Cfm requirements for alcohol injected motors?

[seefour]

Enderle offers bug, bird. Buzzard catchers.
Rons offers toilet bowls 4.0 dia rated at 1425 cfm
The enderle stuff has 3 butterflies that out cfm a toilet.
How does one figure the required cfm for a alcohol motor vs gas?
Wouldn't air speed be greater in a single plane with a toilet vs a t ram set up with three butterflies?

Mike

[DaveMcLain]

A friend of mine ran just about every possible combination of Ron's Toilets, big, small, one or two. Enderle "Buzzard" hat too and all of them ran virtually identical at the drag strip. But the smaller ones gave much better drivability than the great big Enderle hat. That thing made the throttle tough to control while driving through the pits, loading up after the races etc.

https://www.youtube.com/watch?v=bSYvvymvVj0

With Enderle hat on tunnel ram 557 Ford.

[Adger Smith]

Use the system that keeps the plenum size more near correct for your combination as well as the CFM in line with the engine size. It will drive /accelerate better.

[DaveMcLain]

Use the system that keeps the plenum size more near correct for your combination as well as the CFM in line with the engine size. It will drive /accelerate better.

In the example I gave he experimented using an A 460 tunnel ram as well as two different versions of the single carburetor single plane intake for those heads and it just didn't perform any differently at the track. Drivability was the best with the smallest Ron's in a single throttle application but once the throttle or throttles were wide open it just didn't seem to make any difference.

[Adger Smith]

Dave,
Very interesting that it didn't make an appreciable difference from small to big.
Must have maxed out the air flow capabilities of the heads-engine combination with the small stuff.

[DaveMcLain]

Dave,
Very interesting that it didn't make an appreciable difference from small to big.
Must have maxed out the air flow capabilities of the heads-engine combination with the small stuff.

I think so. Even the single one flowed enough air to satisfy the engine, 557 cubic inches at about 7000rpm. Another thing to think about was that he was always leaving the starting line WOT against a trans brake. I wonder if he would have been relying on having to snap the throttle open to go if it would have been better with the big or small throttles?

[Adger Smith]

Dave, I've had a couple of customers find out they are quicker in both reaction time and ET when they stay just back of the converter stall a few hundred RPM.
There seems to be something about it losing TQ multiplication when the engine is up against the converter. If he did tried that I bet the smaller sizes would shine...
Remember air velocity helps acceleration...

[DaveMcLain]

It seems to me that at the time he was running about a 5800 converter and holding it at about 5500 something like that. I think that the 60fts were always around 1.23 or so on the truck. We always theorized that with an injection you're not relying on a venturi signal to supply the fuel and that once the throttle is open the intake runners "see" atmospheric pressure and the overall configuration of the intake just doesn't matter very much. The mixture down low just has to be rich enough to make the engine accelerate well. I would assume that if it was too lean it would tend to not leave very well. With a carburetor I think that it would be a ton more sensitive to these changes because the carburetor's venturi velocity has to react to and change with the sudden changes in engine speed. If not it won't accelerate very well.

One time when he ran the truck with a hood on it we talked about making up a Ron's Toilet that would attach at the front of the tunnel ram to keep the whole thing lower. He ended up just going with a scoop but I think it would have worked fine.

https://youtu.be/UimpCyhWrfo

Idling and messing with the throttle with the Enderle hat on the tunnel ram.

[clutchdude]

I have often wondered how much injector size difference would make.

Right now on my 415" sbc i have a injector with 3 4" blades, i have no clue on the CFM, but with a 5 speed it still drives like a street car around the pits. HP is 810

It has been 8.80 @ 152 in a stock chassis car, average runs are 9.0x- 9.15

I will try to see if i can post a pic

http://s41.photobucket.com/user/clutchd ... g.html?o=2

[seefour]

What weight? And tire

[clutchdude]

Race weight 3100
10.5 x 29

[seefour]

Hmmmm that's nice.