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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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 Posted: Wed Apr 28, 2010 10:25 pm Post subject: e85 a/f readings... |
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My engine was just dynoed last week and my a/f read in the 13.25 to the 14.25 range.... we had to input the specific gravity of the fuel into the dyno to take a reading and we used .77 any input guys
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi |
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newalky
Joined: 30 Sep 2008
Posts: 84
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| Posted: Thu Apr 29, 2010 8:49 am Post subject: |
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.789 is the density of Ethanol so you may have been close.
If those #s were Air/Fuel Ratios, you were way LEAN.
13 #s of air for 1# of fuel
Stoichiometric for E85=9.76#s for 1# of fuel
newalky |
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murphinator
Joined: 08 Jan 2010
Posts: 93
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| Posted: Thu Apr 29, 2010 2:49 pm Post subject: |
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a lot of widebands are set on a gasoline scale - so at stoich they will read 14.7 lambda 1 is lambda 1 whether stoich is 9.8 or 14.7
but 13's is still lean in any case
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PB's 1/4 mi 12.209, 117.75 trap ,1/8 mi 7.76 ,93.99 trap , 1.949 short time 4.53 0-60
I tune with HP Tuners software |
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440Jim
Joined: 01 Jan 2008
Posts: 188
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| Posted: Sat May 01, 2010 4:21 pm Post subject: |
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Rocket Racing Fuels sells a specially blended E-85 and they spec it at 0.789
http://www.rockettbrand.com/productspecs/specs.html
We have to be careful taking A/F ratio with "alternative" fuels, because many people use a wideband oxygen sensor and just leave the readout on the gasoline scale and many people are familiar with those numbers (lean or rich). But as pointed out, E-85 has a Stoichiometric ratio of 9.76, compared to gasoline's 14.7.
I run my race car on E-85 in the range of Lambda 0.84-0.85, and have tried .80-.88
That is a true A/F ratio of .84 x 9.76 = 8.2
On the gas scale it would be .84 x 14.7 = 12.3
That is wide open throttle, at low throttle settings or idle you can go much leaner, all the way to stoichiometric.
If the dyno was using measured fuel flow and air flow (air turbine on top of the carb), it should read true A/F (with the right density/specific gravity). |
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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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| Posted: Mon May 03, 2010 8:22 am Post subject: |
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| 440Jim wrote: | Rocket Racing Fuels sells a specially blended E-85 and they spec it at 0.789
http://www.rockettbrand.com/productspecs/specs.html
We have to be careful taking A/F ratio with "alternative" fuels, because many people use a wideband oxygen sensor and just leave the readout on the gasoline scale and many people are familiar with those numbers (lean or rich). But as pointed out, E-85 has a Stoichiometric ratio of 9.76, compared to gasoline's 14.7.
I run my race car on E-85 in the range of Lambda 0.84-0.85, and have tried .80-.88
That is a true A/F ratio of .84 x 9.76 = 8.2
On the gas scale it would be .84 x 14.7 = 12.3
That is wide open throttle, at low throttle settings or idle you can go much leaner, all the way to stoichiometric.
If the dyno was using measured fuel flow and air flow (air turbine on top of the carb), it should read true A/F (with the right density/specific gravity). |
Thanks for the information Jim,
Now help educate me. If I read in Lambda, it is kind of a, it is what it is reading, its just going to take the information it is given and spit it back out. There are no scales, conversions or anything of that nature. Now, under my situation, no matter what, I was lean it appears. Im not sure what control I will have over my racepak once I get it installed as far as how it spits the numbers out.
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi |
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joeq66
Joined: 13 Jan 2010
Posts: 16
Location: lafayette,IN
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| Posted: Mon May 03, 2010 9:14 am Post subject: any |
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| I have been following this also and would like to understand more.I have a innovate lm1 wideband and im trying to tune in my car with e85.Mine has a lambda scale and normal gas scale.On this particular wideband do I just read lambda and it is what it is.Or is there any kind of conversions.thanks in advance |
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newalky
Joined: 30 Sep 2008
Posts: 84
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| Posted: Wed May 05, 2010 3:07 pm Post subject: |
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Just read lambda. Like Jim said somewhere between .80-.85 lambda will be your MAX power mixture. That means 20%-15% richer than stoich. Watch the lambda readings and your MPH/ETs if you are on the dragstrip.
Mine looks like about .82 also for best ETs. newalky |
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89shortbox
Joined: 04 Nov 2007
Posts: 153
Location: Michigan
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| Posted: Wed May 05, 2010 6:24 pm Post subject: |
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| newalky wrote: | Just read lambda. Like Jim said somewhere between .80-.85 lambda will be your MAX power mixture. That means 20%-15% richer than stoich. Watch the lambda readings and your MPH/ETs if you are on the dragstrip.
Mine looks like about .82 also for best ETs. newalky |
I wouldnt recommend .8-.85 lambda on a boosted application.
That may work on some N/A engines .
Based on what he's got in his signature I wouldnt go leaner than .75 to start. What Ive seen lately on good tuned e85 forced induction motors has been .7-.75
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89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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| Posted: Wed May 05, 2010 8:23 pm Post subject: thanks |
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thanks for all the info guys, keep it coming...im sure im not the only one learning here
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi |
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89shortbox
Joined: 04 Nov 2007
Posts: 153
Location: Michigan
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| Posted: Thu May 06, 2010 1:43 am Post subject: Re: e85 a/f readings... |
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| b-1duster wrote: | | My engine was just dynoed last week and my a/f read in the 13.25 to the 14.25 range.... we had to input the specific gravity of the fuel into the dyno to take a reading and we used .77 any input guys |
How much power are you trying to make. What dyno?
_________________
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89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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| Posted: Thu May 06, 2010 7:39 am Post subject: |
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I was hoping to make 1400 at about 15lbs but I was extremely lean....
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi |
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89shortbox
Joined: 04 Nov 2007
Posts: 153
Location: Michigan
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| Posted: Thu May 06, 2010 12:42 pm Post subject: |
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| b-1duster wrote: | | I was hoping to make 1400 at about 15lbs but I was extremely lean.... |
That shouldnt be a problem. Where you guys using a Wideband to measure fuel ratio. Also what fuel pump, feed line size, return line size do you have. I asked about what dyno it was on cuz if its on an engine dyno and it has the standard fuel flow meter on it then the meter is not going to work on anything nearing 1000hp. I becomes a restriction near there.
I would think that carb should have been close if it was built for this application. You might call C&S. They seem to do the best BT e85 carbs.
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89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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| Posted: Thu May 06, 2010 2:13 pm Post subject: |
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I think it was a DTS dyno. We were using a wide band, and we input the gravity at .77 We were just lean, as far as a fuel system, I dont know. I do know that it supports 2000hp alcohol blower motors, but thats as far as my knowledge travels in the fuel system on the dyno. We also had to bypass the fuel flow meter because it was not set up to bypass at the regulator
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi |
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89shortbox
Joined: 04 Nov 2007
Posts: 153
Location: Michigan
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| Posted: Thu May 06, 2010 3:40 pm Post subject: |
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I dont understand why it would have left the dyno still being lean.
I dont know who dynoed it but I suggest you call Steve Morris at New Era Racecraft.
http://www.neweraracecraft.com/
_________________
----------------------
89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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b-1duster
Joined: 01 Oct 2009
Posts: 11
Location: Indianapolis
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| Posted: Thu May 06, 2010 4:12 pm Post subject: |
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| 89shortbox wrote: | I dont understand why it would have left the dyno still being lean.
I dont know who dynoed it but I suggest you call Steve Morris at New Era Racecraft.
http://www.neweraracecraft.com/ |
Thats just it... we didnt learn that the readings were lean till after we left the dyno...
To read the plug, it looks good, but to read the a/r ratio its bad. I was not educated enough at the time of Dyno to know that I was lean. We thought, because we were uneducated, that once we put in the specific gravity that we were back to the level playing field of 14:1 or so. I can not blame the dyno operator because he told me up front he had no e-85 experience.
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'72 Duster with a 500" B-1 and a 106mm turbo huffing e-85 thru a C&S Domi
Last edited by b-1duster on Fri May 07, 2010 7:49 am; edited 1 time in total |
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