New Arrival Suggestions

[sawood12]

Those full track karts are amazing. capable of 150mph, out accellarate an F1 car to 100mph, race on full GP circuits, sequential gearboxes and alot of other trick stuff. I remember taking a look at a meet at Donington where the karts were out for a practice sessions after a Ferrari event and of course the Ferrari boys throught they'd poke a bit of fun at the karters in ther 'toy cars' - until they saw their laptimes that was. You can't beat karting for really teacing you about driving. Unfotunately it takes a little more guts to be as brave in a full size car weighing 1.5 tons with the relative tyre contact patch of a postage stamp with the body rolling and wallowing with every control input!

 

[944Turbo]

Actually I feel a lot safer in the car and I only drive a 100cc 25bhp kart, OK they have relatively small amounts of momentum but hit a gravel trap at 70mph and you will get gravel everywhere. The 250 gearbox karts have 4 wheel brakes so you may have a bit more control about which direction you enter the gravel.
Tony

 

[944Turbo]

ORIGINAL: Neil Haughey

It seems to me that the Porsche ABS is designed to cut in and out gently allowing the car to have maximum stability. As a comparison the system on my SAAB 9-5 feels much more aggresive. It got the car from 60-0 in 121 feet but the car was all over the road. Obviously designed for emergency stops only and would be a nightmare on a race track (assuming the brakes lasted more then 3 corners before overheating!).

Could this not be more to do with centre of gravity and weight distribution?

I find the 944 ABS slow to pulse with the standard 250 brakes I usually have backed off before the second pulse. I had always put it down to the time when the system was designed. Modern 5 or 6 channel systems (g sensors in addition to wheel sensors) and faster pulsing pumps should be better.

I guess in a real emergency ABS would help, provided you have practised steering with it pulsing, if you have many miles in slippery conditions without ABS it might not be instinctive. (backing off the brakes and very slight smooth steering inputs are better when locking a wheel in a non ABS car)

With BB and yellows on the front I find the ABS is early to trigger in slippery conditions (so it beats (or saves) me), must fit my yellows to rear to see if it improves the balance or if a different bias valve is the way to go.

Tony

 

[Hilux]

I find the 944 ABS slow to pulse with the standard 250 brakes I usually have backed off before the second pulse. I had always put it down to the time when the system was designed.

Glad someone agrees with me []

 

[Neil Haughey]

No I agree that the ABS fitted to our cars cuts in to early. Like he said this is probably down to it being an older design. When I did those tests last year the SAAB would always chirp its tyres maybe 3 or 4 times in an emergency stop. I tried again recently on a smoother road and it still did it once or twice. It is possible that the 944 ABS can't react fast enough to allow this to happen, and as such has been backed of a little from what could be achieved.

I think the stability difference is probably down to the rubbish GM derived suspension (folded steel wishbones, big bushes).

 

[sawood12]

I thought it was the case that the ABS cuts in earlier on modern cars to make them safer. It certainly was the case with my wife's Mini. I could get the ABS to cut in at will on any surface in any condition whereas in my 944 I have only had the ABS cutting in on one or two occations. It's certainly something JC always winges on about along with traction control on TG. It's one of the points he is complimentary about with newer Porsches in that they have their traction control and ABS systems reigned in alot more than their competitors which makes them better to drive. Although I accept the points made earlier in the thread about the merits of using ABS to achive more consistent braking performance on track (although I maintian at a reduced level of performance for those who are more practiced) surely there comes a point where you may has well have it on all the time. There must be a reason why manufactures only have it cutting in just prior to the wheels locking up.

 

[John Sims]

ORIGINAL: sawood12

....... I could get the ABS to cut in at will on any surface in any condition whereas in my 944 I have only had the ABS cutting in on one or two occations. ....... There must be a reason why manufactures only have it cutting in just prior to the wheels locking up.

The ABS on a 944 will only cut in when one or more wheel locks up - they only have wheel sensors.

As Tony said; modern cars have accelerometers (and I assume pedal position sensors) to predict hard braking and can therefore apply the ABS before wheels lock thus maintaining more control. Subject to the level of complexity of the ABS IMHO a modern system would out brake a human no matter how legendary they might be.

 

[944Turbo]

I am not sure even modern ABS is better than a Human on say a race track, you want to be at the point of 'not locking' not just over over it - the newer systems do back your pedal off (to the point of lock) as well though, this must waste distance compared to not locking.
In a real emergency however it might help you out of a panic. My Old man who was a pretty good driver - did some rallying and autocross when he was younger, and averaged at least 25,000 miles a year (often at very illegal speeds in deristicted sections) had an accident on the way to work. He was rounding a long corner on the way to work and a BMW forced him wide (BM was on wrong side of the road) unfortunately as he gathered it up hiding behind the windscreen pillar was a lady who appeared in front causing him to brake hard. He was half on the mud and leaves (no pavement) and could not avoid her. He said there is no way he could back off the brake pedal even though he had locked the wheels. She ended up curled around the front wheel and was shocked but Ok and told him it was the BM's fault there was nothing he could do. Anyway in a real emergency it may be nigh on impossible to remove you foot from the brake, that is when ABS could save you - if you remember to steer.
Tony