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good news guys!

as halle informed me, e85 is now available at the pump for 109c @ fueltown southland!

i have contacted the store and spoken to the manager, and the fuel is supplied by powerplus. the fuel is also a 91/ethanol blend like united's

http://www.powerplusfuel.com.au/

after speaking to geoff, he informed me that getting the fuel from csr was impossible as the big fuel companies have signed contracts for the next 6 months preventing anyone else purchasing e85, however they are not using it themselves... and the contracts are probably going to get renewed.

the fuel, is selling at a rate of only 300l per week, so c'mon guys, lets go help 'em out!

i'll be filling up and testing later this week, and will post results when done.

yeah, we have it for 99c @ united, as they use csr...

but csr stuff cant be used due to contracts, so fueltown are getting it from powerplus, which are a smaller mob and cant match the price :P

but hell... its less than half the distance and at least 10 times more defect friendly

  • 2 weeks later...

As I'm in the final stages of the planning my engine build I have been doing a lot of research on what compression ratio is best for a dual 98 (street use) and E85 (track use). Just curious as to what are people running on dedicated E85 cars? And whether people have thought forward a little and decked the head and running a slightly thicker head gasket to get their desired CR, then all you have to do is get a thinner gasket when E85 becomes more available and you want to run it solely on E85?

I think a 9.5 compression ratio would be good for a dual setup. use 98 for street stuff then take e85 to the track.

I think that would be good (most other people are recommending me 8.7 at the highest), as it allows you take advantage of the extra torque throughout the rev range but will limit your max boost level due to knock setting in earlier. However I guess it all depends what you want to use the car for, and in my case it's circuit so response over max power is what I want.

A bit of light reading for those who want to get technical with CR's. Hopefully this will be insightful to others as it was for me. Original post is at http://www.modularfords.com/forums/showthread.php?t=51059

Is it better to increase the static CR or boost pressure. There are a couple reasons why supercharged or turbocharged engines run lower static compression ratios. A static CR in the range of 8-9 is very common. Here are a couple considerations.

Consideration #1

Heat from compression by a supercharger or turbo can be removed (for the most part) through use of an intercooler. Heat from compression within the cylinder cannot. Also, the cylinder pressure at the end of the compression stroke (prior to ignition) goes up exponentially with an increase in static compression ratio, versus a linear increase with boost pressure. Therefore, increasing the static CR is going to unavoidably push you closer to the knock limit for a given fuel. In other words, the octane requirement goes up more by increasing the static CR than it does by increasing boost.

For example, increasing the static CR from 8.5 to 9.5 increases the temperature within the cylinder at the end of the compression stroke (but before ignition) by ~63°F, (assuming IAT2 = 130°F and ideal adiabatic compression with γ = Cp/Cv = 1.4. I won’t bore anyone with equations. The situation doesn’t change much even if IAT2 were only, say, 100°F. In that case, the increase in temp at the end of the compression stroke goes up by ~60°F for the same increase in static CR). Also, the pressure at the end of the compression stroke (before ignition) goes up by ~97 psi from 574 psi to 671 psi, assuming atmospheric and boost pressures of 14.7 and 14 psi, respectively. On the other hand, increasing the boost pressure from 14 to 15 psi increases the outlet temp of the compressor by only ~11°F, assuming AE=60% and IAT1 = 90°F. And by further assuming an intercooler efficiency of 80%, the increase in IAT2 is only ~2°F. Hence, the increase in temp at the end of the compression stroke will hardly change at all. Also, the increase in cylinder pressure at the end of the compression stroke only goes up by ~18 psi (from 516 to 534 psi) with this increase in boost pressure.

So summarising the effects of increased temp and pressure at the end of the compression stroke for the two cases:

Increased CR from 8.5 to 9.5: ΔT = ~63°F and ΔP = ~97 psi

Increased boost from 14 to 15 psi: ΔT = ~2.4°F and ΔP = ~18 psi

A higher temp and pressure increase the likelihood of deadly preignition for a given octane fuel. And for those astute observers that know the physics I’ve applied, yes, although I’ve idealized things to keep it simple, (by not including effects such as heat loss thru the cylinder walls during the compression stroke or ignition and valve timing in the calculations), I’m sure they’ll also recognize that this doesn’t change the conclusion.

Consideration #2

Power is increased by two completely different mechanisms for the two approaches. Increasing the static compression ratio increases power via an increase in thermal-conversion efficiency. Increasing boost pressure increases power via an increase in mass-air flow rate. There’s less gain in thermal-conversion efficiency (and hence power) via an increased static CR compared to the power gain by increasing the mass-air flow rate via an increase in boost pressure. For example, increasing the static CR from 8.5 to 9.5 results in an increase in thermal-conversion efficiency (for an ideal Otto cycle) of about 3.2%. On the other hand, increasing the boost pressure from just 14 psi to 15 psi, increases the mass-air flow rate by about 3.5%. If boost pressure is increased by 2 psi, (from 14 to 16 psi), the increase in mass-air flow rate will now be more than twice that compared to the increase in thermal-conversion efficiency, (~7% vs ~3.2%), and ΔT and ΔP still won’t be as great as they are when increasing the static CR from 8.5 to 9.5. Therefore, not only can it be “safer” from the knock point of view, but a little more power is gained as well, (relatively speaking that is).

A good friend of mine built his engine solely to run on E85 and his CR is 9.5:1 has run 2.1 bar with no knock at all.

9.0:1 would be the best for both IMO.

Mine is roughly 8.7:1 i think.

I just came across an ethanol content advisor and wondering if anyone has had any experience with them at all? Some guys in Sweden are using it to automatically switch maps from 98 to E85 based on the output of the analyser, so they don't have to run their tanks dry to switch over.

Link: http://www.zeitronix.com/Products/ECA/ECA.htm

I just came across an ethanol content advisor and wondering if anyone has had any experience with them at all? Some guys in Sweden are using it to automatically switch maps from 98 to E85 based on the output of the analyser, so they don't have to run their tanks dry to switch over.

Link: http://www.zeitronix.com/Products/ECA/ECA.htm

i have a s14 customer that whants to run the flex fuel sensor (not interested in the content advisor), just waiting on the parts atm (not cheap). we are just using the 0-5v inputs on the ecu to get it working. will be interesting.

the mob at southland gave me some details to the garage next door, some guy name tom :banana:, who will be doing flex fuel conversions... didn't get any specifics last time i filled up.

reckon the Nistune will handle a 'flex' option Trent?

Im running E85 full time, loving it

Km per $ comparison works out to be about the same with 98 PULP

Just hoping it would be more widely available in sydney

Iv heard that Holden are bringing out an E85 commo this year so this should force availability to increase i think

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