I have dual nozzle smc alky and running straight denatured. With my old maf and cold air kit I was running it at number seven and had to have my fuel on the translator at 14% rich. Didn't realize that the no screen maf was causing it to read lean. I now have the 4" maf pipe from fullthrottle. With everything at base settings it looks like I'm rich (air fuel guage now) Should I back off of the alky first, if so how much or less fuel or more boost? I'm at about 22 to 23 boost.
More fuel or more alky?
- Thread starter Mike70gtx
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The answer I give is a very general one.... and is my opinion on my tuning philosophy.... so take it for what it is worth...
You only need as much alky as required to supress knock.... any more... is wasting alky and likely won't make any additional power. With that said.... if you believe you are rich.... I would cut the alky back as long as you have no knock... if you get to your desired AFR and still have no knock.... you might start cutting the alky back some more but adding fuel to compensate....
In the end... I want to not spray anymore alky than I have to to supress knock.
Like I said....this is my own opinion.... based off lots of reading.
You only need as much alky as required to supress knock.... any more... is wasting alky and likely won't make any additional power. With that said.... if you believe you are rich.... I would cut the alky back as long as you have no knock... if you get to your desired AFR and still have no knock.... you might start cutting the alky back some more but adding fuel to compensate....
In the end... I want to not spray anymore alky than I have to to supress knock.
Like I said....this is my own opinion.... based off lots of reading.
That's right on except that you can also build power with timing. Alky's ability to raise octane will help there.
Blown&Injected
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I have not even finished installing my alky kit but it seems that if you are rich, get that right first and then see what happens - maybe even keep adding alky until you get rich again, then you know when too much is being used. But that might not be a good idea - I don't know.
Mine has been set on "10" for years now.....I just have my turn on point set at about 15psi or so, and all is well. I did gain 2 psi by changing from Isopropyl to Methanol. Changing from denatured to Meth is less of a difference, but still worth it IMO. Plus it's easier to get.
When I had my car tuned on the dyno the tuner perfered to start the alky at low boost with low alky flow and turn up the flow using the progressive gain as the boost came up. This way there isn't a AFR spike when the alky comes on. You go through more alky (speed cost money - how fast do you want to go) but it's easier to tune. With an unstable AFR the timing must be backed off so that it will be acceptable even on a lean swing. With a stable AFR the timing can be more aggressive to build more power. This is one way to tune, not the only way.
kingots2004
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leave the alky alone and the fuel and turn up the boost till it knocks then back it off about half a cup:wink:
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Plug readings???
On my 11.2 run BBHG (Before Blown HeadGasket) with my 3.5 screenless maf. I was on 14% rich (translator) and on 7 setting alky. Now with 4" maf setup. I was on base fuel and alky on 3 with no knock, I ran an 11.5 with. A/F in high 10's and O2's at end of run about 750. (Couldn't get powerlogger to work and then laptop went dead). So these are some numbers I saw on the way down the track trying to keep an eye on everything. I then turned fuel down to 2% lean and ran an 11.4 with the A/F pushing about 11.7 and o2's down to low low 700 but no knock This was all about 24 to 25 pounds of boost. I thinking about going back to base fuel and add some boost. Will I get knock if it is too lean or will I just melt things?
Alcohols like ethanol and Methanol have more specific energy than gasoline. They also increase horsepower simply through charge cooling. If you were to run the car purely on methanol at the same boost level the car would be faster. The more Methanol the better when air fuel ratios are adjusted appropriately.
German engineers had this figured this out 60+ years ago on the Messerschmitt BF-109
