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Suspension geometry.. help me out here please....

Hi all.

ok.. I have now received more info re the cup suspension mods.

3 degrees positive caster added, no change to negative camber, 3mm lowered (Springs and caster), 20 mm wider track front (Wheel offset only), 10 mm wider rear (Wheel offset only)

ps.. the 20 and 10 mm could be slightly out, this is from memory, but I noted the caster and camber !.

Heres an excel spread sheet, hopefully self explanatory. I am looking at the distance the lower front ball joint needs to be moved forward in relation to the strut top mount center pivot point.

Jeeeez, thats quite a way it has changed !!!

... the measurements used for strut length (All mm) and present offset are a quick first take with a simple steel tape rule.

Me brain is fried after a longggg day.. does that look right ???

if so, I still think the cup needs another degree or so.. so to add 4 degrees you would need to redrill the lower arm for both ball joint and anti roll bar, hmmmmmm, not too chalenging.. for camber, an offset top strut to hub bolt would do the trick.. perhaps 1 - 1.5 degrees negative... neutral toe in to slight toe out... ??

Just pondering..



So its only the wheel offset that gives the cup its wider track?

Thats a bit of a con aint it!!!


Hi M8, yep, also, the 3mm drop is caused by the extra inclination of the strut to obtain the caster.

redrill 2 bolts at the bottom arm and you have all the cup suspension mods

it still needs neg camber though.. needs a pair of ofset bolts in the strut to hub mount.


Thats a bit disappointing!

I was looking at getting a cup and would not be happy that the wider track would be so easy to mimic!

Do you know if the Williams wider track was the same? If i remember rightly they use the driveshafts from a 19 16V.


no idea on the Williams, not a car I know really

the track could always be changed with light allow spacers, its such a small change that no unreasonavle load would be placed on the wheel bearings.

the whole cup suspension is so easy to copy for a 172 that it will present no real problems at all.

  mk2 172

he he, sorry but willy is well different, i have wishbones off a valver and off a williams in the garage and the willy one is a fair bit longer. also, its not the same as a 19 16v, maybe in dimensions buth the roll bar mountings are different on the lot of em!


Hi Crags.. just fer info.. I was referring to changing a 172, not a 16v to Willy ???

Hows the Stalion Mobile going on m8.. and give me the dirt on the turbo needing replacement ??.

  mk2 172

i was answering mat joe....and the puto, well errm, i wanna fit a new bottom end cos the cranks a tad noisy but havin trouble finding a low cost engine. also, havent really looked into gettin a new turbo yet till i got summat that can lift out the engine. its all a bit costly sadly. not sure whether or not to just flog it on and get my money back. what ya rekon? or you havent got a punto lump in your shed have you?

  mk2 172

ah yeah joe, the turbo is giving low boost but the oil is leaking from its seals, dont know owt about em, was told by some mechanic i need a new un, maybe hes wrong??


It would be easy to do, trouble is time at the mo, but , the turbo project needs funds though.. so might have a look this weekend. It will be an exchange pair of bottom suspension arms (MK1 or Mk2)

lol at capn

for someone who said the cup is just a clever piece of marketing, youre now going to change your car to be like the true drivers 172...interesting.

it takes a real man to admit when hes wrong boy :->


Interesting concept Chris.. but alas, no, the cup suspension mods need improving on... , thats exactly what is going on here..

Oh sheett, I just realised.. I will have to SUFFER with my aircon, and ABS etc... still, never mind eh ??.. ...

And, sheeeet again, I STILL paid less..

It is clever marketing when someone (like you ??) PAYS MORE FOR LESS...

hee hee


....cmon joe, next thing youll be making a purchase of some back seats out of a fiat panda (im sure thats where the cups are sourced!) and then some mondial blue paint maybe just to top it off :)

respect to you for your knowledge, im only kidding....

btw, i paid quite a bit less than list price so its prolly about the same once ive purchased my box of kleenex for mopping my brow due to the sub tropical stockport climate!


lol Chris..

I got some aircon pumps m8 ???

fiat panda aghhhhhhh... no... remove them completely.. not for weight, but cos of the harnesses....

glad ya got a great deal.. it REALLY is a great car, I just cant live without aircon...

mind you, with 300 BHP Planned for the RS300 turbo.. who gives a stuff about a few kilos lol..

And, I would suggest moving outa stockport.. it really is sub-polar - oooops, tropical around our way aint it ??