Sierra Uprights- Some Questions
Posted: Wed Aug 14, 2013 11:29 am
Please forgive multiple questions that have probably been answered a hundred times, I believe I have sierra uprights from speaking to Rob, I as I have said in other posts am not at home so have some time on the internet and not time with the car, however I have driven the car approx. 1000miles since buying last month and the front is not completely to my liking feels vague especially on bumpy Aberdeenshire roads. Time for my questions, lots of them and many that without the car may not be answered so apologies:
1) I would imagine adding caster to the setup will eliminate this vagueness, I believe the guy I bought it off had tracking done after track rod end replacement so it should be fine, any comments on this?
2) Anyone know what the caster/ camber is with Sierra uprights (assuming standard rocker and wishbone) and if this is different from other setups?
3) What is the geometry problems with ford uprights I have read about (people say geometry is wrong but not specifics)? from looking at pictures they appear to have a different (higher
) kingpin angle than others. steering arm also appears to be placed differently which may be affecting Ackermann geometry
4) Are there any differences with the top rockers and lower wish bones for the sierra uprights
5) point I am leading to: can I take a set of Cortina uprights with hubs and wheel bearings (might go alloy if I am feeling flush- another can of worms I would think) and using the existing rocker and wishbone complete with ball joints replace the sierra uprights? (Just did some more looking and realise this wont work without the modification to the upright or modification to rocker arm- should really have looked before posting
) I have plans to change callipers/ discs to allow me (at a later date) to change to 13" wheels so not bothered about that is easy enough to spec Cortina fitment callipers as opposed to Sierra.
6) I have also been reading a bit about the use of rose joints for rocker arm ends I need to sit and do some proper sums but for road use I would not be keen due to the shear on the thread even going up to 5/8 thread, I may be wrong though has anyone used them on the road on a stylus? I know on the track/ hill they work, but a fully laden car on our potholed roads is a different thing. Obviously with cars with “traditional” suspension design the vertical load is transmitted directly to shock/ pushrod (if your fancy) so they work ok, and lower wishbones are not subject to the vertical (shear) loading so they will work at the moment I am thinking (not immediately) of fabricating new wishbones with adjustment (3x rose joints) but not sure on solutions for the top to gain adjustment, bit of thought needed but I will be keen to see the results of the spherical bearings talked about in other posts, I am thinking use tubular wishbone with adjustment at rocker point and a solid threaded top bar (in compression) which will then take the vertical load and pass it to the shock maybe not explained the best here ( have thoughts of lower wishbone pushrod setup on single seater) will maybe model it up and have a play, does anyone have either a dimensioned photo/ sketch/ drawing of the original top rockers.
7) I know car setup is a personnel thing and will take a lot of trial and error I also know there are base numbers to aim for though, is there anything else I need to be thinking about? I believe Ackermann geometry is pretty good on the stylus although I have de Dion rear so may be slightly different but not noticable I would imagine.
Thanks
Calum
1) I would imagine adding caster to the setup will eliminate this vagueness, I believe the guy I bought it off had tracking done after track rod end replacement so it should be fine, any comments on this?
2) Anyone know what the caster/ camber is with Sierra uprights (assuming standard rocker and wishbone) and if this is different from other setups?
3) What is the geometry problems with ford uprights I have read about (people say geometry is wrong but not specifics)? from looking at pictures they appear to have a different (higher
) kingpin angle than others. steering arm also appears to be placed differently which may be affecting Ackermann geometry 4) Are there any differences with the top rockers and lower wish bones for the sierra uprights
5) point I am leading to: can I take a set of Cortina uprights with hubs and wheel bearings (might go alloy if I am feeling flush- another can of worms I would think) and using the existing rocker and wishbone complete with ball joints replace the sierra uprights? (Just did some more looking and realise this wont work without the modification to the upright or modification to rocker arm- should really have looked before posting
) I have plans to change callipers/ discs to allow me (at a later date) to change to 13" wheels so not bothered about that is easy enough to spec Cortina fitment callipers as opposed to Sierra.6) I have also been reading a bit about the use of rose joints for rocker arm ends I need to sit and do some proper sums but for road use I would not be keen due to the shear on the thread even going up to 5/8 thread, I may be wrong though has anyone used them on the road on a stylus? I know on the track/ hill they work, but a fully laden car on our potholed roads is a different thing. Obviously with cars with “traditional” suspension design the vertical load is transmitted directly to shock/ pushrod (if your fancy) so they work ok, and lower wishbones are not subject to the vertical (shear) loading so they will work at the moment I am thinking (not immediately) of fabricating new wishbones with adjustment (3x rose joints) but not sure on solutions for the top to gain adjustment, bit of thought needed but I will be keen to see the results of the spherical bearings talked about in other posts, I am thinking use tubular wishbone with adjustment at rocker point and a solid threaded top bar (in compression) which will then take the vertical load and pass it to the shock maybe not explained the best here ( have thoughts of lower wishbone pushrod setup on single seater) will maybe model it up and have a play, does anyone have either a dimensioned photo/ sketch/ drawing of the original top rockers.
7) I know car setup is a personnel thing and will take a lot of trial and error I also know there are base numbers to aim for though, is there anything else I need to be thinking about? I believe Ackermann geometry is pretty good on the stylus although I have de Dion rear so may be slightly different but not noticable I would imagine.
Thanks
Calum