Slow Car Fast
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November 15, 2010 - With the video of the first drive getting attention, I'm fielding a few questions about the car.
The most common is about the wide track and the suspension choices, typically with people pointing out that I could have used a bolt-in setup from Fast Cars. I did actually use a rear end similar to their design. But here's a recap of the thinking, all gathered together in one place. This is taken from an email I sent to someone.

About the BGT's suspension - I decided to go with Miata suspension on
the car, in large part because it's a setup I understand very well
given my history. I also have a large collection of spare parts, and
this makes it much easier to keep a fleet of cars happy. Being able to
swap brakes between the Lotus replica and the MG came in handy just
last week as I borrowed some parts off the Lotus to get the MG
driveable. It's also much less expensive than buying one of the
coilover setups on the market for the B, and allowed me to toss the
stock subframe and other bits. As an unplanned side effect, I also
saved quite a bit of weight.

So, going with the Miata front suspension meant I had a wider front
track. I could have narrowed it, but then I would have messed up those
beautifully controlled roll centers that I think are a major
contribution to the Miata's handling.

Now I needed a wider rear track to match. I seriously considered going
with a Miata rear end, which is a nicely packaged independent. I've
seen photos of a BGT with this rear end installed, but there were a
couple of problems. The first is the amount of sheer destruction
required to the rear of the car to make it fit. Secondly, the rear end
wasn't strong enough to deal with the assault from the V8, so I would
have had to modify it for a different differential. That's not a major
problem but it was an additional expense. By mixing the appropriate GM
parts, I was able to use the differential from the Camaro and a
standard-length axle housing to make the best use of what I had. If
the live rear doesn't work out, I'll change it over to a Miata rear
eventually, but I'm pretty happy with the overall engineering of what
I have. The car is stronger for it.
tags: suspension