LB7 and 30 over injectors
- Thread starter pavetim
- Start date
I think this question is better asked on the efi live forum. But basically you just dial back the injectors. I have heard really don't have to change the tune much at all for 30s since they are not that big
Yes on decrease, I would start at about 1200us at 160+mpa. You don't need to decrease the whole table, because at lower pressure the injectors don't flow a true 30% more. Try dropping the idle areas by 5% or so.
So what I was reading in efilive forum so for a stock pulse width of say 1228us at 80mmg and 160mpa. I was told to take that 1228, remove 100us for latency so that's 1128 then add 30% to that which is now 1446us. Then add latency of 100us back in so now it's 1546. Ok and now 30 over injectors don't flow a true 30 so was told to reduce maybe 22%. So now i'll minus 22% so end number is 1205us. Does this sound right? and for 30 overs I really only need to reduce high end of the table, and idle a little bit?
My own rule of thumb is half of the inj oversize. So....15% on the PW and nock timing down the same in the WOT and mid range area if you want to keep stock.
From the tunes I've done using exergy flow sheets, 30 overs is a 10% decrease. I do it across the board. So long as you account for latency and do it in percentages, the corrected fuel table matches the flow sheets.
The ones that I have done started with the small tune around 1550 and the biggest around 2550. That is also using 180 mpa for fuel pressure. In general I make the smallest tune about 10 percent more in effective fuel on the smallest tune and work up from there. I do not decrease fueling across the board on that small of a injector.
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Ok so if i used 10% across board it would go like this for an example. Stock 1100us. So 1100-100 latency=1000us. 30% added is 1300us. So now i take 10%off of that would be 1170 then add latency of 100 back in for a total of 1270. That right or do i take 10% off 1000us for a total of 900 plus then latency of 100 back in?
Stock pulse at 100mm3/160mpa is like 1400us.
1400 x .90 = 1260us
If you subtract your latency, multiply by .90 and add latency back into it you're within 10us total. Like I said, start at around 1200us, that will get you close to stock fueling.
1400 x .90 = 1260us
If you subtract your latency, multiply by .90 and add latency back into it you're within 10us total. Like I said, start at around 1200us, that will get you close to stock fueling.
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You don't add anything in. I subtract for latency, alot of tuners don't. But I subtract 100 from the whole table, subtract 10%, then add the 100 back in except in the 0 portions, and you're done correcting your tables so they should be semi close to actual.
Timing is based off of desired percentages that a tuner would like to see. That number is going to vary from one person to another. If your timing is stock now then you have to get that worked out. If you are basically trying to convert a optimized tune already then you will address timing again but not necessarily by a given percentage like you are trying to do. You should download the timing calculator and experiment with that if you are not familiar with the concepts to gain more knowledge and understanding.
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You don't just readjust a tune for 30 overs, everything changes. You now have injectors injecting the same amount of fuel in less time. Pulse is but a SMALL portion of the tune. Tim8ng needs to be setup for the new sticks, nit just changed by a percentage. You may also need to tweak the pilot tables as well as pilot timing as every injector combo has its own sweet spot. And once you go changing the pulse, timing, and pilot tables, you may find you now have some rough/flare spots, and your defuel tables need tweaked. When you make a turbo change, you can just adjust for it, but an injector change is start over time. And it may run good, but I hope for your engines saje that your timing is set conservatively. 30 overs isn't a big change, but you can get in SERIOUS trouble running your old tune with bigger sticks. Rebuild the tune from the ground up, otherwise something is going to get overlooked, and you could be next in the broken crank thread,