My Saab 93 rolls back although the ignition key is out!

snipped-for-privacy@aber.ac.uk (Andrew Robert Breen) gurgled happily, sounding much like they were saying:

On hydraulically suspended Cits, it's a necessity because the wheelbase changes as the car sinks. Leave it in gear, and put a rear handbrake on, and things may get... interesting.

They shifted from front to back in '87ish, when they put the 9000's brakes on.

That sounds about right. It's a shame they couldn't make it work for these cases though. The system seems to have all the hardware it needs to give you the grip of two tyres instead of one, but it turns out you have to shut it down just when you'd expect it to be be really handy.

Yep. It backed off the throttle to the point that I had to declutch to avoid stalling. If I were writing the software, I think I'd stick in a clause something like "If the back wheels are going at less than 1mph, then leave the throttle alone"

I think Quaife do an ATB for the 9-3. I'd be seriously tempted to get one if my gearbox ever went bang. I wonder how it would interract with the traction control...

It's handy for those over-enthusiastic exits off roundabouts, but I find it pretty useless for standing starts. It's certainly no launch control, which is annoying because I'd say the cars biggest vice is wheelspin.

Cheers,

Colin.

Ah! Fiddle brakes. Banned from trials cars years back as it made them too good. Apparently a lot of the 4x4 trials crowd use 'em now. Nothing new under the Sun, and all that..

As I recall the trick with using the handbrake to control wheelspin #under those conditions was to not be afraid of using the throttle. Got a Citroen GSA though a very deep mud-hole on handbrake control of wheelspin a couple of times, though on one occasions the tachometer was up against the stop for a bit (not that it mattered much, with that engine...). Was a bit more cautious with the 90s in snow, as they were institute cars, but again a bit of throttle and a good tug on the handbrake (but /not/ held on the ratchet) kept the show on the road.

Oh, you've a point there, right enough. Perhaps I just find it more acceptable to believe (or, at least, say) that than to accept that SAAB were responsible for a very ordinary, rather dull and frankly not-that-good car (OK, the 9000 is fine on a motorway or a straight road - ride aside - but it's pretty grim on a winding road).

Well, you've got a very strong case there :)

I've always thought of them as 'emergency brakes', if all else fails, a way to stop the car.

Frank

Traction control doesn't work on proper slippery surfaces, indeedy, I can't think of any car with traction or stability protection that doesn't skit around on ice. The issue with your above ides is that it'll cause excessive wheelspin... (see below).

Our old office car park in York had a small gradient, but it was enough to make it impossible for the company 3-series models to get up or down it. 'Twas brilliant. :)

It shouldn't do anything - but it's arguably over the top most of the time.

Yup; now imagine it won't back off the throttle when the rear wheels are barely moving. :)

That's the front wheel drive aspect... I don't launch the 1.8t much, but when I have, getting it rolling and then nailing it is kinder to the tyres and drivetrain and doesn't seem sluggish...

You'd get no more wheelspin than with the system turned off as you have to do currently - i.e as much wheelspin as you want - but with some braking to the fastest spinner. From my mud-plugging experience, I can report that there seems to be no such thing as excessive wheelspin in that situation anyway.

I'm a fan of RWD, but it does have it's down-side...

Probably right, but I'd love to try driving one.

I'm talking about a cut-off point much slower than walking pace. On normal roads, the back wheels would only ever be going that slowly for a few milliseconds after pulling away.

On the Aero, it's really quite tricky to just get away smartly. There's a fine line between bogging down and lighting up the tyres. The traction control allows too much wheelspin to make real progress, so you have to nurse the throttle all the way through first gear until you can get some power from second. Only then you can nail it - as long as it's crispy dry...

Cheers,

Colin.

Gotcha. I'll try it. I remember asking what the problem was with the

Me too. The issue here was more that the electronics detected wheelspin on both sides and cut the power, as you've described. Issues were more complicated because the car park wasn't especially large and it was often busy.

Me too - but I'd have to upgrade the 1.8t to notice anything first, run that for a few months, then try it.

Right. I'm supposing that there's a reason why this hasn't been done, because as you write, it seems logical enough. Perhaps it's there as a prudence thing?

Yes. I tried a few.

I'm trying to feel sympathetic, but I'm failing, as you have lots and lots of power.

Have you tried launching in second?

The other trick is to get it rolling in first, gently select second (as on don't bang it in gear, bang the clutch out and let rip) and the progressively go? That used to work moderately well in the 9-5 Aero I used to ride around in - as you say, assuming it was bone dry on a god surface.

I'm just a born whinger :o)

I've given it a go, but it feels so hard on the car. There's over 80K miles on the clutch as it is...

It's worth a try...

Actually, there could even be something wrong with the car. I'm sure I read somewhere that torque was supposed to be limited in first and second, but I don't get any indication of that on the "turbo" gauge in second - it happily goes slightly into the red, just as it does in all the other gears. It's harder to tell in first because of the wheelspin, but it doesn't feel limited there either.

Cheers,

Colin.

Yup, my old classic rangie had the propshaft brake for an emergency brake.

No ratchet clicks, just on or off with a button to release the lever position. Always worked.

They switched to back arround the time (one year either way) of the face lift, and used 9000 style brakes front and rear. With some tweaking you can give a facelift C900 a brake upgrade using 9000 aero parts.