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Old 03-15-2013, 02:55 AM   #9 (permalink)
Smokingwheels
EcoModding Lurker
 
Join Date: Feb 2011
Location: Australia
Posts: 21

Smokingwheels - '84 Nissan Bluebird wagon LX
90 day: 35.99 mpg (US)

Red Z - '79 Nissan 280 ZX

Blue Ford - '95 Ford Falcon GLI
90 day: 18.18 mpg (US)
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Quote:
Originally Posted by pete c View Post
what ^^^^^said. combustion takes time. that is why ignition always takes place BTDC, never after.
Yes But in a normal engine it is like that.
I have modified mine.

My engine needs to be fired -3.67 Deg @ 750 Rpm eg 3.67 Deg ATDC to avoid knocking.

I measured what my computer was doing and the Trigger and Firing pluses have been stored on a MP3, anyone can download them and convert the MP3 to a Wav file, then use a good sound editor to work out the timing.
Note: the offset is 62 Degrees BTDC and the Degrees between pluses is 180 for a 4 cylinder 4 stroke engine.

Timing confirmation jan 2013 by smokingwheels on SoundCloud - Hear the world

The file name stores the info.
750-rpm-65-7-d-3-67-set-2-1
rpm =750
total timing = 65.7 deg
d = -3.67 (Actual timing 62 offset)
set = -2.1 (what the computer is tring to run the engine at with 62 offset)
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