I really didnt want to jam up the speed density thread with n00b questions so ill ask here. First of all i have completed the setup with GM IAT and OMNI 4bar and the car runs and drives with the SD patch applied. My car is self tuned and i am not a n00b at tuning on the maf but i am having a little difficulty understanding exactly what i am changing when it comes to SD. First of all i did some logs with the maf connected recording 2byteload and boost in KPA. In excel i made one of the columns Load/MAP to get the VE % but what i am having difficulty with is which table i should be tuning first. i assumed it was the SD MAP sensor VE but every time i touch it the car will barely run.

So for Example on average cruising 47load is aound 57Kpa which is 71%VE i have modified my log files to go into evoscans map tracer the way JCSBANKS recomended.
so 71% of 57KPA is 40
so would i put 57 on the left side of one of the bins on the MAP VE table then 40 on the right side(load %)?
and when i have filled the bins with the most common values i hit when driving the bottom being the highest and the top being the lowest i move on to the RPM VE table?

Thank You for the help

 

Bump for an answer

 

In the simplest sense this speed density patch is really about load. Load determines the fuel delievered thus richer or leaner.

Load = KpatoLoadLookup * RPMVE;

In your example for 57 kpa = 40% load then the kpalookup would be 40 but with 90% VE, which i think is where banks set it in the RPM VE table, that load drops to 36.

More or less it seems the best way to tune the car is to play with map vs load table and leave banks rpm VE thing alone. Once you get the car close to the proper loads you want you can determine if the VE needs changing.

Say your car idles perfect 14.7 at 800rpm but goes rich when loaded up say like 80kPa boost. Say you also know that at higher rpms like 3500 the 80kPa boost range is just dandy. This would be indication that the load is ok but the VE is too high on the low rpm range so its thinking there is more load than reality making the car run rich in that spot but perfect in a higher rpm range. To squash the load down you just lower the VE a bit and adjust the map table to idle.

Map tracer is a good way of figuring out what needs to happen. Sorry got a little long winded there.

 

Thanks alot for the help i def understand it better now

 

hmmm nice thread, i am to am new to SD.

basically there are 2 tunable tables for SD.

SD RPM VE & SD MAP Sensor VE and Calibration

from what i read above you keep the RPM VE tables the same no matter what mods (different turbo/cams, etc) the car has correct?

and you only really alter the other map. that is, map and load in the same way the OP and Roadspike described?

 

The VE is going to change but its not going to change a terrible amount. The settings banks put in the car should be fine to get you going once your get the map settings to a place where you notice oddities like i described in the post above then you change the VE.

 

i am on SD right now however jscbanks setup the map for the stock turbo so i am pretty spot on.

just really want to understand HOW to tune the 2 maps.

 

Its pretty simple i suggest using map tracer to see the averages your car produces for AFR by external and I made myself a custom afr deviation mapping item to show me a percentage of the AFR vs AFRMap.

Basically you look at the map trace from side to side to see how your VE settings are working and from top to bottom how the map settings are doing. Obviously the two blend into each other a little bit so you have to get a feeling as to what is being more effective for treating the situation.

Right now i'm looking at a rich point at 50 load which is across all the rpm's so it seems that my map kpa for 50 load needs to go up. Likewise I noticed that the distrubution of the ranges side to side was broader on the lower rpm's meaning the VE in the lower range needed to be brought down.

Hope thats making sense.

 

thanks i will need to study this post.... and take some time....

my AFRs are exactly whats on my gauge. before my load was high and i suspected a boost leak. realised my stock BOW was leaking @ 10 psi

 

Ah with speed density leaks wont effect AFR but they will effect performance. I do sugguest while tuning to turn off the closed loop portion of the ecu with the periphery bits forcing the car to use the tune instead of correcting it with an o2 sensor.

 

will do thanks...