Regarding the subject, last year PSRX experimented with both Mcpherson and double wishbones in WRX but from my understanding they ended up using Mcpherson after several tests.
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Regarding the subject, last year PSRX experimented with both Mcpherson and double wishbones in WRX but from my understanding they ended up using Mcpherson after several tests.
Yeah but the unsprung weight is bigger meaning that the suspension is slower to react to changes. Sure it's probably stronger in case of a side impact on the wheel and sure, the camber stay the same even when when the suspension is compressed but does this really mean so a lot in rallying or rally cross? I doubt it. On a smooth flat definitely... Dirt and rough asphalt... Probably not.
If they experimented with it I am sure they had a good reason though. I don't follow rallycross closely but I seem to recall that Hoonigan were doing quite well.
IMO the advantage of keeping the camber is more of an advantage in off road races where there is a need of good traction even with rather extreme positions of wheels. On the other hand these cars have usually huge wheels so they don't need to care about small bumps/holes unlike WRC cars with rather small diameter of wheels. Those huge wheels are also heavy so the weight of suspension alone doesn't play that big role.
Double wishbone shall be better for heavy braking as well and as it was already said it's more robust and can take more beating.
IMO there is another advantage of double wishbone and that's freedom of setting the castor. With usual McPherson setup there are massive forces in the steering coming from huge castor (angled strut) and with that more reliability problems appear.
Take is as an amateur talk anyway ;)
If we knew what we were talking about on a truly professional level, we'd be working for one of the teams by now ;)
Pardon my ignorance but how can the caster angle cause forces? I know that the caster determine lift of the body when the wheel is turned (so a heavy landing with the wheels sideways would snap the steering out of your hands... But i think the car would flip before that tbh).
If the scrub radius was large I'd understand it... You'd feel every little bump twisting the wheel out of your hands... But caster?
You said it - the bigger the castor the more you lift the heavy body when You turn the steering wheel. The power steering unit has to generate the force needed to lift the body and the whole steering assembly has to wistand these big forces.
Probably a stupid question but doesn't McPherson allow longer max. travel than double wishbone for given size/weight?
Depends on where you attach the the suspension strut.
Not necessarily actually. A lot of desert buggys and such have super long travel suspension.
https://images.fineartamerica.com/im...ul-svensen.jpg
Edit: or maybe you meant for any given length of the wishbone/control arm. That i can't be sure of, but I'm still not convinced. Theoretically you should be able to manage the same angle of the strut even if you have two suspension arms.