Hi, i want to start a build and as previous threads have already said (and a few weeks trawling ebay, gumtree etc have shown) there arent too many sierras out there at the moment. I dont really want to use an mx5 as a donor because, well, its already kind of a sports car anyway. Omegas dont seem to be used that much, though why is that? Theyre rwd, and theres a few manuals out there. Anyone know why theyre not so popular to use? Im thinking of going down that route but the lack of other people using them as donors makes me wonder if theres something i dont know?
i don't think much of the front end is any use. if i remember right, they use a steering box and drag links. i don't think the front
uprights are much use either.
engine gearbox and diff will be useful but thats about it in my opinion
MX5 is double wishbone, so the uprights are just about perfect size/design for it, with rack and pinion steering, rwd, etc. similar size, light weight
design
MX5 is a much better bet i reckon, though i prefer vauxhall engines. no reason why you couldn't use a MX5 donor and a vauxhall enigne though
[Edited on 6/3/14 by blakep82]
When you could buy a donor for £50 it made sense to get the hole car. Now most rwd cars are fetching good money I would just buy the donor parts piece
by piece, mix and match 
to what ever spec you like.
What would you actually keep from a sierra ? front and rear axles, steering column and gearbox are about it.
The omega would give you the above minus the front uprights. I would stick to tried and tested geometry of ford / mazda front uprights. Not saying the
Omega couldn't be adapted but the further away you diverge from a the book the less likely you will be to finish it. Making just a minor change
to the book has a knock on affect.
[Edited on 7/3/14 by big_wasa]
This is something that new members on the forum inevitably bring up in their first few posts.
The reason that most people are using Sierra or MX5 uprights and various other parts is that so many others have done it before, it's a well worn
path, there is lots of inf and advice on here about stuff thats a known quantity and is known to work well. It would make sense for someone to
experiment with say their second or third build but really theres enough work, enough variables and enough issues to get round without going too far
off piste with an uncertain outcome on a first build. That said, it doesnt have to limit choice, there are enough cars running round out there now
with Sierra IRS, uprights and brakes but running everything from R1 bike engines to Chevy V8s.
if you go on the haynes forum i think there is a chap on there using an omega as a donor.
im using an omega gearbox saab engine and ford diff and uprights on my car so anything is possible if you put your mind to it.
Thats great thanks for the replies. I like the idea using the omegas engine/box/diff etc and sticking to sierra parts for the rest, and as you
say..nowadays the cost of the specific parts will be just as cheap as a whole sierra donor. This will be my first build so i dont want to go too far
off track, but i could manage with the different engine/gearbox from the omega and sell off what i dont use. i'll continue hunting, and hopefully
will get started before long 
the omega box will just fit in the type 9 design haynes chassis which allows a bigger pedal box so dont bother looking for the MT75 version of the plans.
Thanks Ashg, i was assuming from the start i'd need to alter the tunnel to fit the larger looking R25, so thats good to know theres no change needed!
quote:
Originally posted by christim
Performance wise I know the CVH isn't as good as the newer engines but i'm happy to stick with it for now.
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