Engine Displacement Question

[vristang]

I just need some confirmation...

The TwEECer manual was a little unclear what to do with engine displacement on stroker engines. The manual gives the impression that displacement changes are to be used as a global correction instead of changing the MAF and Injector settings.

Should the CID be adjusted with a stroker motor, when maf and injector settings are being changed as well?

Thanks
jason

 

[final5-0]

Jason

Some have used size of the motor to tune. That method does in fact make a global change. It is all about the load.

For the most part, Tweecer tuners I have talked to feel it is best to tell the pcm all the actual facts about your combo.

Things like:

actual airflow for maf
actual inj size for slopes, offsets and other inj values
cubic inch motor size
throttle body air flow
idle air flow
etc

In your motor size scalar you are gonna be changing the load for all tables.

You would wanna do this before you start to change each table or work with scaling the load for the entire set of tables.

Grady

 

[vristang]

Thanks for the response Grady.

I would think that telling the computer what is actually there would be better than trying to trick it.

Here is what I have changed tonight.
Function - Changed MAF Transfer to 73mm C&L w/ Green sample tube
Scalar - Changed Inj High/Low Slopes to 30.5/38.5 - (Low Slope = 1.26 * High Slope)
Scalar - Changed CID to 408
Scalar - Changed Idle in Neutral to 850
Scalar - Changed Thermactor Air Control Logic to Disabled
Scalar - Changed EGR System Type to Disabled
Scalar - Changed MAF Voltage Min = 0
Scalar - Changed MAF Voltage Max = 4.999

The maf transfer was included in CalEdit. I may have to order the Green Tube.
(C&L sucks with a tweecer!)

I'll go see if I can find
Idle air flow
and
Throttle body air flow

thanks again
jason

 

[final5-0]

Jason

Don't forget to load in the offsets for your 30's as you now have offsets for 19's.

I can't be of much help with the C&L

Quite a few guys on the Tweecer site use them however

Grady

 

[vristang]

So I found a formula for calculating the TB airflow, but it is based on the Maf at idle airflow. Where do I find the idle maf airflow number?

I held off on doing the injector offsets because the numbers I found that I should use (I think from the Tweecer manual), were significantly different than what was in the file, by an order of magnitude. I later found another source that gave me the same numbers though, so I think it is ok.

I'm not too worried about the C&L right now; I probably even have the right tube (green) sitting in the garage already.

Thanks for the advice Grady!

 

[final5-0]

So I found a formula for calculating the TB airflow, but it is based on the Maf at idle airflow. Where do I find the idle maf airflow number?

I held off on doing the injector offsets because the numbers I found that I should use (I think from the Tweecer manual), were significantly different than what was in the file, by an order of magnitude. I later found another source that gave me the same numbers though, so I think it is ok.

I'm not too worried about the C&L right now; I probably even have the right tube (green) sitting in the garage already.

Thanks for the advice Grady!

I gotta go in a min or two but

Here are a couple of sources

EEC Analyzer
and
http://eectuning.org/forums/viewforum.php?f=2

Be sure you stay with CBAZA as I think Fox stuff does not work correctly for us in this case.

Grady