Looking at doing a suspension swap on an FB shell (front A arms on custom cross member, rear IRS on custom strut tower/diff mount U bar, steering knuckles, r&p steering rack)

So which would make more sense? Using FC or Miata donor parts?

My instincts tell me the Miata ones might suit the FB better, but the "purist" in me (if that term can apply to such chop-shop engineering) likes the all-RX approach.

Thoughts and opinions of 1 vs the other?

(note how that leaves out "why bother?" Why ask why? )

 

i think fc have more stronger parts that the miata, specially the rear end and axles but i dont know about suspention and i think (my opinion) fc have more option of suspention that miatas anyway (my opinion again) is better doit out of a fc.

 

well id go miata i dont know why but hell be different =D
just my $.02 centavos.

 

Miata.

There are several interchangeable parts between SE's and miatas. I don't recall specifically - but the limited slip rear ends is one, and I personally know that a Miata Oil pan is the same as a GSL-SE, just placed in reverse.

 

Wow - a Miata oil pan fits a rotary? neat

 

i wouldn't use the 2nd gen reae suspension unless you've investigated it. plus it has a "passive" rear steer via a special "ed" bushing. kind of annoying. i believe miatas are double wishbone out back aren't they? if so the 2nd might be easier to fabricate in. if you want i'll scan my haynes underbelly shot on the rear suspension of the 2nd gen so you can get an idea if you don't know already.

 

Already got the Hayes 2nd gen manual but thanks

My concern with the FC IRS was the trailing arm setup - that config is prone to squat under accelleration. The bushing issue just furthers my desire to use Miata parts instead.

Ideally I'd like an IRS similar to the original 240Z setup - Chapman strut (Macpherson above, A arm below) 3 point linkage, but I like the all-Mazda solution for my own reasons

 

do both have the same width? is the width the same as an FB? It seems like the miata would be easier to swap and seems like all the dimesions are similar. What about cost and availabilty? FC stuff is probably more abundant. If you have a miata donor in mind already than go with that. my $.02

 

Yeah, I'm going to go with the Miata setup on this one. Two reasons:
First, the miata is very similar in weight and weight distribution to an FB, which means the suspension will be engineered more to those specs.
Second, I've never really found the FC rear end to be a particularly appealing setup, with the whole trailing arm/circular "around the axle" hubs, and such.

 

The "around the axle" hubs are also used in the DeLorean DMC-12 and the Lotus Esprit Turbo

not keen on the trailing arms, though.

As to track width, with custom crossmembers track can be altered a little bit either way (not ridiculously so - any change effects the suspension geometries) but in this case a custom front and rear crossmember is a must anyhow...

REALLY thinking of doing this to the parts bitch shell. Trying to decide between this and self-funding a new short film, or both and eating KD for awhile *L*

 

Well, I'm not sure... I kinda thought about something simular, but haven't tried it yet. I would like to ask you to go FC, as I have a complete donor FC, and then you could let me know what you did, and I could copy :-)
Well, as for being purist and using FC parts would be a rather stupid thing (if you are a purist you don't d this at all), you should simply consider what parts are easiest to get, and easiest to fit. The rearwheel steering on FC's can be eleminated by using the RB bushings, so that's no argument. I'd go with the FC for sentimental reasons (it all stays RX7 - just like in my car with some FD and FC parts) but I can't say that's a real argument either...

 

Also consider wheel bolt patterns and brake size. I am not sure, are they the same? The Miata(mx-5) IRS seems simpler. Also track width, which is closer? I would personally go Miata(mx-5). Hey, it's still a Mazda, and it still has an "x" in it's name!

 

So this would become an MX-7? or MR-7? *L*

 

For some reason every time I open this thread my "a" drive starts chugging like it is searching for something.. What's up with that!

 

odd, my floppy a drive does that too.

 

it's weird!

 

mine too ! !

 

i'd say miata as well. just cuz the size is more similar between 1gen and miata. call me crazy, but i think miatas are the closest relative to the 1st gens. i love 'em all(esp. 1st and 3rdgens), but 2nd and 3rd gens don't seem to have much in common with 1st gens other than being rotary. miatas, however, do. small, nimble, simple. put a hatchback on one and it'll darn near look like a first gen too.

 

I totally agree with that. Except I think the front of the Miata (1st gen) looks like a toned down 3rd gen 7.

 

Miata's, or MX5 like we call them overhere, are indeed wonderfull cars, and do have the same spirit as the first gen: small, not too expensive sports cars.
3rd gen is great, but hey, look at the price... It's really more a rx9 then a seven, if you know what I mean...