Author Topic: Full Delkevic exhaust, no cats, and Dynojet Autotune  (Read 409 times)

Offline jwolffie

  • Jr. Member
  • **
  • Posts: 91
  • Country: us
Full Delkevic exhaust, no cats, and Dynojet Autotune
« on: June 27, 2020, 01:35:29 pm »
If anyone is using a Dynojet PC5 and an Auotune let me know what you think
I upgraded my Delkevic 18 inch slip on to a full Delkevic system and added a Power Commander V with a Autotune module. I am running the stock air filter and I have a Guhl reflash that I got when I added the muffler a couple of years ago. I run it with the baffle out.
I decided to use the Autotune instead of having it set up on a dyno, so far it seems to have a lot more throttle response and more power from 2500 RPM and up. It lost a little power off idle but not enough to matter. I wasn't sure after reading the instructions if this made it work like a closed loop system instead of the open loop system we all have so I asked Dynojet tech support and here is the reply
"Hello Jon, anytime the AT is running, it is creating trims in the TRIM table(s).  These are created and used in real time until you retrieve the map and either clear or apply them.  The AT has a limit of + or - 20% that it can adjust by default.  If you hit this limit in a cell, it cannot make any more changes in that cell until the trims are cleared or applied, otherwise it will run and adjust all the time."
So, yes it works like a closed loop system.  :) I am not going to accept any suggested changes from the Autotune system and just let it decide what is best for the current days condition.
I decided to load a map that makes zero changes to the trim tables and a Air/Fuel map from a full Muzzy dual system as that was the closest one I had. I have tested it for a week now and I checked the suggested Autotune trim table and it isn't making any huge adjustments. I accepted the trim values and saved the map just for reference and loaded a new map that is still a zero trim map but with slightly adjusted A/F tables. I leaned it out just a little in my low throttle cruise range for gas mileage and richened it up in the top end high RPM and load range for power. I am going to try this this week and see where the trims are. I also upped the trim range to +/- 25% because I am running it as a closed loop system. Most cars can adjust 25% short term plus 25% long term trim for a total of 50% so I don't see a problem there. My gas mileage this week was about 3 MPG better than before the changes so so far so good. 
« Last Edit: June 27, 2020, 11:17:12 pm by jwolffie »
Black 2011

Offline maxtog

  • Elite Member
  • ******
  • Posts: 8345
  • Country: us
  • 2011 Silver
Re: Full Delkevic exhaust, no cats, and Dynojet Autotune
« Reply #1 on: June 27, 2020, 08:59:11 pm »
I wasn't sure after reading the instructions if this made it work like a closed loop system instead of the open loop system we all have so I asked Dynojet tech support and here is the reply [...]So, yes it works like a closed loop system.

Does it?  Did you install an oxygen sensor?  My understanding is that a "closed loop" is one in which the computer can directly detect the output/results of its initial mix and adjust accordingly, which requires an O2 sensor.  Perhaps my understanding is incorrect.
Shoodaben (was Guhl) Mountain Runner ECU flash, Canyon Cages front/rear, Helibars risers, Phil's wedges, Grip Puppies, Sargent World seat-low & heated & pod, Muzzy lowering links, Soupy's stand, Nautilus air horn, Admore lightbar, Ronnie's highway pegs, front running lights, all LED, helmet locks, RAM Xgrip, Sena SMH10, Throttle Tamer, MRA X-Creen, BearingUp Shifter, PR4-GT, Scorpion EXO-T1200,etc

Offline jwolffie

  • Jr. Member
  • **
  • Posts: 91
  • Country: us
Re: Full Delkevic exhaust, no cats, and Dynojet Autotune
« Reply #2 on: June 27, 2020, 11:19:55 pm »
Yes, It uses a wide band Oxygen sensor installed in the primary pipe to make it a closed loop system. It seems to be working because in cold air it is using more fuel with the denser air according to my instant MPG display. It sounds better too without the cats and there is less lag on freeway acceleration.
Black 2011

Offline maxtog

  • Elite Member
  • ******
  • Posts: 8345
  • Country: us
  • 2011 Silver
Re: Full Delkevic exhaust, no cats, and Dynojet Autotune
« Reply #3 on: June 28, 2020, 06:10:03 am »
 :finger_fing11:
Shoodaben (was Guhl) Mountain Runner ECU flash, Canyon Cages front/rear, Helibars risers, Phil's wedges, Grip Puppies, Sargent World seat-low & heated & pod, Muzzy lowering links, Soupy's stand, Nautilus air horn, Admore lightbar, Ronnie's highway pegs, front running lights, all LED, helmet locks, RAM Xgrip, Sena SMH10, Throttle Tamer, MRA X-Creen, BearingUp Shifter, PR4-GT, Scorpion EXO-T1200,etc