shitstang

iTrader: (4)

I posted this on hptuners and got no help (yet again) here are my 2 posts:

Trying to get an e85 tune setup and ran into a problem. The car starts but runs horrible and all my ve error numbers are very positive (tried adjusting in realtime with no change). The stoich is changed to 9.8 but I never changed the settings for the wideband in my input. My question is if I change the numbers to volts/1.067+6.054 will that allow me to use the gas VE error histogram, right now I have it as volts/0.714+9? If not what will allow me to use the VE error histogram? I know tuning in lambda is easier but the wife drives it too and its easier if its in AFR, for her anyway.

I left the transfer function for e85 the same as gas and just changed stoich to 9.8, well after starting the wideband would read 9.8 but at cruising would be mid to high 11s. The car actually runs better in the 11s (probably because I'm trying for 11.6 on a gas scale). My fuel trims are around 25 so I would copy and paste into realtime and the car would run like complete **** so I would undo and it would run (not great but run). It seems like the wideband is reading opposite of what it should and I'm wondering if I need to change the transfer function for the correct trims and I have no idea why the wideband is reading 9.8 because all I changed was stoich.

Brad Campbell

iTrader: (19)

OK. So let me come up to speed with you on this. All you have changed with your tune is the "Stoich AFR" under the general fuel settings in hptuners, and then you filled it with E85? Now you are trying to figure out how to change the transfer function to suit the corresponding stoich afr value of E85?

shitstang

iTrader: (4)

Yes I changed the stoich to 9.8 and added a little to cranking fuel (to help with starting). I left the wideband transfer fuction the same as my gas tune and filled up with E85.

shitstang

iTrader: (4)

The car idles at ~9.8 but cruising its somewhere in the mid 11's ( runs a lot better). If I copy the ve afr error and paste into realtime tuning it runs like complete **** so I undo it and it runs OK (good enough to drive) Im wondering if the ve afr error is wrong because the stoich is 9.8 but the transfer function is setup for gas.

Brad Campbell

iTrader: (19)

I agree. You could set the transfer function up to read lambda, then setup your error based on lambda too. Your gauge can still read gas values but the voltage to the logger will be translated to lambda and compared as lambda... Or as you suggested before modify your transfer function to read E85 values.

shitstang

iTrader: (4)

ok so just changing the transfer function should make wideband read correctly (14.7 stoich) and fix ve afr error? Ive tried setting up the lambda function with multiple function strings and couldnt get it to work so I said F it.

shoemike

iTrader: (25)

There's a couple of spreadsheets posted for WBO2 outputs.

I know of at least one that will build the custom pid based off the Lambda & voltage range.

Brad Campbell

iTrader: (19)

Right. It will now compare e85 values to e85 values instead of E85 to gas and give you massive error. You wouldn't have to change anything with the gauge, and it will still read afr on a gas scale.

shitstang

iTrader: (4)

ok ill try to mess with it tomorrow and see what happens, thanks a bunch