Westfield Elevens

Sounds like you should have an interesting time!!

I think we're still aiming for the trackday on the 1st, its tricky finding trackdays that allow 105db.

Have you fitted an LSD yet?
I find the back a lot more predictable with it with most slides being catchable.

No LSD yet. £600 or thereabouts is a big chunk of budget. From my limited experience of rear drive cars with an LSD I know it would help throttle steer in a corner. It should probably be the next major item of spend. I'll see what difference the new suspension makes. I did think I'd got one on Ebay, but it turned out to be for an early MGB or MGA. However the good news is that I made over £100 profit just by putting it back on Ebay! I should have realised that 4.3 was not a ratio for the small BMC axle.

The problem of a quick transition into over steer is a product of the XI's high roll center. Lower the Panhard rod a couple of inches (well, I didn't say that it would be easy), and you can get, dare I say it, a grip on the problem. With the high roll center, the rear axle follows the body roll, which leads to some unpredictable handling at the limit if everything is not perfectly set up.

Softer rear springs can help improve grip, but most of you have figured that out. Also, if the chassis doesn't have the shear plates on the chassis' rear suspension arm mounts, install them. Then you can run the rear bushings a little looser, giving a bit more compliance and articulation in the rear, and a smoother transition. Proper selection of a front anti sway bar will also help, along with double adjustable rear dampers.

Adding a clutch type LSD, like the TranX, set up tight, might also help. Having less slip between the wheels off throttle will add just a bit of under steer that might help to balance the chassis. My current setup is 45/90. This seems to work pretty well, as my car is neutral with a smooth transition to oversteer, or can be throttle steered. The big advantage is that on corner exit, you have drive out of the corner, rather than inside wheel spin (as the inside wheel lifts, due to the high roll center...). Just remember that when you install the LSD to the BMC rear axle, you need to replace the axle shafts as well with race units. If you don't, you will snap them like stale linguini. Especially if you have 100 or so HP.

Lowering the panhard rod is in the list! My later chassis has the shear plates on the radius rods. As you say, the snag wth the LSD is that it can put more load on the shafts (although my standard shafts have survived a season and a half of racing). So not only £600 for the diff but anouther close to £400 for the shafts. My current thoughts are that I'd sooner replace the rear with a narrowed Caterham deDion set up. I get a tougher Ford diff and LSD, less unsprung weight and rear discs. I'd use the four links instead of the A frame, with a Watts linkage. That would future proof the rear end for any potential engine upgrades beyond A Series...

My standard axles lasted about 300 miles with the LSD. I drive in the canyons nearly daily, and the driving out of the corners with all the torque going into the outside axle broke BOTH in short order. The left simply twisted in half at the splines, the right twisted the shaft out of the drive plate. Having more than 100 lb.ft. of torque also makes a difference.

I purchased a set of two piece race axles from Mini Mania on sale for $400. I picked up a second set of wire wheel axles from Peter May for around $600, including the spline hubs. The TranX cost about $850 delivered here in the US. Around £600, I guess. Of course, I don't pay the VAT, but I do pay shipping.

I am not convinced that the DeDion (one of my favorite suspensions, being over a century old) would really be lighter when installed. The car would have to be "back halfed" as we say in drag racing, with an entirely new structure to hold it all together. It would be a whole new car. Remember, 4 links are what you have now, and they are equal length and binding in roll, which will cause the same problem you're having now, a reduction in articulation. I like the idea a lot, but you would need to use the back half of a Lotus 7 Series 1, or an 11 to make it work (note that those cars used different length suspension arms, and were about twice as long, moving the mounting points near the driver's elbow. It isn't exactly a "plug and play"). Besides, it will take a very long time to properly build and engineer that. Yes, it would be a new car. I am thinking that adjustable screw jack mountings for the Panhard rod would be better.

I am working with an owner here locally. We have been going through everything on his car. We are finishing the work on the Protech dampers, then it's on to the SPC CR gearbox, then maybe an adjustable Panhard rod, if there is actually room in the chassis for it, and sufficient ground clearance.