N/A swap to E85 without tune?
Intermediate
Joined: Jul 2013
Posts: 27
Likes: 0
From: Canton Massachusetts
See my thread if you'd like.
I know we're different in terms of mods/cars a little bit but I'm using the stock LS7 injectors on a relatively stock 08 Z06 and I maxed them out on E85 at 125% duty cycle at 4900 rpms. Even 52s won't cut it I need 60 lbs minimum. And yes you need a tune as the AFRs are different as are the fuel and timing maps. Plus you can then add more timing while tuning to take full advantage of the E85.
Best of luck...
I know we're different in terms of mods/cars a little bit but I'm using the stock LS7 injectors on a relatively stock 08 Z06 and I maxed them out on E85 at 125% duty cycle at 4900 rpms. Even 52s won't cut it I need 60 lbs minimum. And yes you need a tune as the AFRs are different as are the fuel and timing maps. Plus you can then add more timing while tuning to take full advantage of the E85.
Best of luck...
Thread Starter
Pro
Joined: Jan 2012
Posts: 580
Likes: 15
I'm still playing with e85 without a tune... after reading your replies and some more research, I will agree I should get a tune soon to change afr and will try to get around to putting in a bigger fuel pump soon...
I did a little over a 1000 miles on 95% e85 and a little vp110 mixed in each tank... only problems were longer crank time, different sounding idle, and occasionally check engine lights saying something about a lean condition... ran absolutely great though...
Now another 600+ miles on half e85, half 91... No more check engine light, or weird idle sound, but still takes longer to crank... Seems to run perfect...
25mpg on straight e85 @ 80mph
31mpg on half mix @ 70mph
I did a little over a 1000 miles on 95% e85 and a little vp110 mixed in each tank... only problems were longer crank time, different sounding idle, and occasionally check engine lights saying something about a lean condition... ran absolutely great though...
Now another 600+ miles on half e85, half 91... No more check engine light, or weird idle sound, but still takes longer to crank... Seems to run perfect...
25mpg on straight e85 @ 80mph
31mpg on half mix @ 70mph
Le Mans Master
Joined: Mar 2002
Posts: 6,885
Likes: 2
From: Corpus Christi TX
the only reason you're getting away with this to this point is attributable to the incredible cooling and detonation suppression E85 is capable of. But.....it's still stupid and is a ticking time bomb at those AFR levels you are surely exposing that motor to.
You are on the right track to explore the wonderful world of E85...but you need a wideband, datalogs, and possibly fuel pump upgrades as well as a solid, reputable tune taking everything into account.
Good luck
You are on the right track to explore the wonderful world of E85...but you need a wideband, datalogs, and possibly fuel pump upgrades as well as a solid, reputable tune taking everything into account.
Good luck
Drifting
Joined: Nov 2012
Posts: 1,782
Likes: 42
Safety Car
Joined: May 2006
Posts: 4,016
Likes: 93
From: St. Louis, MO
Tech Contributor
Other then afr's, this article backs up what I'm saying... For the most part, just aggressive timing and bigger injectors is all that is needed.... I haven't experimented with tuning my car myself yet, but I'm far from stupid. Fuel injected cars have computers with sensors and can do a little changing of their own parameters... As if the millions of flex fuel cars/suvs/pickups on the road magically have 30% or more bigger injectors and fuel flow when you fill them with e85... If i'm wrong then so be it, i'll just build a high compression stroker engine and get it tuned for e85 once rebuilt. For now, it definitely seems to run fine and def seat of the pants is better...
I'm still playing with e85 without a tune... after reading your replies and some more research, I will agree I should get a tune soon to change afr and will try to get around to putting in a bigger fuel pump soon...
I did a little over a 1000 miles on 95% e85 and a little vp110 mixed in each tank... only problems were longer crank time, different sounding idle, and occasionally check engine lights saying something about a lean condition... ran absolutely great though...
Now another 600+ miles on half e85, half 91... No more check engine light, or weird idle sound, but still takes longer to crank... Seems to run perfect...
25mpg on straight e85 @ 80mph
31mpg on half mix @ 70mph
I did a little over a 1000 miles on 95% e85 and a little vp110 mixed in each tank... only problems were longer crank time, different sounding idle, and occasionally check engine lights saying something about a lean condition... ran absolutely great though...
Now another 600+ miles on half e85, half 91... No more check engine light, or weird idle sound, but still takes longer to crank... Seems to run perfect...
25mpg on straight e85 @ 80mph
31mpg on half mix @ 70mph
I'll read your fortune for twenty bucks. You in?
Instructor
Joined: Oct 2007
Posts: 138
Likes: 2
Just because you're running E85, doesn't mean you're getting any performance benefits from it. The idea of E85 is you can make more power, run additional timing safely, car runs cooler ect. I picked up 15whp by the switch on a basic bolt on car. All you have done is killed your fuel mileage, and potentially set yourself up for catastrophic failure.
I am a believer in E85, but as note I did switch back to pump gas. I just wasn't seeing the type of performance benefits I thought I should (even with a proper tune). I will likely revisit it once I get some additional mods.
I am a believer in E85, but as note I did switch back to pump gas. I just wasn't seeing the type of performance benefits I thought I should (even with a proper tune). I will likely revisit it once I get some additional mods.
Thread Starter
Pro
Joined: Jan 2012
Posts: 580
Likes: 15
Part of me is waiting for your "JUST KIDDING" post. You obviously don't know how flex fuel vehicles work at all, and you're trying to paint the Mona Lisa with finger paint while drunk. You are making way too many assumptions.
If you think that's your actual fuel economy, you're dumb. Sorry, but that's just the blunt truth. The fuel economy is based off of injector pulse width, engine speed, and programmed injector flow rate. You put bigger injectors in without adjusting the calibration... That makes your fuel economy reading completely null and void.
I'll read your fortune for twenty bucks. You in?
If you think that's your actual fuel economy, you're dumb. Sorry, but that's just the blunt truth. The fuel economy is based off of injector pulse width, engine speed, and programmed injector flow rate. You put bigger injectors in without adjusting the calibration... That makes your fuel economy reading completely null and void.
I'll read your fortune for twenty bucks. You in?
One more road trip tomorrow of 300+ miles... When I get home I will probably swap back to stock injectors and back to 91 until I get a tune... But seriously guys, was just an experiment... Tomorrow will put me at around 2000 miles of playing with e85 with nothing bad happening... I drive like a jack@$$ more often then not... If it was gonna blow up, it probably would have by now...
I did 4 trips in the last 2 weeks, all to same town, all just a touch over 300 miles round trip, computer read around 25mpg, just grabbed a gas receipt and it hand calculated out to 23.3, so the computer is not very far off...
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Drifting
Joined: Oct 2012
Posts: 1,424
Likes: 21
From: Austin TX
E85 is a more forgiving fuel than pump gas, but find the best tuner in your area and get full PCM tune before you lean on it hard.
Your injector table will need to be scaled to the new injectors and your fuel stoich value adjusted (pump gas is ~14.7 E85 is ~9.8). You may need more fuel pump. It might be working OK now just by blind chance. Get a full retune.
Your injector table will need to be scaled to the new injectors and your fuel stoich value adjusted (pump gas is ~14.7 E85 is ~9.8). You may need more fuel pump. It might be working OK now just by blind chance. Get a full retune.
Last edited by TWS Racing; Aug 25, 2013 at 04:02 PM.