Pardon me, but would you mind imparting some E30/Spitfire wisdom on me?

well.. isn't the M20 canted over.. while the GT6 engine is upright?

For the 4X100, I used the same offset drilling method as above on my TR8. The lugs I used were for a Dodge pick up. Just ask to see the Dorman catalog at the auto parts store. It will have all of the specs for just about every wheel bolt or stud and just pick out the 1/2 20 that has the biggest knurled end. You get 10 in a box when you order them, so plan on some leftovers.

tr8todd wrote: For the 4X100, I used the same offset drilling method as above on my TR8. The lugs I used were for a Dodge pick up. Just ask to see the Dorman catalog at the auto parts store. It will have all of the specs for just about every wheel bolt or stud and just pick out the 1/2 20 that has the biggest knurled end. You get 10 in a box when you order them, so plan on some leftovers.

Thanks for the memory jog. You're right, the lugs I used were listed for a full sized Dodge. Just my personal opinion but I wouldn't fiddle with the front suspension too much. The factory did a very good job at that end. The Spitfire/Herold front suspension were used on tons of Formula cars back in the day. The rear suspension could use some help though and, as others have already pointed out, the stock setup struggles to hold up to the original 75 hp.

Didn't your mag build a roto-spit, which examined a lot of the questions you're asking now? I know you changed the front and rear suspesnions, and you've got to have the connection for the hp handling power of the diff someplace in those articles. A tape measure and some time spent with your spitfire and E30 would answer a lot of your questions while you're in your driveway. I'd think your Dad's connecions with the triumph vintage racing scene would also help answer a lot of your questions. FWIW, removing and replacing the front suspension on a Spit with some other suspension grafted in place would seem to be a waste of time and money. As Wayslow points out, it's pretty competent. Throw in the Spitfire Competition Preparation Manual, various editions available to cover the models you have, (E-bay), and you're on your way.

mad_machine wrote: well.. isn't the M20 canted over.. while the GT6 engine is upright?

Exactly. Even then it uses an off-set intake manifold so the tops of the carbs will clear the bonnet. The bubble only clears the valve cover. Barely.

The biggest issue with a slant motor in a Spit with be the width - the exhaust exits where the suspension tower and frame rails live. We run into the same problems with motor swaps into Volvo 1800's (where they often shfit the engine back into the firewall in order to clear the front suspension).

To be honest, I've had the same thoughts as triumph5...

M20 a light motor, not sure what thats compared to, but its pretty tough. turns out we may of put down our fastest time of the day with a busted rocker bouncing around in there. Obviously tougher rockers arent in the budet, but if you could learn to use the megasquirt, and keep evrything under control thatd be great. We were bouncing past 20psi last challenge on stock everything- if we took a little more precaution in certain areas, I think it couldve made it through the challenge and then some

I busted plenty of Spit and GT6 diffs with a bone stock 2000cc Pinto motor. What usually happens: the differential 'spool' breaks in half right at the spider gear pin hole. That's why I went through all the trouble to use the 2nd gen RX7 and Miata stuff under my car.

The Spitfire stock front suspension geometry (camber cuve, etc) is pretty good.

OTOH, the steering geometry is so screwed up it ain't funny. The rack is about 3" too far forward which causes reverse Ackerman and that will snatch the steering wheel right out of your hands with sticky tires. I thought the Abomination was going to break my thumb once or twice. I moved the steering rack back so it was 3/4" behind the centerline of the outer tie rods, this fixed that problem. Unfortunately, with an engine in the stock Spitfire position that puts the rack right about where the #1 connecting rod is when the piston is all the way down in the cylinder. As it is, it clears the 12A's front pulley by about 3/4 of an inch or so, and that's only because I put the entire motor behind the front axle centerline. The rack is also too long, making for serious bump steer. It's pretty obvious someone at Triumph went overboard with cost cutting.

At one point I seriously considered building a paralellogram steering setup for the car.