Megasquirt Timing and Fuel Map Thread

[turbski]

ill set the overboost to 12psi to start. i sent the tuner an email to see if he has a log from my final run, we can all check it. i appreciate the feedback.

[Jaxx_]

It'd say it looks *too* polished. Doesn't look like real world numbers. Too smooth and too many matching cells.

That's what I'm saying. It's not real values, just interpolation all over the place. It looks like the tuner did a few pulls and then interpolated and called it a day. It's not smooth, it's flat.

Pulling a few degrees is not going to hurt anything. I just don't see your fuel table as being safe if it is so flat. If it was tuned on a steady state dyno the ignition map is probably close, but changing the fuel table will have an effect on optimal ignition values. You should try to see a log with that tune and see if AFRs look safe.

You only need 1 or 2 extra rows of fuel and spark tables to have coverage for over boost. The fact your overboost trigger is at 21psi worries me. Set it to like 12.

[Digitalwave]

Yes, I missed the only 8psi part. You weren't using those cells at all then, they were probably just added as a safety margin for an overboost situation.

[turbski]

I get what your saying. I guess I better get a log for everyone to review. I could ask the tuner to send one over if he still has it. would it matter if we only tuned it to 8psi, hence the matching cells above that range?
sorry if this is a bit much on the questions. just trying to understand better

[Digitalwave]

It just wouldn't make sense that you'd have the same values from 180kpa through 240kpa, for example.

[turbski]

It'd say it looks *too* polished. Doesn't look like real world numbers. Too smooth and too many matching cells.

I don't know if this makes any difference but it was tuned on a steady state dyno

[Digitalwave]

Your fuel table looks very... Unpolished. What are you boost targets? 8psi? And boost cut at 21psi?

It'd say it looks *too* polished. Doesn't look like real world numbers. Too smooth and too many matching cells.

[turbski]

It's the tables you posted? I'm honestly surprised it runs well. Your fuel table looks very... Unpolished. What are you boost targets? 8psi? And boost cut at 21psi?

It is a little hard to tell the AFRs you are seeing on your dyno sheet, simply because the scale isn't great—wanna post a log?

yes, running wastegate only for the time being. would it be ok to take a few degrees out in the are of the map that you guys think might be to much? and if so where and how much. I don't think I will be putting it back on the dyno this year but as soon as I can get it on the road I will hook up the laptop and get a log for review

[turbski]

I don't know if I have a log of post tuning. that I will have to look for. we did have the remote knock detectors hooked up on the block while tuning. I wont be able to post a log for a while, looking out the window...… and its friggin snowing again....

[Jaxx_]

from what I have seen posted for other maps my ignition advance does not look a whole lot different from most of them. I am new at tuning 100%. could you educate me on what you are seeing with the tune im currently running? the car seems to run very well in most areas of it, the exception being cold starts (no icv) and cruising in 3rd gear with steady throttle.

It's the tables you posted? I'm honestly surprised it runs well. Your fuel table looks very... Unpolished. What are you boost targets? 8psi? And boost cut at 21psi?

It is a little hard to tell the AFRs you are seeing on your dyno sheet, simply because the scale isn't great—wanna post a log?

[ForcedFirebird]

Start with -2° off the stock tables for timing for 1psi of boost. I posted the stock tables earlier in the thread. Then add timing while listening for knock.

[turbski]

from what I have seen posted for other maps my ignition advance does not look a whole lot different from most of them. I am new at tuning 100%. could you educate me on what you are seeing with the tune im currently running? the car seems to run very well in most areas of it, the exception being cold starts (no icv) and cruising in 3rd gear with steady throttle.

[ForcedFirebird]

Oops, I've been running 23-25° at 145kPa for a while now. Good thing that's a transient area and it's pretty much impossible for me to hold that manifold pressure due to creep. I run 12° to 14° advance at my target of 205kPa, generally have a dip of a couple of degrees around where I'm guessing peak torque is (~4,500rpm). No dyno time here of course just 'best guess' and trial and error on the street, my advance table would probably change drastically if I put it on the dyno and moved the values to see where they are relative to 'best power'.

He is at 25° peak TQ and 175kpa....23° isn't going to blow you up at 140kpa if you listened for knock.

[SLEEPYDUB]

Oops, I've been running 23-25° at 145kPa for a while now. Good thing that's a transient area and it's pretty much impossible for me to hold that manifold pressure due to creep. I run 12° to 14° advance at my target of 205kPa, generally have a dip of a couple of degrees around where I'm guessing peak torque is (~4,500rpm). No dyno time here of course just 'best guess' and trial and error on the street, my advance table would probably change drastically if I put it on the dyno and moved the values to see where they are relative to 'best power'.

I've been running about that much too on E85. I definitely hit that amount of timing at that pressure

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[varg]

I would bet on the timing being too aggressive. ~21-22° at 140kpa is pushing the limit on a stock gasket and 93 pump fuel. Even in NA form, the engine doesn't need over 30.

Oops, I've been running 23-25° at 145kPa for a while now. Good thing that's a transient area and it's pretty much impossible for me to hold that manifold pressure due to creep. I run 12° to 14° advance at my target of 205kPa, generally have a dip of a couple of degrees around where I'm guessing peak torque is (~4,500rpm). No dyno time here of course just 'best guess' and trial and error on the street, my advance table would probably change drastically if I put it on the dyno and moved the values to see where they are relative to 'best power'.