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04 GTO Magnacharged, knock problems

 
Old 01-03-2019, 07:23 PM
  #41  
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Originally Posted by pdxmotorhead View Post
IIRC,, the original law that mandated E10, has a rising content requirement, I coulda sworn that 2018 mandated E15 and 2020 is E30 (Or something up that direction.) Need to go google it up see if I can find it..

Its the whole bio fuel fiasco thats got nothing to do with real emissions and everything to do with $$.. Sorry small soapbox popped up there..
Especially ridiculous when you consider that making ethanol consumes MORE energy per unit of measure than you get burning it! Talk about backward thinking......
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Old 01-03-2019, 09:22 PM
  #42  
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Originally Posted by LilJayV10 View Post
Correct.

Make sure you pull timing out of it so you don't hurt it while you are doing your fueling.

Also what spark plugs are you using and what gap?
This is the method I found:

In order to properly dial in a MAF curve via wideband, you have to:

1) Make absolutely sure you're only working off the MAF. Set the "min RPM to disable dyn_air" to below idle speed.
2) Make absolutely sure you've disabled Closed Loop controls and zeroed out the learned fuel trims
3) Look at MAF Hz instead of g/sec or lb/hr.
4) Log AFR error (actual AFR/commanded AFR) to come up with the proper corection factor.
5) Take measurements in STEADY STATE at each Hz breakpoint as much as possible. (Avoid transient or tip-in conditions when reading delivered AFR)
6) Apply the correction factor to the corresponding airflow number below the Hz breakpoint where each measurement was taken.

Of course, I would need to find an appropriate area where this sort of thing would work. Not easy in Los Angeles traffic.
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Old 01-04-2019, 07:30 PM
  #43  
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I just got a package with AC Delco part number 12615136 - 2-bar map sensor. I'm going to try to sort out the existing tune first, and then play around with the 2-bar tune. Because I have to pass smog in California, I will need to have a good, working stock tune. The rest of the time, I can run the car with the 2-bar OS. It will be a couple of years before I have to switch back and smog it again. I'm assuming that as long as I modify the map scaling in the 1-bar tune, I don't need to change back to a stock 1-bar map sensor to get the car smogged?

We have had the OBD-II plug-in test in California for a few years now. They still do a visual check on components, but there is no sniffer anymore.
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Old 01-27-2019, 06:56 PM
  #44  
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I adjusted the MAF scaling to give it more fuel. It wound up needing 12% additional fuel towards the top. I may even still add a bit more. I cut as much as 4 degrees of timing in places as well. I don't have nearly the same knock problem. Go figure. It feels just as strong. There is still a bit of knock at the top of third gear. The same conditions (~5,000 RPM and 0.93 cyl air mass) don't result in knock in first and second gear, but third gear does knock from the longer pull, I guess. I don't think it's having a problem with burst knock, but not sure.

The log shows boost now. I am using a 2 bar MAP with a single bar OS. With a bit of algebra, I figured out the equation to use that gives vacuum/boost pressures from the MAP voltage. It sees a max of 144 kPa/6.3 psi.
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