View Single Post
Divani-Kingston's Avatar
Divani-Kingston Divani-Kingston is offline
New Member
Posts: 8
Join Date: Jan 2020
Car: 2017 Volvo S90 T6 Inscription
Default 05-05-2020, 06:29 PM


Having gathered an understanding of this JB4 unit, I'm fairly confident in the growth of this platform as a stout tuning option. Thank you so much @Payam and @Terry!

The E85 virtual sensor is a little finicky, but it works well enough. On one particularly hard run, I know I had a 40.5% Ethanol content with what I'm calling the "Borealis" tune (Map#6 tapering the low end and high end with a max of +6--subject to change with farther exploration of Tubo limits and viability for a higher end coded map) but it jumped from 4-6 (number as a reading) depending on the log.

On lesser runs, it showed content from 45-55 (number as a reading). It's all good. I like that it exists and it is definitely welcome... The car has auto-tuned for the increase in Ethanol Content after driving for a few miles. I have switched back to 93 octane and it's running a bit rich, but it's trending down again (Trims leaning) to help revert.

So, for right now, I know the car can learn that it's running on a higher concentration of Ethanol and make changes. I haven't tried a full tank of E85, yet, but I'll work up to that after I get a reading of the car's output on the current maps.

Seems like the turbocharger is plenty happy dancing around the 25-28psi range, and in "Polestar" mode, the factory DME likes to request 23-25psi at WOT with 93. IATs are regularly close to ambient temperature (Within 8 degrees) after spirited jaunts.

There are some weird dips in timing at certain RPM, but after doing some research, that's hardcoded into the DME between the Switchpoints of the Supercharger and turbocharger (The Supercharger decouples after the turbo takes over, and they tuned in a drop of ignition when it comes on and when the turbo comes in) It's not noticeable in the power delivery and it's only a few degrees of retard.

The stock DME tends to cut throttle pretty regularly, in comparison to the N54, so I'm not freaking out about it snapping the blade closed to control Boost Pressure.

Anyway, I just wanted to update everyone in case they're waiting for this product.
Reply With Quote