beev Posted April 4, 2020 Report Share Posted April 4, 2020 Hello Again, Just gathering some information but I was looking for what do people suggest for a distributor curve or even better share an ignition table. I would also be curious to see any AFR tables as I am new to this tuning thing. I did a search and couldn't find tables, lots of curve examples but the more information the better. Please keep it related to NA L series. I have a L20b with flatops, cold static compression is 185. I have been told high 9s for compression but take that as you will. When it was on a dizzy I was running roughly 15 degrees at idle and was all in at 35 around 3000-3500 RPM. I have the mid points somewhere too I just can't find it. Many thanks! Quote Link to comment
datzenmike Posted April 4, 2020 Report Share Posted April 4, 2020 35 total is on the high end and probably because of the static 15 initial advance. It should be 12 for a stock engine and this will reduce the total back to a better 32. Generally you want the total (32-34) to come in at or before 3,000 and modified, even earlier maybe 2,000-2,500 but I've asked and never gotten a reply as to why. Your total advance @ 3,500 is definitely on the high side of what popular wisdom says. AFR? Is this a stock carburetor? you don't say. Idle can be anywhere between 14 and 15.5 with 14.7 being perfect. It's a bell curve and not that much difference on either side of stoichiometric. Under light throttle it should begin falling slightly and more and more as throttle increases and anywhere in the high 12s and low 13 at WOT (wide open throttle) If you have EFI you should say so. Some after market systems can 'learn' what's best by driving it. Quote Link to comment
beev Posted April 4, 2020 Author Report Share Posted April 4, 2020 Thanks Mike for the info on timing. AFR is Air Fuel Ratio. I am running throttle body EFI with wasted spark. You practically wouldn't have a AFR table without EFI. As you said the lamda/stoic target changes depending on load and RPM that is what I am after. I have a Microsquirt with autotune on Tunerstudio which will adjust the VE table but it needs the ARF table for targets. Once I am happy with those you are correct I go for a spin. Quote Link to comment
datzenmike Posted April 4, 2020 Report Share Posted April 4, 2020 That's out of my wheel house. Is the timing adjusted by the EFI???? That would be best case. Maybe a knock sensor so it can be kept below pinging? Quote Link to comment
beev Posted April 4, 2020 Author Report Share Posted April 4, 2020 Yup timing is also adjustable to load and rpm. I don't have a knock sensor however. Quote Link to comment
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