2001c5z06

2001 c5 z06 2nd gear pull hear is the graph, can anyone let me know if that looks good. Knock stayed 0 this pull but on another run bumped as high as 2.

Any insight would be much appreciated.

aaronc7

This datalog is pretty useless, the Y axis scaling doesn't tell you anything.

Fuel trims look pretty good
What is your peak timing at wide open throttle/high rpm?

2001c5z06

Hey thanks for the reply! This was at WOT but I do not know the peak timing since this is just the Performance Program that comes on the diablosport device I have not tweaked anything myself.

I am not familiar with data logging/tuning so if you have advice on what I should log and display I would happy to take more data and repost with better graphs.

aaronc7

I'm not familiar with that program so I can't really help ya there. If there's a way to export the data to excel, you could upload that (.csv is a common format/extension).

Most datalogging software programs have a way to select a "column" of data to display at a given time. See in the upper right hand corner of the screen.... it's showing all data for those parameters at time 0:00:00.000.

Find where you went WOT in the log and see how timing and other parameters change thru the rev range. For example the stock tune will usually run 22* of timing above 4000 RPM at WOT. I can see timing ramping up and then flatling at the end of the datalog, but there's no way to tell what the actual values are based on the pic you posted.

2001c5z06

At 4000 rpm 24.5 degrees spark advance at 4400 rpm 23 degrees and then 22 or 22.5 to redline

aaronc7

Sounds like it's a very conservative tune. I run around 27* max at WOT on 93 octane, only seen 1blip of 0.2 knock ever.

What octane gas you running?

tblu92

Typically you want to data log in the gear that is 1:1 ratio-- If you log in a lower gear there is not enough load on the engine to accurately make adjustments to both fuel and spark--- In 2nd gear the AFR will be richer and the timing will not show any KR cause there is not enough load on the engine----On an Automatic for example 3rd gear is 1:1 so you would need to log it there----It becomes difficult because in 3rd at 6000 RPM's you are way over 100 MPH and it becomes a safety issue---Running a data log in 3nd gear on an automatic will show richer AFR's --can be about 3-5 tenths !! and you'll get no KR --so its not a good way to tune
PS: you will notice on dyno tunes they always look at the numbers in the gear that's 1:1---to be accurate

2001c5z06

I am in CA and only have 91 octane gas. I will run another log in the next few days in third gear and try to make a graph that is actually useful.

aaronc7

True you want to dyno in gear closest to 1:1 ratio. For datalogging, it comes down to what you're able to do on the street. Higher gears work better as it takes longer to go thru the rev range with the datalogger recording stuff at a constant rate-- so you get more 'resolution'/more data points.

For full gear datalogs I try to get a 3rd gear pull in. 2nd isn't ideal, but obviously much easier and safer to get done on the street- better than nothing either way.

SVT_Z06

Strange. Typically, timing is lower at peak tq, then it ramps up to redline.

How does it feel? Any mods?

Also, get a third gear log. That will provide better and more appropriate results for reviewing/critiquing.

As the others mentioned, see if you can export the .csv file and post it.

Supercharged111

Typical of GM, their timing always drops off the end of the earth as the motor approaches redline. Get a dyno tune and that'll never happen.

2001c5z06

I took a bunch more logs and they all look pretty much the same.

Diablo tune holds about 22 degrees of timing after 4k rpm

Stock tune holds about 20 degrees of timing after 4k rpm


Depending on each run whether stock or diablo it will pull 0 up to 2 degrees of timing, usually 0 or 1. I think this is based mostly just on heat and crappy gas.

2001c5z06

More logs that actually so the rpms climb...

2001c5z06

So based off old posts on the diablosport forums and using DSLogRedux I made some changes.

I started with -4 on injector slope (makes it richer) and -2 on fuel enrichment (leans out WOT). Still lean at cruising and have eventually moved myself to -6 on injector slope and -4 on fuel enrichment. I started logging AFR as well, although not extremely accurate it shows me holding 12.7 at WOT except for maybe a small rich bit in between shifts to 12 or 11.7.

ltft on long cruises is still a little positive so I may -1 or -2 more from injector slope and then tune fuel enrichment accordingly (prob -1)

What does everyone think of that? Once I get that squared away I will look into possibly bumping up timing. Although probably not much since I am on CA gas.

2001c5z06

With settings injector slope -6 and fuel enrichment -4 I took this cruising log around 2k rpms for a couple minutes. Here are the ltft and what dslogredux suggests.