Bringing up the rear.
Going tried and true with a 9" diff.
As much as I liked the ride of the Jag Independent Rear Suspension in my previous Cobra, I just knew that the Jag parts wouldn't cut it in this car. I'm using a standard XY Ford length 9" housing with Moser 31 spline Axles. I've used Moser axles before, and they can take more abuse than I could ever throw at them. I have a LSD centre with a billet hat and moonshot 3.0 gears. I'm not too confident about the clutch packs holding up, but I didn't want to use a Detroit Locker or a spool. Detroit Tru-Trac centres are probably my best option, and I hope to collect one from the States mid June 2003. If the LSD doesn't hold up that long, I might have to ship one over sooner than that though...
UPDATE!!!
While I had all the differential parts required to get the car on the road, to get the wheels sitting perfectly in the wheel arch required 14mm less track width. To achieve this, I planned to machine down the axle at the point that the wheel bearing locates. To machine this shoulder back 14mm would allow me to use the Moser 31 spline axles without any other changes. It wasn't this easy, as the first pass on the lathe went straight through the heat treating of the axle, much to the surprise of the gearbox/diff builder that was doing the machine work. He has never had this problem with other brands of axles.... After numerous unanswered emails to Moser in an attempt to find the heat-treating specs to repair the axle, I gave up and ordered a new pair of axles. I had always been concerned that the weak link in the diff would be the stock Ford case (pumpkin). I considered the thought of buying an aftermarket case at the same time as I bought the axles, and it worked out exactly the same price whether I bought 28, 31 or 35 spline axles. Twist my arm - give me the 35s!!! This spur of the moment decision lead to me then having to complete the new rear end assembly. It now consists of:
I'm using a 4 link based suspension setup in the rear, but with a slight difference. Whereas other Cobras run super short upper bars (which aim directly at your spine...), I have equal length upper and lower bars. The upper bars actually run from above the diff, out into the boot space and finish up at the rearmost point of the car. By doing this, I don't have a massive bar ready to impale me in a rear-end accident. The other advantage is having all rod-ends (heim joints) in compression during acceleration. Broken rod-ends are not a good thing when leaving the line hard!!!
The rear end is located via a Mumford Bar assembly. This allows infinite adjustment of your rear roll centre, and effectively keeps your inside tyre from unloading during heavy cornering. As always, I only have dodgy photos, but here you can see the left upper bar running through the boot. That's a Triangle Engineering fuel cell They are a true work of art - the welding is perfect! It's a 70 litre tank, with 2x 1/2" outlets, fuel level sender and foam blocks inside.
Copyright © 2002 - Craig Marsh
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Email - cobraracer@yahoo.com