Technical Suspension and shock questions

[autocomman]

Another one on my 66 Ghia...I put an abarth reverse eye spring in the front to bring it down cause it was sitting much too high. The ride height is great now, pretty stiff though. My concern however is the rear. Its got stock coils so far as I know. I put a set of Koni Classics on, and well its pretty unbalanced. I had to crank the shocks in the rear all the way up to get them to keep the rear from rebounding excessively. Usually with Koni's just setting em at their lowest or normal settings they work fine on stock springs...Thoughts?

This is a road car so it doesnt need to be stiff, but getting the front down level with the rear was proving to be a challenge. And Im sure it doesnt help that this is an EV and the battery weight may have loaded the rear of the car a bit more than the gas engine did

 

[MOD500]

The Koni Classics are recommended for the car based on the weight. If the car is now an EV the weight will be greater so will need different shocks.


If you can weigh the rear axle weight, front axle weight and total weight of the car you could get in touch with Koni or any other manufacturer who can recommend a set that matches your car.

 

[autocomman]

Understandable. Car max capacity is 700lbs...so If I have 400 lbs in it, wouldnt you say the shocks should be able to compensate for that? Its like having 2 adults in the car with some luggage...and being a 'station wagon' its ment to have more weight than a normal coupe. Part number is the same either way...In my eyes, the shocks should be able to deal with the weight...this isnt a oh it bounces a little more, its literally like there were no shocks in the car...bounce it a few times by hand it will bounce 7-8 times easily boing boing boing

 

[1500500]

Is the battery weight further back than the rear passengers would sit? Maybe it is the extra weight over the rear of the car that means the shocks need more adjustment than usual?

 

[autocomman]

Being a Ghia, a station wagon really thats where the weight would be. Im well within max capacity for this car and it should not behave the way it is. Does anyone know the spring rate for the rear of a Ghia vs a regular coupe?

 

[F123C]

Did you follow the procedure for bleeding out any entrapped air before fitting the shock absorbers?

Iirc, the procedure was to invert the shock, extend fully, turn right way up and compress, repeating a few times if necessary. (Or might the opposite way around :chin: )


AL.

 

[MOD500]

Being a Ghia, a station wagon really thats where the weight would be.QUOTE]

Im well within max capacity for this car and it should not behave the way it is.?

You might be within the max capacity of the car, but if the weight distribution has been affected then it may be causing an issue. Or look at it another way. If you determine the axle weight and overall weight to be ok and the weight distribution to be ok, then you have a better case to put to Koni to ask why the shocks aren't working correctly.

 

[autocomman]

Shocks have no air in them, at least I never felt any thing odd when cycling them by hand...Im going to get the car on scales today and fire out the weight front rear and total.

 

[autocomman]

514 Lbs front
963 Lbs rear
1477 Total

Anyone have weight specs from a Ghia?? I found a spec of 1220 lbs, Im at 1477

As far as bateries and gear goes added 200lbs and change to the rear and 100ish to the front. So consider a full tank of fuel to the front, we didnt add much. And the rear im guessing the electric motor weighs a bit less than the gas that came out. The Ghia was ment for hauling, so we are not outa range here for the vehicle. Well within the weight capacity of the car, it should be fine with the shocks on the lowest setting. koni seems to think they need to be revalved, and for warranty they want them sent back for testing. But if the need to be revalved, they dont do it there anymore. I need to goto one of 3 service centers, one of which is 15 miles from our shop. So im gonna talk to them to have them checked and/or revalved if need be, then get back to koni to go WTF.

So far as im concerned, there is no reason the Konis out of the box shouldn't have worked fine. I also dont have possibly 3 weeks turn around that Koni needs. But we will see what happens.

 

[MOD500]

a 20l fiat fuel tank filled should be about 20kg including the weight of the tank. (petrol is around 0.77kg/l).
A pancake motor could be as low as 11kg so that sounds about right.
Your overall weight figures don't look far out from original spec.


You'll just have to wait and see what Koni have to say about it. Since it's modified they would probably want to rule out modifications first.

 

[the hobbler]

You call you car a 'GHIA' and mention that it is an estate---is it a Giardiniera? The weights for a Giardy are:--Total kerb weight:--1234lbs
Front axle weight:--481lbs (39% of kerb weight)
Rear axle weight:---753lbs(61% of kerb weight)
Total payload is--------------------------------------- 705lbs

As far as I can ascertain regarding dampers:-extended length, rear----271mm
extended length, front----335mm
telescoped length, rear----180mm
telescoped length, front---212mm
The spring free height on the Giardy prior to number 141707 is---------222mm
after number 141707 is---------220mm
The rear spring rate for the Giardy is-------------------------------12mm/100kgf
I don't know if you have any contact with (or are even a member of the same company), but a company called "Classic Chrome" (classic-chrome.net) who are in Mortlake, London have just put an EV (classic) 500 on the road--it might be worth having a word with them to see how they solved damper/spring problems

 

[autocomman]

Thats great info hobbler! My springs with a basic test of putting weight on the spring to find the 1" drop was approx 250 lbs for a 1" compression and that would make it a 250 in.lb. spring 100kg is 220 lbs, and the spec is 12mm @ 100kg, that would be a 1/2" drop at 220 lbs. At 200lbs I had about a 3/4 " drop, so the springs are probably on the tired side which is to be expected for a 50+ year old car. If anything the shocks should have an easier time with that. When I say drop I mean a bench top test of putting weight directly on the springs and measuring the compression amount.

And again, as far as the weight goes I see no reason that the shocks shouldnt be able to handle what we did to the car. I mean when I would bounce the car by hand in the rear it should stop pretty much after i let it go, and it doesnt. It bounces like it has no shocks in it.

I have the shocks out to one of the 3 authorized Koni service centers they told me to use. The time frame to ship shocks back to Koni to be tested for warranty, to find out they may or may not need to be revalved then get them back then have them revalved, I could easily be put back 3-4 weeks. Koni said they no longer revalve in house.
Hopefully Ill hear from the company today on the condition of em, then Ill go back to Koni with the results. Also we are not in the UK, we are in California USA, so I dont know about the other EV build that was done. And yeah, the car is a Giardiniera. I want to spell it with a GH in my head for what ever reason. When we have press on this car I will gladly post up info about it, I think its damn impressive

Mark

 

[the hobbler]

When I was a 'MOT' tester (I will admit,many years ago) The normal damper 'return to stop bouncing' position was about 1-1/2 bounces. The fact that you say it feels that you don't have any dampers fitted would lead one to believe that the dampers are (very) faulty. Even if your springs were ' a bit on the weak side' the dampers, if correct, should still stop 'bouncing' after about 1-1/2 'bounces. Have you tried just refitting the original damper? Even if THEY are a bit soft, if they improve the ride it will prove that the Koni dampers are, to use an old English expression---knackered!
It might be of benefit to both you and "Classic Chrome" if you were to put your heads together---they might be able to give guidance regarding springs and dampers.

 

[autocomman]

So they are new out of the box Koni classics. I had to turn the adjustment to its maximum rebound setting to get the back of the car to settle down after 2 bounces, for a vehicle with stock suspension and no more weight than an adult in the car this isnt correct, and Koni felt that was the case also.

I heard back from the shop testing them and they said they are operating correctly. What the valving is inside and weather its correct for the part number is a question unless its disassembled, but chances are its got the correct valving in them. But correct for what? A stock 500 coupe?

Hobbler, where did the spring info come from? If im reading that correctly, to get the srping to compress 1 inch I would need almost 450lbs, that seems excessive for a car that only weighs 1300lbs to begin with. 12mm 100kgf, thats correct?? Also what is the rear spring rate for a standard 500 coupe?

Oh, and the original dampers were trashed and unfortunately have been tossed already, car bounced a good 3-4 times easily

 

[autocomman]

Ok well I sent the shocks to performance shock in sonoma california, one of the reommended places by Koni. They were working properly, no issues with them out of the box, but on the vehicle they did not work well at all. They revalved em and 1 full turn on the adjustment they are perfect. Why they had to be revalved, no one can say why they had to be valved, as its the correct part number, blah blah blah, etc etc etc. But it rides properly now.