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Some question about cts v e67 ecm. Hptuners

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Been using hptuners platform for awhile. But this 2011 cts v was the first 4th gen platform I've gotten to mess with. We converted it to flex fuel. But something I've noticed if I dial in the maf on pump gas then go to e85 ours is usualy around e70 to e85 range. The car will be lean. Stock stoich table from gm that would be flex fuel. I'll command the same eq ratio in pe while tuning. So there no difference when blending the pe tables between e85 and 93. Is it normal to have to skew the stoich table some to make things match better. As of now I can command 11.6 on pump but have to fudge the pe table for alcohol to get my goal without messing with the maf cal which is correct on pump. The car has a dsx tuning flex fuel sensor. Setup on car has been running couple years but I'm retuning it now from some more mods and would like to make it better and the numbers match better. I hate fudging PE Table or stoich tables if there is a proper way to achieve a good tune.

Also how do we adjust the fuel change it makes according to air temp it doesnt seem to be aggressive enough and when it gets cold it leans up some. The weather we have now can be 70 degrees f one day and 40 degress f the next.

Cars mods are 2.45 upper pulley, 2 inch headers full 3 inch dual exhaust and x pipe. Id1000s with there injector data. Airaid intake with green filter.

Any help would be appreciated. I can post a tune later but as of now I'm at work and dont have my computer with me.

Hi Joseph, please post up your calibration when you get the chance and I'd be happy to take a look. One of the problems with flex fuel is that the actual injector flow varies slightly between pump gas and E85 due to the viscosity of the two fuels and this isn't something that GM seem to address within the calibration. What sort of variation are you seeing in your trims? What is your commanded 11.6:1 actually giving you?

I attached the current tune file. at this point the maf curve is pretty off. he added a way better flowing filter to the car and it seems to have leaned the car up in pe. and I haven't had time to look at the car. I have decided to start over with it. we always had a problem with it not wanting to rev from idle it would just bog/stumble if you tried to hit gas fast from idle not exactly to wot just quick small pop of the throttle would do it. this realy all started after the id1000 install. but ive checked the injector data multiple times. so I think the injector spray pattern must be different than the stock ones so the transient modeling must be off. if you look at the tune I posted the eq ratio in alcohol is super high and that's to achieve around 11.6 but like I said he added a better filter and it got worse so I didn't have time to tune it yet so I told him I could make a quick a change so it would be safe. so I did. but before this it would normaly be fine on pump gas which is what I tuned it on. then on e85 I always had to ask for roughly 1 point richer to get it to the same 11.6 I had on pump. then to add to it if it gets cold outside it leans up another half point. I have read where people use iat modifier in the injector characteristics to help with the temp changing the fuel. we are going to start over and tune the maf and also actually tune the vve this time instead of maf only to hopefully help with the transient tuning. any tips or things you see in the tune that you think is incorrect though please tell.

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