Engine feels slow - please check out my log

[TXjeepTJ]

I have a 1970 Chevelle with a 2005 6.0L LQ4 w/ 2005 4L80E. I have a comp cam in it 232/240 .595/.608 115LSA, long tube headers, and a 3000 rpm stalled torque converter.

When I go WOT, it feels slower than a stock truck.. and I mean slower than a stock 5.3L silverado, which weighs more than the Chevelle (mine is completely gutted, nothing but seats inside of it).

First WOT on the log is from 6:35 to 6:40
Next WOT is 7:26 to 7:37
Next WOT 13:13 to 13:22
Next WOT 13:42 13:44 (this is where it felt like it was bogging down, barely moving at WOT)
Next WOT 15:17 to 15:24
Next WOT 20:17 to 20:30 You can see the shifts by looking at the injector duty cycle. When it hits 3rd gear it feels like it pulls way harder than any other gear.. idk why

From looking at the Commanded Lambda vs actual --- it looks like my VE table is tuned very good

The only thing I haven't messed with is the timing. Is this where I could have a lot of potential? or.. this engine could be worn out. Had 150,000 miles on it. Same with the transmission - could be slipping maybe?

Tuning Setup_WideBand.cfg
WOT RUNS 3-19.hpl
Chevelle Current Tune.hpt

[5FDP]

Post the tune.


Why arent you logging o2 sensors or fuel trims at all???


Something is taking all the timing out of this thing, you are running maybe 13-14 degree's then it drops all the way down to 8-9 and that just killing all your power.

[TXjeepTJ]

Tune has been added to the original post - Currently, I'm running it open loop - I do not have front O2 sensors, so it is straight up tune

[TXjeepTJ]

Comparing the tunes spark table vs what it is actually running, it is not pulling any timing - it is using the timing that is in the tune. Do I need to just tune the timing tables and increase the timing?

[matty b]

What type of intake are you running? I've seen this with a Street and Performance MAF/filter.

[5FDP]

I didnt see the tune yet because it wasn't posted at the time. So was assuming it's pulling it all away.

[TXjeepTJ]

It is a MAFless system - SD tune. I just have a cone filter connected straight to the throttle body. Maybe the intake temps are pulling timing? But as I said earlier, I looked at the timing tables vs actual and it doesn't show timing being pulled

[TXjeepTJ]

Actually, there is some knock retard at 7:27, not sure why - air intake temp is around the same temp (90 degrees) that it is for the whole run

[JoshR]

Under power enrichment set your ramp in to 3.5-4 and change your enrichment ratio to 1.13 or 1.14. Also on your main spark tables your timing is way too low. My stock Silverado with an LQ4 had more than what you're running. Bump it up to around 22 in your WOT sections and see how she likes it and go from there. Under spark zero out the base table in your ECT Spark and in the IAT Spark you can knock them in half from 86* to about 122 and go from there on that table as well as zero'ing out the multiplier table.

[TXjeepTJ]

Under power enrichment set your ramp in to 3.5-4 and change your enrichment ratio to 1.13 or 1.14. Also on your main spark tables your timing is way too low. My stock Silverado with an LQ4 had more than what you're running. Bump it up to around 22 in your WOT sections and see how she likes it and go from there. Under spark zero out the base table in your ECT Spark and in the IAT Spark you can knock them in half from 86* to about 122 and go from there on that table as well as zero'ing out the multiplier table.

Made the changes, will report back tomorrow - THANKS!!!

[TXjeepTJ]

Under power enrichment set your ramp in to 3.5-4 and change your enrichment ratio to 1.13 or 1.14. Also on your main spark tables your timing is way too low. My stock Silverado with an LQ4 had more than what you're running. Bump it up to around 22 in your WOT sections and see how she likes it and go from there. Under spark zero out the base table in your ECT Spark and in the IAT Spark you can knock them in half from 86* to about 122 and go from there on that table as well as zero'ing out the multiplier table.

So I made the changes, I also bumped up the entire timing table by 4 - uploaded to the PCM today and just now went for a drive

COMPLETELY different car now. Thanks!!! And I didn't log any knock retard the entire time, so I can still bump it up some more. I guess messing with the timing is where you gain all the power.. seems too easy to be true lol

Thanks again man

[5FDP]

Don't tune for knock, that's not the right way to do it.

Just because you tossed more timing at and see no knock doesnt mean you should keep adding more untill you do. More often than not you could raise timing even more and not make any more power and even lose power in some cases.

I'd leave it be for now and start fine tuning the rest of the stuff. Get the VE table dialed in better and then work on the MAF tuning and it'll be a great driver.