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View Full Version : Understeer values for a range of cars


abc
21 March 2008, 01:31
Found this on Wiki. (Here: Understeer - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Understeer))

Having read this, I still can't quite believe just how relatively badly scoobies understeer, though having kerbed mine today, I know what a pain it is in practice!

"Here are the measured linear range values [for understeer] for some cars.[1] The higher the number the more the car understeers:
Car model Understeer value
Nissan 350Z 19
Mazda MX-5 21
Nissan 350Z Roadster 21
Ford Mustang GT 22
Renault Megane Sport 22
Maserati Gran Sport 23
Mini Cooper S 23
BMW 330i 25
Alfa Romeo 147 GTA 27
Corvette C6 27
Corvette Z06 28
Lotus Elise 111R 28
Porsche 997 Carrera S 28
Saab 9-3 Aero combi 28
Škoda Octavia RS 28
Porsche 997 Carrera 29
Porsche Cayman S 29
VW Golf GTI 29
Porsche 987 Boxster S 31
BMW M6 32
Range Rover Sport Supertech 32
Ford Focus ST 33
Mitsubishi Lancer EVO8 34
Porsche 968CS 34
Audi RS4 35
BMW M5 35
BMW Z4 Roadster M 35
BMW M3 Comp Package 36
Opel Astra OPC 36
BMW Z4 3.0i 37
Subaru Impreza WRX STi 37
Subaru Legacy 3.0 aut 38
Volvo V70 T5 39
Audi A4 2.0 T Q 41
Mercedes E55 AMG 42
Audi A4 V6 3.2 Q Avant 43
Porsche Cayenne Turbo 45
Smart ForFour Brabus 45
Mercedes SLK 350 47
TVR Tuscan 49
Alfa Romeo 159 2.2 JTS 51
Morgan Roadster V6 71

s70rjw
27 March 2008, 21:16
That table doesn't take into account the vehicle's steering ratio. eg a Tuscan has far quicker rack than an MX5. A Tuscan does not understeer more than an MX5. A Tuscan merely needs more steering input than an MX5 does when the Tuscan does understeer.
Most manufacturers build understeer into a cars chassis as for the majority of drivers its easier to deal with than oversteer. The Impreza does understeer
Hope that makes sense...

abc
28 March 2008, 12:07
Thanks, s70rjw

That explains why an STi has such a high value relative to an Astra. But, since a Megane Sport has, I assume a quickish rack, does this imply that the Megane handles relatively better than an STi so far as perceived proneness to understeer goes?

rickya
28 March 2008, 13:48
My 350z used to understeer like a bit%h when pushed!!

ps though they mave have something to do with me changing front alloys/tyre width from 225 to 245? :norty:

172sport
28 March 2008, 18:23
Never had a problem with mine TBH, perhaps its the way you drive it?

dunx
29 March 2008, 00:45
Whiteline rear ARB + STI = 0
(sorted !)

LOL

DunxC

P.S. Porsche 997 is that really bad then ?

finalzero
29 March 2008, 20:55
I don't experience understeer ;)

Nah seriously, 90% of the time I never get it thanks to the DCCD but had it on 2nd green light and noticed some bad understeer as I was navigating a bend, I wound up the diff to lock and gave more throttle input to let the car pull itself straight.

I am pretty sure tyres have a big part to play and would be nice to find the right tyre combination/wheel size that gives good all round grip in wet and dry weather.

One thing I have noticed is that the 4wd grip is only affective when your applying throttle, I know with understeer the natural reaction is to come off the throttle but I have found in the wet, with the 1st orange light (which gives about the same lock as a non-dccd equipped STi), as soon as you feel some understeer just turn in a bit more and give more throttle input, the front wheels start doing their work and pull the car through... however is scary the first time you try it as you end up coming out of a bend faster than you went in!

dunx
29 March 2008, 23:42
You are supposed to come out the bend faster than you went in....

I agree sometimes you need to trust the car's natural abilities, I've just spent all day at Blyton (rally-X circuit) and fighting under/over steer (non-DCCD).
I couldn't tell which end was going to slide at any given time, so just kept my foot-in and steered at the "line" I wanted !

Tired now tho'.

DunxC