Afternoon all.
Why do they let you start a manual in gear, but not an auto? While off road I was tought it is acceptable to start in low ratio while in gear without
clutch down. This isn't possible in an auto with standard wiring. I also like the idea of an emergency get yourself off the road with the starter
motor.
Are there parts of the MOT or IVA that dropping this requirement would have? Perhaps I could achieve this by having the interlock wired as per-usual
but with a push button defeat to use in emergency?
Ok. Checked the M1 test manual and couldn't find any requirements for a start inhibit device.
Question remains is there any reason why some cars permit start in gear on a manual but not an automatic? Perhaps I shoudl re-post in the
engine/transimission section?
I dont think you'll ever get a starter motor to spin enough to engage an auto box, I may try it on my Saab. No I wont it wont let me. Doh !!
I've used a starter motor to move a Pug 205 before, easy enough and easier than pushing it too.
Maybe auto-boxes have electronics that prevent you doing so?
As far as I'm aware, the only reason is as a safety feature; on account of the fact that a torque converter automatic would happily fire
in gear and then creep forward at a pace that might not attract attetion, whereas you need to make a really determined effort to start a manual box in
gear, and really couldn't do it inadvertently.
As sprintB+ suggests, you almost certainly won't get enough torque from the starter motor to move the car forward, once you've allowed for
the slip in the torque converter, so it would be a pretty pointless exercise, anyway - you'd have to get the engine to fire before you got any
forward motion.
Your starter motor is designed to provide the given torque for a very short period of time, and even for this period of time it has to draw current
down some pretty thick cables. Think of the extra load if it had to drag a car around at the same time - your battery wouldn't last and the
cabling etc. would get dangerously hot.
Furthermore, for every time you use your 'emergency pull you along' feature, you'd probably put it through a wall more often.
I think the interlocks are there more so because they were easier to do with an auto, and with the torque converter continuously engaged, there's
no option to disengage the drive between the engine and box - you need the box to be in neutral.
Quite a few manual cars now won't let you start unless the clutch is down. I only drive autos on the road myself, so wouldn't know much of
this thing called "clutches"
quote:
Originally posted by sprintB+
I dont think you'll ever get a starter motor to spin enough to engage an auto box...
good point - my point above presupposes the starter motor can do that, and I think the torque converter slip means I may be wrong there. I know admitting one may be wrong is a crime on the internet, but there you go.
The pool cars at work, need the HandBrake on, in neutral & Clutch pushed, before the starter does anything.
Great fun watching the look on peoples faces until they remember.
quote:
Originally posted by FuryRebuild
Your starter motor is designed to provide the given torque for a very short period of time, and even for this period of time it has to draw current down some pretty thick cables. Think of the extra load if it had to drag a car around at the same time - your battery wouldn't last and the cabling etc. would get dangerously hot.
Furthermore, for every time you use your 'emergency pull you along' feature, you'd probably put it through a wall more often.
On some US market manual transmission cars the starter cannot energise without depressing the clutch.
A lot of classic cars are very reluctant start due to the extra friction with the clutch depressed even if out of gear.
[Edited on 17/12/15 by britishtrident]
quote:
Originally posted by ken555
The pool cars at work, need the HandBrake on, in neutral & Clutch pushed, before the starter does anything.
Great fun watching the look on peoples faces until they remember.
My old '74 beetle would roll along nicely on the starter which got me out of a couple of awkward situations!
quote:
Originally posted by FuryRebuild
Quite a few manual cars now won't let you start unless the clutch is down. I only drive autos on the road myself, so wouldn't know much of this thing called "clutches"
quote:
Originally posted by ken555
The pool cars at work, need the HandBrake on, in neutral & Clutch pushed, before the starter does anything.
Great fun watching the look on peoples faces until they remember.
quote:
Originally posted by britishtrident
On some US market manual transmission cars the starter cannot energise without depressing the clutch.
Good point that. I've stalled many times while pulling away and a quick dip of the clutch and spin of the starter can often be done quick enough
to save too much embarassment! Requiring the hand brake to be up is mad.
Can't see how I would stall it while pulling away (although it did stall while idling before strip down due to dodgy air valve) but a just in
case defeat would save from rushing the selector into N to restart, missing and getting R or P!
It's a safety issue with auto's, in gear they will start easily as no load, the engine picks up and the car starts to moves.
Manual car it's a lot less lightly to happen due to the load, you also get a very positive indication as the car jerks forward.
quote:
Originally posted by SteveWalker
quote:
Originally posted by britishtrident
Many cars these days are too heavy to push (especially for women or the elderly) and using the starter is a good way to get them out of the way and to safety if you break down in an awkward spot.
Indeed, most cars are too heavy to push on your own these days - particularly if you want to steer and brake as well.
TBH a 205 is that light weight it's not hard to push, but the task of stopping it once it's moving is harder!
WesBrooks - 5/1/16 at 03:58 PMquote:
Originally posted by nick205
TBH a 205 is that light weight it's not hard to push, but the task of stopping it once it's moving is harder!
Reminds me of a track taster day at Manchester Velodrome many moons ago on the fixed gear bikes. While you fully appreciate how hard it is to get a bike moving in a high gear you get a new found appreciation for the amount of work bike brakes do when you try to stop after a lap sprint! Sprint from my perspective that is, not sprint from the perspective of others riding on those boards!