Contemplating Different Ethanol Blends .

[britz1]

we ran alot of drift cars on e42 (E85 100l mixed with 100l or BP98) just use a 200l drum... it worked well all last year, i have a 600hp built rb26 we went from pump fuel with 850cc injectors and 25+psi to 1100cc injectors on e42 with 550hp and 18psi...

[STATUS]

I'd like to see some comparitive results of E50 vs E85 if you have them Trent . What sort of difference are you finding power and ignition timing wise ? I don't suppose you've blended anything lower like say E40 ?

For me I can be bothered and because I'm no stranger to fuel containers its not really any extra effort . Fuel prices piss me off no end and range is important - to me .

I'm also interested to see what you think of the E50 for round town type driving .

Thanks , A .

we have run at every blend in 5% increments to 90% i could try chase up some results 50% is a pretty sweet ratio for power gains, even united 100 octane (10% ethanol) fuel is on average 2-3 degrees extra across the range 50% is 4-5 on the conservative side. E70-85 is interesting and i have different rules for different engines and setups obviously.... i will say ive seen a few tuners add around 12degrees over the whole map but its a recipe for disaster.

[discopotato03]

Interesting , thank you .

Trent how do the 25-45% ratios look compared to E50 ? I should add that if your into modest turbos like say GTRSs and cap at say 1 bar of boost this may not need lots of "help" above 98 ULP to keep the timing where it needs to be .

I suppose the more pulp you run the better the normal use consumption should be .

I have heard about United 100 E10 but not used it so far . Are we to assume they add ethanol to 98 PULP to get it up to the 100 octane ? If so a splash of E85 or Eflex would easily get everyones favorite Ultimate 98 up to or over the ton . 10% of 55L is 5.5L (ethanol wise) which is a hair under 8L of EFlex or 6.5L of E85 . Even easier if you could lay your hands on 5.5L of E100 and only the very lazy would claim that pouring in 5.5L is too hard . Jeez I can easily get easily get 11L into some of my "10L" fuel containers and it would be a snap to make a tank of 98PULP + E20 .

Is it possible to buy E100 in Sydneys south side ?

Cheers A .

[discopotato03]

I found another thread that looks interesting but don't shoot me if it turns out lame because its from a Green looking site .

http://www.greenhybr...u-should-16411/

I don't know where my time goes , cheers A .

Edit , this one is a link to a technical paper looking at optimum mid level ethanol fuel blends (greater than E10/less than E85) to see what works best - or as well or better than straight ULP anyway .

http://www.ethanol.org/pdf/contentmgmt/ACE_Optimal_Ethanol_Blend_Level_Study_final_12507.pdf

I noticed people saying in the first thread above that E10 is useless because there only enough ethanol to screw things up and not enough to do anything positive . I guess we also have to remember that most of these blends consist of ethanol and cheap mouthwash substituting for ULP . If it was 95 or 98 ULP outcomes may be different .

A .

Edited November 14, 2012 by discopotato03

[discopotato03]

From reading more in that site it seems that the reason they and we ended up with garbage grade E10 was because of tax credits and in their case minimum levels of oxygenates in their fuels .

The interesting thing is that while in general peoples fuel consumption drops between straight petrol and 10% ethanol (E10) it tends to climb back up as the percentage climbs to a point anyway . In that site someone reckons the American EPA has tested and approved E20-E30 in non flex fueled cars but their manufacturers have said nothing . Avoiding potential claims ?

I gather all their ethanol fuel blends include garbage grade base stocks as the petrol component and no one seems to have tried home brewing E70/E85 with premium fuels .

It would be good to find that 98ULP mixed with enough E70 or E85 ie 20 to 30% ethanol gave as good or better fuel consumption to the straight 98ULP - and a potential performance boost as well .

Interesting times , cheers A .

[discopotato03]

Next try today is going to be a pre mixed E25 based on Eflex and BP 98 PULP .

I did some number crunching in case anyone else decided to try this blending business and I think the only practical approach is this .

1) Calculate how much ethanol you want to make up the desired percentage ie 27.5L in 55L = 50%

2) Calculate how much E70 or E85 you need to get 1L of ethanol .

3) Multiply that number by how many L of ethanol you want and you know how much E70 or E85 to add to the petrol when you fill right up .

E70 . 1.4285 x 0.70 = 1L (or 0.99995 if you are exacting) .

E85 . 1.1764 x 0.85 = 1L (or 0.99994 if you are exacting) .

So if I want E25 I need a quarter of a tank or 13.75L of ethanol .

13.75 x 1.4285 = 19.64L of Eflex which I'll round up to 20L or 14L ethanol for conveniences sake .

This works out to E25.45 , (14/55 x 100 = 25.45%) .

My PFC injector trims will come down to 55.4 with 740 Nismos .

Tip in 20L of Eflex and fill to the top with petrol in my case BP98 to get E25.45 .

Don't even try to work out how to make lesser amounts because there is so much scope for silly errors and wrong calcs . It is possible but its messy trying to put in a given amount of Eflex and a given amount of petrol and no containers are graduated or exactly 5/10/20L either .

If you have a "20L" container with 20L in it you know you are going to get close to the right mix if you fill from virtually empty , being a few percent out at low ratios isn't the end of the world if not tuned on the bleeding edge .

If my consumption still doesn't improve markedly I'm going back to straight 98 and may give Uniteds 100 E10 a go if its easy to get .

A .

Edited November 16, 2012 by discopotato03

[scotty nm35]

The fuel price is right so why not just extend your fuel system with a 20L poly surge tank with a Walbro 400L e85 pump and be done. I'm sticking mine in the wheel well of the Stagea.

Or carry a jerry in the boot?

[discopotato03]

The BP98/E25 is working out really well for me at the moment . My car has regained a significant amount of part throttle torque and its off idle drivability is much better though I need to do the idle learn again .

Not sure but I think that there are advantages and disadvantages with the lower jjjjjjenergy alcohol fuels . We know that developing heat and therefore pressure in our cylinders is what drives us down the road and in some circumstances the more heat the better . My guess is that at part throttle when the effective compression and air consumption rate is low you struggle to get enough heat and cylinder pressure from high ethanol content fuels and so you lose some torque . I'm not sure that adding more fuel at these points makes any difference as in generates any more heat .

I spoke to a few people that have worked on a greaat variety of engines all their lives and they think that ethanol is not a magic bullet .

[scotty nm35]

Because we all drive stupidly low compression engines that are definitely not designed with ethanol in mind. Try bumping the compression up to 12:1 and the low end will spice up, but it will limit the amount of boost you can then run. Again, there is a happy medium for everything.

[Lithium]

The BP98/E25 is working out really well for me at the moment . My car has regained a significant amount of part throttle torque and its off idle drivability is much better though I need to do the idle learn again .

Not sure but I think that there are advantages and disadvantages with the lower jjjjjjenergy alcohol fuels . We know that developing heat and therefore pressure in our cylinders is what drives us down the road and in some circumstances the more heat the better . My guess is that at part throttle when the effective compression and air consumption rate is low you struggle to get enough heat and cylinder pressure from high ethanol content fuels and so you lose some torque . I'm not sure that adding more fuel at these points makes any difference as in generates any more heat .

I spoke to a few people that have worked on a greaat variety of engines all their lives and they think that ethanol is not a magic bullet .

Interesting, we find with E85 the part throttle/heavy throttle/everything gets noticeably more keen. E85 = makes the car drive like it has a bigger engine. I have done a bit of flex fuel tuning and recently we drained the tank of E60-something and put straight pump gas back in and the car felt like it'd lost its lust for life it most conditions - went fine, just with no real sense of eagerness.

[discopotato03]

Reposted because of a computer issue , site wouldn't let me edit my last post .

So far my current BP98/E25 blend is working out quite well and at least is about as easy as it gets when you have to blend your own juice .

Basically you add 20L Eflex and fill , if you want half a tank add 10 of Eflex and 17 1/2 L of petrol , a quarter 5L to 8 3/4 .

As I said the Americans reckon 20 to 30% ethanol is the sweet spot for a non flex fueled car and 25 falls in the middle .

I've noticed that the higher 75% petrol content allows me to run AFRs closer to the chemically correct (Lambda = 1) mixtures though atm its floating more around the 0.94 - 0.96 these days . This is at light to medium loads BTW .

My engine has regained a lot of part throttle torque compared to using the E50 and E70 blends . I get the feeling that you lose combustion heat and pressure at part/small throttle openings and fiddling with the mixtures with high ethanol content fuels didn't seem to match higher petrol content performance .

Maybe this is an area where you really need some way to measure exhaust gas temperature close to the exhaust ports and dial in whatever gives the most heat . I tried all sorts of fueling and timing settings and I could not get the part throttle performance with E50 and E70 no matter what I did .

I also noticed that they made the turbos response more lazy and I'd say for the same reason - less heat would equal lower exhaust gas velocity and not as much energy to get the turbine spinning fast enough . This is with a GTRS and they are not known to be laggy units , with the 75% petrol its response is noticably better and I can sail up the hills in 5th at 80 around here now with bugger all throttle . Needed more throttle and a bit harder to do this with E50 and E70 . I've got that bigger engine feel back again .

Theorising . It may well be my questionable tuning skills here but I get the feeling that high ethanol content fuels are fine when there is a definite need for more octane than 98ULP can provide . Things like very high compression ratios or high boost apps where an engines chambers and pistons are not very efficient designs and suffer chronic detonation because of it . In other words excessive combustion heat and pressure may leave you with nowhere else to go other than a fuel that really resists detonation - compared to pump 98 anyway .

For a road car that spends 90% of its life being driven around at urban speeds and light loads I reckon high eth fuels do very little for you - other than to add cost and complications . It may be a case where for dual purpose such as commute through the week and race on a weekend E85 would be fine with a change of maps and a boost increase at the track , Roy mentioned something like this .

IMO ATM production engines are not set up to run high eth content fuels and their overall performance and consumption will suffer because of it .

Maybe if NA engines had 11-12 to 1 static CRs and maybe turbo ones 10 plus the situation may turn around but I dont see that happening any time soon . Imagine screwing up at a servo and refuelling a car/engine like these with 91 ULP and trying to drive it .

Anyway my consumption is looking good so far but I'm only 60 km into a full tank and my R33 shows full till ~ 50 km and drops like a brick to the 3/4 mark . I'm still trimming my mixtures to not use any excess fuel anywhere and my mentors are telling me lean isn't necessarily economical so a bit of a juggle to strike a good compromise .

A .

Edited November 19, 2012 by discopotato03

[simpletool]

I'm going to give E10 a try. Mixing E85 with 98RON. From the technical paper here, and a few people's thoughts (such as Trent's approx timing advance - which agrees with the technical paper) everything seems to point to these outcomes:

E10 is approximately 30% of the way to E85 for RON, timing and power.

E50 is 2/3 the way to E85.

I have an RB25 with a AX53B70 and S15 inejctors so they're small (440cc). Current tune is 11.5:1 @ WOT at 15psi, timing is 15 - 16°. For practical reasons I can fill a 20L jerry can to 21 litres of E-flex (E75). If I pour in 7L of E-flex before a 3/4 tank fill then I'll have E10 for 3 tanks before needing a refill.

I'll see how it runs at first, and then look at adding 1 to 2° to the entire map. Shouldn't need to change the mixture as it's on the rich side for open loop, and closed loop will sort itself out. Not expecting miracles, but if I can notice a bit more response (prob only 5 or 6rwkw) then I'll be happy with it. It's no effort really and gives me something to play with.

I guess I'll look to book it into EFI for some numbers, maybe.

Edited November 20, 2012 by simpletool

[simpletool]

United sell E10, 100RON up here in Brisbane.......stupid me !

and yes, from the MSDS you can be fairly confident that United 100 is 98RON + 10% ethanol. That also makes sense with my quick calcs.

Edited November 20, 2012 by simpletool

[discopotato03]

I've just about used up the tank of BP98/25.45% Ethanol and its worked out well giving over 400 km/55L . If I ran it right out I guess I'd get ~ 440 but note I had a lot of traffic driving particularly getting screwed around on the M5 and King Georges Rd carparks .

The learning curve is still going and the main thing is that I found having mixture ratios around the mid 0.90s Lambda wise works better at least with the higher petrol percentage blends .

I think the trouble with higher ethanol percentage blends at least for the novice tuner is that you can run it leaner than is best without getting bad drivability pinging etc . Its possible that if I used the Lambda numbers I'm running now but with E70 both performance and consumption could be better .

I may try half a tank of E70 tosee how it works with lower Lambda numbers , cheers A .

[discopotato03]

Back on the E70 for a tank just to use up what I had here , I think my home brewed E25 worked better and certainly gives better MPG .

If I can squeese 12L of E70 into one of my larger "10L" containers that would equate to E15.3 in a tank of otherwise straight petrol .

Cheers A .

[discopotato03]

I was crunching some numbers last night so I could have a reference of how many litres of E70 makes what ethanol blend in a full tank and the injector trim numbers to make my "universal" timing and fuel maps work .

We assume E70 is 70% ethanol and the R33 tank volume is 55L . Divide 70 by 55 and get 1.272727 . Multiply the number of litres of E70 and you get the blend percentage or effective E number , for example 8L of E70 (should) equal 5.6L of ethanol so multiply 5.6 by 1.272727 to get 10.2 meaning 10.2% or approx E10 .

My injector trims are 50 with straight petrol (Nismo 740s) and 65 on E70 because 15 is half the generic +30% fuel for E70 .

The trim correction is ethanol content in litres divided by 55 then multiplied by 15 ie E50 = 27.5 divide 55 times 15 to get 7.5 , therefore with e50 the injector trim number for me is 57.5 .

E10 would be 5.5 divide 55 times 15 equals 1.5 making the trim 51.5 .

I reckon this is as easy as it gets to be using a Power FC/Datalogit/Wide Band and a lap top for doing "manual " flex fuel .

Without an ethanol content sensor it relies on you always blending with a virtually empty tank . With a content sensor all you have to know is the trim change calc .

Most people couldn't be bothered with all this and it does show up the limitations of computers like PFCs . It gets a bit tiresom doing the idle learning stuff with major ethanol content changes and we really need access to those parameters to chage them quickly/easily .

Also you often have to change accel and cold start enrichment each time as well .

In the end done carefully this will give you a usable car that can run on a variety of ethanol blends , but I would NOT cain the ass off it without propper tuning because the mapping won't be good enough and engine damage could result . I would not attempt this on anything but a car in a very mild state of tune or if it wasn't one driven reasonably sedately .

A .