Rear axle hop

[mr.jwhey]

I posted this on the Flavia forum last week but no response.  I'm a newbie to Lancia and just learned the Fulvia S3 rear suspension format is nearly identical to the 2000, so I'm posting again here hoping someone who has tracked a Fulvia will have some advice.

"My car suffers from lateral rear suspension hop during hard cornering over bumps.  All bushings/shocks recent and in good condition. Shock mounting angle is such that they are ineffective near upper travel limit.  Wondering if any racers out there know a fix to keep wheels on the ground?  Larger anti-sway bar?  Spax or HRW adjustable shocks?  Would appreciate any advice."

[Richard Fridd]

How far does it hop? My Fulvia did give a feeling of a mild hop when encountering a bump on the road. However it was always  ok on a smooth racing circuit. My Fulvia had a Flavia sourced front anti roll bar. I lowered the 3 leaf springs and then had altered ( by others)the front wishbones to a negative camber to suit. Wheels 6 inch Campagnolos, offset not recorded. No change to rear camber.

  Richard

[lancialulu]

What shock absorbers are you running at the back?

And what provokes the lateral hop?

Cant say any of my Fulvias do this so I suspect weak / incorrect rear springs giving the rear shock absorber no ability to work properly. A side photo of your car may be helpful.

[mr.jwhey]

Shocks are Tecno Suspension circa 2018.  I probably should have disconnected and tested them before posting.  Will do that today.

The hop is most pronounced over abrupt bumps like bridge expansion joints.  Rear ride height looks OK to me.  Springs were repainted and there's rust underneath but plastic sliders look OK and movement is smooth (no stiction) with a jack.

Can't believe Fulvia's dominated rallye circuit w/ rear axle that handles like mine.

Do either of you know where to get a list of suspension components shared by 2000 and Fulvia S3?  Suppliers don't offer much in way of upgrades for 2000.  Would like to find set of poly bushes and bigger sway bars.

Thanks for the help.

[Richard Fridd]

My exact memory of this hop is going over an expansion joint on the corner of Maidstone bridge in the gyratrory system.
 "Just a twitch" is how my passenger described this experience.
 Not sure regarding interchangeable parts.
 

  Richard

[lancialulu]

As Prof Fessia said when designing the front wheel drive Lancia Flavia and Fulvia - you just worry about the front ,  the rear takes care of its self.

I would not  change the sway bar (check the cotton reel bushes are in good order) nor would think poly  bushes  will sort your  problem. Rear springs can either be too stiff or too soft compared with the factory desigN. Also rear shocks are kinda critical. You should try to find the Decarbon shock (quite difficult to find nowadays, but there are several licensees - Corte, delphi who made them). Failing that gas spax set on around 4-6 fromsoft.

I worries me when you say the shocks are near horizontal....

[mr.jwhey]

Shocks are at 52 deg full bump, but that's the way Lancia designed it.  Ricambi lists DeCarbon for Fulvia, but not Flavia.

[mr.jwhey]

Just to close this thread, I've determined by measuring spring camber that someone fitter stiffer springs.  The shocks are bad- about 5x the spec travel rate under 22kg load.  I'm going to try Spax while I look around for set of original spec springs and DeCarbon shocks.

Thanks to all who responded to this thread.

[DavidLaver]

Sounds like you can now look forward to a better ride AND road holding.