Configuring airflow for dual Hellcat throttle bodies

Ladies and gentlemen,
I'd love some feedback on figuring out how best to set the tables for my throttle setup. This is a 2006 Chrysler 300c SRT8 using the original PCM.
Engine is a 6.1 based 398ci with a 248/[email protected] cam and a 6-71 Supercharger.
Current throttle body setup:

• 2 x OEM Hellcat throttle bodies
• Primary TB runs drive by wire
• Secondary TB coverted to manual
• TB1 connects to TB2 via progressive, mechanical linkage
• Secondary begins opening around 1/4 throttle
• both reach WOT at the same time

My first attempt takes the airflow numbers out of the ETC Throttle Body Airflow table from a stock Hellcat tune.
Using these numbers, I built a new table combining the airflow of both with respect to the proportional opening of the secondary. (see attached pic)

Now, I'd love some opinions about using this info. Should I throw these numbers into my table as is? Do these numbers need to be raised to tame the throttle response? (very touchy with the blower)
How does this table relate to the Small and Large Desired Throttle Range tables?
Do I even bother with these tables and just tweak the Torque/Airflow Factor table?

So much great info on here, but I just can't put it together to make sense of this.
Thanks to all.

Attachment 87762

For those not familiar with the setup. Here's a picture of it and a video showing its operation.

Attachment 87776 https://youtu.be/qynyDH0_YAs

While the one throttle only is activating it should be able to use the airflow from a stock hellcat tune. Then airflow would increase sharply as the 2nd throttle comes in. But in reading some other threads on here about airflow tuning, it seems like part throttle airflow tables are not necessarily what they seem.

Personally I?d start with your stock airflow tables and then go by feel. Things should change sharply as the 2nd throttle starts to open so you will probably need to calm that down.

Quote:

---

Originally Posted by spoolboy

While the one throttle only is activating it should be able to use the airflow from a stock hellcat tune. Then airflow would increase sharply as the 2nd throttle comes in. But in reading some other threads on here about airflow tuning, it seems like part throttle airflow tables are not necessarily what they seem.

Personally I?d start with your stock airflow tables and then go by feel. Things should change sharply as the 2nd throttle starts to open so you will probably need to calm that down.

---

That was my thinking as well.
I did screw up the chart I attached to the first post. I mixed data between g/s and lb/hr...DUH!!!
So, here's a new chart with the correct data, all in lb/h, showing the OEM Hellcat Airflow data, the interpolated airflow over my voltage range (one less breakpoint), and Small/Large Desired Throttle Range.

The main problem I see is that the Hellcat numbers max out the airflow to 13,003 lb/h at 3.80v and the Max Airflow Limit is 12,699 lb/h of a maximum 13,003.
So, when I add the airflow of two of these throttle bodies, you can see the calculated airflow hits that limit at 3.40v. My formulas default to the Max Airflow Limit if it goes over the set limit.

Attachment 87791

A little update after doing the drive/log/flash/repeat process a bunch of times.
What seems to be working is ramping up the Throttle Airflow tables right of off idle. This seems to reduce the "light switch" effect to more manageable levels. I'll attache a screen shot and file.
I have a lot of tweaking "to taste" in how the throttle responds.

I'd be great if anyone can offer some insight as to how to handle the desired small and large range tables.
My comprehension of how these relate is a tad fuzzy still. Usually, they're just an inverse of the main TB Airflow table. But I'm not sure if it's better to expand the breakpoints of the Mass Airflow (max 501 lb/hr on small range) or just interpolate the voltages.

I'm happy to hear any insights.

Attachment 88455

Attachment 88456

Rule of thumb is bigger numbers make the throttle open slower, as you are telling the ecu you have a bigger throttle body so to achieve the same airflow you need less throttle opening. Looking good.

Personally I always just match the small and large table to points on the larger TB table.

With the 92mm Hellcat TB on my 6.4L, I've found success by using stock Hellcat values for the TB Airflow Model.

I then tweak the small and large tables for what I need. Using idle for example, smaller values in the small/large table closes the TB, and vice versa with larger numbers.

I had all kinds of problems trying to trick the system with small values, etc.

It actually makes sense that the car has a known model and you request more or less airflow from that model using the large and small tables. I may be completely wrong, but it does work for me.