AFC Mod Question-Less low end fuel!

moneymaker44 said:
MOVE TO TEXAS and give it a try :eek:wned:
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But its a dry heat! Don't kid yourself it gets plenty hot up here, just not as often!
 
Treed said:
just a thought do you run additives, I started using cenpeco pulling additive and it makes a noticeable difference in spoolup on my GT42.

Travis
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Care to extrapolate more on the Cenpeco additive? Cost, how much you run per gallon, where to get it?
 
I run what it says on the bottle, let me get more info, I got it from my wife's uncle, he pulls pro-stock tractors. I'll see where he gets it, pretty expensive I think.
 
I pulled apart an AFC I had at the shop and sure enough, it will reduce rack travel probably 2-3mm, should be a big difference!
I'll see if I can do some testing tomorrow night.
 
Bobcat698 said:
I pulled apart an AFC I had at the shop and sure enough, it will reduce rack travel probably 2-3mm, should be a big difference!
I'll see if I can do some testing tomorrow night.
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Leave the AFC off & put a plate if you have enough air or nitrous!
 
DART505 said:
Leave the AFC off & put a plate if you have enough air or nitrous!
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Then I'd NEVER be able to light this charger, come hell or high water!

The AFC isn't a restriction of fuel as long as it is properly modified, it can be quite handy for streetability or in my case to light a BIG charger without putting the fire out!
 
Bobcat698 said:
But its a dry heat! Don't kid yourself it gets plenty hot up here, just not as often!
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DRY HEAT TEXAS ???? been awhile since you been down here LOL
yes i know it gets hot up there as well we just get to enjoy the plentiful heat longer than others.
 
Throttle control!I know a couple that were Fast trucks but hung on to the last minute to the afc.When thet finally removed it it was even faster,drag racing of course.I do not have a problem with the twins lighting up easy on the loud pedal but had a 7.3 that could not light with too much fuel so I hear ya!I run have run a 0 plate & thought that it was all the fuel she could get,then went to no plate on the street & WOW!The werd thing is my vallet still works with no plate!! What do you run for a charger?
 
I'll say this as nice as I can! The person that removes the AFC all together on a street truck is doing this because they don't understand it, nor know how to modify and tune it to work to there advantage.

It's like having an employee and having an issue with them, you can either fix the problem or fire them.

Stick to your plan Garrett, if you need anything just ask! Having a hand held air regulator for a 12V is a must, without it everything is a guess.

Jim
 
just reading all this about the afc adjustments ,,,jim what would you set the afc at what psi with my mods and ,,, i'm trying to get my turbo to spool better and quicker ,,,, i have a sps62 and a sps66 both are new with only a few hundred miles on them which one would be the best... both with 14cm exhaust housings
 
DART505 said:
Throttle control!I know a couple that were Fast trucks but hung on to the last minute to the afc.When thet finally removed it it was even faster,drag racing of course.I do not have a problem with the twins lighting up easy on the loud pedal but had a 7.3 that could not light with too much fuel so I hear ya!I run have run a 0 plate & thought that it was all the fuel she could get,then went to no plate on the street & WOW!The werd thing is my vallet still works with no plate!! What do you run for a charger?
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if they removed the AFC and went faster, they should have modified it to give them the necessary rack travel.

same goes with the fuel plate. I have a plate that I ground that has a bottom taper a little more agressive than a 10, but FAR more travel than a 0 from there on up.

if you look at how the AFC works, you'll realize why it's not a wierd thing that your valet still works
 
Jim Fulmer said:
I'll say this as nice as I can! The person that removes the AFC all together on a street truck is doing this because they don't understand it, nor know how to modify and tune it to work to there advantage.

It's like having an employee and having an issue with them, you can either fix the problem or fire them.

Stick to your plan Garrett, if you need anything just ask! Having a hand held air regulator for a 12V is a must, without it everything is a guess.

Jim
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I am always wanting to learn! I am all ears!Removing it is a all out effort!The only adjustments that I have tried is the star wheel & did not notise a differense from one extreme to another.I had a 0 plate in it before then removed it & even more power.Low throttle I am light on the pedal but would like to know what adjustments can be done to what & what part of the throttle does it effect.
Let the schooling begin.:bow:
 
AWESOME INFO!

i will be printing these for my refrence! thanks again for the post!

Rick
 
is it a safe guess that if i back my starwheel out some i will clear some low end smoke and get better spoolup?
 
The star wheel does NOTHING but add or release tension on the spring, read Westons' thread.

Jim
 
let me rephrase this or make it more clear.


The starwheel adds tension or can remove it, no tension means no pressure on the diaphram which means more low end fuel. Tension on the diaphram means less low end fuel. If that holds true (and im not mistaken) then is it possible to kill the fire down low until boost is reached? I have followed wesons suggestions to the T, but my low end seems to be lacking, so i was wondering , with the starwheel alone, is it possible to kill the low end? Or does the starwheel not provied enough low end fuel to make a difference.

Did that clear things up, or am i still mistaken?
 
inline6359 said:
let me rephrase this or make it more clear.


The starwheel adds tension or can remove it, no tension means no pressure on the diaphram which means more low end fuel. Tension on the diaphram means less low end fuel. If that holds true (and im not mistaken) then is it possible to kill the fire down low until boost is reached? I have followed wesons suggestions to the T, but my low end seems to be lacking, so i was wondering , with the starwheel alone, is it possible to kill the low end? Or does the starwheel not provied enough low end fuel to make a difference.

Did that clear things up, or am i still mistaken?
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Very true, it can fine tune to add tension to the spring, but if it is too tight it will limit travel so this, along with everything else should set and checked on the bench with regulated shop air.

Jim
 
I backed out the pre-load screw on the back of the AFC, and I figure I gained (lost) about 1.5mm of AFC foot reduction.

I still have quite a bit of low end fuel.
Also, I did some bench testing on my AFC and got full travel from the foot by 25 PSI, obviously if I went too tight rack travel was limited.

I have a 215 AFC, I may take the spring out of it and put it in my AFC, but I don't really rely on the spring to take care of low end fuel (you should be able to figure it out by watching this video:
Click here to see Video

That is with the old pump, however.
 
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