Slow Car Fast
LIFE OF A GT
October 31, 2008 - Of course, a power upgrade of this magnitude will have implications that reach throughout the car.
One victim will be the rear axle. I could cut down a rear from a Mustang or something similar - but why not go with an independent setup? Much more my style. And the obvious choice is a Miata one. I have access to cords of Miata parts, I know how well it works and I can use my access to aftermarket parts to tune the handling.
I'll need a different differential, but that engineering has already been done for the LS1 Miata. So all I need to do is fit the subframe to the car.
Luckily, I have a series of photos showing this being done. Perhaps not with the most subtle techniques, but it's a proof-of-concept. The biggest problem is that the MG's body is narrower than the Miata's, so I'm looking at narrowing the suspension by almost 7". Not difficult, really, but I was amazed at just how much.
entry 65 - tags: rear suspension, planning
November 1, 2008 - I measured the maximum fender width of the MG at 58" front and 57.5" rear.
That's a bit approximate, and it assumes the fenders are fully rolled. Measuring a complete Miata subframe with 205-series tires came up with 61" front and 62" rear. So I don't need to narrow things as much as I'd feared, as long as I don't do anything too foolish with wheel and tire choices.
The picture is of a tubular subframe that's made for installing an LS1 in a Miata. I'm not sure if I'm going to cut down a stock Miata part or build a tubular one like this. The latter will be more work - of course - but will offer more room. Remember, I have to narrow the track by about 3".
entry 66 - tags: planning, subframe, suspension
June 19, 2009 - I welded the new frame rail to the car last night.
It's not really a frame rail, most like a lower suspension mounting point that's two feet long. But still. 30 or so rosette welds plus a solid connection at each end, I think it should work well enough.
It sure looks weird peeking under the car and not seeing any visible connection between this new rail and the floor. But I know it's there!
entry 188 - tags: frame, rear suspension
November 19, 2009 - A big box full of MG suspension parts arrived in the mail!
Well, I know they're MG suspension parts. Most people probably wouldn't identify them as such.
A collection of swedged rods for my trailing arms along with 4 left-hand thread ends. I'm sure I ordered the latter back in the summer, but they're nowhere to be found. At worst, I have some spares.
I also picked up a couple of weld-in bungs so I can build the Panhard bar. I'm pretty close to that point. Cool.
entry 213 - tags: rear axle, suspension
November 20, 2009 - The axle in its new home!
It took a bit of fiddling around with trailing arm length to get it in just the right place, and I think I'm going to have to pick up some lower ones that are an inch longer. No worries, they're only about $12 each. I'm actually really liking these, I'm trying to think of other cool places to use them. It's super-easy to adjust the pinion angle and the rear axle angle.
In this picture, I have the jackstands at different heights - the arms are usually parallel! I also took the shot before I went on a major garage cleaning binge. That's how it usually works, right?
entry 215 - tags: rear axle, suspension
December 2, 2009 - The Panhard bar mount welded in place.
This is one solid sucker, I'm very happy about that. The bend in the body makes it good and strong.
entry 221 - tags: panhard, rear axle, suspension
December 16, 2009 - The front shock mounting is much easier to figure out.
The shock is basically the same design we worked out for the Miata application, but fitted with a different upper mount. The bottom bolts right in to the Miata control arm, and a simple bracket will take care of the top. Lots of clearance. I left that upright on the frame for this purpose, looks like I got the dimensions just about perfect. It'll be tied into the unibody and hopefully cross-braced across the engine bay once I know how much room is available to me.
entry 229 - tags: suspension, front suspension