egt comparison

Randy do you mean taking advantage of the oxygen content of the fuel itself ?

I leaned it down this weekend a little , the track would not hold us good at all , but I did lose rpm on the fall back after the shift. I am thinking I might should richen back up and retune the high speed leanout , it did not pickup any significant mph.

DaveMcLain wrote:I think I figured it out one time and with methanol fuel the actual liquid fuel vs air is in a ratio of about 1:3400 so the fuel taking up room in the intake tract idea is largely mythology.

I.m.o. that'd be the case if the intake track was as big or bigger than it needed to be. Or, do you think blowing the fuel in the system down stream with an injection is a better deal than letting a carb put alky in the plenum?

Yes

never saw a deal where a carb was faster than injection.

I'd suspect you are speaking of alky?

Lem Evans wrote:I'd suspect you are speaking of alky?

yes

And why do you think that is so Mr Richter ? Seriously I want to hear what is on your mind .

Ms Ky mustang is not to fond of the M-5 exhaust fumes They caused her to double hit the record button so the run got split into 2 videos

M5 is the bad mofo.............

did you fatten up the bv any?

Here is the rest of that run it won't let me post both video's on one thread

next time out I'm gonna have the cameraman just focus on the crowd..........its priceless when the M5 pimp slaps um'...................

richter69 wrote:M5 is the bad mofo.............

did you fatten up the bv any?

Technically no , but I had to pop some new o rings in the barrel valve because they were dripping a little fuel and it is set a little richer than it was due to the arm not being exactly in the same place.

I am still not not sure the bv has much to do with performance other than that first hit of the throttle. I know some think it does though.

Becca said she wished she had videoed the crowd she said they were all rubbing their eyes when she turned around

Yeah the bv has nothing really to do with the run, messing with the M5 in the carb the idle mixture has to be a bit fatter, then the idle needs to come down.......so by doing that you lean the bv out anyway, so its just an adjustment thing.

I never messed with a timing change as its a bit of a pain with the crank trigger and I'm lazy.....on the dyno the 306 wanted 2 degrees less with the M5, was worth a few hp.

KY JELLY wrote:Do you mean the unused oxygen caused by an over rich / lean condition or a manifold or head flow problem ?

Take the victor manifold for instance it is lean on the corners with a carb and rich with an injector , that's got to be caused by a runner length / taper design problem , and an air flow problem , not injected fuel displacing the air. I would suspect the center runners are "stealing" air from the corners.

Well, intake manifold distribution dictates that you take the best you can get.
You need to try to USE all the oxygen efficiently which enters the engine and want to intake as much oxygen as you can, (air is usually only about 1/5 oxygen), in order to oxidize the fuel and burn it to make cylinder pressure. You want the mixture to be slightly rich enough that you will use all that oxygen in it. Being richer than that amount and you are simply displacing area in the intake tract, (the alcohol density is twice that of gasoline), which could otherwise be available for more air, (oxygen), to get into the engine which in turn can burn more fuel to make more cylinder pressure for high end horsepower. It is a snowball effect and getting it right with by-passes is a luxury to most racers. If it's WAY to rich you will also have a bad ratio of mixture and don't get a complete burn which wastes even more oxygen.
That is what getting a perfect tune is all about. Alcohol is more forgiving than gasoline in the respect of not having a perfect tune, (as long as it's on the rich side), so it still runs well.

It's chemistry at work...!

In a street car, you would want the opposite, to be sure to burn ALL the fuel and waste some air to get the best efficiency from a gallon of gas.

This is more in depth than most people want to try to absorb but, I think you can handle it ... lol.