FWD Hubs

[LeonN]

can you use front wheel drive hubs on the front of a roadster? there are plentey of cheeper moor available cars with front wheel drive and a lot of them look good for using. ford ka and vauxhall corsa and mk3 golf but....

[Talonmotorsport]

Ford Fiesta mk3 type front upright is easy enough just cut the CV joint surround off the drive flange, how ever you might run into problems with the bottom ball joint mounts as there is considerably less material to take a maxi ball joint as some are split with a pinch bolt not castle nut locked on. It'll take a lot of searching with mix and match parts. You might also have to adjust the lengths of the wishbones to get the correct camber and caster so the car turns in to corners and self centres.

[Chris Gibbs]

It can be difficult, some front wheel drive hubs have poor geometry simply because they're for a fwd car. These uprights are designed for things like torque steer and are usually not tall enough for our purposes.

The only way to get the ideal upright is to design and build your own.

Uprights other than Ford will not have the 4/108 PCD either which means that you'll have to redrill the hubs or use different wheels front to back.

Having said that Tiger used to use the Mk2 Golf upright.

Cheers

Chris :)

[LeonN]

as regard the pcd i was looking for 4x100 as aposed 4x108 to match the bmw parts at the back. so mk2 golf wood work.
off to look at tiger.

[Talonmotorsport]

So why not use the BMW front uprights?

[LeonN]

i dont need them yet so am still thinking.
the bmw ones need a strut fabricating for them. there are drawring about for them but no sizes that i have seen.

[NEroadster]

I would second what Chris has said the geometry in a front hub such as King-pin inclination axis and steering axis offset are often set completly differently in a front wheel drive car due to a diferent set of requirements. Net result geometry that can be difficult to modify to acheive good cornering and feel when driving the car. Usually not imposible but none the less more work

[Land Locked]

Would anybody have drawings of how Tiger have utilised the golf front uprights? (a link would do fine too)

[londonsean69]

Another small point to bear in mind is the mixing of parts from different manufacturers.

Imagine needing a wheel bearing from a Golf, brake pads from a Corsa and disc from a Sierra. Ordering parts would be a nightmare.

Life will be so much easier if all the rear end was from a <insert model> and all the front end was from a <insert other model>

I don't have a donor, my rear end is 4x4 cosworth and my front end is a real hodge podge (Sierra uprights, Hi-Spec 4 pot calipers, Focus ST170 discs) but all of it is ford, or ford replacements.

To be fair, Sierra hubs are not expensive, but if you are looking for a diffeent PCD, why not just re-drill sierra hubs to suit?

[LeonN]

re driled seirra hubs seems to be the easeyest of solutions for the front.

[chrisunwin]

Hi

Can anyone post dimensions of an "Ideal" front hub. Height between top and bottom ball joint, offset top to bottom etc. Then if anyone is looking at something other than the Sierra they will have dimensions to work to.
My current "flavor" is to use a Nissan 200SX (Silvia). The front hubs here pose a problem in that they steer from the back not the front, the strut is fastened to the inside top of the hub with two lugs and not 'plugged in' as on the Sierra.
I should be able to sort out the top ball joint without too much of a problem, not sure on the steering attachment yet, maybe a fabricated arm of some sort. Got the manual for the car at least, so have some idea of what the bits look like.

Regards

Chris

[georgenewman1]

is it not possible to switch the hubs so they steer from the front??

[3GE Components]

The problem with FWD hubs, is that the ackerman angle is built in, if you reverse the hubs the steering arms will point to a point in front of the car and not the rear axle line as intended, this will mess up the steering action.

Kind regards

John

[Chris Gibbs]

As well as the Akerman that John mentioned the other thing you need to consider if you swap hubs "side for side" is that the caster angle is facing the wrong way. You can design around this but it means some difficult wishbone angles, this is the main problem in using the Vauxhall Omega as a donor.

In answer to the perfect upright question - there isn't one. All suspension design is a compromise based on weight, required steering effort, principal use of the vehicle etc. It's a complicated process and the ability to design your own upright is part of the process that is a good thing if you can do it as you can optimise that part of the design. Usually you have to work around the limitations of the upright you're stuck with.

I've been forunate in designing the single seater so that I have an optimised upright for that particular vehicle. It might be that that upright is better for the Roadster too, it won't be optimal though as it's not purpose desugned but it might be an improvement.

Cheers

Chris :)

[Big Vern]

I thought Tiger used the Golf track control arm as the 'lower wishbone' arm as the ball joint suited the Sierra upright. That's how I remember it on their Cat E1.

BV.