Mx-5 Donor - SSC

[spud69]

Originally Posted by skov

Can't wait Spud, I'm itching to get started on my rear end!

I've decided not to use my MX5 now (it's too good to break), but if all goes well I should be purchasing another MX5 for my donor tomorrow
It's a 1991 1.6, so hopefully I'll be able to confirm that that fits too (it is a 1.8 you're using isn't it?)

Its the same car and gearbox skov just the smaller engine so all should be the same including engine mountings.

Andrew

[CTWV50]

Got my eye on a local mx5 donor too, raised some cash this morning for it's purchase. Good to know the gearbox is strong. I have really never looked twice at mx5's before so have a lot of research to do. Hoping to inspire and involve my 7 year old in the build over the coming years, really want him to have a good engineering mind, although at the moment he just wants to be a racing driver! Don't we all!! Great pictures on your Saturn Site, I shall show the young'un tonight.

Can you tell me what other parts are required (if any) from other vehicles. Is an escort mk1 steering rack still required?

[HandyAndy]

Originally Posted by skov

I'm itching to get started on my rear end!

I spent the afternoon at Saturns unit, the "rear end" has now been finalised for its dimensions, I,ll email you this evening Skov with part I.D. codes & dimensions of each piece.

I,d just like to say that Spud has done a fantastic job putting this chassis together, the work put into getting it spot on takes quite a bit ( alot ) of time, but the time & effort Spud has put into this will help lots of builders using the MX5 as a donor & will ensure the Roadster will have a long future indeed.

Well done Spud

cheers
andy

[flyerncle]

Another £50 in the post !!!!!!!

[spud69]

Well its all done, steering column fixings and brackets finished this evening. Have put up some latest pics:

http://www.flickr.com/photos/saturns...7625932340212/

Next stage is to cad it all up, create a build guide and plans, put together a chassis cutting list, chassis plate list, fully weld the chassis and get the engine and rolling chassis complete next week. Parts, where applicable, and all the plans / guides should be ready within 1 or 2 weeks now that all the hard work is done. Soon be time to sleep.......

Then when all this is done start again for a version of a single seater now we have the bodywork molds to......

Thanks for the support to all so far..........Andrew

[TQ_uk]

Hi Andy,

quick question - any reason for not using the MX5 rack? Reason I ask is I've a complete front subframe inc PAS and thought if you were maintaining the MX5 geometry (?) it would've been logical to use the rack, apparently easily modded to get rid of PAS system...

[Airhead]

The MX5 rack is about 140mm too long. In order for the rack to function correctly with respect the steering geometry the pivot points need to all align. Put a rubber band between the center of the bolt holes on the top and bottom suspension mounts the pivots on the rack also need to fall on this line.

Matt

[spud69]

Cheers Matt, you beat me to it.

Just to keep the steering geometry the same, and its easier to get semi quick and quick racks for the escort.


Andrew

[TQ_uk]

So the geometry is based on the existing Sierra setup in terms of wishbone lengths, pivot positions etc ( albeit using MX5 uprights) rather than lifting the complete MX5 geometry?

What problems would doing the latter involve? Is it more a case of the brackets on the chassis would be in an awkward place? I only ask as having a complete front end in the garage would have thought the simplest way not to mess about with geometry would be to copy it with more aesthetic wishbones etc?
I know the rack pivots need to align with the wishbone pivots (rubber band analogy) but from a single donor/budget perspective wondered why not go with what you (I)'ve got.

[skov]

Originally Posted by TQ_uk

So the geometry is based on the existing Sierra setup in terms of wishbone lengths, pivot positions etc ( albeit using MX5 uprights) rather than lifting the complete MX5 geometry?

What problems would doing the latter involve? Is it more a case of the brackets on the chassis would be in an awkward place? I only ask as having a complete front end in the garage would have thought the simplest way not to mess about with geometry would be to copy it with more aesthetic wishbones etc?
I know the rack pivots need to align with the wishbone pivots (rubber band analogy) but from a single donor/budget perspective wondered why not go with what you (I)'ve got.

Um, doesn't the original version use a sierra donor, yet an escort rack...?

The MX5 rack's wider, which would mean the wishbone mounts would need to come out, meaning a wider front end (I think!)

I really like Spud's approach of keeping the MX5 chassis as close as possible to the original. It's making my life easier building it, as most of the book, parts, and the knowledge on this forum still applies.