Author Topic: probably a dumb idea, but...... (Read 3950 times)

boosted_diesel_84 · « **on:** May 08, 2007, 10:03:32 pm »

what if, i were to back the nut off a few turns on the main fueling loctite it in place, get something like a choke cable but instead of it pulling in and out, was able to find something that twists and have a knob inside the car that was connected to the main fueling on the other end that could be adjusted while driving? but have various positions around the knob marked so you know how much to adjust, you would be able to make power by turning it up and be able to control egt's instantly and get good economy by leaning it out all without having to get under the hood and mess with it, kind of a on demand deal? this is probably a really dumb idea and im sure there is some factor i am not taking into consideration, so let me know what you think!

i have to much time to think of dumb *** to do to my cars, lol

jtanguay · « **Reply #1 on:** May 08, 2007, 10:09:44 pm »

actually it isn't a dumb idea at all... there was a thread way back where someone had envisioned using something like a servo motor to electrically actuate the fuel screw.

i doubt you would really need any loctite on the fuel screw... it might seize it in too which would be really bad.

are you thinking of using something like the flex shaft on those rotary tools???

you will need to measure how much turn you need to actually turn the screw in.. the shaft might take double or triple the torque to turn the fuel screw... although it seems pretty loose with a regular screw driver... only issue i can see is you turning the knob so much, creating a springload condition... then when the screw actually gets going, the springload tension turns the screw too much.. throwing everything off!

maybe instead of loctite, you lubricate the screw with something good???

this would be a killer smoke mod... smoke on demand lol and it's mechanical so it has the cool factor.

Vincent Waldon · « **Reply #2 on:** May 08, 2007, 10:16:27 pm »

Hey, airplanes have had cockpit adjustable mixture controls for years... it sure would make tuning easy... see some smoke in the rear view mirror.. crank it down. Want more power.... crank it up.

jtanguay · « **Reply #3 on:** May 09, 2007, 06:31:37 am »

lol Andrew you manage to ruin everyone's fun :lol:

but you must agree that this mod would be great for multi-drivers.

pretty hard to tell someone "hey watch the black smoke... i turned the screw wayyy out!! don't floor it or we won't have a motor anymore"

Vincent Waldon · « **Reply #4 on:** May 09, 2007, 08:23:09 am »

That same magic lever... the so-called "accelerator pedal", also controls boost in a very direct and reproducible fashion

Magic... magic I tells ya.

Vince

Black Smokin' Diesel · « **Reply #5 on:** May 09, 2007, 09:34:10 am »

We know about the accelerator pedal and it's magical purpose but the idea of having a "valet" mode is nice.

Could a speedo cable be used for this? I know it can spin in one direction but I'm not sure if spinning it the other way would "untwist" it.

There was a user on whoretex that had a custom servo on the fuel screw. However he never shared with us the way it worked and how it was actuated. Username was "vdubs".

bert · « **Reply #6 on:** May 09, 2007, 10:39:17 am »

When im feeling tight and going on a long motorway run i block off the pressure pipe to the aneroid so no extra fuel or cooking oil under load :lol:
Bert

Darth Garry · « **Reply #7 on:** May 09, 2007, 11:13:11 am »

So you're saying that that lever on the floor next to the brake makes the car go faster???!!!???

That's awesome! I'll have to try it!

I think that a servo is the best route to go, although I don't know how to hook it up or calibrate it. But, it'll probably be more reliable than a mechanical solution after you figure it out.

I've always looked at my fuel screws as "holy" and have never touched them, especially on my current IP as it was calibrated on a test bench when the pump was built. I don't know if I'll finally defile it when I add the intercooler and feel the need for more fuel.

Garry

Otis2 · « **Reply #8 on:** May 09, 2007, 01:56:17 pm »

Quote from: "libbybapa"

Basically what the max fuel screw adjusts is the maximum fuel injected when the pedal is floored.

I disagree with you here Andrew.

The "max fuel" screw also operates as "min fuel" screw. As soon as you turn it up, your idle goes up, too.

The issue is, for some of us, after cranking up that "max fuel" screw, then even when we bottom out the the idle speed screws to drop the idle, it has no effect. We end up with 1100 rpm idle speed or thereabouts.

It may be more accurate to say that max-fuel screw sets the *range* of fueling within which the accellerator lever will function. It doesn't just effect the fueling at the full extent of the accellerator arm travel.

For me, the servo idea would best be used to manually (and temporarily) drop the idle in gridlock traffic situations. Not worth the effort for me, though, I'll just put up with the high idle, because I want the higher range of fueling that the max-fuel screw tweak provides.

RabbitJockey · « **Reply #9 on:** May 09, 2007, 02:13:16 pm »

i think it's a bad idea as well. really pointless when it comes down to it.

foxracer1 · « **Reply #10 on:** May 09, 2007, 06:24:56 pm »

I've noticed that with the screw turned in it is very hard to limit excess fuel as the % of change from throttle positions is exagerated(sp?). But here i go talking about excess fuel and i have an N/A. good i dea but gonna be kinda hard to make it easy to adjust easily while crusin around.

clbanman · « **Reply #11 on:** May 10, 2007, 06:39:49 am »

Quote from: "Darth Garry"

So you're saying that that lever on the floor next to the brake makes the car go faster???!!!???

Garry

I find that on my 1.6 NA the lever on the floor to the right of the brake pedal doesn't actually do all that much to make the car go faster. The one to the left of the brake pedal lets the engine run faster but then the car slows down even more. :lol: