alexb76

I got a question... if one's coming down the straight into a sharp right hand corner, and need to slow down from ~115 MPH to ~50 MPH, and basically going to downshift from top end of 4th to 2nd, what's the best way to do this on a manual 997.1?

- Brake hard and heel-toe from 4th to 2nd right at end of braking zone
- Brake gradually and heel-toe from 4th to 3rd, then from 3rd to 2nd at end of braking zone

I am mostly interested in what's safest with least wear on the engine/tranny/clutch... but I assume the smoothest would be the fastest anyways.

Thanks

Veloce Raptor

IMO more of the former than the lattter. Come on brakes smoothly but firmly, w/o stabbing them & pitching the nose of the car down. As you begin rolling oout of brake pressure, begin the 4-3-2 double downshift cadence towards the end of th ebrake zone (smaller blip required, less wear & tear, less difference between engine speed & wheel speed, etc.) so that the downshifting is all done as you begin leaning the car into the corner as you fade off the brakes.

alexb76

Thanks, sorry for not knowing the lingo, what is "4-3-2 double downshift cadence"?

Does it mean, while clutch depressed, go from 4-->3-->2, then blip, dis-engage slowly while getting off brake?

claykos

I personally like to go through every gear and let the clutch up in between as I think it helps keep the car more stable, and the downshifts are easier than skipping a gear. However, I don't think there's a "right" and "wrong" answer to skip shifting or not. Some very fast drivers skip shift, some don't.

Either way, it's best to save downshifts until late in the braking zone as you're less likely to over rev, it's easier on the clutch, gearbox, etc. Also you want to do you hard braking at the beginning of the braking zone and be rolling off the brakes to have the car nice and stable as you're turning in rather than all the weight jacked onto the front with the front tires on fire.

quickxotica

Most people have trouble matching revs accurately on a 2-gear downchange. So even though in theory skipping 3rd would be less wear and less distraction for the driver (so you can concentrate more on turn-in & brake-release), all of which is really nice... lots of people will still go through 3rd & release the clutch momentarily just out of habit/comfort, etc.

For me personally in my own car, I skip the middle gear because there is only one corner where this is needed and I have simply made it part of my routine at that location. I find this preferable because too often when heel & toeing I have a bad habit of easing my brake pressure unintentionally. Skipping 3rd helps delay the downshift as late as possible helps me avoid this risk. YMMV.

Z-man

Hmm - sounds a little like the end of the front straight at Monticello.

I would do the 4-3-2 progression. Heel-toe downshift for both. If of course, you have a sufficient braking zone. If you really don't have the space or the time to do so, then do the 4-2 downshift, being careful not to over-rev your motor!

Of course the other option is to just go from 4th to 3rd, and take the corner at 65mph, if you can.

That said, when braking, I've heard this:
"Stay on it, stay on it, stay on it until you see God, then tap the brakes g-e-n-t-l-y."

-Z

bella1

Using Turn 1 VIR as an example in my 2001 996, I apply brake pressure with the clutch engaged. Smoothly as suggested above and not a hard aggressive stab at first for easier weight transfer. By brake marker 2 to 1, I press the clutch pedal, blip and shift to second with right foot still braking which gets me to turn in and release clutch to match the revs, trail braking a bit and proceeding to the apex.

In reading Skip Barber's "Going Faster," different drivers like different techniques. Some shift through every gear and blip the throttle each time. Others feel they cannot get this right every time so they skip gears like I do. I have tried going through the gears and I cannot do it well. So my way of shifting so far has been easy on my transmission while trying to keep the number of things I am trying to do at a minimum.

schwank

I have a very similar braking zone at Portland coming in to turn 1 from around 120 to about 45-50mph.

For me it is a 5-3 downshift, and I do it as one shift with a heel-toe rev match at the end of the braking zone before turn in. I feel it allows better focus on threshold braking and less chance for mistakes. This is a 944 though so a 997 may be different.

mrbill_fl

are you using the transmission to slow the car? or just matching rev's and changing gears?


(transmissions are very expensive brakes!)

Ray S

+1

Coming into turn 5 at Road America for example, as I go from 5th to 2nd I touch both 4th and 3rd (rev matching on each shift) as I brake for the turn.

TheOtherEric

It's really hard to make a case for rowing through the gears. The only reasonable argument that I know is that there's less chance of blowing up your engine if you go 4 -> 2 too quickly. Driving styles evolve over time, and you may find yourself shifting early in braking zones. If you do that on a 4 -> 2 downshift, you just ruined your engine.

That said, 4 ->3 ->2 is really just wasting mental effort, upsetting the car, and putting added wear on your clutch, tranny, and engine. So *you* have to decide if that wear is worth reducing the risk of a money shift.

Veloce Raptor

I go through every gear. Not right or wrong, just what I think is the best approach, for mechanical sympathy, safety, and even remembering which gear you're in.

bauerjab

Could you be more precise in your explanation of braking. Specifically, the time between you lift off of the gas and onto the brake. Sounds like you are advocating coasting for a split second while applying the brakes, i.e., "come on brakes smoothly". Is that what you meant?

Veloce Raptor

No, I advocate an immediate transition, no coasting. However, to be precise: many folks come on the brakes initially like gangbusters...BAM!! All this does is surprise the car, ands it makes everything else harder. Instead, apply brakes firmly but with slightly softer feet....no BAM. Think of braking as a 4 part cadence. You want the majority of the 115 to 50 MPH speed reduction in the first quarter of it, IMO. And the remaining 3 quarters are smooth gradual release of brakes, along with downshhifting, to allow the rear of the chassis to settle gently & give you maximuum grip and stability entering the corner.

But no coasting!

bauerjab

I assumed that is what you meant. I just thought it would be useful for you to explain it in a little more detail.