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Injector angle/timing for power

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Getting conflicting information, so seeking clarification. I'm looking for power increase not emissions/economy, I believe it's more for the later but let's see.

I run speeduino, on a 3 pot 12v turbo that has been fully tuned. The last thing is to look at injection angle as they call it, I've got the default 355 degrees and a had a little play on the dyno and did 1 quick wot pull from 2000 to 5000 rpm so not a full pull as I ran out of time - as I reduced 35 degrees from the angle to make it 320 it made the afr in WOT a little richer maybe 0.2 I can't remember but definitely richer. Now I thought this was going in the right direction but been told I need to go the other way ie increase till it goes leaner for power? Is this correct it doesn't make sense to me?

Side note my duty cycle is at 80% (toward top end) so open most of the engine cycles so potentially I'm wasting my time other than tuning for smoother idle and economy? Or is there power to be gained in wot?

Lastly would cam opening/closing data help and how would I interpret it and use?

Thanks

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What, exactly, is the engine? I can think of several that meet that description?

Your results puzzle me a bit - but that isn't difficult - if the lambda is reading rich, that means less oxygen is left in the exhaust gases, which means, if the fuelling is the same, less air is being drawn into the cylinder for combustion and/or the mixing and combustion is more efficient. This is where 4/5 gas analysers are useful, as I might expect a slight drop in CO?

While you weren't able to do a full pull, how did it compare to the other pulls through the same rpm range?

As for "leaner for power", that's going to depend on where you are, and what the engine wants - you may find some playing with timing and fuelling will increase your torque/power, sometimes trading of one, sometimes the other, for the best results WITHIN THE LIMITS OF DETONATION AND EGTS!

There is another way of looking at the "leaner for power", as timing the camshaft(s) to draw the most air into the engine will 'lean it out' as the air mass increases and will need more fuel to compensate - but again this is a trade-off, not much point taking more in if you're putting more straight out the exhaust port.

Hi Gord,

It is a charade gtti cb70/80 I see your from NZ, I believe they were relatively popular back in the day ha in NZ.

Timing has been optimised it's relatively high due to the CR, fueling in my opinion it's a tiny engine running 1.5 bar with good iats, although I could gain more power leaner I target around 11.5 mid range and towards redline 11.3 purely for cooling and reliability, I also inject more in cylinder 2 that can be prone to cracking between the valves.

Unfortunately it was only one pull I recall power didn't change but afr did.

Wrt to leaner for power and injection angle that's where I'm confused, when altering angle I've been told right direction is change till afr gets leaner as this is correct way to go for more power?. I thought adjust till it's richer then adjust ve fueling appropriately so, for arguments sake I want to target same afr above and killer question is altering injection angle (which ever method is correct) can it result in more power in wot?

Lastly I thought cam opening/closing would help in my head to get correct figure or ball park?.

Thanks

Finding the ideal injection timing, can increase the fuel efficiency of engine (all fuel injected is being used optimally). But I don't think it will increase power by itself.

By adjusting the injection timing to the richest mixture (lowest Lambda value), you are by definition combusting more of the fuel that was injected. If this is richer than your target, you can lower the fuel amount injected and therefore increase the fuel efficiency of the tune.

Now this is the opposite of things that affect airflow (like valve timing) -- Airflow changes increase the engines efficiency (i.e. power) if provided with the proper fuel amount and ignition timing. So for that you tune for leanest condition, then give it more fuel (and adjust ignition timing) to make the power.

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