Finished design of front suspension Rx7 FC to 323 sub-frame

So I threw out the original design as I didn't like a few aspects of it, mainly being that it was overly complicated, not as flexible with the position of the steering rack to the Lower Control Arms(LCA) and not as strong. To address some of these design flaws i re-designed it around some 25X50X2.5 rectangular stock I had in the shed. I also changed the design of the brackets for the power steering rack to make them easier to position providing more flexibility during construction. I've made the height of both the the LCA's and the steering rack adjustable by 60mm in three 20mm increments.

The I've sent the parts of to the laser cutters to be cut in 3mm mild steel with all the files available here. Once they are back I'll mig weld them together as I don't posses a TIG welder at this time.

New Sub-Frame Design

Old Sub-Frame Design

I built the old design in cardboard after printing it on paper sticking it to the cardboard and cutting it out. This identified a couple of issues with the position of various holes which I corrected.

Current Status of the Mazda, old engine, gearbox and steering out.

Comments

Shortening the Diff

I have a Ford 8.8 inch diff from a EF/EB Ford Falcon with a Limited Slip Differential. I want to shorten it down to suit the 323. Due to the RX7 LCA in the front, the front tyres(205X50X15) now protrude from the front guards by 65mm. Making the overall front track width 1,675mm. With 225X50X15 tyres on the rear and the standard diff the rear is 1,610mm. Meaning that the rear track width is 32.5mm narrower on each side. To widen the rear when I shorten it, I'll make the rear axle 65mm wider than the standard rear axle. The standard 323 Diff width is 1,338mm and the Ford 8.8 is 1,547mm for a total difference of 209mm. So the Diff needs to be shortened by 209mm - 65 = 144mm or 72mm per side.

Suspension Design Solid works

To assist with integrating the Mazda RX7 S4 FC front suspension into my Mazda 323, I've decided to see if I can create a solid works model for the suspension and then one for the Mazda chassis to see what fabrication work is need to integrate it. Looking online into engineering tutorials I found a site called Grab CAD community and a tutorial on there around spring design in solid works which looks fairly strait forward. https://grabcad.com/tutorials/tutorial-how-to-model-a-suspension-spring-in-solidworks-and-show-design-intent The main issue I have is the Lower Control Arms (LCA's) are a rather complex shape and will require me to up-skill in SolidWorks to be able to reproduce them. I'm in the process of sandblasting the part and taking some better images from which to model it. *UPDATE -- 1FEB17 nearly finished sketching the LCA and spindles

Mazda_323

Mazda_323 The above link is for a suspension model I measured from the stock Mazda 323 suspension and setup in the model creating tool at Racing ASP to assist in mapping the stock Roll Center and predicting the new roll center with the RX7 FC Suspension.

Sams Shed

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