Jump to content
SAU Community

Recommended Posts

  simpletool said:
From wiki (but significant figures improved):

Table:

The following table shows the range of air fuel ratios typically used for burning gasoline, E85, and pure ethanol (E100) under an assortment of assumed operating conditions:

post-23086-1285738056_thumb.jpg

This seems to back the testing we have done, if you read my previous post (page 1) we are tuning E85 to around 0.84 lambda (12.4-12.5 afr).

  • Replies 61
  • Created
  • Last Reply

Top Posters In This Topic

  scotty nm35 said:
It seems I am the only customer of Springvale Caltex so I dont think it will be a problem for quite a while. I hope the stuff doesnt go off like petrol...

If I set the winter blend for around 11.5 it should work out around 12.0 - 12.2 on e85, that would be fine right?

how do you find the springvale caltex? thats literally 2kms from my place but i was thinking of going southland stuff for more consistency when i eventually get around to getting a retune.

  linkems said:
how do you find the springvale caltex? thats literally 2kms from my place but i was thinking of going southland stuff for more consistency when i eventually get around to getting a retune.

Other than the price fluctuating, its a great fuel. They may stop the pump and ask if your car is suitable over the loudspeaker though. My car wont start well on the southland e85, Caltex no issues. Obviously wont be a problem once the weather warms up.

You should be able to tune rich enough on the e70 to run safe when they switch the mix. I will let everyone know if my wideband shows any change.

  scotty nm35 said:
Other than the price fluctuating, its a great fuel. They may stop the pump and ask if your car is suitable over the loudspeaker though. My car wont start well on the southland e85, Caltex no issues. Obviously wont be a problem once the weather warms up.

You should be able to tune rich enough on the e70 to run safe when they switch the mix. I will let everyone know if my wideband shows any change.

is it hot or cold your issues? i found a trick with the other E85's to start even on a key flick when cold.

  STATUS said:
is it hot or cold your issues? i found a trick with the other E85's to start even on a key flick when cold.

Cold start mate, I have added fuel and leaned it out with temp adjustment but the only thing that seems to help is 10 degrees advance on the timing. I dont like the knock I get though with no oil in the bearings.

Trade secret or you willing to share? ;)

  STATUS said:
This seems to back the testing we have done, if you read my previous post (page 1) we are tuning E85 to around 0.84 lambda (12.4-12.5 afr).

Yep, I sure did. I was just adding some theory to your results to confirm. Also liked that you used lambda :) (your AFR would be more like 8.2 though ;) )

Also you mentioned you can add 5 degrees after optimum with no gain - I assume with no ping also. Would you consider this another example of the larger optimal timing window with E85 - a safety feature if you use the lowest advance that gives maximum torque?

Edited by simpletool
  simpletool said:
Yep, I sure did. I was just adding some theory to your results to confirm. Also liked that you used lambda :) (your AFR would be more like 8.2 though ;) )

Also you mentioned you can add 5 degrees after optimum with no gain - I assume with no ping also. Would you consider this another example of the larger optimal timing window with E85 - a safety feature if you use the lowest advance that gives maximum torque?

im not sure if your aware but if you leave the AFR gauge set to petrol it will read the relevant AFR's i posted above, it will only read 8.2 AFR if your set (most wont change it as its confusing) it to alcohol or e85 so the 12.5 etc are usable as a reference. I dont like it though so Lambda for me.

  STATUS said:
im not sure if your aware but if you leave the AFR gauge set to petrol it will read the relevant AFR's i posted above, it will only read 8.2 AFR if your set (most wont change it as its confusing) it to alcohol or e85 so the 12.5 etc are usable as a reference. I dont like it though so Lambda for me.

yea thats true when you convert the numbers it still ends up being almost the same number in AFR as gas on a gas gauge.

Yeah I know it will say 12.5 on the gauge if it's calibrated with a different fuel and used with another. That is my point exactly. It's the wrong scale. The lambda is still correct but the Air Fuel Ratio isn't correct. I mean people aren't using anywhere near a ratio of 12.5 air to fuel. It's just going to confuse people.

If people had a temperature gauge that read kelvin and Fahrenheit and Celsius but the Fahrenheit was calibrated with the wrong scale (ie. Celsius standards by accident because nobody bothers to calibrate with Fahrenheit, hence the wrong offset) would they still give the reading in the wrongly calibrated scale? Or would you just give it in kelvin - since that scale is correct and a universal reference. What people are saying in this thread is the equivalent of saying that 293K equals 20°F, which is doesn't. 293K equals 20°C. And people using the correct calibration or factoring for it will wonder why it doesn't make sense (sure most will work it out). Same thing here, if people search through theses threads in 6 months time (which most SAU members like people to do) and think "ohhh....Status tuning (who honestly by all accounts seems to be an excellent member and tuner with great knowledge of RB and SR engines) says he gets best results at 12.4:1 with E85. Why doesn't mine work like that."

IT also makes no sense to injector flow rates.

I'm just trying to save confusion and keep SAU a good reference for people. Currently it looks a touch silly to be using the wrong scale and saying that's OK since most people will use the wrong scale anyway.

Edited by simpletool

So I should get out the laptop and recalibrate the wideband to display afr's for ethanol when I change to e85, (which is the flick of a switch) and then recalibrate my brain to read it at wot? :D

I probably should have started with lambda to get used to it as that is what the sensor is reading anyway, unfortunately lambda just confuses me more.

The truth is even afr's for ethanol wont be accurate as it is a mix of around 70% for me atm.

  DVS32R said:
richer or leaner?

come on buddy fess up :P

i havent touched a e85 car yet but be good to know, if its richer then have you tried pre start priming?

I manually pre prime mine with 98, button on the dash to a one litre canister in the engine bay. I was going to try and automate it but its only needed when the temperature is below 12 degrees or so.

Trent, I dont think the emanage can adjust for cranking, only temp compensation, I thought perhaps I should just run it rich until the temp comes up. I added 20% and it didnt seem to change much, are you talking about putting twice the cranking fuel?

  DVS32R said:
richer or leaner?

come on buddy fess up ;)

i havent touched a e85 car yet but be good to know, if its richer then have you tried pre start priming?

rish as f*ck with no timing is what i've read from a very reputable tuner out of the states. he says up to 50% more fuel than from a petrol tune, and 0 or 5 degrees timing

Any body been monitoring EGT's with increased compression ratio's while using E85 - have seen some pretty interesting results on aspirated engines in regards to reduced EGT's with higher compression - would expect the same on boosted engine tho havn't proved it yet.

  rob82 said:
Any body been monitoring EGT's with increased compression ratio's while using E85 - have seen some pretty interesting results on aspirated engines in regards to reduced EGT's with higher compression - would expect the same on boosted engine tho havn't proved it yet.

I run 21 psi on a tiny stock housing, my egt's remain at 600 degrees (turbine outlet) no matter what I do on the dyno. Best bet would be to run an NA engine on e85 at 20psi, should hold the temps much better. Does this mean the ethanol burns much quicker than 98 under high boost?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • GTSboy, thank you again. i’ve been reading all the other SAU RB25 vacuum line threads and you have the utmost patience for people asking “where do my vacuum lines go”. it’s appreciated. i did also enlist a few other RB guys local to me.  i would like to run 5 to 4. turbo pressure side to wastegate actuator. i would like to run 3 to 1. power steering air valve line to intercooler outlet. (this is how it was previously). i was told 2 is the bleed port for the boost solenoid - which i’m not running - so should be capped.   anyone see any problems with that?    
    • So yes. All of them. Something like 98% of all fuel in the USA has 10% ethanol: https://afdc.energy.gov/fuels/ethanol-fuel-basics It's labelled as like, AKI, 87, 91, 93 with an E10 or E5 or E15 label on the pump. At a certain point, it's not just "E10" instead of 91. It is 91, 95, 98, and all of them have 10% Ethanol in them. You can also get E85 and E30 which is why you do see some people rolling around with E30 tunes in them.
    • Thanks for the response. This is an 04 EP3 Type R. JDM spec. Fairly certain they're just basic BC racing coils. I do plan to keep as the ride quality on stock I've been told is pretty meh given Sydney roads. If I were to go down that avenue, does NSW require them to be a certain spec (close to original) etc?
    • Should have asked what is the car?
    • I've had two super conflicting experiences with blue slips. My 30 year old E39 waltzed through with no issues but my brother in law was knocked back on 12 y/o 3 series due to wiper blades and some cracking in a control arm bush.  What kind of coil overs? Do you want to keep them after?  If it was me I'd get some dirt cheap shocks and springs from eBay or scumtree. Not ideal but will get you over the line and might even be less than $1k.
×
×
  • Create New...