oakley6575

iTrader: (5)

Good to know. I will apply the 3 bar OS and change the PIDs in the scanner. Thanks for the help man!

subeone

no problem bro post some videos when youre done

oakley6575

iTrader: (5)

Will do! I applied the 3 bar OS and I'm going through the tune. Isn't there a rule of thumb when setting up a boosted VE? Take the last row of your N/A VE and multiply by X-amount and paste into the 320kpa row?? Then I'll be able to interpolate...

Also since my airflow calcs are off in the stock tune like we discussed, won't my VE be way off when I apply this SD tune? I will have to start from scratch if I am thinking about this correctly

subeone

yep if your original VE tune was off then you will have to start all over, if it was dead on then copy and paste the old VE into the new one and interpolate to the new kpa values! rule of thumb is increase by 6 percent for every 7kpa so lets say u had a 2 bar and now have 3 bar, remainder is 1 bar~14psi approx. every 1 psi*1.06, 6 percent times 14= 84 percent increase when you hit 14psi~300/320 kpa so multiply the last line of the 2 bar by 1.84 and should be fine for the last row the new ve then interpolate!

the 6 percent also changes depending on your engine's pumping efficiency but if you are running alot of boost and pump gas then increase by 8 percent every 7kpa (1psi) and go from there to see if you need less or more fuel. If you are running e85 in this case then you tell the pcm what your ethanol content and should adjust accordingly, or just have a sensor that automatically knows.

oakley6575

iTrader: (5)

Writing a new VE is kinda scary. That is the main reason I wanted to run the 4.8L N/A before putting the turbo on. I wanted to have a good starting VE that would be safe when I added boost. I got the 3 bar tune set up last night and I will write it to the pcm when I get the new MAP hooked up. Thanks again for the help^^

smokeshow

iTrader: (16)

That's a bit extreme for a VE increase... The only things that increase VE are the characteristics by which air flows into the cylinder. Camshafts change that, intake manifolds change that, and with boost, pressure differential across the intake valve changes it. But the increase is very gradual. Remember that VE is just a multiplying coefficient for the sensory inputs for generating an airflow model of the engine. Extra air mass due to boost is accounted for in the speed density equation using the MAP sensor. The VE just multiplies the result to modify the output of the equation to ensure the delivered fuel matches the actual airflow of the engine.

oakley6575

iTrader: (5)

Can somebody upload a screenshot of there 3 bar VE? Just so I can get an idea of the values you guys are seeing in your set ups. With the current VE I'm running N/A, my VE has some crazy high values in the boosted regions in the 3 bar tune.

subeone

its better to be rich than lean, so if theres too much fuel then he just removes, if he were to increase by say 3 percent per psi then he could be lean and risk engine damage and i dont think he is using the dyno to just gun it and stare at the laptop. Either way, everything you stated is complete fact so can't argue with that each setup reacts different to pressure difference

oakley6575

iTrader: (5)

HPTuners recommends multiplying the last row of a 2 bar VE by 1.25 instead of 1.86 like mentioned earlier... Is it kind of a guessing game until you actually start tuning?

subeone

It is completely a guessing game. You have to get on it then let off when the engine leans up if it doesnt lean up then you can do a complete wot sweep. So thats why I recommend u multiply by such numbers, I dont want to risk to increase 25 percent after 1 bar increase of boost. If you have too much fuel the engine will just misfire and if u dnt have enough fuel under boost then you could see problems. So its better to over shoot the fuel than undershoot. 1.86 is alot but I dont know ur experience so its better for ur engine to misfire than lean out but if need be try .04 increase per psi. Would lead to 1.56 at the 320 kpa row. Just keep an eye on the wideband