i am going to try to make time to build this tonight and dug this up from the old forum... thanks for the info jake!
Hey guys,
IT WORKS! Yee-hah!
I am talking about the turbo-timer, designed and installed by yours truly.
A turbo timer, upon triggering, allows the engine to continue running after
the ignition is switched off. Mine runs the engine for a little over 1
minute.
Why? Well, according to studies by Schwitzer Turbochargers, 90% of all
turbocharger failures are caused by maintainence/preventable issues - more
often than not, oil allowed to sit in the bearing area of the turbocharger
cooks and "cokes" if the bearing is too hot and the exhaust gasses and oil
circulation is cut off by shutting down the engine when things are too hot.
The turbo-timer automatically idles the engine so you don't have to sit
there and wait. Also, if you have to do the waiting the duration tends to
be minimal, especially if you're in a hurry getting to lecture, or into a
meeting, etc!
This is the latest update on the homebrew turbo-timer I've discussed in
earlier messages.
Parts required, and what it cost me:
(1) "slow" glow plug relay; part # 321 911 261 ($13 from friend, used)
(1) glow plug relay holder + wires ($2 from wrecking yard, used)
(3) diodes; silicone, I got the 3a continuous with high-peak current ($2 at
radio shack)
(1) T 1 3/4 light emitting diode (for viewing the status of the circuit, if
desired) color of your choice
misc - solder, multimeter, etc
Notes:
* This circuit is suitable for any VW / Audi / Volvo turbo diesel (four,
five, or six cylinders...) which is mechanically regulated by a governor
mechanism. (not a TDI)
* See above pic for schematic with wiring details
* Relay holder snaps along top row of relays on top of fusebox for a neat
installation (for US-built A1's at least) or could be strapped to some
fixture under the dash, etc. I just soldered two of the diodes directly
behind the relay holder; and third is wired in-line to the fuel shut-off
solenoid lead.
* Some key wire color codes are given, but colors may vary on models other
than my US-built Rabbit.
* Circuit is designed so that there is zero battery drain and no current
consumption until circuit is activated.
To activate the circuit, I just flick the high-beam headlights prior to
shut down. Once the timer is in a cycle additional high-beam trigger
signals have no effect. Once a ~1 minute cycle is completed the timer is
ready to begin another. Triggering is virtually instant (only a fraction
of a second is needed with the high-beams activated in order to flick the
relay)
There are LED "blanks" in the existing instrument cluster which hopefully
will be easy to adapt an additional LED for the timer status indicator,
much like the yellow glow plug status LED.
The one downside I could see is if the engine oil pressure suddenly becomes
zero for whatever reason (say you happen to run completely out of motor oil
and need to shut her down---quick!) and if you have happened to just switch
on your high beams thus triggering the circuit... well, it might be a while
before you can get to shutting it down. But my thoughts are that it is
unlikely that both these conditions occur. But if it does- I'll probably
be yanking the relay from that fuse box with superhuman speed and agility!
BTW, I've heard it is an offense in some cities to leave your vehicle
idling unattended. I think this could be fun. Say a police officer is
writing a ticket for an idling vehicle he sees which is unattended, and
before he can finish with the ticket it turns itself off Might be good for
some strange looks too! ;-)
------
and the rest of the thread from the old forum is at...
http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4037&t=141
Topic: DIY Turbo Timer (Read 15118 times)
