PCA SDR

I was wondering when down shifting on a big track how people do this. DO they do it sequentially or in one shift. Some folks shift into each gear until the desrired gear is attained while others shift directly to the desired gears.

If done on the freeway you get a Zone 2 overrev....
b

bryanearll wrote:If done on the freeway you get a Zone 2 overrev....
b

I believe that is only for option 3 in the poll. Option 2 would not create an over rev.

Actually, Kary, I do both.

At Fontana, coming out of the bank in 5th and preparing for the infield turn-in with 2nd, I go... 5th to 4th; and then 4th to 2nd... braking/heel-toe/waiting to match rev's. I can't remember who showed me that, or if I thought of it myself, but going to 4th before 2nd, I can avoid the gearshift handle bouncing out of 5th, and the transition to 2nd from 4th is smoother and easier for me.

But, that could just be me.

Cool survey. What's your intent?

Like Dan said this question would apply well to Fontana off NASCAR bank T-2 in 5th gear entering the infield T-3/4 2nd gear turn.

If there is no traffic...
I prefer to skip from 5th to 2nd; obviously waiting till slowed enough before releasing the clutch in 2nd gear.
When I downshifted through every gear it just kept me busy and really did not add to the stability or deceleration. For me the precious awareness required to downshift through all those gears is better spent on situational awareness, like scanning for cup cars that seem to really be moving in that particular area.
Kinda funny the sound of my straight pipes blipping each downshift and then the same but delayed sound coming back from the outside wall had me looking for traffic when there was none.
I suppose skipping gears while downshifting reduces the amount of shifts and possible mis-shifts.

If there is traffic in the braking zone and there is a chance I might want to get on the gas then I'd be sure to stay in the correct gear to keep the engine in its power band.

If I had a production car with brake fade issues as a last resort I guess using the engine braking might be better than nothing.

I shift to the gear and blip to match revs. But, I've seen some great drivers go through all of the gears. So, I've secretly admired the style.

On the other hand, I was in a TracQuest instructor's older BMW once, and he was downshifting every gear and double-clutch every shift. It was driving me crazy how long it took to do that.

Seems that if you have some big anti-lock brakes, you don't want to start shifting and braking five seconds before you get to the corner.

I personally like to go thru the gears. It seems easier with a 901 transmission to do it that way. Some times going from 5th to 4th and then to 2nd works. I don't downshift to slow down, I do it to make sure of the shift.

I don't do a lot of shifting with the 928, but at Fontana I do go down from 4th to 2nd and although I move the shifter down through each of the gears, I don't let the clutch out until slowed and just before coming off the brakes.
It makse no sense to me to upset the car with letting the clutch out in each gear as the brakes should be slowing the car, but for me to keep a good idea which gear I am in and going to I go down through each gear in the box. If I felt better about knowing which gear I was downshifting, I would probably shift to that gear directly.
But to keep my simple mind straight I go down through each gear, but with the clutch in.
Greg

Good news is that no one admits to option 3 yet!

I go sequentially, as I have seen too many people who are not patient enough and pop the clutch too early resulting in a type 2 over-rev. None of these have led to immediate problems, but I cringe everytime thinking of the wear, tear and stress occuring at redline ++

On the street I will skip gears on upshifts and downshifts, but the shift linkage is not made for those motions and I am extra slow extra careful to get the correct gear and rev. Tranny's are designed for the 5-4 downshift, not the 5-2. (I have also seen quite a few people accidently find 4th, trying for second, not a big problem, just lost time). I personally have a much harder time matching revs perfectly going from 5th, braking a while, and guessing where in the 2nd gear rev range I will end up. I just go from 4K to 6K rpm for every shift.

For now at least, my shifting is much faster than my braking, so I feel there is less chance of a catastrophic mis-shift running through the gears, plus as Mike said, it is nice to be in the correct gear for any given speed in case things change and you need to GO!

Interesting so far it looks like it is 50/50.

I wounder what a Porsche guru like Steve G thinks about gear, clutch and brake wear using the two different downshifting methods.

It depends on the situation. Generally early on in a weekend I will run through the gears to get accustomed to what gears I should be in at various points on the track. (eg. Do I really need to go down to second in this corner?) Once I'm comfortable with the track and where the shift points are then I will skip gears. The advantage of skipping gears is that you can brake more efficiently without having to blip the throttle with each gear change.
The disadvantage to skipping gears is the obvious risk of overrevving because you didn't wait long enough before you release the clutch. In the heat of battle this can be difficult to do.
Therefore I'm more likely to NOT skip if I'm downshifting into the top of the rev range of a gear. Also if the braking is more leisurely (eg. traffic ahead) then I will row through the gears so (like Mike) I'm in the right gear if I need it.

Interesting..........
To me braking and downshifting are 2 separate functions. My downshifting never takes longer than my braking. If you go from 5th to 3rd, you have to brake for some time before blipping the throttle and releasing the clutch.....how do you know how much to blip? You have no clue....You don't know what rpm to get to because you've been out of gear for 2-3 seconds. You risk over revving the engine upon clutch release and unbalancing the car. I'd go through the gears.
After the car rotates and it's time to pick up the throttle, will you be ready to accellerate?
Who can host some video?

As it is with Pro drivers it is unlikely this forum shall reach consensus on this issue. But half the fun is discussing it.

Here is Carroll Smiths comments on the subject. From Drive to Win by Carroll Smith chapter 4 Braking. Carroll drops names and mentions Senna, Prost and Donohue did skip gears yet both the Andrettis disagree with the idea of skipping gears.

Carroll Smith page 2-25
“rowing down through all the gears is both a waste of time and effort and a detriment to efficient braking. To me the engine is for making the car go forward and the brakes are for slowing it down. Concentrate your efforts on braking efficiently and when the car has slowed sufficiently, downshift into the required gear-(taking care to properly sync the revs) and get the job done”.

Carroll goes on with a good point that 1st gear is too weak for this technique and he prefers to row into 3rd or 2nd prior to downshifting into 1st.

Carroll's opinion is that in the past rowing down all the gears was once the traditional Euro style and skipping gears was thought to be a technique more common in America.

Tim Comeau wrote:
"To me braking and downshifting are 2 separate functions. My downshifting never takes longer than my braking. If you go from 5th to 3rd, you have to brake for some time before blipping the throttle and releasing the clutch.....how do you know how much to blip? You have no clue....You don't know what rpm to get to because you've been out of gear for 2-3 seconds. You risk over revving the engine upon clutch release and unbalancing the car. I'd go through the gears."

Braking and downshifting aren't separate because you're using the right foot in both.
From "Going Faster" by Skip Barber :
"In our data collection we have found that even very experienced and talented drivers tend to release some brake pressure when they blip the throttle for downshifts. Three down shifts would mean three variations in brake pressure, so it stands to reason that you'd want to do just one to minimize braking changes"
Also, it's still possible to mismatch revs and unbalance the car even if you do row through the gears. The execution would be easier but you are doing it 2-3 times more often

Dan Chambers wrote:
Cool survey. What's your intent?

I think the answers might answer your question.