Car Forum / BMW Cars / August 2005
Redlining a Steptonic
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chris.mckinley@gmail.com - 17 Aug 2005 18:43 GMT I have a 2006 325i Steptronic. Is it possible to damage the transmission if I manually downshift from say 3rd to 2nd if I were already driving in 3rd at a high rate of speed, or is there some kind of limiter that will stop the engine from damaging itself if it looks like the downshift will redline the tranny?
R. Mark Clayton - 17 Aug 2005 19:05 GMT >I have a 2006 325i Steptronic. Is it possible to damage the > transmission if I manually downshift from say 3rd to 2nd if I were > already driving in 3rd at a high rate of speed, or is there some kind > of limiter that will stop the engine from damaging itself if it looks > like the downshift will redline the tranny? In theory no.
but in practice...
Dave Plowman (News) - 17 Aug 2005 21:44 GMT > >I have a 2006 325i Steptronic. Is it possible to damage the > > transmission if I manually downshift from say 3rd to 2nd if I were > > already driving in 3rd at a high rate of speed, or is there some kind > > of limiter that will stop the engine from damaging itself if it looks > > like the downshift will redline the tranny?
> In theory no.
> but in practice... Describe.
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R. Mark Clayton - 18 Aug 2005 12:49 GMT >> >I have a 2006 325i Steptronic. Is it possible to damage the >> > transmission if I manually downshift from say 3rd to 2nd if I were [quoted text clipped - 7 lines] > > Describe. I broke a 4 speed box in a [1983] 735i in 1991 by shifting from reverse to drive while dong ~3,000rpm*.
This was supposed to have interlock to prevent this sort of damage, just like the Steptronic.
* I was momentarily distracted by the appearance of a car behind me, while a criminal with a machete tried to chop his way in through the driver's door window as I was reversing away from him.
Dave Plowman (News) - 18 Aug 2005 13:47 GMT > >> >I have a 2006 325i Steptronic. Is it possible to damage the > >> > transmission if I manually downshift from say 3rd to 2nd if I were [quoted text clipped - 10 lines] > I broke a 4 speed box in a [1983] 735i in 1991 by shifting from reverse > to drive while dong ~3,000rpm*. Not a Steptronic, then?
> This was supposed to have interlock to prevent this sort of damage, just > like the Steptronic. It's not possible to select reverse when in Steptronic mode. Or neutral or park. Just the forward gears.
BTW, I'm surprised you broke any auto by selecting reverse at speed - or the other way round. Usually, the wheels just break traction. Or a driveshaft breaks.
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zerouali - 18 Aug 2005 15:14 GMT Steptronic is just a bit more technically advanced than your '83 box! I'd wager that the '83 box was fully mechanical, whereas the steptronic is electrically controlled. Much less chance of the computer accepting an incorrect signal than there is of you forcing a physical link into the wrong place. Don't think you can really compare them.
Both gearboxes, however, are just as effective in propelling your car forward and over said criminal ;-)
R. Mark Clayton - 18 Aug 2005 16:29 GMT > Steptronic is just a bit more technically advanced than your '83 box! I'd > wager that the '83 box was fully mechanical, whereas the steptronic is [quoted text clipped - 4 lines] > Both gearboxes, however, are just as effective in propelling your car > forward and over said criminal ;-) As he came towards me I reversed and he stuck and broke the [laminated] windscreen, then he went round the side of the car, but despite three tries could not angle the blow properly to smash the side screen.
me9@privacy.net - 20 Aug 2005 03:27 GMT >> Steptronic is just a bit more technically advanced than your '83 box! I'd >> wager that the '83 box was fully mechanical, whereas the steptronic is [quoted text clipped - 8 lines] >windscreen, then he went round the side of the car, but despite three tries >could not angle the blow properly to smash the side screen. You must be a bank manager or a solicitor;-) jack
Peter Bozz - 19 Aug 2005 13:14 GMT >>Describe. > [quoted text clipped - 7 lines] > criminal with a machete tried to chop his way in through the driver's door > window as I was reversing away from him. How did you get away finally? I mean, with a broken gearbox?
fbloogyudsr - 17 Aug 2005 19:07 GMT >I have a 2006 325i Steptronic. Is it possible to damage the > transmission if I manually downshift from say 3rd to 2nd if I were > already driving in 3rd at a high rate of speed, or is there some kind > of limiter that will stop the engine from damaging itself if it looks > like the downshift will redline the tranny? I virtually certain that the transmission won't downshift if it would over-rev the engine. Same goes for the SMG transmissions.
Floyd
J Strickland - 17 Aug 2005 19:21 GMT If I were screaming along anywhere near the Red Line, the very last thing I'd be considering is a downshift. Maybe what you need is an Ejection Seat to launch your a.s out of the car if you downshift while at red line.
>I have a 2006 325i Steptronic. Is it possible to damage the > transmission if I manually downshift from say 3rd to 2nd if I were > already driving in 3rd at a high rate of speed, or is there some kind > of limiter that will stop the engine from damaging itself if it looks > like the downshift will redline the tranny? Russell - 17 Aug 2005 19:47 GMT If you mix up pushing and pulling (down and up) it wont down shift if it would be near the red line.
> If I were screaming along anywhere near the Red Line, the very last thing > I'd be considering is a downshift. Maybe what you need is an Ejection Seat [quoted text clipped - 5 lines] >> of limiter that will stop the engine from damaging itself if it looks >> like the downshift will redline the tranny? Dave Plowman (News) - 17 Aug 2005 21:43 GMT > I have a 2006 325i Steptronic. Is it possible to damage the > transmission if I manually downshift from say 3rd to 2nd if I were > already driving in 3rd at a high rate of speed, or is there some kind > of limiter that will stop the engine from damaging itself if it looks > like the downshift will redline the tranny? No. You can neither over-rev or labour the engine with Steptronic. Nanny state rools. ;-)
With my old E34, I'd often leave it in third for town use start and stop, and it didn't complain.
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Dan Buchan - 18 Aug 2005 22:43 GMT >> I have a 2006 325i Steptronic. Is it possible to damage the >> transmission if I manually downshift from say 3rd to 2nd if I were [quoted text clipped - 3 lines] > No. You can neither over-rev or labour the engine with Steptronic. Nanny > state rools. ;-) That's right, steptronic won't let you do anything naughty. It's actually quite irritating and makes the manual mode not worth bothering with. If, say, you are in third and try to engage second at what it thinks would be too high an engine speed, the display briefly changes to "2" but then goes back to "3" without doing anything. I would rather it beeped or something (if it physically blocked the lever from being moved back, that would be great, you could really drive it enthusiastically in manual mode). Also, if I remember, it changes up if you redline. I would prefer if it just cut out at the limiter. After all, if you wanted auto mode you probably wouldn't have engaged manual.
Dave Plowman (News) - 19 Aug 2005 00:09 GMT > Also, if I remember, it changes up if you redline. I would prefer if it > just cut out at the limiter. After all, if you wanted auto mode you > probably wouldn't have engaged manual. Yup - my main problem with it.
If you have a manual box, you can hold it on the limiter as long as you like. But with the Steptronic, hit the limiter and it changes up. Not what you want when darting between corners on a twisty road. Indeed, positively dangerous.
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Keith Kratochvil - 19 Aug 2005 12:55 GMT Guys, remember Steptronic *is* an automatic transmission. Sounds like you want SMG. (if they ever work the bugs out)
>>Also, if I remember, it changes up if you redline. I would prefer if it >>just cut out at the limiter. After all, if you wanted auto mode you [quoted text clipped - 6 lines] > you want when darting between corners on a twisty road. Indeed, positively > dangerous. Dave Plowman (News) - 19 Aug 2005 13:22 GMT > Guys, remember Steptronic *is* an automatic transmission. It's an auto which is said to provide manual control. There's no intrinsic reason why that manual control is over-ridden under some circumstances. My previous 5 speed ZF fitted to an E34 525 stayed in the gear you selected manually regardless, and a third gear start for example could be useful in slippery conditions.
> Sounds like you want SMG. (if they ever work the bugs out) Only when BMW finally adopts the twin clutch system used by Audi, etc. The present SMG just isn't much good in auto mode. Whilst I'm happy with 'snappy' changes when pressing on, I want near seamless changing in town, or when driving gently.
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