Build #2, No huge car progress...but...cool new toys! Options

[jd74914]

Hello all.

I figured I’d throw up a progress thread for my car’s second rebuild. For those who don’t know me my name is James and I’ve been a 914 addict since age 13 (now 26) and used to hang around here a bunch more. It seems like a good start to this thread would be some background information. Its first build took place when I was in high school (age 13) and ended as a freshman in college. When I originally purchased the car it didn’t run and had some pretty serious external rust problems. I rebuilt the motor, fixed tons of electrical issues, replaced all of the rotten metal with new (all hand-formed since I didn’t have the money to pay for reproduction pieces), and repainted. Everything was done in my garage with the exception of turning/balancing the flywheel and I learned how to MIG weld and paint from my dad, some books, and through a lot of practice.

After reassembly, it was my daily driver for 3.5 years during my undergrad degree. I pretty much drove it hard and put it away wet for the entirety of these years and it never saw a garage. Something about getting a mechanical engineering degree, dating a few girls, working throughout the year as a design engineering intern, and finding FSAE cars really limited the amount of time I spend on my own car. By the end of my undergrad degree there were some pretty rough spots, mostly in terms of the suspension/brakes and a pesky ignition switch (replaced 3 or 4 times and it kept failing), which pushed me to taking it off the road and fixing everything correctly. I thought it might take about a year-that was 3.5 years ago! (IMG:style_emoticons/default/wacko.gif)

Just like after the first rebuild, life got in the way and the car sat as I went through a master’s degree, worked full time, continued to play with FSAE cars, and starting working on friend’s real racecars. Now I’ve finally finished my MS (and know way too much about fluid dynamics and heat transfer (IMG:style_emoticons/default/laugh.gif) ), am applying to schools for a Ph.D., still haven’t stopped [advising] FSAE design, and really want to drive her! The play was to start and finish rebuilding the suspension last summer (I saw Chris Foley-Racer Chris in the grocery store one day and told him this), but I got carried away and a bit behind. This thread is to chronicle the build back to the road.

We’ll start with a few pictures from when it was originally completed in 2006/7 (well, it's missing the plates and still has the original windshield but...).

[jd74914]

Threw together the first iteration of the front sway bar arms yesterday night and tonight. The original arms are machined aluminum blanks pre-made by Schroder (1"x48 spline to match the sway bar ends). They needed to be cut down significantly to even fit within the fenders. Most companies seem to just drill holes in the arms and have a single-shear fastener attaching the heim joint on the drop-link. That's really not great engineering and frankly scares me a bit, even though with a properly sized fastener it's perfectly safe. In retrospect, I wish I had bought the steel arms like Stephen (914forme) did since it's pretty easy to cut off the ends and weld on some steel double shear plates. I could do the same with these aluminum arms, but that's also a little worrisome since they would need post-weld heat treat.

Given those facts, the easiest way I can come up with to put the whole assembly in double shear is to machine some blocks which fit into a groove in the arm. This will make the actual load bearing part of the block on the arm a long surface (bolts not only for clamping force). On the drop link side, the block will be machined into a spacer to allow some extra heim misalignment.

The fasteners are NAS AN6-14A meaning that they are 3/8"-24 with a 1-19/32" overall length and 15/16" grip length. They are a bit more expensive than generic bolts at McMaster Carr (best NAS prices are at Aircraft Spruce) but the extended grip length means that the threads are never held in shear which is nice for peace of mind. (IMG:style_emoticons/default/smile.gif)

Thinking about it now the 3/8" hardware might be a little overkill-5/16" might be better. Gotta do some math. Overall weight of the assembly as shown is ~1.4# per side.

Anyone have any thoughts?