"the tuning bible"

[Roelof]

Originally Posted by NitroWD

if high idle takes a longer time to drop, it's not as rich as one which the high idle takes a lesser time to drop.

A dropping idle can also be caused by just cooling down the engine which is atomaticly done at idle when getting the right/rich mixture. The cilinder sceezes again giving the piston more friction and so slowing it down.
Depending on the status of the P/S set the effect can be more or less noticeable.

[unsp0ken]

question for you guys...

is the fuel being consumed at any given moment proportional to the amount that the throttle is being pulled?

so is there a decent amount of difference in fuel consumption at 1/2 throttle vs full throttle?

[Racecrafter]

Originally Posted by unsp0ken

question for you guys...

is the fuel being consumed at any given moment proportional to the amount that the throttle is being pulled?

so is there a decent amount of difference in fuel consumption at 1/2 throttle vs full throttle?

Proportionally speaking it depends alot on the carburetor and the needle taper being used.

[unsp0ken]

Originally Posted by Racecrafter

Proportionally speaking it depends alot on the carburetor and the needle taper being used.

just to make sure i'm understanding correctly...

i think you are saying that there is a relationship between the amount of throttle pull and consumption but the relationship varies depending on the carburetor?

[Lille-bror]

Hi.

On my plane engines the throttle opening vs rpm is not linear:

Half open throttle = approx. 8500 RPM
Fully open throttle = approx. 12400 RPM

It is not the same type of carburators, but the function is the same.

It makes good sense, that you can drive a car as fast with a modest throttle finger instead of idle/fully open throttle. My guess is that the perhaps last 3000 RPM is the RPM range that really needs A LOT of fuel to achieve.

Cheers

EDIT: I could make some tests next year and calculate the RPM's with 1/4, 1/2, 3/4 and 1/1 open throttle. Could be alot of fun

[houston]

Originally Posted by Lille-bror

Hi.

On my plane engines the throttle opening vs rpm is not linear:

Half open throttle = approx. 8500 RPM
Fully open throttle = approx. 12400 RPM

It is not the same type of carburators, but the function is the same.

It makes good sense, that you can drive a car as fast with a modest throttle finger instead of idle/fully open throttle. My guess is that the perhaps last 3000 RPM is the RPM range that really needs A LOT of fuel to achieve.

Cheers

EDIT: I could make some tests next year and calculate the RPM's with 1/4, 1/2, 3/4 and 1/1 open throttle. Could be alot of fun

I see rod replacement in your future ;-) LOL

[Lille-bror]

... with the car driving on the track god damn it!

[houston]

Originally Posted by Lille-bror

... with the car driving on the track god damn it!

Easy now , don't get too excited

[hadspimou]

I think this is enough .....
I do agree with you. Those are the most effective way