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Spitfire First Autocross in my Spitfire 1500

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The later swing spring did help with the wheel tuck problem but the car also suffered from more body roll because of it, which is why it has a larger front sway bar. One of the tricks to get the earlier cars to handle better is to fit the later sway bar to help eliminate body roll. Camber compensators are good but you can pretty much do the same thing by putting a small lowering block between the spring and diff. This gives slightly more camber on the rear wheels and with a stiffer suspension and lower roll center cuts the wheel tuck problem. There is also a company that sells adjustable vertical links for the rear so you can set more positive camber in and adjust rear ride height more accurately. I believe I have a couple Mk3 cams. One I have complete with lifters pulled from a running 44k engine.
 
It's great to see someone autocrossing a Spit. They can be competitive. There are even a couple that run Nationals. I run a 78 and was second in my class last year in FSP. I had to switch to GP this year though because I have a cam. You're lucky to be able to run in Dec. our season runs April to Sept. Are you sure you meant understeer? They tend to oversteer with the rear breaking out long before the front. Mine is setup with KYB shocks all around, GT6 springs with 2 1/2 coils removed in front to give a 1 inch drop, poly bushings all around, a 3/4 inch lowering block in the rear, a pace setter header, Weber DGV (I have a set of SU HS4s I need to rebuild) and a mild cam.
 
Oh it was understeer. I only got oversteer on the off camber stuff. Part of it is the suspension setup, part was the Sumitomo low profile tires. New development: front carb dashpot bolts were all MIA this morning! Put new ones in, runs slightly better, but I can wiggle the throttle shaft visibly. Of course, I have put 9000+ miles on the car since March, so no wonder they're wearing out. I guess it's time to break down and fully rebuild the carbs. This is motivation to get my 71 MGB out of my friend's garage. Only need tires, hoses, belts, fluids, all hydraulics bled, simple, right?
 
AXing a Spit is ALL about knowing the car and it's strengths and weaknesses. It doesn't have a lot of acceleration and is real tailhappy. but it's only six feet wide and slaloms like crazy. I love spin cones because you can lift the throttle and break loose to rotate then jump on it. Tight boxes are fun too. The trick is carrying enough speed through corners without losing it. What tires are you running?
 
My wife and I love autocrossing the 1500.

I've done some engine upgrades but have found that suspension upgrades have been a much bigger improvement in times than the engine changes.
 
OK, I apologize for my previous mostly negative post. Yes, you can make a Spitfire competitive for autocross but it will be very difficult to drive on the street.

Back in the day I both autocrossed and raced a very modified MK3. Very light, highly modified engine, trick rear suspension,locked rear with 4:88 gear, lowered etc etc probably much like your friends car. Very competitive, very fun, but not the car to go to the grocery store.

Everything is a compromise, at some point, the faster you make the car the less usable it will become. You have to decide what you really want from it. Bob
 
No problem. I'm not too far off the pace as is. The suspension can handle quite a bit more power, so first I need to dial in the timing, rebuild the carbs, and check the valves. After that it's al about how much do I want to tear into the engine. I had a GT6 in the 90's that routinely got top 3 overall and was my everday car. It was fast, hot, and loud. Everything a mid 20's guy into Triumphs could want. Plus BMW 2002 and even then current Corvettes were no match for it.

I don't need much more power. Just a bit more of a rev range. If my engine would hit redline and not start to hesitate I'd be happy. Between a little more revs and me getting my technique back, I think I can be in the hunt for class wins. As to usability, I won't build an intractable car. Did it once. Waste of time and money. Another 10hp and I'd be thrilled.
 
Ok seems we are not dealing with a novice so serious hints are needed. With my previously mentioned MK3 using a reground stock MK3 cam and STOCK valve springs it was designed to peak out at 7200 and would consistently do that on the main straight at Lime Rock (7500 in a panaic situation). To get the revs, if the valve springs are good (new, cheap) you have to look at the ignition, possibly floating points or tired coil / condenser / wires.

I would skip the alum flywheel especially if you are going to upgrade the cam. A hotter cam will suck up some of the low rpm torque you need to get moving so the "heavy" flywheel becomes more important. As mentioned earlier the carbs will get you a little more than zero HP but will make the car idle better, don't spend a lot of money there.

If you're going to do any serious engine work I'd go for more compression. Per the factory Spit tuning book, for the MK3 at least, you can chop about a quarter inch off the head. Maybe not a 1/4 but a really BIG number. It does change the rocker geometry some but not a deal breaker.

Maybe you can get that thing into the winners circle yet, Bob
 
Bob,
Your MK3 was probably a small crank 1300 right? A 1500 isn't good for much over 6 grand. That's why track racers all use the 1300. The 1500 does have better low end torque though which IMHO makes for a better autocrosser.
Mike,
Before you do anything you should download a copy of the SCCA rule book and decide what class you want to run in. FSP doesn't allow a different cam, lightened flywheel or headwork beyond porting and polishing to an inch in from the manifold. Also the interior and seats need to be intact and body lightening is out. I run GP because I have a cam. It looks like you would then be up against your buddy and his pretty serious looking Spit. I don't know how it is in your neighborhood but here in the northwest GP tends to be lightly populated and FSP is highly competitive. The other option would be SSM (2 seat Street Mod) but then you're up against Vettes and there's no point to that. But almost nobody wins an autocross because they have a faster car. They win because they can drive their car faster.
By the way 9000 miles since March? AWESOME!
 
The interior is intact, it's basically stock. I'm going to stick with the SU carbs, just rebuild them. I'll polish the head, etc, within the rules, and look at exhaust options. Aluminum flywheels are nice on a track, but driving one every day is something I'll never do again. I may put flat top pistons in when the engine needs a rebuild, and will shave some more off the head next time I replace the head gasket. The igntion is all new, Pertronix in the distributor and a new coil to go with it.

Once I get the carbs sorted and adjust my valves, I think I'll have enough to crack the top 3 in FSP. It's competitive, but so am I, lol! Hopefully I'll have my barnfind 1971 MGB running this spring so the Spit can get some much needed love.

Here's a video my friend shot with my camera from the autocross. Robert's GP Spit is most likely the oldest racing Spit in the world. I believe the 920th or so of the line.

https://youtu.be/GgbGZMShr7U
 
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