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MG Midget and Sprite Technical - Wanted - Scrap lower front wishbones

Hi all,

As per I title I am after a couple of scrap lower front wishbones for a Spridget if anyone has old ones they have taken off with wornout fulcrum 'threads'.

Ideally in the West Mids and I can then pick them up

Cheers

Spencer
S Deakin

I'm sure you will be offered some but if you aren't, I have a couple in Pembrokeshire.
Neil K

Hi Neil,

That is very kind of you,

I'll just have a look how cfar it is to your neck of the Woods

Cheers

Spencer
S Deakin

Spencer,

Are you planning an alternative outer trunnion fitment?.
David Billington

Hi David. That's the engineer coming out in you.
Neil
Neil K

David,

Yes part a front suspension revamp

I have already converted to 'modern' press fit metalastic bushes for the inner bushes for the FLWB.

I have toyed with a few options for the 'trunnion':

Not dissimilar to your flanged oilite bush solution, but currently I have limited lathe access.

Small spherical bearings i.p.o. of the trunnion - difficult to seal and not convinced about longevity.

So I have gone for an upright conversion as well, it took quite a bit of sorting the kinematics out as I wasn't prepared to hack the front crossmember to relocate the upper wishbone and it's all to easy to end up with poor camber gain, bumpsteer and roll centre position / migration etc...

So I am just part way through mocking everything up to confirm the kinematics.

This is my first hacked up wishbone just to sort out damper motion ratios and general packaging stuff.








S Deakin

I'm just deciding on the best way to integrate it to the std wishbone construction.

It would be easier to fabricate tubular wishbones but I want to try and keep the FLWB looking standardish, so trying to base it on the original item.

The mockup here is not in anyway how the structure will hold the lower ball joint, but the thro' bolt is part of the LBJ design.

Currently part way through having some Protech dampers revalved and will probably mount them similar way to your upper wishbone / telescopic damper top link.

I have tried to package a coilover on the FLWB centreline to avoid twisting but it would involve too much crossmember top modification to allow it

Cheers

Spencer


S Deakin

Spencer

I've got a few that you can play with.
Dave O'Neill 2

Dave,

That sounds perfect, Thank you.

I pass the turn off for Solihull on the M42 Mon - Thurs to and from work

Thurs would be ideal to pop by as I finish early

Can I have your contact details to try and arrange a visit

Thanks again

Spencer
S Deakin

Spencer,

What upright are you using?, something like a Ford cortina, IIRC you can get them in ally from rally parts places. Regarding the LBJ, I always thought that joints such as used on the old Chevette made a neater installation as they pressed into a collar rather than bolted on but then you need to find a suitable joints which might require rummaging in a friendly parts store.

Some years back I met a guy that mentioned converting a bunch of lower wishbones to use Triumph Spitfire trunnion parts, I think that would be similar to what I did.
David Billington

David,

I have looked at just about every option (Ok an exaggeration) but it felt that way.

My intial work with an MX5 upright didn't look promising as I was trying to be too strict in the kinematic behaviour it gave, so I looked elsewhere.

The Triumph Spitfire / GT6 option you mention (as used on Caterham / RWD Lotus Elan etc...)If used as std still has the same trunnion type issues (albeit vertical) Canley do a replacement lower ball joint to go with this upright but it is not sealed (they maintain it doesn't need to be?)

Caterham do some very niced lightweight looking uprights which are geometrically identical / similar to the Triumph unit.

For both of the above options the costs starts to add up very quickly, especially the Caterham options.

Looking at the kinematics for these uprights it didn't help much compared to the MX5 unit (i.e. trying to use the midget crossmember essentially as is) so I didn't persue these.

I looked at the Sierra / Cortina units and the RD Alu alternatives but again once you add spindles / hubs / studs / steering arms / ball joints it gets quite expensive bearing in mind you still have to make upper and lower wishbones to boot! Also looked at the Wilwood generic Alu upright.

So I ended up revisiting the MX5 upright (lighter than the Midget unit) bigger vented brakes, proper UBJ / LBJ. Cheap (I bought a whole car and broke it - suspension cost nothing)

I just had to compromise on the camber gain in rebound as there is very little correction (but no worse than the std car) and need to make a revised steering arm pickup - (not just an extension) (Std MX5 has low mount rack - MG rack is relatively high), pretty well every other metric is equal or better IMO.

My biggest concern is double checking the bumpsteer with physical mockup parts as it is quite sensitive to part placement and it has to be right

Cheers

Spencer

S Deakin

Spencer

I have a bespoke set up on my sprite which uses Triumph TR3 uprights. I'm not happy with the top wishbone and Spax set up for road use, so I'm going to do some further work on it.

Karl


K W Seddon

Hi Karl,

Looks interesting,

I do remember seeing photos of it and the top wishbone especially stuck in my memory with the rearward link being against the inner footwell?

Do you use it on the road?

Did you do the geometry work / do you know the bumpsteer charactersitics?

Your coilover positioning looks similar to what I would have needed to do - i.e. cutting away the top wishbone mounting area for clearance.

I will probably retain the original spring mounting and use the usual side mounted damper at the rear of the lower wishbone.

Cheers

Spencer

S Deakin

Spencer

My project is taking an age, I've made some recent progress, albeit very slowly. Currently I'm trying to finish the turbo installation, rad, cooler etc. Once this is done I will start on the front suspension again.

The original design was for a track set up and I've decided to us the car principally for the road use, hence the rethink. I've been speaking to Mike Youles who has several interesting Sprite and Mini race cars and will probably replicate something similar to his HTCC racing Sprite (see picture). He has also offered to help set up the geometry once I get it on the road. Probably because I sold him a cheap but good Sprite shell that he's going to extend and drop onto a Lotus Spyder chassis, but that's another storey.

Karl


K W Seddon

Karl,

Yes the only other car I have seen with a similar top wishbone rearward link is the Mike Youles car (only 'seen' via t'internet.) Also based on the Triumph upright, looks nicely engineered.

I think I read on the Sebring Sprite website about the Midget body on the Elan backbone, along with a wheelbase stretch that he was planning.

I think one of the '7080 AC' incarnations had an Elan chassis back in the day?

Yes it is quite tricky to get sensible geometry with such a short top wishbone length.

It will be interesting to see you progress, do you have any other photos or a build diary anywhere?

Cheers

Spencer
S Deakin

Spencer

I've seen Mike's Sprite in the flesh and it's beautifully put together, much better than mine. It should be really, as I believe it is owned by a director of Ricardo's. Mike invited my son and me to Brands late last year to help in the pits and see him race it, but he destroyed the Sprites engine in the previous race, so I'll have to wait until this season starts to see it in action.

Our front suspension designs were put together quite independently, but seeing Mikes and having decided for mainly road use I'm going to do some fairly drastic revisions to mine (even contemplating changing the top wishbone completely - see photo). The main problem I'm having is space due to the position of the turbo.

I've started to post my very slow progress on BBS Twin Cam's page, see 'K Sprite Turbo'. Once a little further on I'll probably set up my own diary on flickr, in the same way as Carl Taylor who I've met a couple of times (he lives close to me). He has fitted a 1.8VVC engine in his Midget which gave me the bug for more torque (I was originally going for just 1.4 K series power).

Good luck with your suspension please keep us posted.

Karl



K W Seddon

Spencer

Give me a call...

ZERO 7803 231283
Dave O'Neill 2

Dave,

Thanks for the wishbones today from your collection!

It was a shame about the weather as it would have been nice to chat for a bit longer

Thanks again

Spencer

S Deakin

Did you ever finish your front suspension upgrade using the MX5 Spindles?

I was thinking of doing the same.

Cheers

Graham
G Heath

This thread was discussed between 24/01/2011 and 01/03/2016

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