6.7L Compound Turbo Tuning - Need Advise/Help
2017 Ram 2500 6.7L G56 with s475 over Stock VGT Turbo.
It seems ive given myself the hardest thing to tune and need some help dialing it in.
Problems:
- Getting boost before 2100 RPM
- Injector/Fuel/Timing noise
- VGT creating backpressure? (Sounds like its sucking hard through a straw)
I got Tired of the box tuners so took it into my own hands. So far its the best my truck has driven but somethings are really getting on my nerves. 0-200 SOFT CCV Tune. I cannot get boost unless its 2K plus with significant throttle when it lights...it LIGHTS. I bumped my 50% TPS TQ Call along with 100% to help get this G56 moving and shifting better and it feels fantastic. I opened the vanes sooner for the compounds and it helps with the s475 but sometimes its a sucking air sound and not a turbo whistle. South bend DD Clutch has been quieter with other tuning while driving but not as quiet as I have it at idle. Taking off it sounds like a cummins and doesnt sound like its got 2 turbos until well into the 2k zone. i do have a larger intercooler, boost tubes, 4" intake horn. if i rev it in N itll hit about 2,300rpm choke out and puff black then white or hold 1st or 2nd too long itll choke/burp and you can see white. Arp 625s were installed with the compound system.
Things Ive Tried:
- Scaling MAF | Worked Amazing gave me response down low
- Messed with vane position to reduce suction sound | Works to a point
- Messed with charge reference 2 tables | cant really tell
- Bumped 50% TQ (1500rpm+ to 550) 100% (1500rpm+ to 1600) | Response shoulda came like this from factory
My Questions:
- What "Charge reference" values do i need with this turbo setup.
- Seems like i have a TON of air, (stock fueling except fass165gph) i dont want it to smoke till it lights i already got rid of that mess but the injector noise seems like its trying to dump fuel to get it to spool, do i need to add fuel down lower? truly think im too lean down low but i have no idea where to add it with the g56 i feel things can get dirty quick. ive researched that retarding the timing can get it to spool but advanced will use its power. not sure where that would be needed or if needed with a fuel bump down low.
- are any of the stock values even useful to build off of with a compound setup?
- Can the ecm only see 160 mg of fuel? or is that max for stock injectors
- no idea why itll choke out (vanes open in wrong area or too soon of map? or to much air and then too much fuel too late?)
Any help would be greatly appreciated (logging the truck is difficult with a mvpi3 and a 3rd pedal need a right angle obd2 adapter lol) this second turbo and the vgt with it being a 6.7 has like 0 insite, even ended up in powerstoke and duramax forums and the information isnt the most helpful with the available info. most compound advice seems to be with a 5.9l :banghead:
