It's a question that's been on my mind ever since I got the 993 a few years ago.
Going straight is, of course, not complicated. The only thing I can tell you is that there's no point revving the engine and dropping the clutch. A factory standard non-turbo engine dies doing that. As for braking, it's worthwhile learning to toe-heel well and keep the car balanced as you slow down.
But the correct way to take a corner is open to more debate. The huge weight of the engine behind the car's centre of gravity makes this a critical question. While this offers tremendous traction in the rear, it leaves the front-end very light.
Beginner track drivers are warned to always brake in a straight line but Vic Elford in the "Porsche High Performance Driving Handbook" explains that you should gradually ease the brake off right up to the apex. This makes sense in order to keep the weight on the front wheels as long as possible. This is called "trail braking".
A friend and I went to the Trackdays event up at Rockingham (very quickly in his 996). It was a nice event but unfortunately it was poorly attended. At a near empty seminar, I was able to pose this question to Mike Wilds who is a very accomplished race car driver and instructor. It turns out he also owns a Porsche 911. Here are some of his comments.
- Look up and through the corner. Don't watch your dials.
- Toe-heel brake smoothly up to the turn-in point. Position is key.
- Make a single turn of the steering wheel ("commitment") avoid steering adjustments
- Never turn hand over hand. If you must, slip the wheel through one hand keeping the position of the other.
- Don't bother driving fast until you can consistently drive the race line well hitting a perfect tangent at the apex.
- "slow in, fast out" - enter the corner slower than you might think and gradually increase power all the way out. If the car is understeering, you're entering the corner too fast.
As for trail braking, he believed it wasn't really needed. This agrees with the "point and shoot" description I've heard for driving a 911. But he did say it was fine to trail brake but the technique was to apply the throttle at the turn-in point while still keeping the brake on up to the apex. Using both at the same time was a new idea for me.
This obviously calls for a trackday to try some of these things out.
If you want to just have fun you don't need to trail brake. If you want to get better lap times you must trail brake. A Porsche DE instructor will likely not tell you this since it puts the car more on edge than you may want to do. But if you really want to hit a fast lap time, trail braking is needed. Both from a standpoint of extending the length of the straight you are coming off of as well as rotating the car. Look at http://racing.latestfiasco.com/?p=33 for an analysis of trail braking including an example of how much time can be saved in a single corner.ReplyDelete
Thanks. Nice site and an excellent analysis!ReplyDelete
I've been following the "How to drive your 911 properly" series of articles in "911 & Porsche World" magazine written by Mark Hales. In part 4 in the June 2006 issue there's an interesting paragraph relating to cornering a 996 GT3...ReplyDelete
"As delivered, though, the emphasis is on stability at the back - and that makes it more important than ever to get the front end pointed in. You do that by transferring weight to the nose as you brake, then pinning it there as you ease the wheel into the turn before squeezing on the power progressively from the apex twoards the exit of the turn. That nabs the possible effect of weight at the rear, which would swing the tail by squatting more on the back and lifting some from the front tyres." (p45)
In other words, trail braking. Point. Shoot.
We need more porsches -- those 911sReplyDelete
As an aside, there's a fantastic engine mod for 993's by Ninemeister. It's a top end rebuild using a custom head with redesigned ports that will take the engine from 285hp to 350hp!! Lots of discussion on rennlist but it sounds awesome. Cost is quite steep at £10,000 but if you had to do a rebuild anyway....ReplyDelete