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What's a J Damper?

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#1 Chiara

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Posted 11 June 2008 - 10:06

Could someone please highlight what a J Damper is.....seems Pat Symonds would like to know ;)


Renault has fended off suggestions that its 2008 car could be tainted by the espionage scandals of last year.

Earlier this season, it emerged that the French squad delayed using a particular suspension innovation until very recently, following the scandal surrounding engineer Phil Mackereth's defection from McLaren.

In the World Motor Sport Council hearings before Christmas about the Renault spy case, it was revealed that among Mackereth's McLaren drawings was a device referred to as a 'J-damper'.

It is suggested that the R28 raced by Fernando Alonso and Nelson Piquet now features similar technology.

"I don't know. What's a J-damper?" Renault's engineering chief, Pat Symonds, said at Montreal last weekend.

"If you can tell me what that is, I can tell you whether we've got one, I guess. It's not an engineering term.

"All I can say is that everything on our car has been checked by the FIA," the Briton added.

Symonds explained that, following the mass damper episode and banning of 2006, Renault now always gets FIA clearance before debuting any significant new technologies.

He said: "It is true that we ran new suspension components on the car in Barcelona and I can confirm that we checked very carefully with the FIA whether they felt that those suspension components infringed any technical regulations, sporting regulations or indeed the laws of the land."

Source: GMM
© CAPSIS International


#2 Mika Mika

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Posted 11 June 2008 - 10:08


Benatton... sorry Renault cheating.... NEVER ;)

#3 Owen

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Posted 11 June 2008 - 10:11

Just what the sport needs. Another spygate. :rolleyes:

#4 Timstr11

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Posted 11 June 2008 - 10:16

Duplicate thread: http://forums.autosp...threadid=100601

#5 Buttoneer

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Posted 11 June 2008 - 10:16

Symonds is being disingenuous here. No, J-Damper is not a technical term, it is a made up name used by McLaren to cover the true purpose and operation of the device. Renault had a nice picture of it last year and didn't understand it. It now appears that they do. Have a search for the term on this board Chiara and you'll spot another thread about it from when it was first used by Renault in Barcelona.

Edit: thanks Timstr

#6 scarbs

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Posted 11 June 2008 - 10:18

A J-Damper is McLarens terms for an Inerter, which is a suspension device which recreates the effect of a Mass Damper. Other teams run these Inerters and call them their own name I-Damper, K-Damper etc. Not knowing what Renaults one looks like I cant be sure (currently only fitted to the front so you cant see it), but they all work on a similar principle which is a weight which is made to spin on the shaft of the damper-like device from the movement of the suspension. The spinning up and down of the mass takes energy from the suspension slowing it at certain frequencies. The mass is tuned to negate the bounce of the tyres from upsetting the carsuspensioncontact patch.
Inerters are a legal part of the suspension and are used by several teams (Ferrari, Red bull, Williams, Renault and Mac) and all relate to research done by Cambridge Don; Malcolm smith. His work has been in the public domain since 2002 and hence is far from being directly related to the Spy saga.

Here's my fuller journal article on the devices (subscription)...


#7 Buttoneer

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Posted 11 June 2008 - 11:18

Originally posted by scarbs
His work has been in the public domain since 2002 and hence is far from being directly related to the Spy saga.

But Renault stated they had no idea how the device worked despite having drawings. If the information was in the public domain, it seems odd to me that this claim could be made.

#8 Bernd Rosemeyer

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Posted 01 July 2008 - 22:51

Originally posted by Mika Mika

Benatton... sorry Renault cheating.... NEVER ;)

Are you talking about Toleman? ;)