Flashed my 2016 A8 on E85 for some easy power. Car is bone stock with 7k miles.

 

I’m assuming a zo6 right? Great numbers....but have a hard time believing a gain of 85 rwhp by adding e85? Myself and others usually see a gain of maybe 30rwhp?

 

yes bone stock. Z06

 

 

Thats a nice clean gain all the way around! I would have guessed about 60. I wished I could run full E85 but I probalby could if I turned down the boost. Mixing is a hassle at the pump sometimes.

 

Hmm... I know nothing about this, but am interested, what did you do here? Did you flash yourself, or take it somewhere, what did you / they use?

 

HP tuners, my cousin has a shop with a dyno jet. we did it after hrs

 

You're just seeing peak numbers at like 2700. That little jump. It's more like 40-60 across the RPM range.

 

Thats a great gain. I just did E85 on my stock 2016 C7 (not Z06) and it made 434. However I went from a stock 93 octane pass of 12.06@116 to an E85 pass last weekend of 11.58@121 so no matter what you put it on if you have the fuel system its going to make great power. The temp and DA were higher Saturday then they were a few weeks back and it was on the same track. Just 3 weeks apart. Congrats on the new found power. I was on E72 on my passes. What was your total Alky content on Hp Tuners log?

 

Oppps just looked a little closer and saw E75.

 

I run E-85. I like it, on a dynojet my Z made 60+ MORE RWHP on E-70 than on 91 octane E-10. Around here the pump E-85 varies from about E-60 in the Winter to about E-75 in summer. I also run a flex-fuel sensor and because of that, I can run flex fuel, from 0% ethanol to 100% ethanol. I don't see how a stock Z can run this fuel with it's extremely variable amount of Ethanol without tuning. Your tune needs to accomodate the different percentages of E. If not, your air to fuel ratio will vary with the variance in fuel while in open loop or PE. The more ethanol in the fuel the leaner your tune will be. The PE ratio will change from the GM desired 12.4:1 to as high as 15:1. It wll also vary each time you fill up with an unknown percentage of E. Yes, when the engine goes into COT it goes VERY rich, but my engine doesn't go immediatly into COT when I go WOT. I'll bet your's doesn't either.

How is this good for your engine?

Without a flex-fuel sensor you will either live with these undesireable changes to your basic tune, or you have to laboriously mix your fuel, adding premium or E-85 till you get the mix you desire, AND you have to have a means to measure the % of E in the tank AND you have to keep in mind there are two tanks which have to mix completely to measure the % correctly. I just don't see this as a viable means of adding horsepower safely.

Please show me how I'm wrong.

 

I wouldn't run it without a sensor.

 

Lord no...The sensor is the center point of flexfuel and it protects you if you get like e50 for example in the winter when alcohol contents tend to be lower. Having the flex fuel sensor will tell the ecu to dial back the timing. Unless you just run straight up e98 all the time but you aint getting that from the pump.

 

running straight E85 at the moment until the flex fuel sensor comes, I test at the pump and I have E85 at a lot of stations here local to me. I did some street data logging and the ethanol content will fine along with fuel pressure.

 

Exactly and the sensor relays back to the ECU what percentage it is seeing as fuel passes thru the sensor and once the E starts to drop it starts pulling timing from the max amount of E set up by your tuner. Mine is set up at 4 degrees above the stock GM timing from the factory for 91 or 93. Not sure which formula GM would use but I would guess it 91 since that is considered premium. Right now I'm at E56 since I had to put in 91 after I left the track since there was no E available. When I logged a pull on the road I saw that it pulled a 1.5 degrees of timing at WOT. So its really important that you find a tuner familiar E85 setup. I love mine and anyone that does this mod should also purchase HP Tuners MPVi2 to log your runs and it allows you to plug in a read the E after you fill up. Not all stations sell the same amount of E. In KCMO I purchased it at an AMACO and it was E75 and when I got back to Columbia MO it was only E70 and wouldn't have known that without either a gauge or HP Tuners.