AFC simplified

Interesting findings today:

Pressure tested my AFC today for the hell of it, shocked to see with the starwheel halfway in the plug it was coil binding before full travel. This was with 40 psi and stock spring. To get full travel I had to loosen it til it was near the edge of the plug. Truck smokes like crazy so I'm probably gonna opt for the TST heavy spring. Thoughts?
 
I tried to heat a gov spring and stretch it and now it lost its spring properties and now is mush. Oh well anybody have stock gov springs they want to get rid of?
 
straight 6 roar said:
Interesting findings today:

Pressure tested my AFC today for the hell of it, shocked to see with the starwheel halfway in the plug it was coil binding before full travel. This was with 40 psi and stock spring. To get full travel I had to loosen it til it was near the edge of the plug. Truck smokes like crazy so I'm probably gonna opt for the TST heavy spring. Thoughts?
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Just put your plate in and slide it back.
 
Mo Smoke said:
I tried to heat a gov spring and stretch it and now it lost its spring properties and now is mush. Oh well anybody have stock gov springs they want to get rid of?
Click to expand...

Ummm, not sure what else you expected to happen. They're tempered btw. Lol ,Yea I have a set out of a '96. What ya give me for them?
 
Guys, have any of you measured full travel stroke of the afc foot before and after the mods? I measured 14-14.6mm of travel last night on my modified afc. Also measured full travel around 50psi with the governor spring as verified with the regulator gauge on my air compressor with the AFC lever set in the farthest down into the pump position (with the slotted shaft on the front of the afc turned full clockwise).

The spring I have in my AFC most resembles the "60 psi spring" shown on the first page by Weston.
 
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I actually had mine off over the weekend to play with it, I found 14.5-15mm of travel on my modded one as well. Funny I was actually going to ask how much travel others are getting........

I had the TST light spring in and it smoked way too much. Found the AFC would move like 2-3mm @2lbs of boost, was half travel by 9 and full travel by 18.

With the TST medium spring its a whole new beast. Full travel is 24lbs of boost, considerably less smoke, more responsive, much slower egt rise, feels much better.

I'll have to go back to the drawing board when I get the twins built.......
 
I've been messing around with some different springs from the local hardware store, but I can't seem to find one I like. Quite a few of them have too many coils and the spring is in a bind before it gets to full travel. I'm actually running a combination of 2 springs now, A TST heavy and the other that gives me full travel around 40 psi. The local Fastenal has some springs that I'm going to mess around with and see if I can't find something I like.
 
when you want ure truck to be fatster should oyu move the level up or down and how much should u crank starwheel and which way cause i wanna adjust mine and make a lil more power:thankyou2:
 
94cumminsboyy said:
how much should you adjust all of these to make your truck have more power.. is there a post on it
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I suggest setting up your AFC on the bench with shop air so you get full travel at the psi you want. Then you can adjust the preboost screw to gain the low end fuel you want.
 
I've been playing with springs forever! with my setup the stock 180 spring heated and stretched to 38mm long works the best. I just used a pencil blow lamp in a couple of places whilst the spring was pushed over a deep socket, clamped to it at 1 end with vice grips, then just pulled the other end with pliers worked great!
 
Does anyone have any AFC lever measurements for the barrel and foot on a stock 160 pump? I was going to start on mine but the barrel appears to be already shortened and I'm not sure on the foot.
*edit* after looking at Westons pics again I can easily tell the barrel is already gronud down but I would still like measurements to see how much was taken off
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IMG_20110610_200104.jpg

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IMG_20110610_200125.jpg
 
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