DuronClocker

iTrader: (25)

Just curious. Someone told me the other day that they were told by a turbo supplier that a 76mm turbo wouldn't be big enough for them because they were running E85 instead of regular gasoline....but if they were running standard gasoline, it would have been the right size.

On an EFI car such as ours...there is no fuel being run through the turbo at all, so I don't see how this would affect anything. The turbo is just cramming the air into the motor, and then fueling is done after the fact. With E85, you just need to run it fatter and advance the timing to make up for the lower energy output (and then some)...right? Clearly this would require higher fuel pressures and/or larger injectors and fuel pump.

smokinHawk

iTrader: (48)

shouldnt matter, e85 is the fuel(and timing changes) side, shouldnt effect the air side

MECHAM

iTrader: (4)

i dont know the answer...but have seen a few posts by drturbo on this subject E85 & turbo sizing.


The Turbo Project has Begun......
Posted By DrTurbo

One problem with your build. That is the E85 will choke the small GTK turbine wheel. Small is relative....as it would be fine for 700rwhp on a regular gas engine setup, but small as in it will probably only make 600-650 before it really chokes the turbine side. Going to E85, E95, Methanol fuels is a whole different world guys. The turbos have to be adapted to the application as well.


BW S388 turbo?
Posted By DrTurbo

[QUOTE=camaroandreas;8077908]363 cui, manley oversized valves,ported,Edelbrook intake,compcams valvetrain and XER287HR cam. I´m will have 9.2 compression and run on E85 ethanol. I have a own tuning shop here in sweden with a dynapack dyno, but this it the first V8 i ever build. So i´m greatful for all help. /Andreas On E85 you will need the larger turbine side for sure. The full S88 would be the ticket. It would spool awesome and make HUGE power on E85.

DuronClocker

iTrader: (25)

Right...he's the only person I've ever seen say anything like this, and was just curious as to what others felt about this advice being given to people.

gametech

iTrader: (1)

Alcohol fuels burn cooler than gasoline, so it figures that something that is driven off hot exhaust gases (ie, a turbo) would have different requirements with different fuels. I have no idea why this would affect the compressor side, however.

mahhddgtp

Ah CRAPPPPPPPPPPPPP. This throws a wrench into things... I would think you'd need a larger turbo with E85. You burn a lot more fuel when running E85 (approx 1.35 times more) and it burns hotter. I wouldn't see why not.

This never occurred to me.

DuronClocker

iTrader: (25)

I don't see how needing to burn more fuel for the same amount of air equates to needing to shove more air in?

I can understand the exhaust gas thing, but then that would mean you need a smaller exhaust side, not a larger one. You can't remedy less exhaust flow with a bigger cold side because then more than likely you're losing efficiency then.

gametech

iTrader: (1)

The amount of fuel burned is irrelevant. The compressor side is all about air intake. And E85 does NOT burn hotter. Ethanol and methanol burn MUCH cooler than gasoline. I'm guessing (no real world experience) that the cooler exhaust gases would screw with the backpressure ratio versus a same sized gasoline turbo.

DuronClocker

iTrader: (25)

Okay, but that still means you would need a smaller exhaust side in order for the turbo to spool up better. If you were to go larger on the cold side, like I said above, you'd start having to worry about running the compressor (below) out of its better efficiency range, again, showing that a larger turbo would be worse, no?

mahhddgtp

****, you're right. I knew this, but I don't know what I was thinking . But I'm going to wait until DrTurbo posts.

camaroandreas

That is not correct, we always get more power with E85 then gasoline on the same setup. Backpressure will also be lowered when you add a lot of timing.
( I work with dynotesting/mapping)

rking

iTrader: (3)

subscribing...

DrTurbo

iTrader: (3)

Yes the volume of exhaust gases of a E85 car is more (your burning 30% more which passes through the turbine wheel). That is why Outlaw and the big drag cars that swap to alky based fuels have to go larger on the exhaust side.

smokinHawk

iTrader: (48)

so would running e85 help with spool then?

DrTurbo

iTrader: (3)

Yes sir it does........very nicely.

MECHAM

iTrader: (4)

i run 5gals 91/1gal e85 in my turbo cars.
audi s4/ws6

do i notice a difference...eh
is it a bit cheaper...little
do i change my tune...no
why did i post this...

DrTurbo

iTrader: (3)

Convert to straight E85 and you will notice it. We deal with alot of overseas customers that buy alot of turbos from us and they are all starting to use exclusively E85 in some countries. We have gotten alot of information and feedback on it. The general consensus is they love it. You can add lots of timing and the intake charge is cooler. Hard to argue with that.......great reciepe for making power.

mahhddgtp

And I expected it to work out like this

y2khawk

iTrader: (5)

yet again, throughput is the key

DuronClocker

iTrader: (25)

Right...which is why using E85 over 93 octane shouldn't affect what turbo you buy.