997gt3north

My car has no modifications to the suspension or brakes. I can't tell you with 100% certainty if I was on the Firm or Regular suspension setting, but unless it is raining at Mosport, my default config at Mosport is 3 orange lights (suspension firm, sports mode, TC - off):
- Suspension Firm - it is a fairly smooth track
- Sports Mode - I like the increased throttle sensitivity
- TC off - Turn 5B at Mosport usually lifts the inside rear right tire so this saves the brake pads (there is a large drop off right after the apex where TC goes crazy - 45mph corner in 2nd gear - so no danger)

In the rain, I run with no Orange Lights (Soft, no Sports, TC on)

Again, as I have stated early in this post, given that I know it is now possible in this corner, I can drive around it - just brake earlier and more importantly, take a line mid track (not fully left) so that 'if' it happens again, I would have way more track to dis-engage the brakes and then re-apply them - you would blow the corner for sure, likely still go off, but at least you wouldn't leave the track having done almost no braking (this corner is taken at 1/2 the speed of your corner entry speed).


Using my knowledge of the car, and all the times I have experienced various ABS intervention, if I had to guess where the 'issue' in the program is, this would be my guess:
- when you start braking, if the surface incline, just at the exact point where the brakes engage CHANGES (in my case, lets say 5 degrees uphill to 2 degrees uphill), then you have potentially perfectly replicated, momentarily, the "I'm on black ice" friction surface
- if this happens at the instant the brakes are applied, given the rear engine / 50% rear braking bias of the gt3 (unlike any other production car), the ABS locks out all rear brakes until it is certain it is not on "Black Ice"
- since this 'extremely low friction' environment has now been triggered, additional priority / time is now allocated to determine what the actual surface friction level is (time is passing, you are not slowing) and you are stuck with only your initial brake pressure, which in the case that I described above, is basically zero rear brakes and maybe half the front brakes
- if you release the brakes, you get to start again, but as happened to a few people, sometimes there is no time / enough pavement to do this - unless you knew it might happen and you made sure there was

Again, from a programming logic perspective, the situation is easily fixable if you buy into the premise that the driver knows better than the Computer what is the more desirable outcome. If in the above situation, the braking pressure was slowly reduced from maximum to the black ice threshold as oppose to the opposite (built up from the black ice threshold) which the ABS module clearly does, then the outcome would be slightly flat spotted tires but a car that would have the speed reduction requested by the driver. I believe the easiest way to implement this would be to add another button to the dash (the ABS button) that would simply take this approach.

It is an obvious fix in my opinion and something very much in the spirit of the GT3 - i.e. a car that can be driven on the street and enjoyed during a Porsche DE.

Suspension (Regular, Firm)
TC / SC (ON, OFF)
ABS (Street, Track)

mooty

christ, the car is fine.
just drive it.
when you have ice mode, deal with it, tap, pump, eject.

997gt3north

I agree totally.
I actually deal with mini ice-mode every 2nd lap at Mosport on turn 5A if I don't release the brakes before the car slightly unloads so I'm fully comfortable with the situation - probably have maybe 300+ laps of dealing with it.

If you want to see where it happened, I found this video on youtube of a car following me (me = white gt3 with RS wing) - not from the day but at Mosport. At time index 1:06 at brake marker #2 with car almost fully left is where you start braking - you then carry brakes almost half way from that point to apex. As you can see, if you only get 20% of your brakes at marker #2, and the track goes fully right, and you are fully left, you run out of track in about 2/10ths of a second.

At time index 1:27, my car is hidden by his rear view mirror, is Turn 5A - it is steeply uphill. You ideally want to carry the brakes up the hill as far as you can and carry as much speed as possible to turn 5B (similar to Oak Tree at VIR), but with the 997gt3 if you have not fully released at the Apex the car's ABS will fully release the brakes and you will go straight off the track and miss 5B - I can replicate this every single lap. What you need to do is let 'ice-mode' hit, release the brakes fully and then re-apply - I basically do this every single lap. It is what it is - I deal with it - but at least in coming into 5A I have managed to scrub 85% of the speed off that is required before this happens.

http://www.youtube.com/watch?v=RiI8p...yer_detailpage

mooty

North, I hope you understood what I meant. no slight to you.
And it could be a dangerous situation but the thread is not myth, legend, fact, joke, debate….
Just be aware of the situation and react to it.
There are a WHOLE lot of other issues that makes this hobby deathly.
Abs ice mode… haha… my car almost blew up in fire last week…
The car in front of me may drop coolant due to the poor coolant pipe connection.
I think most of the long time posters like yourself get the drift.

Terry L

Paul, tell the troops what you are using for tires and brake pads, and any other mods which may be relevant.

TRAKCAR

Release, re-apply. Repeat if needed, keep car out of wall. Got it.

Izzone

Another 997.2 rs rip.....

Ceramic brakes

Izzone

Another 997.2 rs rip.....

Ceramic brakes

FTS

At Sebring? T17 again?

jenk12m

do you know what brake pads and fluids they were using

Izzone

No comment, just wanted to state ice mode

I wouldn't want my details on net

superquant

Car is fine. Until it's in a wall. Then it's not.

Coleco

So how much is the motorsport race ABS modules?

I am guessing it's if I have to ask, it's too much...

Nordschleife

The hardware is very good value - for the right car.

The real cost is in finding the right engineers to develop the various non standard software options and all the logging equipment, and the time (its really boring work after a bit), to say nothing of the water bill, and all that shiny fake ice sheeting (or a trip to Scandia)......

Having said that, I do think there is a case for a very expensive properly integrated brake/suspension package to be offered

R+C

PS if you came up with a solution to wet leaves on the road surface in the Autumn/Fall - that would be heroic

deputydog95

I didn't read all 14 pages, but I'm guessing this is still an issue then?