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I am looking for any hints or tricks to ensure that my 383 is properly tuned before I go thrash it on an Autocross or Road Course.

I have been using $EEHack and the TrimAlyzer to analyze my data logs.
Details:
383 LT1
Trick Flow Heads (ported by Lloyd Elliot) 2.08/1.60 64cc combustion chamber 11.2 static compression
Flat top pistons (-5cc) 0.036" quench
36lbs/hr injectors Holley
Camshaft - 223/[email protected] .581/.593 with 1.6 rockers 112 LSA
58mm TB
Ported Intake
MSD ignition coil with stock Opti Spark(new)
Tri-y Original Headers
2 1/2 exhaust.
F-Body MAF

I think that I have the timing correct as I do not see any knock retard at any RPM with 93 octane fuel(10% ethanol).
I have adjusted the calibration with the offset/voltage for the injectors. I have been tweaking the injector constant to minimize how much the PCM will have to correct the fuel mixture.
I have changed the MAF tables for the F-BODY MAF.

I am working on the partial throttle portion and I am wondering if any changes to the VE tables is necessary? Or do I just alter the MAF table? or both. Just seems as if after every data log trimalizer suggest changes to the VE tables which I make and does not seem to do much. Trimalyzer keeps suggesting to reduce the values in the VE tables each time ( I thought that the new motor would require higher values.) I do see the BLMs closing in on the ideal 128, but is this the correct way to do things? Should I also be changing the MAF tables as well. Seems as if this method of tuning is time consuming. Very Slow!

NOTE: I have disabled PE mode for now so that I can broaden the range of areas without going into PE mode.

At idle my BLMs are right at 128 for both sides as I tweaked the cylinder balance table.

I was initially using a $EEB calibration but swapped my data into a $EE calibration. Hopefully I have not messed up anything by doing that data copy.

I am open to suggestions or comments.

Michael
 

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madamorr, you have a Private Message / Conversation waiting for you …
 

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Discussion Starter #3
Thanks Marky Dissod for the hints.
 

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I'm sure Marky Dissod gave good advice, let me just summarize my thoughts:
  1. I would never tune an engine by adjusting the fuel injector parameters. If you have injectors with unknown voltage offsets and short pulse adders, I would tune with known or stock injectors, THEN swap the injectors and adjust those values until the fuel trims matched the known injectors.
  2. Be sure to adjust your O2 gains and delays to match their altered position from stock in the exhaust system.
  3. Yes, adjust the MAF and VE tables to normalize the fuel trims once your injectors are fully characterized and O2 values are set. You can disable the MAF in the tune, or use eehack's "control" menu to force speed density mode in real time, then datalog and tweak the VE tables. You can also back out the correct VE from MAF data in Excel if you're handy with Excel, though trimalyzer might have that capability.
  4. After all of your fueling was correct, then adjust the spark tables.
 

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Thank you sherlock9c1 for the compliment, it's much appreciated. I've been very considerate and careful with my advice and work for several years.
1. Fuel injector parameters, like an engine's bore stroke and displacement, are fixed hardware constants.
Although they age and wear, they do so from known assigned parameters.
Best to avoid adjusting injector parameters til the O2s, MAF, VE, and spark tables have been calibrated to the point of diminishing returns.
2. O2 gains and delays tend to get overlooked whenever headers get installed, especially if the headers have longer runners that somehow manage to keep the O2 sensors in pretty much the same place.
The header length is the important variable, even when the O2 sensors don't move.
3. Although there are trusted spark tables out there, it is still better to tune the MAF & VE tables 1st.
 
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