LS2 tuning questions

SO what would you consider the best PE ratios (would you change them based on RPM ranges) and spark timing or dwell to use for maximum performance? Should the PE ratios be solid across RPM range when tuning SD mode for the VE table? Have been using the EQ ratio and STFT data together to change the VE table. Once the VE table is within 5% then I can do the MAF tuning correct?
I have a stock LS2 with only an OTR intake and upgraded MAF installed. Am Imagining the Evans waterless coolant and 160 thermostat aren't really mods that would effect the tune.
Can provide my tune and latest scan of the VE table if you wouldn't mind critiquing or offering additional wisdom as I am new to this.

A dyno would be the tool to use to determine what timing and fueling make the best power.

Obviously 95% of us do not have that option. So playing a game is all we can do and more often than not it's better to error on the side of caution because anyone that tries to run the engine to the edge of it's limits for 5-10hp that they will never feel in the butt dyno is just fooling themselves.


You ask many guys and they are going to say 12.0 to 12.5 AFR or 1.170-1.190 are pretty safe for stock NA engines on 91-93 octane. Timing in the mid 20's is a safe bet as well. You can pick how you want PE setup, some leave it solid all the way across at first to dial in the fueling, then maybe change it up so that it's a little richer at peak torque. In the end it's not going to a huge factor in this application.

You will need a wideband o2 sensor for this. Using fuel trims is not an option for power enrichment tuning because closed loop and fuel trims are disabled in PE. Pick whichever side of the airflow model you want to do first. The VE can be done before the MAF curve is.

Much appreciated advice and just to be sure I understand everything correctly. Is it wise to disable STFT table while SD tuning and using only the EQ error to adjust VE table? 2ndly how do you disable the STFT? Isn't it easier to just ignore it and use EQ error table or can the STFT table skew the EQ error?
Next on timing... the stock spark tables seem to go up to 40 in many areas but you're saying 20s? I might be missing the table you're referring too but am speaking of the high and low octane tables to adjust. Is there another table I missed that gets adjusted? Also is it safe to say that the higher the ignition timing that the more power can be made minus if you're getting knock?

If you are going to use a wideband to tune it, yes you'd need to turn off the short term fuel trims, long term fuel trims and closed loop.

I don't have your file so I don't know the exact labels it uses for tables. But I would assume there is a closed loop coolant temp enable table for closed loop, a long term fuel trim setting and maybe a STFT open loop disable. Trims and the fuel trim learn can be reset with the VCM scanner as well after those main changes are done.

I was talking mid 20's for timing at full throttle. Timing into the 30's and 40's is totally normal, that's why the stock tables are set this way. Cruising timing in low rpm and low load area's is suppose to run higher timing for good drive ability and fuel mileage.

Higher timing doesn't always mean more power. Say the engine made peak torque at 25 degrees but it could run all the way up to 29 degrees without knock still. The timing above 25 degrees lost power but it was still able to go there. A dyno would show you this but like we said most don't have that option. So we just work with what we got and kind of leave it in the middle. I never try to add timing until it shows some knock retard but it does happen when tuning, so in that case I'd back it off a few degrees and just leave it.

If you can let me know where those tables are your speaking of and if you see any issues with my setup please let me know.

I just noticed you already have a thread about this or very similar. Lots of information already in there.

Poke around the tune file and you'll start to see where stuff is. Having two threads with similar stuff going on just makes it harder to track what is being said.