NA tunes, watch out!

Post by **Gaskleppie** » Thu Nov 05, 2009 6:21 pm

I never thought this would happen to my own car. Let me explain this. I drove all summer with my car NA B16a with no problems at all. AF was around 13,2:1 @ wot and all went fine. But now that the winter came, all of a sudden my AF went like crazy. 14,7:1 @ wot was no exception and 1 day it was all fine, and the next day it was horrible lean again! I messed with the IAT tables, but even when I gave it an extra 15% correction, it was not enough to get the AF at normal values. After days of testing I noticed that not only the AF was changing, but also the air pressure. In summer my old logs showed even 0,24psi boost, and now in winter the air pressure dropped to 970mbar. That made me realize that the software could have read the 11th column during summer, so I opened up the 11th column to see the fuel values. The looked like this the maps below. When I saw the 11th column I knew enough. In summer it was reading a mix of the 10th and the 11th column. The average of these 2 columns was way higher then the average of the 9th and 10th column it was reading in winter when the air pressure is a lot lower. Bottom line of this story: Even when you have a NA car, look further then the 10th column. It can save you a lot of stress! btw, Calvin is making something in the software soit can not happen again. Its not ready yet, so watch out for the 11th column!

1337EJ1 · Post by **1337EJ1** » Thu Nov 05, 2009 6:26 pm

Thanks for it !!

9400RPMS · Post by **9400RPMS** » Fri Nov 06, 2009 11:22 pm

so basically, you weren't reading the last column?

Post by **Gaskleppie** » Sat Nov 07, 2009 5:11 am

9400RPMS wrote:so basically, you weren't reading the last column?

What column do you mean by "last" ? Thats the whole deal. Normally with NA cars, the last is the 10th. But with the high air pressure, the last read out column was the 11th which I never noticed. In summer, it did read the 11th column what gave me a nice AF. I only never new it did that. But in winter, it didnt read it anymore because of the lower air pressure. The result was horrible....

Orthello · Post by **Orthello** » Sat Nov 07, 2009 11:36 am

Good to know. I'm experiencing the same behaviour. So I changed the IAT correction. Which did very well. Last columns are not that much of a difference in my case, but never the less.... it could have happend to me too.

CRX2 · Post by **CRX2** » Sat Nov 07, 2009 5:28 pm

When you make a basemap for a NA engine, it only has 10 collums? The last two are the 980mbar and the 1039mbar. When I tune a car, I allways change the last three collums at the same percentages when I can not get any accurate readings in hose areas. When you have more then 1039mbar is is read as BOOST, a normal stock engine would throw a MAP-error... What does eCtune do? A NA \"boost\" more then a few PSI looks strange to me. What does the PA sensor say? And is the MAP sensor accurate?

Post by **Gaskleppie** » Sun Nov 08, 2009 6:18 am

When I tune a car, I allways change the last three collums at the same percentages when I can not get any accurate readings in hose areas.

And what are the last 3 columns in your opinion? Column 8-9 and 10? I understand what you are doing but I dont think thats the right way to work. If you set the last 3 columns the same you will see also differences when the air pressure drops. Less air pressure will give a richer AF if you dont compensate for this lower air pressure. The best way is to use some kind of step between the columns. (And to set the 11th column until Calvin changed the program.)

Orthello · Post by **Orthello** » Sun Nov 08, 2009 3:19 pm

Frank... keep in mind that we are way below sealevel and thus the AP is higher by default. 1020mbar is not that exeptional in Holland and thus are to most right columns (with NA) much more of an importance to us.

98vtec · Post by **98vtec** » Mon Nov 09, 2009 3:24 am

wow, i have never had that big of a jump in air pressure lol. AT WOT, throughout the seasons i was typically around 1000 - .41psi. Not enough to drop me to a different Column lol

Post by **Gaskleppie** » Mon Nov 09, 2009 4:01 am

I live BELOW sea level. Maybe thats the reason that I suffer these kinds of big differences in air pressure.

fah · Post by **fah** » Mon Nov 09, 2009 12:21 pm

i have experienced this here in jamaica..i was amazed .. i hit possitive pressure with a NA setup

CRX2 · Post by **CRX2** » Tue Nov 10, 2009 7:32 am

Gaskleppie wrote:And what are the last 3 columns in your opinion? Column 8-9 and 10? I understand what you are doing but I dont think thats the right way to work. If you set the last 3 columns the same you will see also differences when the air pressure drops. Less air pressure will give a richer AF if you dont compensate for this lower air pressure. The best way is to use some kind of step between the columns. (And to set the 11th column until Calvin changed the program.)

Once I saw a tuned map wich was tuned at very low air pressures. The last collumn was not changed at all... I allways change the three right collumns with the smae percentage as the collumn in wich you are measuring. You can not tune al collumns , you allways have to "interpolate" a few values. When you do it wich percentages, then it's rather accurate I guess? Example: Tuning the most right collumn, I change also the 2nd and 3rd one from the right with the same percentage...

elevation · Post by **elevation** » Tue Nov 10, 2009 1:55 pm

Set your boost cut to proper mbar just in case.

Post by **Gaskleppie** » Tue Nov 10, 2009 3:38 pm

I allways change the three right collumns with the smae percentage as the collumn in wich you are measuring.

Ah, ok. Sorry, Now I understand you better. Noting wrong with that! But did you also set the 11th column?

Tiewoli09 · Post by **Tiewoli09** » Sat Dec 05, 2009 10:30 pm

no its always my computer that does it. and i found out that its not my laptop, just my desktop

NA tunes, watch out!

NA tunes, watch out!

NA tunes watch out