Megasquirt Timing and Fuel Map Thread

[SLEEPYDUB]

How long can ARPs be reused? Curious Bc I've had mine off 4 times now

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[turbski]

That was the million dollar question. I have a couple friends that run insane boost in their diesels and re use them, I think it really depends on what arp gives for stretch limits and installing them correctly. I wont say it was the head studs fault for what happened because i was never able to get to the "root cause". I followed the recommendations from a lot of sources on this forum and my gut and replaced them as a precaution after hearing that the last time they were replaced there were questionable torque findings after a couple heat cycles

[SLEEPYDUB]

Do you have a dyno graph of that run?

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[turbski]

It was more than likely the culmination of a huge gaskets, older studs, and the fact we threw so much timing at it to attain the power it made on low boost.

I have put a feeler in another section "turbo pcv valve" because i believe my rings are letting go. Im getting more than a little bit of blowby coming from my vented catch can. When the head was off the cylinders showed almost no signs of cross hatch (glazed) im considering pulling the head to hone the cylinders and replace the rings

[turbski]

sure do

[SLEEPYDUB]

I get a ton of blowby too. My rings are definitely shot. But I'm still gonna send it till it can't anymore. Got a built 2.9 on the side ready to go once it does, but till then I'm gonna fill the gap with boost lol

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[turbski]

also forgot to mention that the electronic boost controller was plumbed ass backwards...…. the first 3 pulls we made caused the car to cut fuel due to the 21psi we kept hitting it with. hmmmmm sure that did not help my head gasket hahaha

[turbski]

I get a ton of blowby too. My rings are definitely shot. But I'm still gonna send it till it can't anymore. Got a built 2.9 on the side ready to go once it does, but till then I'm gonna fill the gap with boost lol

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i don't know if i can live with it. i also hate doing thing cheap but funds are limited so when (if) i can get the motor out i am hoping that i can get away with a hone job and new rings to stop the blowby

[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'.

[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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[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.

[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]

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.

[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?

[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....