There are so many assumptions and jumps of logic in this post I feel like I'm reading one of those brain teasers where they show you a proof of 1+1=3 and you're supposed to find what is wrong with it.
We'll just go down from top to bottom. Your first three paragraphs look technical but are difficult to read (run-ons whoa) and are full of red herrings. This annoys a reader, FYI.
So I guess I'll just throw this out there. You all realize that air is pretty heavy as well correct? At 25 lbs of boost you're looking at almost 40 pounds of air right? That is before the air hits the convergence point (the limiting flow point in the entire car) of the cylinder head which is at the base of the valve throats which causes the air pressure to spike and because the fuel is not compressible beyond it's weight injected in liquid form only augmented by the injection amount precalculated we already have an idea of the weight of fuel that will enter the cylinder, allowing us to look at the other variable that people don't seem to think makes a difference. (well one guy said 1% difference)
What I got out of the previous paragraph was that the valves are the limiting point in the flow of the engine, and we know how much fuel is going in. I'm not sure why it had to be written in such a convoluted way. Did I miss anything?
I know you don't think there are 40 pounds of air pushing into each cylinder every time a valve opens, so that is a misleading statement. It doesn't matter, and the weight of the fuel doesn't matter. It doesn't matter that fuel is incompressible.
The pressure just upstream of the valve should be the same as the rest of the pressure in the manifold, excluding micro-variations. It looks like you are trying to say that because the air goes through a valve, the pressure increases. The VELOCITY increases as you neck down the area, and that brings with it a
decrease in static pressure. But, this happens for both fuels, so why is this being brought up? The difference is that the flow(we will assume completely gaseous) with e85 will have a slightly cooler charge temp and MORE volume of gas to bring into the cylinder. Right off the bat, those effects seem to offset each other to me.
Either way, the head geometry is the same for both examples, so it doesn't matter.
So in other words don't ignore the variable that is the volume of air. If AIR volume did not increase adding fuel won't help exhaust energy (force) (which is what spools a turbo, not volume. Volume (mass) just happens to be part of the equation for exhaust energy.)
First of all, energy and force are not the same. Do not wave your hands and say they are. We are in a technical discussion about very specific topics. Get your terms right.
Second, you do not need more air volume! Same volume of air switched to e85 and injector scaled accordingly will give significantly increased exhaust flow, given no other changes.
As I said before, and NASA agrees with me (
http://www.grc.nasa.gov/WWW/K-12/airplane/powtrbth.html), is that the energy able to be extracted by a turbine is directly related to the temperature and pressure ratios. Given a fixed space, gas volume and pressure are directly related. Given that the same amount of heat is released over the same amount of time, the temperatures should be constant. I do not believe NASA would require further investigation of the increase in energy transfer to the turbine wheel.
Gasoline example:
Inclusion of boost outlet temp, small increase in heat from cylinder heat heating (which while somewhat small does have an effect), and the increase of temp that occurs temporarily by air passing and being compressed in the convergence of the head. We'll call this temperature 200 degrees F. I think that's more than fair. At the convergence pressure will also spike, we have 25PSI of boost + atmosphere I'm going to round up to 40 PSI. We'll say the convergence causes a 20 psi spike, this is the intention of the convergence it increase velocity (and therefore pressure) so as to prevent reversion during part of the compression stroke. So total 60 psi.
200 degrees @ 60 psi = .306 pounds per cubic foot.
Let's JUST take into account the cooling effects of E85, and we'll call it 70degrees F.
70 degrees @ 60 psi = .381 lbs per cubic foot.
You're looking at nearly a 25% increase in volume. Which is not only weight that all of you guys are focusing on but o2 density, which is the catalyst which burns the E85 which releases the energy to spool the turbo.
This is where assumptions and typos
beau said:
"small increase in heat from cylinder heat heating (which while somewhat small does have an effect)"
really start to run rampant.
Pulling temperatures and pressures (deltas even) off the top of your head does not inspire confidence. This heating effect from the "converging" flow happens with either setup. I fail to see why that matters. On top of that, assuming each little squirt of E85 will cool charge temps (of 40 pounds of air) by 130 degrees is a stretch in my mind. Got any references?
By your own numbers: if you are burning 25% more air, you should be making 25% more power overall. This would mean that by doing nothing more than swapping a setup to E85 and increasing injector duty cycle to compensate for volume flow, you should ingest 25% more air and therefore make 25% more power.
I am more than willing to accept that this effect exists, simply in the same vane we've always known lower intake temps are better for all the reasons you've posted. But to say that it is a dominating effect to the increased volume->increased pressure ratio is just not correct, nor is much of your reasoning.
I have tried to include credible references to points that we disagree on, so please include an external reference to your side of the case if you are going to respond.
