Suspension experts, your views on this matter please

[PAUL500]

I know there are some boffins in the black art hiding away down in this subforum, so would love to hear your expert opinion on this matter.

The owner of the car below has had a suspension failure, the top of the shock plunger broke away from its mounting, I had previously mentioned that the area in the red circle did not look right, and after the shock broke I suggested the awkward angle in which the wishbone is mounted to the hub could be causing lateral movement in the shock causing the failure. He is adamant it has been set up as per the factory cars and is correct.

I am by no means an expert and typically work on the basis is it looks right then it is, if it does not then why?

I would like to hear the opinion of those well versed in suspension as to why the area in the red circle sits at such an awkward angle.

Edited by PAUL500 on Monday 20th July 19:41

[egomeister]

PAUL500 said:

I would like to hear the opinion of those well versed in suspension as to why the area in the red circle sits at such an awkward angle.

In the photo it looks like it's at the limit of its angularity but it's a bit misleading as the car is up in the air and at full droop - I would expect that when the car is sitting on its wheels it'll look a lot healthier.

[cptsideways]

That is wrong on so many levels, plus the anti roll link/arm is the wrong length for the linkage. Looks like a proper cowboy job to me, nicely made, badly engineered. (Time attack car by any chance?)

The bit circled is simply mounted in the wrong plane the ball joint will be locked out at certain points & will simply break off with ease if it is maxed out.

[Jibberingloon]

Should be proper threaded back with 2 rose joints either end

[PAUL500]

cptsideways said:

That is wrong on so many levels, plus the anti roll link/arm is the wrong length for the linkage. Looks like a proper cowboy job to me, nicely made, badly engineered. (Time attack car by any chance?)

The bit circled is simply mounted in the wrong plane the ball joint will be locked out at certain points & will simply break off with ease if it is maxed out.

I think you will be very shocked when I tell you what it is, and who engineered the suspension, would like to hear a few more views first before anyone guesses the car

[PAUL500]

Jibberingloon said:

Should be proper threaded back with 2 rose joints either end

I believe it uses spherical bearings

[Jibberingloon]

That's what I meant...... 1 bottle of red one and I cant think, type what I mean, I think not sure, blah blah... snore

Anyway it doesn't look right!

[cptsideways]

PAUL500 said:

cptsideways said:

That is wrong on so many levels, plus the anti roll link/arm is the wrong length for the linkage. Looks like a proper cowboy job to me, nicely made, badly engineered. (Time attack car by any chance?)

The bit circled is simply mounted in the wrong plane the ball joint will be locked out at certain points & will simply break off with ease if it is maxed out.

I think you will be very shocked when I tell you what it is, and who engineered the suspension, would like to hear a few more views first before anyone guesses the car

Has it been re-engineered by someone else since though?

[Fastpedeller]

Lower wishbone mount to chassis looks a bit iffy as well IMHO

[PAUL500]

Asked the same question earlier on a motorsport forum frequented by F1 based guys and generally they seem to think the suspension is on full droop, even though it looks level hence the unusual mounting angle of the wishbone, and once loaded it would look far more to spec, and not the cause of the shock failure.

The owner has now found that the collets that sit on top of the shock had been mounted upside down and this allowed lateral movement of the shock which is the probable reason for the break.

The car is a genuine F40 Ferrari that has been converted to full LM race spec using all the correct parts supplied by Michelotto, the famed Ferrari race car builder who constructed the originals.

[ezakimak]

doesn't look right to me, could be better, will it function probably, it would be at full drop there so its as bad as its going to get, the top wishbone looks like it might be on upside down? could just be an illusion of the photo.

this could be worth a read.

this is obviously the original suspension,


http://www.build-threads.com/build-threads/ferrari...

EDIT,
sorry try part 2 it has the updated suspension the same as pictured earlier in the thread.
http://www.build-threads.com/build-threads/ferrari...

EDIT again, its obviously the same car........[face palm, im such a doofus]

Ryan

Edited by ezakimak on Tuesday 21st July 06:22

Edited by ezakimak on Tuesday 21st July 06:24

[cptsideways]

If the above car is the original then the latter new'ness is as I said wrong! Lower arm inner mounts on the old one are in the correct plane too. Running spherical joints instead of bushes does not usually change the axis angle they pivot at

I can guarantee you an original LM car did NOT race successfully like the one with the new bits

[cptsideways]

Front end as a comparison



If this is a road going car you will have a suspension failure within hours of use as it currently stands. Having looked at the original which is obviously correct the latter has a few very obvious wrongs imho

TBH you could build an F40 in your own shed to a better standard than Ferrari did back in the day! They are very crude & pretty simple things.

[Gareth9702]

Why does your second picture show a Triumph Herald front suspension?

[PAUL500]

I think its the angle the photo was taken that is confusing us all, and the fact the wishbones look parallel to the ground. Below is a pic of another LM, if you look at the angle of the driveshafts and stub axle, once the shock is loaded then they will then line up, and that awkward angle where the wishbone mounts to the hub will then also be far more in sync.

Its all been supplied by the original builders of the f40 LM directly so should be correct. Initially I also suggested the top wishbone was on the wrong side of the car, but it's all marked up for assembly in the correct order as supplied.