MG Sports Cars

As my old university roommate used to say, "if it's worth doing, it's worth doing to excess".

I was at a track day at Pueblo last year testing a car and met up with Curtis Jacobson. I've always liked GTs and my wife took a real shine to both the car and the rumble. So I was commanded to make her one as well. And who's going to ignore that?

We bought a black '72 with a tan interior, and naturally found out it was rougher than we'd expected. No rust, though, so there's the ugly stuff avoided. The original plan was to stick a stock 302 inside.

Then I helped put an LS1 in a Miata, and I was blown away. Not only with the performance - and there sure is a whole lot of that - but the packaging of the engine as well as the all-aluminum construction. It's just so tidy. So that's what I'm going to put in the poor little GT. Actually, I'm leaning towards the L33 - an aluminum-block version of the 5.3 with a bit over 300 hp and a short stroke. I found one with 16,000 miles for $1000 shipped, so there's a good start.

And since that's not enough work, I'm planning to graft Miata suspension under the car. It's hard to argue with the handling and I know the car pretty well. I already know how I'll handle the strength of the rear end to deal with the L33 and I'll have IRS and good disc brakes all around. It's not going to be easy, since I want the car to look stock. Rough calculations show that I'll have to narrow the front suspension by 6" and the rear by 7". The rear's easy enough, in the front I'll probably build a new subframe to give myself the room I need. I may end up replacing the entire steering column, who knows.

I'm also open to the idea of using a Corvette transaxle, as I think the packaging should work out. Thoughts?

So, big project. But it should be a fun car when I'm done - the power of a Corvette, the handling of a Miata and the style of a GT. I'll be documenting the whole thing as I go, and I expect I'll have a bunch of questions.

Sounds like a fun project Keith. Check out the Roadmaster and 340 threads for what we found out about IRS setups. We ended up going with the Jag unit on both cars. You can use the search function to narrow things down to the general areas where the relevant info is.

Jim

You might consider using Sebring flares & keeping that extra track width, A Miata suspension won't ride like a Miata when you narrow it 6".

Here's some pics of an MGB/GT project using Miata front & rear suspension:

[www.pbase.com]

I'm not personally a big fan of look of the Sebring flares, so I'd prefer to stick with the stock body. I might flare the fenders out slightly with a fender roller, but not enough to spoil the excellent lines of the car. The 6"/7" numbers were taken from measuring the width of the MB's fenders, then calculating the width of a stock Miata with 205-series tires on a +30 offset wheel based on the published track numbers. I'll back that up with measurements of actual Miata suspension parts that I'll take today.

While the narrower track will mean more weight transfer, the excellent roll center control of the Miata suspension will remain - and thus the good behavior of the car. More importantly, I work on them for a living so I'm surrounded by Miata parts. Thanks for the suggestions of threads to read though, I'll check them out.

I almost bought that rusty GT with the Miata suspension, actually, and I've been going over the pictures fairly carefully of late. I'm not going to copy it exactly but it does give me the general packaging and works as a proof-of-concept.

Here's the car's website: [www.slowcarfast.com]



Edited 1 time(s). Last edit at 10/31/2008 12:54PM by Keith.

Welcome to the message board Keith!!!

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For folks who don't know who Keith is, he's quite well established in the Miata and Locost communities.

His company is a BritishV8 sponsor, and his partner owns one of the car's featured in our last edition:



Bill Cardell's Westfield SDV with Mazda 1.8L Turbo Engine (38 photos!)


Keith has also authored a couple very well regarded books!
How to Build a Cheap Sports Car
Mazda Miata MX- 5 Performance Projects
Mazda MX-5 Miata: Find It. Fix It. Trick It.

So, I feel honored that Keith is posting here on our message board, and I'm excited to know his MGB-V8 project is shifting into gear.

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Keith, please post some snapshots here of your Miata rally car!!!

Thanks for the kind words, Curtis. Janel is starting to ask me why I'm not spending all of my time in the garage working on her car :)

If anyone's interested in pictures and stories of what I've built in the past, the best place to start is [www.slowcarfast.com]. I just realized that I have pictures of three of my cars as bare frames! Here's the rally car, still getting stripped down:


After a little work, we ran it in the Targa Newfoundland and finished 16th out of 46 starters and won our class. Not bad for a novice team. I built the whole thing, including developing the long-travel suspension and painting the car.



The engine's a bit special, and I had a lot of fun designing and building the header. It was worth 15 ft-lb and 10 hp over a Racing Beat unit.