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Author: Subject: Pagani rear suspension design?
geoffreyh

posted on 27/11/05 at 12:16 PM Reply With Quote
Pagani rear suspension design?

Is there someone who can help me figure out how the rear suspension of the pagani zonda is working?

It looks like the top part is pointing to the back and the lower wishbone is pointing straight outwards but I can be wrong.

I think this suspension is adapting toe-in and out when it's moving up and down.

I'm attaching a picture.

Cheers,

Geoff Rescued attachment paganirearsmall.jpg
Rescued attachment paganirearsmall.jpg

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JoelP

posted on 27/11/05 at 12:24 PM Reply With Quote
i bet it has so little travel that the angles barely change.






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Guinness

posted on 27/11/05 at 01:24 PM Reply With Quote
I don't know, but I'll check mine, when I remember where I left it

Mike






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Avoneer

posted on 27/11/05 at 01:28 PM Reply With Quote
No, but it's a lovely piece of engineering.

Pat...





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liam.mccaffrey

posted on 27/11/05 at 02:05 PM Reply With Quote
Its was a Girraffe
Its was a Girraffe


this bit looks a bit flimsy, anyone think?

Zonda weigh in at over a ton doesn't it?

[Edited on 27/11/05 by liam.mccaffrey]





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akumabito

posted on 27/11/05 at 02:48 PM Reply With Quote
quote:
Originally posted by liam.mccaffrey
Its was a Girraffe
Its was a Girraffe


this bit looks a bit flimsy, anyone think?

Zonda weigh in at over a ton doesn't it?

[Edited on 27/11/05 by liam.mccaffrey]


Closer to 1 1/2 ton I believe... what's the point of building an all-carbonfibre vehicle when you're putting such a huge and heavy engine in the back??

[Edited on 27/11/05 by akumabito]

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JoelP

posted on 27/11/05 at 02:51 PM Reply With Quote
because they can. Its a great car either way Carbon for bling, 600+ bhp to make it move






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stevebubs

posted on 27/11/05 at 04:00 PM Reply With Quote
quote:
Originally posted by akumabito
quote:
Originally posted by liam.mccaffrey
Its was a Girraffe
Its was a Girraffe


this bit looks a bit flimsy, anyone think?

Zonda weigh in at over a ton doesn't it?

[Edited on 27/11/05 by liam.mccaffrey]


Closer to 1 1/2 ton I believe... what's the point of building an all-carbonfibre vehicle when you're putting such a huge and heavy engine in the back??

[Edited on 27/11/05 by akumabito]


So you don't end up with a 2 ton vehicle...

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tks

posted on 27/11/05 at 04:32 PM Reply With Quote
mhh

dunno maybe it are high grade ones? or even titanium ones??

anyway its not all realy well in scale..

using an 2M10bolts...but an huge lump of an 'ally' lever???

alse the bracket look like realy thinn material...

Tks





The above comments are always meant to be from the above persons perspective.

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liam.mccaffrey

posted on 27/11/05 at 05:34 PM Reply With Quote
it was specifically the bracket I had reservations about





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geoffreyh

posted on 27/11/05 at 05:48 PM Reply With Quote
Those brackets won't be too bad as I never heard from a big crash with a Zonda.

I started this thread because Jeremy Clarkson once said in Top Gear it was one of best handling cars he ever drove.

If there were some of those cars in my neighbourhood I would have checked it already a long time ago but until now I will have to base my information on pictures.

Cheers,

Geoff

[Edited on 27/11/05 by geoffreyh]

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akumabito

posted on 27/11/05 at 05:56 PM Reply With Quote
quote:
Originally posted by geoffreyh
I started this thread because Jeremy Clarkson once said in Top Gear it was one of best handling cars he ever drove.

[Edited on 27/11/05 by geoffreyh]


He also said that about the Ariel Atom.... and the Atom doesn't use some mystery-suspension...

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geoffreyh

posted on 27/11/05 at 06:15 PM Reply With Quote
That's true but I think they chose for another type of suspension because of the power / torque and weight combination.

The Atom has a lot of power but no weight.

Cheers,

Geoff

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Chippy

posted on 27/11/05 at 11:28 PM Reply With Quote
I read somewhere that this car has anti dive, and anti squat geometry, so the strange angles at the back are almost certainly something to do with that. I dont see much wrong with the mounting bracket, especialy when you look at the Locost bracketry.
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liam.mccaffrey

posted on 28/11/05 at 12:16 AM Reply With Quote
I suppose i expected it to look more substantial, i mean it wouldn't look out of place on a locost

My excuse is the type of work i do everything has to be belt braces and bits of string





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andygtt

posted on 28/11/05 at 12:48 PM Reply With Quote
I'd say its just as likelly that the angle is like that to maximise the wishbone length ie a compromise.





Andy

please redefine your limits.

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tadltd

posted on 28/11/05 at 11:45 PM Reply With Quote
I'd assumed that the wishbone angles help to steer the rear of the car during cornering...

\ \ (front)

/ / (rear)

...however, toe-ing out at the rear seems at odds with convention; in a straight line at least.

In saying that, the Pagani is hardly conventional!





Best Regards,

Steve.
www.turnerautosport.com

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physician

posted on 28/11/05 at 11:49 PM Reply With Quote
it is the main pivot, and it have a secont toe link

my quess is that its to induce some toe in while the suspension compress like when cornering, and some toe out while the rear of the car goes up when you brake hard before starting to turn in.. may give a feel of a leghter car..

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kb58

posted on 29/11/05 at 02:05 AM Reply With Quote
I thought rear toe-out was always a bad thing...

At the moment I have mine set to toe in, in both bump or droop, so I guess I'll see if I've outsmarted myself, considering I really haven't driven it yet...





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physician

posted on 29/11/05 at 03:00 AM Reply With Quote
it's just my extrapolation.. probably give a little toe out to help steer .. may not have a great range
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tadltd

posted on 29/11/05 at 09:24 AM Reply With Quote
Convention suggests that toe-in at the rear is peferential as it aids stability when braking, and - when accelerating - the rear wheels want to toe-out so a touch of toe-in helps counter this.

However, when cornering both sides are doing opposite things (one side in bump the other in droop). If the suspension is designed to give toe-out when compressed (i.e. the loaded side), then designing the other side to give toe-in when uncompressed generates a wee bit of rear steer, which can be beneficial.





Best Regards,

Steve.
www.turnerautosport.com

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andygtt

posted on 29/11/05 at 04:48 PM Reply With Quote
quote:
Originally posted by Syd Bridge
quote:
Originally posted by Chippy
I read somewhere that this car has anti dive, and anti squat geometry, so the strange angles at the back are almost certainly something to do with that. I dont see much wrong with the mounting bracket, especialy when you look at the Locost bracketry.


I've said this many times, but.....

Have a good think,........ What holds the car up?........the springs. What stops it dropping down? The springs!

Now explain how angling the wishbones changes the way the springs hold the car up. All the angled wishbones do is balls up a perfectly good wishbone setup.

Dive and squat are functions of CoM height and location, leading to weight transfer longitudinally. Changing the wishbone angles cannot affect that in any way, shape or form. If you want less dive or squat, use harder springs, or lower the CoM. See modern racecar designs for confirmation. Wishbone inner pivots all parallel to c/l, and ground.



I'd be looking for a geometry reason for the angles, and leave the anti dive/squat in Mr.Staniforth's book, where it belongs.

Syd.


I'm no expert but you also need to consider that this uses inboad dampers so the effective rocker ratio on the top wishbone varies the spring rate depending upon possition of wishbone.....

Its the fact that you have to consider every varient that I decided to use an expert that understands it fully rather than risk it messing it up myself.

I still think that the top wishbone angle is purelly down to the best possition to attach it to the chasis and maximise wishbone length.
If the lower one is parellel to the cars C/L then I'd be even more sure of it as in this instance its the angle of the lower wishbone that will be more critical as it will hold the upright in two possitions (top only holds it in one) therefore dictating its movement the most.

Its all supposition though, until you have all the details its impossible to work out what its actually doing.





Andy

please redefine your limits.

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andygtt

posted on 29/11/05 at 07:55 PM Reply With Quote
I wasn't specifically talking about the wishbone angle only that the rocker ratio on it does change the effective spring rate as the speed it moves the spring increases on compression and thus the top wishbone on this car does effect the spring.

As you say I recon the angle is purelly down to compramise.





Andy

please redefine your limits.

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andkilde

posted on 29/11/05 at 10:22 PM Reply With Quote
You'd need to see what the bottom wishbone was all about to be certain about how the upright will function -- from the looks of it, the toe link is at the front of the upright so if the bottom inner wishbone pivots are parallel to the chassis c/l the wheel will toe-in under bump (same as the Porsche Weissach axle or Mitsubishi's, best forgotten, 4ws system from the early 90's), if the bottom wishbone pickups are parallel to the top it should keep the wheel straight throughout wheel travel.

The anti squat/dive geometries (with apologies to Syd) are all about having the wishbone pivots at different heights fore and aft.

Cheers, Ted

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Stephant

posted on 30/11/05 at 06:42 PM Reply With Quote
anti squat

Hi
Anti Squat has nothing to do with "old scool of thinking",but is mainly used on FWD Cars as it gives more traction ,but
makes rear wheel driven cars more difficult to drive at the limit.3° is said to be the useble maximum.The mini is one of the best handling FWD cars,so have a close look at the front axle.Alec surely was no fool?!
Best regards,Stephan

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