E85 on stock turbo

[DarkMx-6]

there are people on this site that have tuned before and probably explain it better than i can but what could be happening is that it works better on 1/2 throttle because the a/f (air fuel ratio) is closer or above the ideal (14.7:1). remember if the a/f ratio becomes too high you could detonate. the car may feel like it has more power with a lean mixture (which could be happening durring your half throttle). At the same time durring full throttle you might be choking it with a rich mixture, giving it too much fuel.

Like i said I do know the basic concepts but I have yet to actually tune.

[Alcoholicprobe]

I gotcha, that make a lot of sense.
I appreciate the help dark. I really wish more members of this board shared info or would at least throw their two cents in. Especially people who have experimented with e85.
I really wonder what my a/f ratio is. I guess I'm gunna have to wait until I can get a wideband.

[Alcoholicprobe]

From my limited knowledge shouldn't one aim for around 11:1 for max power, on gasoline of course ? but lambda is lambda so 11:1 should be relevant to e85.
On a side note.. Has anyone used the ms1 v2.2 on glens garage? Iirc it's only around 140$ for the unassembled kit

Glen's Garage

[mx_masta]

From my limited knowledge shouldn't one aim for around 11:1 for max power, on gasoline of course ? but lambda is lambda so 11:1 should be relevant to e85.

Nope, max power on gasoline should be at 12.5:1.

Yes lambda 1 is lambda 1 and stoich is stoich but that doesn't mean that 11:1 gas A/F is 11:1 E85 A/F.

If fact if your running E85 and your gasoline calibrated A/F gauge says 11:1 your actually be running roughly a 7.3:1 E85 ratio which is way richer than you need for safely making power on E85 due to it's high octane and charge cooling properties.

Generally people tune E85 to a 12-12.5:1 gas A/F which equals about 8-8.3:1 E85 A/F.

None of which really matters, just tune using your gas calibrated A/F gauge like you usually would, it just takes ~30% more E85 to do it.

However nobody should be tuning to 11:1 gas A/F if what they are after is max power.

[Alcoholicprobe]

Ok that makes sense.
I hear about the ~30% more all of the time. It makes me wonder why someone couldn't just inject ~30% more fuel and call it good, mAybe even mess with ignition timing a bit?
In fact, I get better mileage in my probe than my daily driver (22-26 mpg, mainly in town driving) sure my car doesn't run perfect but as long as I keep it around half throttle I can spool relatively quickly and it seems to have plenty of power. Power wise I feel is pretty darn good for no tune at all.
Can anyone comment on the power of the stock turbo? Like as soon as I hit full boost rolling on the throttle in second she breaks lose. Is this typical of a stock turbo probe with higher boost??
By the way, my tires are not "high performance" by any means but they have PLENTY of tread.
I know burn outs are a terrible/ricy way to judge power but without a wideband atm I can't really judge if my car is at least running up to par compared to other stock turbo f2t's.

[mx_masta]

The crap running at full throttle could be lots of different things.

From bogging out rich to valve bounce from insanely high exhaust manifold pressure.

Like I said before, if you want to be running high boost and expect the car to make power the stock turbo is not the weapon of choice.
The stock turbo flows enough air for about 180hp max but that'll be damn hot air.
Whereas my bolt on VF12 hybrid flows enough air for about 280-300hp.
The turbine side of my turbo is also slightly larger than stock meaning reduced exhaust manifold pressure.
I also have upgraded valve springs to prevent any valve bounce.

[zlyricist]

ive found it to be ~30% more fuel idle and cruise, and a little less for WOT. dont ask me why, thats just what it seems to reflect when i tune from gasoline to e85

get a wideband and put a bigger turbo on that unit, like a 16g..... get the a/fs right and let her rip. you could in theory advance the timing slightly, but i sure wouldnt mess w that on the stock turbo. youll probably snap the shaft sooner or later at that boost pressure