Boost Compensation tuning explained (again) MicroSecBit too!

[Gordo]

My Microsec/bit is about 75 and looking at raw, my peak #s are like 50

I am using a hybrid map (Boost comp above 0psi and regular in vac areas).

I would like to adjust to about 30ms/bit which would give me pretty close to 100-200 raw values.

Question is, I have already tuned my car for 19psi (11-11.5afr) but I would like more finer adjustment for vac areas for regular driving.

Any harm in doing this portion below, to adjust my ms/bit?

So, before yuo go playing with that number realize it will have BIG impacts on your fueling. Here's how you change it "safely". Open the fuel map, right click, View Duty Cycle. Highlight the ENTIRE map, right click, Copy to clipboard. Now modify MSecBit up or down and then Paste the fuel mapping back while still looking at Duty Cycle. Right Click, View RAW. Any numbers over 255? IF yes then MSecBit is too small, switch back to Duty Cycle view, make it bigger, Paste the previously saved table, and check the RAW view again until the numbers are big but not huge. Note that if you use Boost Comp as explained above you'll also gain granularity. Doen CORRECTLY fueling shouldn't change much and the car shouldn't need too much retuning when you now upload this mapping to the ECU.

[SB]

Try right-clicking the fuel map and selecting "Rescale Fuel Map" from the dropdown menu. This will rescale the microsec/bit and fuel map for you.

[Gordo]

As I asked earlier, will I have to retune my fuel map if I went ahead and lowered the MicrosecBit (using the method mentioned by copying original fuel map and pasting it again)?

[SB]

Gordo, the procedure you referenced should work, but I believe that procedure was written before the "rescale fuel map" function existed. What you are doing is manually rescaling the fuel map.

Either way, the Crank Injector Time table uses MicroSec/bit but will not be changed when you rescale the fuel map (whether you do it manually or let AEMPro do it for you), so you should calculate the fuel pulse resulting from the old Crank Injector Time table  (for instance, if you have 100 in the crank injector time table and microsec/bit is 50, you're injecting 50*100 = 5000 microsec  = 5.0 ms of fuel when cranking).  To find the new values for the Crank Injector Time table,  multiply the old crank injector time by the ratio of the old microsecbit  / new microsecbit.   For instance, if you decrease the microsec bit down to 25,   you will need (100 * 50 / 25  =  200)  in the Crank Injector Time table to get the same 5000 microsec  of fuel when cranking.

  By the way, you won't need to worry about MicrosecBit and Raw values in the future, because AEMTuner will dynamically check to see if the fuel map needs to be rescaled and then do it for you.

[tonster]

What values are supposed to be the same vertically? Injector Pulse Width, Raw, or Duty-cycle? I can only get my raw numbers to be the same vertically.

[Jared]

What values are supposed to be the same vertically? Injector Pulse Width, Raw, or Duty-cycle? I can only get my raw numbers to be the same vertically.

pw

[tonster]

How are you getting them to be the same vertically then? I am using the set value function and it does not change the values to what I am desiring.

[tonster]

Ok, I have my boost fuel correction table setup. I am still having trouble getting the pulsewidth the same vertically? Should I go out and retune the car with the boost fuel correction table setup at the lowest load? With this allow a change in the raw values so I will be able to scale my columns to be the same (pulsewidth) for each rpm breakpoint?

[angelauto]

Wow, I definatly read the entire first post and rescaled my map(after reading the first page of the thread about 20 times over to understand it) then did it all manually just to read(and remembered) that there is a rescale function. Oh well.

[Vantta]

i've found how to change microbit sec. But my only doubt is: CT1=orignal number in the crank time table, that number is Crank advance (in degree) Found in engine start menu?¿? is the number that i need to change? i'm not sure about. Help please

Copy/paste from the first page of this post:

when you change microbit/sec you will also have to modify the crank time table ( the main table in the startup template).  i devised this forumula to correctly change that table.  we will assume the crank time table is all set to one number

CT1=orignal number in the crank time table
MBS1= orignal micro bit/sec
MBS2= new microbit/sec
CT2= new value for the crank time table

(CT1*MBS1)/(MBS2)=CT2

changin microbit sec will also get you alot more resolution for cranking so you can dial that in better.


Thanks!

[dsm_gsx97]

i've found how to change microbit sec. But my only doubt is: CT1=orignal number in the crank time table, that number is Crank advance (in degree) Found in engine start menu?¿? is the number that i need to change? i'm not sure about. Help please

In AEMPro....The crank injector time table is among a few of the tables that pop up when you click on the startup options button. Or you can click on the Startup drop down and select it from there also.

Your crank advance and crank injector time table are 2 very different things but both are in the startup menu so try not to confuse them. You're looking for the crank injector time table with that calculation you posted up since it is not modified in AEMPro when you change your microbit and you need to change it to match.

Hope that points you in the right direction. You want some fun with the whole microbit changing experience plug your cal file into AEMTuner and then change your microbit and watch your crank injector time table transform automagically for you. It might help you grasp everything going on to see it happen in AEMTuner. Try it in AEMPro though first before confusing yourself with AEMTuner and its optimization skills.

[Vantta]

i've found how to change microbit sec. But my only doubt is: CT1=orignal number in the crank time table, that number is Crank advance (in degree) Found in engine start menu?¿? is the number that i need to change? i'm not sure about. Help please

Great Dsm_Gsx97!! finally i've found what i was looking for

The crank injector time table goes from 0% to 84% with RAW 20, from more than 84% to 96% RAW is 0.

The value that i'll get with the calculation must be written from 0 to 84% only? do i've to change something from 84% to 96%?¿

Thanks!

PD: I wish to everybody Happy New Year

In AEMPro....The crank injector time table is among a few of the tables that pop up when you click on the startup options button. Or you can click on the Startup drop down and select it from there also.

Your crank advance and crank injector time table are 2 very different things but both are in the startup menu so try not to confuse them. You're looking for the crank injector time table with that calculation you posted up since it is not modified in AEMPro when you change your microbit and you need to change it to match.

Hope that points you in the right direction. You want some fun with the whole microbit changing experience plug your cal file into AEMTuner and then change your microbit and watch your crank injector time table transform automagically for you. It might help you grasp everything going on to see it happen in AEMTuner. Try it in AEMPro though first before confusing yourself with AEMTuner and its optimization skills.

[dsm_gsx97]

Great Dsm_Gsx97!! finally i've found what i was looking for

The crank injector time table goes from 0% to 84% with RAW 20, from more than 84% to 96% RAW is 0.

The value that i'll get with the calculation must be written from 0 to 84% only? do i've to change something from 84% to 96%?¿

Thanks!

PD: I wish to everybody Happy New Year

So you'll still want to be reading from AEMPro user manual to explain some of this stuff for you. Each section explains the tables and how you use them. I'd start reading at the startup section that starts on page 72 of the manual to get a better understanding of the tables you are using and why you'd use them and then move on to the idle section to get a heads up of what is going to go on with that procedure. Here is a copy and paste from the startup section that answers why crank injector time table is only to 84%

Crank Injector Time table
Units: Fuel vs Throttle %
Description: Fuel (bit value x MicroSec/bit) injected upon cam/crank sensor synchronization when in the crank condition. If the engine cranks excessively and throttle input does not help, this typically means there is not enough fuel. Note: It is a good idea to take out fuel at high throttle conditions to clear extra fuel in the event the engine becomes flooded.

[Vantta]

Great Dsm_Gsx97!! finally i've found what i was looking for

The crank injector time table goes from 0% to 84% with RAW 20, from more than 84% to 96% RAW is 0.

The value that i'll get with the calculation must be written from 0 to 84% only? do i've to change something from 84% to 96%?¿

Thanks!

PD: I wish to everybody Happy New Year

So you'll still want to be reading from AEMPro user manual to explain some of this stuff for you. Each section explains the tables and how you use them. I'd start reading at the startup section that starts on page 72 of the manual to get a better understanding of the tables you are using and why you'd use them and then move on to the idle section to get a heads up of what is going to go on with that procedure. Here is a copy and paste from the startup section that answers why crank injector time table is only to 84%

Crank Injector Time table
Units: Fuel vs Throttle %
Description: Fuel (bit value x MicroSec/bit) injected upon cam/crank sensor synchronization when in the crank condition. If the engine cranks excessively and throttle input does not help, this typically means there is not enough fuel. Note: It is a good idea to take out fuel at high throttle conditions to clear extra fuel in the event the engine becomes flooded.

Sorry, i had not seen that part. I'm trying to understand what is everything, before making any change. I've readed so many parts of the manual. I'll read it entire before asking again

So, during crank (table which enters when angine revs over 50 rpm and exits when engine revs over 500rpm), theres a fixed amount of fuel, and depending of the temp conditions, some fuel could be added.

But if i step to full throttle, no fuel is injected?

Now i've understood, thanks

[more-revs]

When using boost comp, does it matter if i manipulated the psi break points @ higher loads vs. letting the aem divide the load break points evenly?

the boost fuel correct table reflects my load spacing, but it equally interpolates between the end points, while my load range is not equally spaced....

maybe i need to allow for equal spacing when constructing a boost comp cal file?