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Preserving a 1975 Porsche 914

Restoration and improved performance for autocross fun

Scenario: A 1975 Porsche 914 sits in your garage, the product of true impulse buying. The boxy little two-seater with its mid-mounted air-cooled 4-cylinder engine is a true European sports car enthusiast's delight, but possibly the least practical car ever built.

You love it, anyway. It's just that there aren't that many occasions to drive it. Only when the weather is perfect, and you have nothing to carry and no errands that result in picking up anything bigger than a 9x12 envelope. And there are few if any big rigs (to whom you are invisible) to worry about encountering en route.

Sense of Purpose

Despite these drawbacks, you won't sell your beloved 914 because you'll never find another car that handles so well for so little money. Then what do you do with it? Autocross it.

If there ever was a club-racing event that perfectly suited a vehicle, it's autocrossing. This timed race over a relatively short course has enough S-turns and chicanes to challenge the unique stability of the short, wide, and perfectly balanced 914. During the timed trials, there may be one other vehicle on the track, but you're racing the clock, not wheel-to-wheel.

Autocross and daily driving exist in parallel universes, with one rarely overlapping the other. Everything you want to avoid on the street—brake lock-ups, skids, hitting the red line—are used to maneuver the vehicle through the course. Despite these worlds apart, the changes you make in the 914 to go autocrossing do have some value in a street car, especially an older one in need of repair and restoration.

But your 914 is stock and your bank account limited, you say. How can you compete against the modified, power-enhanced real Porsches of the veteran autocrossers? No problem.

With Porsche club events, you compete against similar vehicles. In the case of the stock 914, your times will be recorded against other 4-cylinder 914s and 356s in your class, all racing with street-legal tires and only basic performance enhancements like trick air filters and exhaust systems. Once you've attended a couple of club events, or enrolled in a club driving school (a euphemism for autocross school) and been thoroughly bitten by the racing bug, there are a few modifications you can make to really kick up the adrenaline. The added bonus is that some of these changes can improve the car's performance on the street as well.

Street Benefits

For instance, check your battery tray, one of the car's weak points. Most events put you through a tech check, so if your battery support is completely thrashed, you've already been bumped. The 914's battery is tucked behind the passenger seat, pretty much on top of the engine, under a vented cover. That means the battery gets drenched if you dare drive the car in the rain or, God forbid, don't have it garaged. The water picks up acid from washing over the battery and ends up trickling on the metal platform on which it's attached. Over time, the metal corrodes and your battery is secured to a little metal doily.

The radical turns of autocross dislodge everything that's not lashed down, including the battery. A quick fix, if the battery housing isn't completely shot, is as simple as a few layers of fiberglass to keep the metal from deteriorating any further.

Harness Force

Next, invest in a five-point harness. You'll look scary-cool on the street, but the harness is more than macho window dressing. There are autocrossers with permanent bruises on their left knees from bracing themselves against the door.

They teach you in autocross school to feed the steering wheel through your hands in a turn; that's hard to do if you've got a death grip on the wheel to hold yourself in the seat. Those turns are sharp and you're heading into them at maximum speed, hitting the brake then powering out at red line. You don't want to be wasting valuable seconds making body adjustments.

Stiff Suspension

If you can bounce your little 914 up and down, you need suspension upgrades. In this parallel universe, you want a non-compliant, stiff-as-a-board suspension. Think downhill ski racer—he's making good time as long as his skis are on the snow, as soon as he's in the air, the seconds tick by with loss of solid forward motion.

The same is true in autocross. You want to maintain the near-perfect weight distribution of the 914 through left turns that threaten to dump you out of the vehicle. A compliant suspension will pitch wildly through the turns. What you want is a suspension that holds the vehicle level. The answer is performance shocks, heavy springs and sway bars in the back. All these elements will create the sensation of riding on rails.

Word of caution: Test your newly stiffened 914 out before you take it on the street. The ride is different. It's not very comfortable, but if comfort were your goal you wouldn't have bought the 914 to begin with.

A compliantly suspended 914 won't skid, the rear end stays put. The energy is absorbed by those mushy shocks and spent springs. With the enhanced suspension, your 914's rear end has a mind of its own. What, are you trying to get me killed, you ask. No, we're just making you faster.

The art of autocross is to go full out with as little steering wheel motion as possible. You study the line of each turn to figure out how to go in and come out as straight as possible. The line through the inevitable chicane is nearly straight, a line achieved by throttle steering. You let off on the throttle, just a tad, and the rear end kicks to the right, the nose to the left and you're through the pylons before you know it. The performance suspension allows you to use the skid to your advantage. Skidding, exquisitely finessed and masterfully controlled, is a good thing.

Tires and Brakes

That takes us to the brakes. The 914s come with 17mm master cylinder; the 914s are also notorious for sloppy braking. A 19mm cylinder gives you that much better braking power. The reason braking plays a part in a race is simple: you need to slow yourself down through sharp turns as quickly as possible. Every second you're not on the throttle is dead time. When you hit the brake you need to feel like you'd fly through the windshield if you weren't strapped down. That's where the harness comes in handy, but it's a good thing to have better brakes on the street, too.

As for tires, don't sweat it. Street legal, Z-rated tires just a hair wider than stock are ideal-they'll adhere to the course and keep you in your class. There's not that much room in the 914s wheel wells to go super wide, and racing slicks are for the big boys. Since you're still on street legal tires, you'll find some performance advantage when using them around town, too.

Driving as Art

You may have noticed we haven't suggested any true horsepower enhancements. With the exception of a performance air filter and possibly a flow-through exhaust system, you really don't need them. Autocross is a test of skill and agility. And hot-rod parts don't always make for a good stop-and-go driving on the street, either.

The bottom line: you don't have to refinance your house to get your 914 race ready, and still keep it streetable. One warning, though. After a year or so screaming your 914 through the course and watching your times getting faster and faster, you may find yourself thinking about making a few changes. Such as boring out the cylinders, chopping off the fender flares to accommodate massive tires and a hundred other modifications that will render your 914 faster and less suitable for the street. But that's another story!