Fun-Fact: that axle is called the "Weissach Achse" wich actually does not refer to Porsches main engineering centre in a town called Weissach (near Stuttgart) but stands for "*W*inkel *ei*nstellende *s*elbst *s*tabilisierende *A*usgleichs-*Ch*arakteristik" (freely translated to angle adjusting self stabilizing compensation characteristic). I guess Porsche engineers had quite a good time though choosing that acronym. Greetings from Germany :)

I actually once owned a 1996 Ford Contour V6 with all the go fast bits. It had elongated, oval like rear rear control arm bushings. They would slightly give-way under cornering pressure for a type of rear steering. Loved that car so much. Totaled in a T-bone crash after somebody ran a red light into me. R.I.P.

In its infinite wisdom, the KZread Algorithm started suggesting me your videos yesterday, and I'm glad it did. Proper knowledge and fascinating subjects... And I think I'll have to get your book as well!

My 968 works the same way and when pushed hard, is just spectacular. With power on, it drifts ever so slightly giving a fantastic steering feel at the limit. It’s easier to experience than it is to describe, and that’s what I love about it.

Another great video

@JulianEdgar

2 жыл бұрын

Glad you enjoyed it

I had a Peugeot 306 - with passive rear bushing steering- brilliant in corners!

really cool videos, love these tech bits

I heard one of the mx5 series did this as well. Rear wheels would point towards the inside of the turn purely through selective bush deflection

@JulianEdgar

2 жыл бұрын

Yes, as I said in the video, many cars today do this.

Good old Weissach axle :-)

if i remember correctly 90's and early 2000's psa cars (peugeot and citroen) on their torsion beam suspension named CATT

@JulianEdgar

2 жыл бұрын

I have done a video on torsion beam suspension - kzread.info/dash/bejne/g5mOzaWykcS2nto.html

@androidemulator6952

9 ай бұрын

Yep, my Peugeot 306 had passive rear steering also.. ;) ( i miss the old 306) :(

great video, ive been doing suspension development on a Gen2 Rav4 coupe and it has similar rear end dynamics. you can tune in almost a full degree of tow in under brakes!

@JulianEdgar

2 жыл бұрын

That's really interesting. How are you measuring that?

@somegi9

2 жыл бұрын

@@JulianEdgar combination of using an external camera aimed at braking zone, a gopro mounted above the wheel arch and removing the rear spring and running the car through the full travel of the suspension. the car dives a ton under brakes and has alot of body roll so its been bloody tricky actually getting a quality measurement.

Very cool - i didn't know this...

Great video

@JulianEdgar

2 жыл бұрын

Thanks! You might want to check out my 200+ other videos as well.

Interesting video, sorry if my question sounds stupid. From what I understand, the rear suspension here is designed such that the forces under braking are directed into the bush, but the bush is mounted at a different angle which affects how much the wheel moves under braking. Is this analogous to anti-geometries, e.g. antisquat and antidive but for the rear suspension? Is using the bush the best way to do this? Is there to get toe in under braking on the rear using pure geometry constraints? i.e. if you were using rose joints on every link is the same effect achievable? Thanks for the videos.

@JulianEdgar

2 жыл бұрын

'Anti' geometries work in a completely different way. I imagine you could get toe-in under braking with pure geometry but I don't know any way of doing that without having adverse impacts in other suspension movements.

Sorry Julian, the pic depicts what is a 928 S4 which commenced in 197 and this red car looks like it could be a 928 GT - S4 with some mods. Cheers Tony

@JulianEdgar

2 жыл бұрын

Not sure that it changes the fundamental idea?

My Mazda MX5 steers like this. Let go of the accelerator in a turn, and it turns in

It was a great car. Also had double wishbone front suspension at front. 911 had McPherson strut until very recently. I think why 928 wasn’t a huge success was it’s design. It was ugly back then and has not improved with time.

@JulianEdgar

2 жыл бұрын

I always liked its shape, but obviously lots didn't agree!