pyro719

iTrader: (5)

Im just trying to lean how to use tunercats. Im trying to get my afr down to 13/1 or so from 15/1 how would I go about doing this in tunercats? Ill be tuning on the dyno. Thanks in advance Nick.

AutomagicLS1

iTrader: (18)

Never used tunercats but I would look for a PE-power enrichment table then make changes in your maf/ve table for the extra fuel. If your afrs at 15's at wot I would add 20% fuel at wot to be safe for a first pull on the dyno

pyro719

iTrader: (5)

I beleive I can change the a/f ratio in the %change air fuel vs rpm? Just not sure how to do it?

AutomagicLS1

iTrader: (18)

Take stoich 14.62857/desired afr 14.62857/12.8 afr = 1.14

pyro719

iTrader: (5)

Awesome thats too easy lol

This is how my tables are

2xLS1

iTrader: (25)

That's not how you do it with OBD1 or OBD2 LT1s These are the two accepted formulas. They both give roughly the same result.

(1 - ([# in Temp Table] + [# in RPM Table])/100)*14.7

14.7/(1+Number in the Cool temp table/100+ number in the RPM table /100)

I've attached a excel file you can plug the numbers into from your cal and it will show the A/F you are commanding. It is already set up with stock values from the temp table.

pyro719

iTrader: (5)

Thanks alot! ill be playing with this when I get off work.

JonCR96Z

iTrader: (33)

Here is an easier way:

Just scale the Cool. Temp table from around 30% at -40 C to 0% 56 C. Then zero out 56 C-104 C, and scale back up to around 7-8% from 104 C-128 C.

That will take the ECT multiplier out of the equation at normal operating temps and make the math a little bit easier.

With that you'll just need to take 14.7/ (1+%change vs rpm)= commanded AFR.

For 13:1 with the ECT at 0 % the RPM would need to be 13%.

14.7/(1+.13)=
14.7/1.13=
13.00884

And to figure out the RPM % change using this method. Just divide 14.7 by the AFR you desire, subtract one from that answer and multiply by 100.

For 12.5 AFR:

14.7 / 12.5 = 1.176
1.176 -1 = .176
.176 x 100 = 17.6
17.6 would be the RPM % change for 12.5:1 with the cool temp set at 0%

JonCR96Z

iTrader: (33)

Let me add that in order for this to work like it is supposed to, the MAF and/or VE tables need to be correct.

So it would be best to set your AFR to 13:0 and if there is any variance from actual wideband readings, then adjust the airflow tables.

pyro719

iTrader: (5)

Thank you 2xLS1 You are the man if this works! The excel spreadsheet does all the work for you. I was able to get my tables to read a 13.0/1 air/fuel ratio in the spreadsheet. Hopefully My car will produce a 13/1 afr across the board now.

JonCR96Z

iTrader: (33)

Or you could have done it the way I said and had your tables done before you even entered all the info into the spreadsheet.

That's probably the reason the LS1s do it that way. Because GM realized that other **** was retarded. LS1 > LT1

pyro719

iTrader: (5)

Jon your way is the same as the spreadsheet all I had to do was scale my rpm table and past it to make sure and BAM 13/1 afr. I do apreciate your method though jon. Im just not good at math lol.

JonCR96Z

iTrader: (33)

It's better to learn than to have to rely on a spreadsheet. Plus, all new cars use equivalence ratios similar to method I used above. So getting use to seeing the same numbers all the time would help you if you decided to migrate to a different car later down the road.

2xLS1

iTrader: (25)

I'm glad it helped. Did the values that were in your tune show that it should have been that lean? Your sig says you had a pcmforless tune. I can't imagin them having it that lean in their tune. Make sure you have a clean MAF and no air leaks downstream of it. If it is still way leaner than what you are commanding, you will need to scale your MAF table higher.

pyro719

iTrader: (5)

You dont happen to have a spreadsheet for maf calibration do you? Here is my afr according to your spreadsheet and my tune. I havent learned how to calibrate the maf yet, but im learning.

400 12.21945137
800 12.21945137
1200 12.80487805
1600 12.80487805
2000 12.80487805
2400 12.80487805
2800 12.80487805
3200 12.5
3600 12.5
4000 12.5
4400 12.5
4800 12.89473684
5200 13.30316742
5600 13.78986867
6000 13.78986867
6400 13.78986867
6800 13.78986867

Alvin

iTrader: (2)

You might want to take your MAF off and spray it really good with brake cleaner or MAF cleaner. i've seen over a piont difference with a dirty maf.

pyro719

iTrader: (5)

Will do! How often does the maf need cleaned?

pyro719

iTrader: (5)

Anybody got any info on calibrating the maf tables? And waht about this vemaster, does it work?

pyro719

iTrader: (5)

Still trying to figure out how to tune the ve tables and maf tables. Anyone have write up for this in tunercats?

JonCR96Z

iTrader: (33)

What software are you using to log?