteer.
No not rubbish at all. With a RWD car the oversteer is easier to control and slightly more predictable than with a FWD car. What do you do in a RWD? Nail the throttle? More oversteer. Lift off? More oversteer.
FWD cars are never tail happy nor should they be.
theshrew said:
No not rubbish at all. With a RWD car the oversteer is easier to control and slightly more predictable than with a FWD car.
FWD cars are never tail happy nor should they be.
huh.. what?FWD cars are never tail happy nor should they be.
Go watch the video again, including the interview afterwards where the professional racing driver says how it's easy to recover from oversteer in a FWD, "just nail the throttle" I believe he said.
Now maybe if you had a s***ty LSD with unpredictable response you could get some snap counter steer but normally, in a FWD, it's p**s easy.
Why you are convinced the opposite is true I can't begin to imagine.
scarble said:
huh.. what?
Go watch the video again, including the interview afterwards where the professional racing driver says how it's easy to recover from oversteer in a FWD, "just nail the throttle" I believe he said.
Now maybe if you had a s***ty LSD with unpredictable response you could get some snap counter steer but normally, in a FWD, it's p**s easy.
Why you are convinced the opposite is true I can't begin to imagine.
Just don't forget which car you are driving if you happen to have one of each, and say nail the throttle in a mid-engined RWD car when it begins to lose the back end on a wet roundabout...Go watch the video again, including the interview afterwards where the professional racing driver says how it's easy to recover from oversteer in a FWD, "just nail the throttle" I believe he said.
Now maybe if you had a s***ty LSD with unpredictable response you could get some snap counter steer but normally, in a FWD, it's p**s easy.
Why you are convinced the opposite is true I can't begin to imagine.
Toe out, change to Toe in
Look at Fiesta toe settings as a clue
Spring rates will make a difference as will tyre pressures
Change one at a time, easiest first, note settings before change so you can go back if it don't work
Overstear
Increase front spring rate or
Decrease rear spring rate
Stiffen front damper or
Soften rear damper
Increase rear tyre width or
Decrease front tyre width
Increase rear tyre pressure or
Decrease front tyre pressure
More positive front camber or
More negative rear camber
Stiffer front anti-roll bar or
Softer rear anti-roll bar
More weight to the front or
Less weight to the rear
Look at Fiesta toe settings as a clue
Spring rates will make a difference as will tyre pressures
Change one at a time, easiest first, note settings before change so you can go back if it don't work
Overstear
Increase front spring rate or
Decrease rear spring rate
Stiffen front damper or
Soften rear damper
Increase rear tyre width or
Decrease front tyre width
Increase rear tyre pressure or
Decrease front tyre pressure
More positive front camber or
More negative rear camber
Stiffer front anti-roll bar or
Softer rear anti-roll bar
More weight to the front or
Less weight to the rear
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