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pointers for starting an e30 tune

PostPosted: September 27th, 2018, 4:14 pm
by Bigmike7645
I'm working with a gen 2, fully bolted with a cs turbo and a 2 stage progressive meth injection setup. I've got a nice pump gas tune right now. I want to start playing with ethanol blends. Besides setting specific gravity and setting all the afr target tables accordingly, does anything else need to be changed in the fueling of the ecu? I realize I'll be maxing out the injectors more quickly and need to be more aggressive with my meth injection to compensate. Does the maf table need to be manipulated or are setting the afr targets good enough? Thanks in advance!

Re: pointers for starting an e30 tune

PostPosted: October 4th, 2018, 9:12 am
by mituc
The MAF calibration will definitely have to be adjusted, just like you did with meth.
As for the AFRs, all the tables in versatuner are in lambda so that's fine. You may only want to tackle the AFRs so that they will work better with E30.

I think besides adjusting the fuel specific gravity, the MAF calibration and the timing tables you don't need to do much. You will eventually figure out the load targets based on the combined capabilities of the fuelling systems you now have on the car.

Re: pointers for starting an e30 tune

PostPosted: August 26th, 2019, 5:47 am
by campeck
I'm trying to wrap my head around why he would need to tweak his maf cal? If his maf cal is good already wouldn't he only need to change the requested AFR to account for the stoich diff with e30? Why mess with the maf cal if no changes to the intake path are being made?

Thanks,
Campeck

Re: pointers for starting an e30 tune

PostPosted: August 30th, 2019, 8:37 am
by mituc
campeck wrote:Why mess with the maf cal if no changes to the intake path are being made?


Because ethanol is a more oxygenated fuel, so it's like you're using pump gas but drawing more air in.
You can leave the MAF cal in place and leave the fuel trims adjustments on in the higher load areas, but your car may run like shit when the fuel trims go around 15% or above.

I also suggest you go with a reputable e-tuner which knows about this stuff.

Re: pointers for starting an e30 tune

PostPosted: October 3rd, 2019, 8:16 pm
by Enki
The FSG changes in the tune should account for this. If they don't, what's the point of even having them?

Re: pointers for starting an e30 tune

PostPosted: October 4th, 2019, 3:25 am
by mituc
Enki wrote:The FSG changes in the tune should account for this. If they don't, what's the point of even having them?


Fuel density params have more to do with the injection timing because they help computing the mass of fuel that has to be injected. So they can indirectly affect MAF, therefore unless you adjust the actual MAF curve the ECU logic will work using the fuel trims to compensate, at least in closed loop.