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I am thinking of using 16-18 degrees initial timing plus 12 degrees vacuum advance and 12 degrees mechanical advance. So,
Idle (with vacuum advance disconnected) 16-18 degrees
Cruising at 100km/h 40-42 degrees
Full load 28-30 degrees
Does anyone have any other values they think may be better than these for LPG in the 3/9 litre?
After some playing around with the vacuum gauge to get the best idle timing figure and, with my brother driving, while I changed the values for the higher rpm/speed I have a map that works very well.
Attachment 181934
I reckon you might be ahead having an hour on a dyno and really nailing it.Quote:
Originally Posted by Richard Kaye
I think what you've done is inspirational and it is great you've shared it. I'm still looking at getting 2 of these things next year (one for petrol, one for gas) and when they're in it'll be be a dyno tune rather than me faffing about.
cheers, DL
I'm hoping that table goes beyond 4600rpm....[wink11]
i.e. it is simply window size that's obscuring the rest of the table..
curious to know what the timing is at WOT and 5500rpm.
Anything above 4600rpm uses the same values as the 4600rpm row. So, at 5500rpm, the values are the same as 4600rpm.
I have finally got a MAP that works well. I had too much timing across the board, had to remove around 8 degrees from the previous MAP I was using. There is a hill I regularly drive up and before it used to reach 80km/h (with a tail wind). Now with the new motor and timing sorted I can get to nearly 100km/h.
Next is to determine the fuel efficiency, see if I can get better than the 22-24 L/100km I was averaging on LPG.
Wow that's a thirst for LPG. I get that on my unopened POS running on 98. IOTW, you should be getting a solid 4-5L less per 100km than me with a much fresher motor.
Has anyone else fitted one of these CB Black Boxes yet. Would like to compare MAP's.
No Richard, not on my agenda -
Looks like you're still the guniea pig.
How's it working out?
Big gains or law of diminishing returns?
It's actually running very well at the moment, still on LPG. I have the standard 3.9 camshaft in it, and it pulls well from about 1200rpm to 4000rpm. It won't really rev past 4500rpm, not sure if that is the camshaft limiting the revs or something else. I should have put another camshaft in while I had the motor apart recently.
It is a lot more lively than it was with the new MAP I have in it and fuel economy has also improved, now down to around 20 litres per 100km, or a little better.
So, it's using less fuel and going better so happy with that (for now).
