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+--- Thread: Turbo Table Settings (/showthread.php?tid=4094)
Turbo Table Settings - Lonestar10 - 02-03-2019
So finally checked my intake manifold air out of the port by the IMAP on CM871. my OEM boost gauge is sitting below 0 on the gauge basicaly on the peg. but when pulled the plug i get enough air to probably float a few peices of paper stacked ontop of eachother instead of just a flutter. my min table is 54% in the idle area and max is 59% in the idle area of 0-1000rpm and 0-75 fueling tables.
if ive understood correctly i should be looking for a flutter instead of a jet of air.
when i get to a flutter point do i need to adjust anything above the 0-1000rpm and 0-75 fueling or leave them be? and do i need to adjust both tables or just the one that makes the turbo open up more.
thanks for an input1
RE: Turbo Table Settings - Lonestar10 - 02-03-2019
Turbo Table
For some reason i can change the numbers and the computer recognizes it and changes the VGT cmd to them and i was about to get down to a low amount of air coming out of the port with a puff feeling to it but the computer wont hold the cal when i shut down the truck and edit the table to the settings every time i reload CT it comes back with these settings not my changed ones.
RE: Turbo Table Settings - ynot - 02-03-2019
Sounds like your doing some live editing, ya the ecm won't save those changes they have too be downloaded. Live editing is awesome for trying different things while rolling down the road the it resets on key of an you can try something else.
Now about your turbo question the goal is too get positive pressure so the turbo is pushing air vs the motor sucking air from the turbo which depending on the turbo also suck oil from the turbo into the intake.
I haven't messed with an 871 in awhile so I may not be a 100% on my numbers.
Setting the min max tables is as much personal preference as it is function, me personally in the idle range 0-30mg I'd keep it in the 15-18% cause I hate that annoying whistling sound of a pre spoiled vgt, it wouldnt be as responsive on take off as the vgt sitting at 30+% which I know some guys do but again too me it sounded better. So that's personal preference, the function side of it is as I mentioned the more closed the vgt the quicker it'll respond getting you your power quicker an helping with mpg too so you don't have too push the pedal harder too get the turbo lit up.
Think of the min max tables like this the min table is too control your boost curve, what psi's you want at what rpm/fueling. And the max table is too control your limits, your max boost of 40psi for instance, an or boost spikes do you want your boost too spike up quick an drop back down or would you want it too follow your boost curve smoothly through the rpm range.
If your super adventurous you can even ditch those tables an turn em off an control the vgt using the mcf, but that's a different discussion for another time lol
RE: Turbo Table Settings - Lonestar10 - 02-04-2019
ok didnt remember having to download the new settings when i turned load based speed control off. but thats probably the issue as far as pressure ive seen some people say barely moving a peice of paper when i checked it it would have held up up a few peices of paper stacked easy.
RE: Turbo Table Settings - ynot - 02-04-2019
If you live edited the load based speed stuff you might wanna go back an check it, it's probably not saved in the ecm unless you edited a call an downloaded it too the ecm.
I also should have added the more closed the vgt is at idle the more the motor has too work too fight the back pressure burning more fuel then needed. It's great for warming up the motor quicker but at the cost of some fuel.
RE: Turbo Table Settings - Lonestar10 - 02-04-2019
im looking for more open = less air movement at idle. so were good there but the load based crap is off i actualy have power in my lower gears now and it shows off in CT
RE: Turbo Table Settings - Unilevers - 02-04-2019
some toggles can be switched off permanently live. Any tables or alot of other parameters will not stay. You should read the writeup with the MM document as all this is explained thoroughly in there.
RE: Turbo Table Settings - Lonestar10 - 02-04-2019
My bad I've got 2016 version goes into theories and how Todo overlays but don't remember it going into detail about custom settings
RE: Turbo Table Settings - schISM - 02-05-2019
(02-03-2019 )ynot Wrote: If your super adventurous you can even ditch those tables an turn em off an control the vgt using the mcf, but that's a different discussion for another time lol
That’s what I ended up using in my 2350 cal. With the egr ref. tables zeroed out and the MCF tables tweaked at the very bottom in the idle range I was able to get just what I wanted. The 2350 has a command to reference FAF when the egr valve is closed and that did the trick to get boost to a minimum but still adjust for ambient temps. It maxed out at 32-33 psi on hot days but pulled back to 26-27 when it got cold out. It always kept the egts right in the 700-800 range.