Don't be surprised if the e85 doesn't improve the spool RPM, might actually hurt it. I haven't been able to find any direct discussion on the topic, but e85 has a lower EGT, and the turbo is harvesting heat energy.

I was under the impression that it would help because I'm physically burning more fuel to make the same kaboom. So producing more exhaust gasses at the same rpms to spin the turbine.

If not the thing's going to be a slug when I bolt on a potato. Maybe 2560r. Different thread for that haha

Same amount of air for more fuel.

We'll see after a decent pair of id1000's come up for sale in the classifieds

You dont need ID1000 for a 2554r. Kinda overkill

Everyone needs ID1000.

If the ID100's are cheap, why not? They'll idle a stock NA6 better than OEM injectors. Headroom to run 240whp that a NB head will make on E85 at NA fuel pressure. I say do it if they are a bargain. If not a bargain, I'd go Deatchwerks 450's or Denso yellow 440's.

E85 is oxygenated, so there's effectively more air. Empirically, E85 does not hurt spool.

lol, yeah, I held my tongue ... 400 on e85 with a 1.6 yo!

fascinating ... had not considered the oxygenation component. Would still love to see an apples to apples comparison (which may not be fair due to flame front speed) with turbine inlet pressures and EGTs recorded. May be more proper to compare MBT tuning, but that introduces a fair amount on complex interaction churn. I will actually be in a position to take this measurement at some point here this summer (hopefully ...).

Yeah oke thats right. I also have 1000s. But that was more for a future plan. Idle is really good. The yellow rx8 are to small for me. At 15 psi i was at 85% duty cycle iirc.

now with the 1000s at 20 psi my duty cycle is around 55%. So there is enough left for future plans

54 isn't staying forever and I bought a spare engine for cheaps that I'd like to build up. I figure the 1000's and my dw300 will totally future proof my fueling

The oxygen that's carried along in ethanol doesn't contribute to combustion. It's already bonded to a hydrogen and a carbon, meaning that it's already "burned" and is just along for the ride. To contribute to combustion, oxygen in the input molecule needs to be bound to something less stable than the Hs and Cs in the product, which is why high explosives are full of nitro compounds (a nitrogen with two oxygens bonded to it) and why Top Fuel cars burn nitromethane.

You get more power from E85 because it's got higher octane (so you can advance the timing/run more boost and thus turn more of the heat energy into useful work), and because it's got a higher H/C ratio than gasoline does. Combining oxygen with hydrogen releases more energy than combining it with carbon does, so for a given amount of input oxygen (which is ultimately what displacement, boost, VE, etc are all about), you want to maximize the amount of H you burn. Methanol is better than ethanol, and pure hydrogen is even better than that. High performance rocket engines burn liquid hydrogen with liquid oxygen, partly for this reason.

What that means for spool -- more timing means more energy in the piston, meaning less in the exhaust for the turbine to use. OTOH, more energy in the piston means the engine accelerates through the RPM band faster, meaning it gets to the higher-flow revs sooner, and the higher H/C ratio giving more energy overall means that even if you're getting a lower percentage of it in the turbine it's coming out of a larger total. Empirically, as Savington says, it doesn't really make a significant difference either way, so who cares.

--Ian

Have to say, I fucking love the scientifically way of saying "it doesn't matter" that's why this forum is great.

Side note, a buddy just made 430whp on his built KA24 with e85 on ID1000 at 70psi base fuel pressure then 90% duty cycle peak and it idles better than my FFI.

Engine: 99 1.8l
Turbo: GT3076R 56 .60 A/R
Manifold: BEGi CastExt. Wastgate
Downpipe Size/Style: Single tube 2.5"
Exhaust Size: 2.5"
Exhaust Components: Resonator & Magnaflow Muffler
Intercooler Core Size: BEGI #2
Intake Manifold: Stock
Headwork: unknown
Engine Management: Hydra
Other Spoolin' Helpers/Hurters: Basically FM plumbing
Trans & Rear End Ratio: 5-speed, 4.1 LSD
Rear tire size: 225/45/15

Fith GEAR PULL:

RPM Boost(psi)
2700 0
2800 .6
2900 1.8
3000 1.8
3100 2.4
3200 3
3300 3.7
3400 4.9
3500 5.5
3600 6.1
3700 7.3
3800 8.6
3900 9.7
4000 10.4
4100 11
4200 12.9
4300 14.1
4400 15.3
4500 17.2
4600 17.3
4700 18

Long spool?

Forever, and quite linear. Is that BB or journal? For real Garrett or eBay?

start the pulls at 2k not 3
get 3" exhaust like discussed in your thread
intercooler is likely choking too

I will redo my pull
Talked to Abe today, so a 3" is on the way.
The intercooler never crossed my mind.

Oh yeah sooo long. It is BB

Garrett Turbo.

You can check intercooler restrictiveness by checking pressure between the compressor and intercooler and comparing that to MAP when you're at WOT. I was concerned about whether or not my standard FM intercooler was big enough, but when I checked it there was only about a 1-2 psi drop across it.

--Ian