BetterMakeWay

My gearbox is perfect. Either at full throttle the lock up occurs the car still accelerates very very hard. And no, in my car i get better times when i accelerate using the 1st kickdown, then feathering the throttle...of course that's no slouch also because of the HUGE torque ready to be delivered at low rpm, usually that's just like a boost button. The car accelerates mindblowing from mere 1000rpm. Of course when i press the throttle harder it changes down a gear or even 2 (if i'm at low rpm) and i'm off, torque lock-up or not, i'm off like a crazy cock. It's like you stop being civilised about it and the engine talks dirty back at you. When i floor it to the metal i get real kickdown and in some cases the gearbox drops 3 gears like from 6th to 3rd and yes then...well the scenary starts to move away faster and faster and all the cars seem to remain standstill. That's a warp driving .
Don't bother about the troque lock-up. It's normal in an automatic and a good thing. It helps your performance.
And yes i do agree that given the narrower rev band of a diesel, under normal driving, gear changes occur less often because of the huge torque available from low rpm. Opposite on the petrol engine especially the high revving ones from the M divison where you have to work the gearbox alot to give the best out of the engine. Drive it at 1500rpm and you get nothing at all, work the gearbox more and drop a few gears and then you start to get the juice.

needforspeed

I think you may be right in respect of the turbo, cause that it what's helping my puny 3.0 diesel engine generate all that torque.

I still don't think your right about the cog swapping though. Because of the large amount of torque, you are LESS likely to have to drop a cog to overtake in a 530d, than in a 530i. The diesel has a wider powerband at low revs. The petrol engine has more power overall and this really kicks in at higher revs.

This should mean that the 530i would start to pull away from the 530d near the limit, but from what I understand (never done it myself) the beauty of 530d is that it doesn't start to lose power like other deisels until very close to it's top limit.

needforspeed

OK I've just been looking here to see how a torque converter works (I don't know much about autos cos this is my first one)

http://auto.howstuffworks.com/torque-converter.htm

So I've got the theory how does this relate to the driving observations I have made?

0700700

i was reffering to monster e55 with 700nm of torque mate

needforspeed

In which case then yes I might have to change gear to beat it - but we're not talking apples and apples are we

0700700

more like go in overdrive and throw some glass on the road and blow his tyres....

0700700

no... youve goone soft needforspeed

havard@haslerud.no

Checked out the howstuffworks link. Great link by the way!

The "tourque lockup clutch" thingy. Do we (the E60/61) have it? When does it lock up?

Never noticed the lock up, with a resulting drop in RPM I assume, on my car.

Have heard of it though, but never understood how it was suppose to work.

needforspeed

Ok I had a nice 200mile run in the car today and paid a bit of attention to the rpm when accelerating.

This does seem to be linked to gearchange.

If I accelerate very hard, the box drops a cog and RPM moves faster than speed.

When the gearbox next changes up a cog, the rpm drops (obviously), but then stays stock still for a couple of seconds while the speed continues increases.

So do I understand correctly - the engine speed is constant, but the torque converter is initially holding back the torque, gradually releasing it as it spins away, then finally locking up to fully apply the engine speed to the driveshaft ?

2 questions:

1. Why so slow - surely the car would be a lot faster if it locked up sooner (can it be tweaked?)
2. Is this more prominent on a diesel and or a bigger engined petrol model due to the high levels of torque?