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Heel & Toe Inexperience Talking

PostPosted: Mon Dec 13, 2004 9:25 pm
by bryanearll
Very Excited :P

Nothing like a newbie boiling over with enthusiasm to run up a string of no account posts.

OK, so I've been working on that "heel and toe" technique every chance I get. It's much harder in the lower gears than the upper gears, AND it's harder the closer one gets to the ominous Red Line. Something I haven't even gotten close to.

I can pretty much match the burp of the throttle with anything third gear and above now. It's that very useful, I presume, 3rd to 2nd shift that seems elusive. High end (speed wise) of 2nd is about 70mph. I'm not prepared to get that dicey with a $30000 motor. So I find my comfort zone to be about 45-50mph on the burb.

The comfort zone must be the experience zone because I cannot ascertain ANY value trying to be cagey with 2nd gear going into the turn. I can see the "not shifting" during the turn, but if the clutch is depressed entering on a type 2 turn, dropping the lever sometime just before hasn't yielded much difference. At least it seems.

My experience has been; Bryan's coming in kind of hot after the long straight piece of road so he brakes before the turn and shifts to second, giving it steady or increasing throttle on the exit.

At the Driving School, I was definetely chirping the tires shifting into second while the brakes were strongly held dropping from 75-80mph into the hard right turn. I was probably cornering "the right/left 90 degree turn " at 20-30 mph max. Using the "Bryan doesn't want to hurt his car theory" that means I probably had depressed the clutch close to when I started hitting the brakes. For the sake of convienance let's call the clutch depression 60mph. Well within, but at the high end, of the Red Line danger unhappy place.

Bryan would like to think he has the sand to do what it takes, burb the throttle and decelerate smoothly into the turn. However, what it seems like is that Bryan has the inexperience/wisdom to use the brake pads to decelerate to an area "well within the margin of safety" before he engages the clutch, by which time the whole burping of the throttle has long passed it's usefulness by.

So Saturday, somebody has to show me how it's done right.
Bryan

PostPosted: Mon Dec 13, 2004 10:51 pm
by Jad
Patience oh excited one. As you said, you are braking from 75-80 mph down to 30 mph, why are you trying to shift while still traveling at 60 mph? Wait until you are almost done braking, then blip the throttle and shift. No one wants to risk their engine and heel toe should reduce this catastrophie, not increase it. Your engine has PLENTY of torque so you should never downshift near redline. If you are that close to redline, you can't excelerate without shifting back anyway so just leave it in the higher gear or wait until you have slowed well into the rev range for the next gear. I almost never bother taking my car over 5500 or maybe 6000 rpms because as long as I keep the revs above 4000, the acceleration is virtually identical regardless of gear.

Don't drive with the clutch depressed either. It should be out whenever you are moving except for about 1/2 second as you shift up or down. Be done with the shifting BEFORE the corner, that way you will be back on the gas lightly (which balances the car) for the first part of the corner and accelerating hard by the apex. Trying to carry speed and squeeling and fighting around the corners feels fast, but slow in fast out is always faster to the clock.

Keep practicing on the street, just be patient and work on smoothness, as if it isn't smooth, you are not helping your times or your car.

Re: Heel & Toe Inexperience Talking

PostPosted: Tue Dec 14, 2004 7:43 am
by ttweed
bryanearll wrote: I'm not prepared to get that dicey with a $30000 motor.
You have a 996, Bryan, no? I don't know if it will make you feel any better about your shifting efforts, but the engines for those cars are less than half that-- I believe I have heard $13K as the cost for a new engine from the dealer. $30K is approaching the cost for a race-prepped GT3-RS motor from PMNA.

TT

PostPosted: Tue Dec 14, 2004 9:22 am
by bryanearll
Tom, you're right, that is quite reasonable!!

Jad, so in addition to your comment on slowing into the turn are you also suggesting shifting a little earlier on a long straight, say at 5500-6000 rpm rather than carrying the rpm's a little higher just to hear the pipes sing?
b

PostPosted: Tue Dec 14, 2004 9:41 am
by Mike
Bryan's car has abs and computer systems that may prevent this from happening... on Mike's old 911 his braking bias is close to perfect, if he were to downshift and release the clutch at too high an rpm the engine braking could disrupt his ideal brake bias.:wink:

Talking thrid person about yourself is more difficult that heel toe down shifting. :D
Another reason not to race around at red line.....
For a newer AX racer you might consider trying to stay more in the middle of your power band. You car will not act as nervous and more importantly with a 911 you will have improved car control with more throttle steer available.

Pitch and catch/911 car control is great fun , but you can't catch it if you can't accelerate.

PostPosted: Tue Dec 14, 2004 9:52 am
by bryanearll
Well, it's not like we are going to have too many opportunities to shift while driving around the Q anyway.

Has the course layout been decided by the Oracle of Speed yet?
B

PostPosted: Tue Dec 14, 2004 10:05 am
by Mike
true but everyshift should be perfect, a missed shift could :shock:

Just another thought...
Your upshift points should be based on your engines power band. If it stops making power above 6500 then ideally you would shift at that time. Exception (disclaimer, this may be too much for some street engines) is at the end of straight aproaching a turn where you could complete an upshift but then asap would have to start braking,,,you might just leave it in gear and eliminate both an upshift and a downshift and for a second put it on the rev limiter.
That normally would happen to me only once or twice a year on certain AX tracks.

Good luck!

PostPosted: Tue Dec 14, 2004 11:57 am
by Jad
bryanearll wrote:Tom, you're right, that is quite reasonable!!

Jad, so in addition to your comment on slowing into the turn are you also suggesting shifting a little earlier on a long straight, say at 5500-6000 rpm rather than carrying the rpm's a little higher just to hear the pipes sing?
b


Sometimes :?: There are a lot of factors at work here. I don't know what year your 996 is and the 3.4 engine is different than the 3.6 as is the gearing and redline. In general, in first gear the gear advantage of 1st is greater than the power drop of the engine (look at your power curve in your manual), so take first to near redline, second gear is quite often close so it doesn't matter if you shift a few hundred rpm early and save a little engine wear, 3rd gear generally can be shifted several hundred short of redline for optimal performance (maybe 1-2K before redline in a Corvette). In theory, you try to stay between peak torque and peak hp, so bumping off the rev limiter is usually not the fastest and is hard on the engine. As was pointed out, this is occasionally done if your gearing is just wrong, but if this happens in practice, I just shift early and assume I will improve throughout the day and need to shift by the end, so why not be use to shifting there?

As I said, I always shift early, one because I like my car and 944's don't like being above 6k rpm for long and two, because the power drops off above 6K so it generally costs time to hold the gear to redline.

This is pretty complex, my point was that ringing every rpm out of the engine is often not the fastest way, so don't worry much about keeping the car at redline, the 4-6k range is a good range for street Porsche engines (not for sound of course :wink: , but for drivability and wear)

PostPosted: Tue Dec 14, 2004 5:53 pm
by Tim Comeau
Bryan,
I'd be happy to show you some down shifting at the Q this weekend. It sounds like you might be downshifting too early? I'm not near redline when I get into the next gear. I run through all gears. Some drivers wait, then go straight to the gear they'll exit the turn in. Like 5th-to 2nd. I have some video of some heel and toe work because I'm working on an instructional CD to sell. Please find my black and white striped 924S at the AX.
Tim :D