Slow Car Fast
October 31, 2008 - A new plan.
The original intent was to install a Ford 302 into the MG, as it's cheap and readily available. However, that was before I got mixed up with transplanting an LS1 into a Miata. I fell in love with not only the performance, but also the packaging and the (relatively) light weight of the engine. So I've switched plans. It's going to be an LS1.
entry 63 - tags: engine choice, planning
October 31, 2008 - Sharp eyes will notice the giant "LS2" on the last engine.
Okay, so I cheated on the picture. And here's the engine I'm really considering. It's marketed as the "Vortec 5300" and it's found in late model Chevy Silverado trucks. But in the 1500 extended cab 4wd versions, it's a special high output version called the L33. Unlike the usual truck motors, it has an aluminum block so it's a lot lighter.
It's also taller, but the LS1/LS6 intake manifold and oil pan should bolt right on. Hopefully it won't be too big a deal to drop the alternator somewhat as well. It's a 5.3 versus the 5.7 of the LS1, and that's simply due to a smaller bore. With the right parts bolted on, it'll basically end up a slightly smaller version of the LS1, and all the same hop-up parts will fit. LS6 cam, perhaps?
But the big reason is that they're a lot more affordable. LS1s are well known and are expensive. Truck motors are not sought after by most enthusiasts. I've been able - without trying too hard - to find a 16,000 mile example for under $1000 shipped. I'm sure I can do better. I'll still have to buy a few parts to make it work, but it'll come in well under the price for an LS1. And with 335 lb-ft and 310 hp, it's not going to be a slouch.
entry 64 - tags: engine choice, planning
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