RussK log lower than expected?
RussK log lower than expected? I am working on my poor idling Trans Am. I logged the Idle Desired Airflow vs. Engine Coolant Temp. My tuner did not touch the stock values. After I got my car back from the tuner I put in values around 10g/s at operating temp because it seemed typical and it worked much better than the stock values.
I logged this morning and ended up with the following:
°F ------g/s
-40
-4
32
68------13.3
104 ----8.9
140-----6.9
176-----6.0
212-----5.6
248
284
This looks low to me. Everything is set up for g/s. I am sure I am doing something stupid.
Why is this about half of what I would expect?
My setup is in my signature.
I logged this morning and ended up with the following:
°F ------g/s
-40
-4
32
68------13.3
104 ----8.9
140-----6.9
176-----6.0
212-----5.6
248
284
This looks low to me. Everything is set up for g/s. I am sure I am doing something stupid.
Why is this about half of what I would expect?
My setup is in my signature.
Last edited by NH_Z06; Aug 20, 2018 at 11:25 AM. Reason: Clarified values in log
I am working on my poor idling Trans Am. I logged the Idle Desired Airflow vs. Engine Coolant Temp. My tuner did not touch the stock values. After I got my car back from the tuner I put in values around 10g/s at operating temp because it seemed typical and it worked much better than the stock values.
I logged this morning and ended up with the following:
°F ------g/s
-40
-4
32
68------13.3
104 ----8.9
140-----6.9
176-----6.0
212-----5.6
248
284
This looks low to me. Everything is set up for g/s. I am sure I am doing something stupid.
Why is this about half of what I would expect?
My setup is in my signature.
I logged this morning and ended up with the following:
°F ------g/s
-40
-4
32
68------13.3
104 ----8.9
140-----6.9
176-----6.0
212-----5.6
248
284
This looks low to me. Everything is set up for g/s. I am sure I am doing something stupid.
Why is this about half of what I would expect?
My setup is in my signature.
I have since learned (three years later) if your IAC effective area table results in commanded airflows that are very different from actual airflows, then you're spinning your wheels. First, look at your desired airflow and your dynamic airflow at idle. If desired air and dynamic air are within 1-2 g/s of each other, run with it. If the two are way off from each other, Don't use the RussK values. Use the dynamic airflow values instead so you don't stall.
Should my IAC area table be off since I have a stock TB? The TB is ported, but I guess that would have little effect.
I will compare Idle and Dynamic air and see what I get.
Thanks for the reply. I have learned a lot from reading your posts.
I will compare Idle and Dynamic air and see what I get.
Thanks for the reply. I have learned a lot from reading your posts.
Porting it will affect it a little. What affects it more than porting is rezeroing the blade or drilling a bigger hole. If you drill out that hole to, say 3/16", you are now flowing more air with the IAC fully closed than factory. The ECU won't know this unless you touch the table. If you are at, say 0.55 volts at idle, and your IAC counts are high, so you open the set screw to, say 0.67 volts to get your coutns down, and then rezero the TPS, then you are flowing more air with the IAC fully closed than factory. And again, the ECU won't know unless you touch the table. Easy thing to do to rough it in is 16 steps is *about* 1-g/s. So if you're off by 2- g/s, you can subtract the entire table by 32 and be closer. Sometimes, guys will also move the table 5 cells to the right. 10 cells if it's a 102 throttle. Those are just starting points though.
The fun part is trying to actually calibrate the table. You cannot log the effective area directly, so you can't set up a histogram int he scanner to copy and paste. You have to do it indirectly in Excel, which is a PITA and is a manual process. DBW guys are missing out...
But since your values are way too low to be useful, use your dynamic airflow numbers instead of your desired airflow numbers. Even if the idle hangs, it won't stall.
