964 C4 "toss and catch"

[iamtheari]

Okay, I've read through a lot of old posts on this forum and elsewhere and I found the first two parts of the old Excellence articles on Wringing Out the Carrera 4. What I learned is that there is a technique referred to in those articles as "toss and catch" which approximates trail braking but isn't quite. Has anyone here had some experience with that to give some pointers on specifics to making use of the technique? I'll be on the track later this month and would like to give it a shot as my '90 C4 does push quite a bit. I won't have an opportunity to throw money and parts at the issue this year, so I want to work on what's between my ears for now. Thanks in advance.

[haasfogle]

toss: induce trailing throttle oversteer. (lift, or as my car just knows what to do it just steps out on its own.)
catch: steer hard with right foot and mild steering input to maintain desired direction of travel.
reminder: when looking at driving on the edge it is easy to step off of it.
ymmv.
i track a 964 C2 and am a PCA instructor.
cheers and good luck, haas

[iamtheari]

My car doesn't oversteer on its own. My understanding is that even minimal brake input overrides the PDAS command that would otherwise lock up the rear differential and force the car to understeer, so the theory here is that trail braking will make it behave more like a 911 on entry. Once you apex or are at least pointed at the apex, you get back on the throttle which makes the car straighten up and drive out of the corner. Late apexing sounds like it would help this technique. But what I do not know is what it looks like in practice. Mostly, how much braking input do you maintain as you turn in?

[porterdog]

Any braking will deactivate PDAS; the engineer-types who designed the system decided that ABS should take priority. Aside from that, it's standard trail-braking. Trial and error (careful!) and try with the left foot if you're skilled.

Another way- if your entry is hot enough just disabling the PDAS under trailing throttle will probably give rise to rotation (if your front/rear bar balance is setup to avoid massive understeer); if you're not then use trail-braking to achieve the same end.

[iamtheari]

I'll give trail braking a shot. I'd be fine disabling the PDAS for the track if I knew how. Too bad there's not a switch like my '96 Trans Am had to disable traction control.

[utah914]

I'll give trail braking a shot. I'd be fine disabling the PDAS for the track if I knew how. Too bad there's not a switch like my '96 Trans Am had to disable traction control.

There is. Over on Rennlist we figured out that one can hold the PDAS switch for 10+ seconds and the PDAS will be disabled. Listen for a series of beeps and the PDAS warning light to come on (indicating PDAS inactive). The reduced understeer was noticeable for me on the track. As this isn't part of the manual, try at your own risk. I've done it many times and everything returns back to normal when the car is turned off.

[iamtheari]

I had heard rumors of that. Thanks for confirming it. I will try the next time I drive the car. The manual and various sources do say to turn the knob and hold it for less than 10 seconds to engage the offroading mode (well, to lock up the differentials until you reach a few miles per hour, at any rate) but no official source seems to tell you what will happen if you hold it for longer than that.

Does the direction you turn the switch matter? I still don't get why it's a knob.

[cgfen]

Originally Posted by iamtheari

I'll give trail braking a shot. I'd be fine disabling the PDAS for the track if I knew how. Too bad there's not a switch like my '96 Trans Am had to disable traction control.

pitch and catch does not equal anything like trailbraking
as explained above;
pitch = deliberately unsettle the car such that the rear end oversteers, (usually accompished by a bit of steering input and lifting off the throttle)
catch = on the gas and steer as required to go where you want to go

trail brake = light braking required to transfer weight to the front to "set the nose" and gain additional steering input for cornering.

IMO P&C works very well for AX events
Trail braking is better suited for DE / track / spirited street driving

[porterdog]

Originally Posted by cgfen

pitch and catch does not equal anything like trailbraking
as explained above;
pitch = deliberately unsettle the car such that the rear end oversteers, (usually accompished by a bit of steering input and lifting off the throttle)
catch = on the gas and steer as required to go where you want to go

trail brake = light braking required to transfer weight to the front to "set the nose" and gain additional steering input for cornering.

IMO P&C works very well for AX events
Trail braking is better suited for DE / track / spirited street driving

Must respectfully disagree. Twice.

First, 'pitch and catch' has a relatively specialized definition in the context of the 964 C4; you'd need to read the "Wringing out.." articles for the whole story, but essentially some enthusiast drivers tired of the conservative understeer that Porsche built into the 964 C4 and discovered that by riding the brakes on corner entry the PDAS (early stability control) function was disabled which drastically reduced understeer.

Second, trail braking can be used to promote rotation, depending on how hard you're braking and how much weight transfer off the rear results.

[utah914]

Originally Posted by iamtheari

I had heard rumors of that. Thanks for confirming it. I will try the next time I drive the car. The manual and various sources do say to turn the knob and hold it for less than 10 seconds to engage the offroading mode (well, to lock up the differentials until you reach a few miles per hour, at any rate) but no official source seems to tell you what will happen if you hold it for longer than that.

Does the direction you turn the switch matter? I still don't get why it's a knob.

Not sure on the direction. I've always turned it to the right.

[iamtheari]

For those not familiar, the first two parts of the "Wringing Out the Carrera 4" article are available at this link: Porsche 964 reviews - 1992

I don't know if there is a third part or beyond.