I am looking for sierra IRS info. mainly I am looking for drawings for changing the book plans for either using the stock subframe or a wishbone setup. thanx for helping a yank

nick

Take a look on the help page of the locost car club site at www.locostcarclub.co.uk theres at diagram that might help. Cheers Scutter

that kinda helped a little bit. now do you know where to find wishbone drawings? maybe even cad files?

nick

85 merkur xr4ti donor

Hey Nick,

Are finding that the Merkur is exactly like the Sierra? or are there some subtle differences? I ask because it was on my donor shortlist.
Where are you based? Did Jim recommend you joining here too? Good idea for Sierra info.

oh I already knew it was about the same.....just a few differences....split quarter windows, and a larger engine, left hand drive....larger hood....some other things. anyways over here in the states I can't find much along the lines of rear wishbone setups and getting them shipped over is out of the question, same goes for a chassis. but seeing how all the swap parts are the same and an IRS is nice to have I thought a xr4 swap would be nice. the only difference is that I will be running a 2.3L ohc turbo motor with a BW T5 transmission with the 7.5"? 3.36:1 rear. although I might look into doing a 8.8" US rear since they are real common and have tons of gears and diffs available (same as a mustang). but who knows this might turn into my senior design project in two years . So basicly I am looking for info to do my own "indy" chassis since I have access to the full shop at school (welding, plasma, cnc mill/lathe) and plenty of equipment at home (MIG, Oxy, chop saw, band saw, hoist, grinders) also if anyone has dimensions for the diff/axles/hubs/uprights or anythign else I could use that for designng my own (cad background)

nick

Nick,

This is a good build site:

http://www.hoverd.org/Tim/index.html

Shows a westfield and a Dax build, both I think use the sierra diff, one is IRS the other is De Dion.

what the hell is up with the DeDion rear? it looks to me like a irs converted to a solid axle? or is this just from teh couple pics I have seen? I would imagine that the geometery chages somehow when a wheel travels up and down.

btw I hail from peoria, il midway between chitown and STlouis

DeDion is a really old concept.

its an evolution of a live axle.

For a locost, its less complex than a full IRS system and can share similarities to the live axle.

its key advantage is a reduction in unsprung weight. All you have unsprung is the wheels and hubs and the beam. The shafts and diff are part of the sprung weight of the car.


A lot of small european FWD cars use a 'similar' beam axle - obviously with out shafts or diffs!


atb

steve

Here's a quick snapshot of the de Dion back axle in MK's own demonstrator, if it's of any use to you...

http://homepage.virgin.net/d.w.jenkins/MVC-010X.JPG

Not enough to help you build your own, but good enough to give an impression of size and layout.

David

The other key advantage to the De Dion axle is its ability to keep both wheels vertical to the road surface whilst cornering, something which it is very difficult to get IRS sytems to do

John

well I got bored at work today (damn economy) so I opened up a sierra IRS chassis file I d/l and found it to have no dimensions and was a assembly. so I got started pulling it apart and saving off each part to print later this week. one thing through me for a loop though someone used a dark dark grey to draw the shocks and their mounts and it wasn't showing up on my black screen to well (basicly I thought they were missing) this chassis doesn't look too bad though. it will need a little tweaking as the dimensions are metric and I need to convert to SAE for my steel stock.

put pics of my irs in photo archives, bu write up is inprofiled w/bones