Why dual coilovers per corner?

[Pcar928]

The older jaguars and the ferrari testarossa have at each rear corner have two shock and springs, one coil over shock and spring fore and aft of the drive axle. The only explaination I have been given is for the jaguar with the suspension and shocks mounted to a subframe that was very compliantly mounted to the body. Where they were placed one fore and one aft for even load distribution so the compliant bushes between the subframe and main frame compressed evenly. I do not know if this is the full story however and I have heard no explaination for the ferrari. Any insight?

 

[GregLocock]

Find a picture of the Jag. Ferrari would have done it for any old reason, they designed suspensions by the American method.



Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Pcar928]

What is the "American method"? The previous Boxer model had this as well FYI. Heres a pic of the jag...

http://www.bevenyoung.com.au/hdk3b9ad770.htm

Sometimes this setup is seen with a trailing arm attached to the "I" arm.

 

[GregLocock]

I'd guess they did that to keep it compact (primarily) and prevent a single spring/shock from overturning the arm.

The American method- to get good handling from any suspension just keep winding the spring rates up until the wheels stop moving in undesirable ways.





Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Pcar928]

Come to think of it compactness was another reason Ive seen as you have noted. Seems like a lot of extra cost and weight just to save a little space....

 

[MikeHalloran]

The American Method, in the immortal words of the fictional Stroker McGurk: "If some is good, and more is better, then too much is just enough."

Witness our Monster Trucks, with four or more shocks per corner, to suspend a body and chassis that has to weigh less than the tires.

I.e., it's a fashion thing.



Mike Halloran
Pembroke Pines, FL, USA

 

[Pcar928]

WOW, I was expecting some sort of purpose for it, but what has been given seems like a lack of fore thought. The monster truck stuff seems like a huge megamoniacal show of rediculousness, so I wouldn't be surprised to see something stupid there like 16 shocks supporting a tube frame truck, but for there to be no greater reason than space with the ferrari... I guess the boxer 12 was wide and directly over the suspension though.

 

[patprimmer]

In my opinion the Jaguar used that suspension so they could get a very compact system with exceptional performance for its day.

The main advantage re compact dimensions was to allow a lower boot floor over the suspension sub frame so that the boot had enough depth with a low body line.

I guess it allowed for a good all round compromise of good ride, good handling, low profile styling and good boot room.

Also an extra pair of shockers should give better damping.

Regards
Pat
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[thundair]

I always thought the shocks might be bias for dampening characteristics and with no reservoir the heat would be divided.

I don't know anything but the people that do.

 

[NormPeterson]

For the early Jaguar - perhaps an attempt at suppressing wheel hop via shock damping was involved.


Norm