How does denatured alcohol affect your A/F ratio???

Quick6

New Member
Joined
May 25, 2001
Went to the dyno today and at 18~19psi of boost and fuel pressure set to 42 with the hose off and running alcohol (denatured) my A/F ratio was in the 9.x/1 range. I was so pig rich I was off the scale! I was running a Caspers thumbwheel chip on bluetops. Does alcohol enrichen your A/F this much??
 
Stolen from one of the other posts.

Vout Lambda Petrol LPG Ethanol Diesel
1.40 0.686 10.08 10.63 4.39 9.94
1.45 0.696 10.23 10.79 4.45 10.09
1.50 0.706 10.38 10.94 4.52 10.24
1.55 0.716 10.53 11.10 4.58 10.39
1.60 0.727 10.69 11.27 4.65 10.54
1.65 0.739 10.86 11.45 4.73 10.71
1.70 0.750 11.03 11.63 4.80 10.88
1.75 0.762 11.20 11.81 4.88 11.05
1.80 0.774 11.38 12.00 4.95 11.23
1.85 0.787 11.57 12.20 5.04 11.41
1.90 0.800 11.76 12.40 5.12 11.60
1.95 0.814 11.96 12.61 5.21 11.80
2.00 0.828 12.17 12.83 5.30 12.00
2.05 0.842 12.38 13.05 5.39 12.21
2.10 0.857 12.60 13.29 5.49 12.43
2.15 0.873 12.83 13.53 5.59 12.66
2.20 0.889 13.07 13.78 5.69 12.89
2.25 0.905 13.31 14.03 5.79 13.13
2.30 0.923 13.57 14.31 5.91 13.39
2.35 0.941 13.84 14.59 6.03 13.65
2.40 0.960 14.11 14.88 6.14 13.92
2.45 0.980 14.40 15.18 6.27 14.20
2.50 1.000 14.70 15.50 6.40 14.50
2.55 1.037 15.25 16.08 6.64 15.04
2.60 1.078 15.84 16.70 6.90 15.62
2.65 1.121 16.48 17.38 7.17 16.26
2.70 1.169 17.18 18.11 7.48 16.95
2.75 1.220 17.93 18.91 7.81 17.69
2.80 1.276 18.76 19.78 8.17 18.50
2.85 1.337 19.66 20.73 8.56 19.39
2.90 1.405 20.66 21.78 8.99 20.38
. . .
4.00 free-air (can be used for calibration)

So, to answer your question, yes.
 
Quick6 you just need to tune your alky setup. Why wouldnt it richen your a/f ratio? You are dumping raw alcohol into the mix at over a gallon per minute. If you had been running race gas instead none of that extra fuel would be in there.

A: you need more boost. to run alky at 18psi is a waste. Turn the boost up or just run xylene

B: Sounds like you could use more timing too. I dont know what you are running now but you should be in the 22-23 degree range at least.

C: your pump speed is too high for your boost and timing. If you dont want more boost or timing, crank the pump speed down
 
The good and bad thing with running 100 percent denatured is that your engine will chew it up, but at what cost to power? De-natured is very forgiving as far as not drowning the spark, but running pure isn't the way to go IMO. A 70% solutiuon is attainable by most of us, and seems to be the way to go for a majority. (IMO)

I'd suggest seeing how much alchy you are flowing in 12 seconds. (I know a pain in the a$$ to do!) You should be around 4-8 ounces. I know the blackbuick87 is flowing 12 ounces, (ounce per second) but his is the exception. (or should I say exceptional;)) He is really using alchy as a fuel. For just starting out, you want to avoid doing this, as it can be dangerous. High timing, high boost, (the ported heads flow the equivilent of 24 psi, at 20 psi) high dependence on your tuning ability. Get some experience first...

I'd suggest lowering the nozzle size until you are flowing around, say, 8-9 ounces at full pump speed. Use 2-3 nozzles for best atomization. As you tune over time, you can gradually add timing, boost, and importantly water.

To answer your question, I don't have experience using a WB with alchy. I can tell you that one member posted that after he had tuned his system in it was one full point richer than what he had running race gas. For what it's worth...
 
i got a single M-15 mozzle runing 100% denatured. 20-21 psi boost, 20* timing, FP is like 40 or so, pump speed 6 -6.5. O2s are in the 855's consistently. i found a few vacuum leaks after we were tuning it, fixed them and it pigged it out. boost did seem to climb HIgher after leaks were fixed. gotta go retune it. at 800 o2s it had 0.0* KR and was pullin hard. its not sluggish now just not as fast. on another note, IMO tuning w/a Scanmaster is like trying to fish with a bow and arrow. DS is far more useful.
 
Thanks for all responses guys, I can see I have more tuning work to do with alcohol.
 
I just read this thread after I posted about something strange I noticed when using 100% denatured. Could it be possible that the alky is able to cause my EGT's to go up the more pump speed I give it and the O2's to not be linier with the equation? For instance, at pump speed #5 my EGT's were ~1456º, turn the speed up to #6 and the EGT's were in the high 1400º range, turn the pump speed up to #8 and the EGT's were just a fuzz under 1600º with all other things being the same??? Along with this, what is the low/high boost turn on range for the SMC alky kit? I seem to get 19.9º of KR at 23-26 MPH consistantly. Thought I had another false knock problem, but I've kinda ruled that out for now. Just wondering if maybe I have the turn on point too high for the initial boost spike thus causing my KR??? The only problem I have with turning the turn on point lower is that trhe motor stumbles and doesn't seem as crisp in the lower RPM/boost levels....any ideas?
 
You have had that system for quite a while - right? Most likely the 19* is false knock. Most likely because it would be rare to get that kind of knock in first gear. I would try a smaller nozzle, and thus an earlier turn-on point.

It seems like you are flooding it, drowning the spark. Un-burned fuel in the headers causing the high temps.
 
i was trying to tune it last nite and was getting little/no KR at night on 5 pump speed so i set it to 5.5 and today in the heat it was worse KR. i tried taking 2% fuel out with the Translator at WOT and ill see how that goes. i got the pump speed at 7. i think my problem is that im trying to lean it out by not giving it what it needs most, alcohol, which goes against what im trying to do. O2s were at 830-850 range today. hopefully i can get them down in the 780-800 range with maybe a little more pump speed. i need to realize im trying to run 21 or more psi and a pump speed of 5 just wont cut it for me, IMO, it just needs more alky.
 
Hey, there's a great article on alcohol & other fuels in the new/current DRAG RACER magazine! :)
 
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