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tuning!

3K views 28 replies 8 participants last post by  PhilipR 
#1 ·
ok since i live in ohio and the weather is getting worse the tuning of my truck needs fixed!!!! my truck has a very bad lag and i need to fix it before the snow falls! i was driving this weekend and went to get on the highway on raining roads and punched it to get in front of traffic and the trucked lag for a second then hit hard and almost put the truck sideways! kinda freaked the girl i was out with out a bit and made me remember that i need to fix it before the snow falls!! my sig has all my mods!!!
 
#4 ·
Increase tension on the AFC spring. This will require more boost to get to full fuel. Sliding the housing rearward will help with this too. That way, you won't be building boost as fast. And it will take it a little longer to come up to full fuel.
Sean
 
#5 ·
thanks guys! i will give this a try and let you know how it works as soon as i get over this cold!
 
#6 ·
I agree. I tamed down my AFC settings and like it much better now. Much more smoke control, and smoother from the start. Find the sweet spot with your AFC tuning, and it will not take away overall power. It'll just make it nicer to use.
Max fuel right out of the gate is not what you want unless you're just blowing smoke.
 
#7 ·
i finally am over this stupid flu now if the weather hold i can do it soon! really hope this works!
 
#9 ·
lol well i moved the afc all the way back and now the truck can barely get out of it own way till 2k rpms, and no black smoke till then. why? going to move it to the half way point and try. i really have never had any black smoke some under wot, but that is it not a freight train style smoke either, could it be something else?
 
#11 ·
at wot it is still like 38 to 40(yes i know i have to adjust the boost elbow to 35 just have not got there yet lol) but you can see the boost struggle to get to 10psi then it hit and it takes less then a second for it to hit 38psi! smoke comes about the time the truck comes alive no smoke till then
 
#13 ·
Yeah, you are taking too long to come to full boost. With the amount of fuel you have, your spring is too tight right now. The further you can move the housing forward, the more overall travel you will have, and the more fuel you will get on top. Like garret said, I would try sliding the housing forward, and adjusting the star wheel from there to put tension on the spring and diaphragm.

Maybe start with them both in the middle position and see what you think, If it needs more fuel sooner, either slide the housing forward more, or back of the star wheel depending on what you want up top. It might be helpful to try a different spring as well.
Sean
 
#14 ·
Is the stock GSK spring stiffer or lighter than the stock AFC spring?
 
#15 ·
did some adjusting and it is alittle better but i will have to keep trying! can i make the adjustments to the starwheel with the truck running?
 
#16 ·
It will spray some oil out. If you want you can bring it by and we can mess with it.
 
#17 ·
for real? dude that would rock! i would love to have some help with this!!! and would love to see this truck i hear about!
 
#18 ·
Sure. I'm not a major expert but I have been in and out of the AFC and know my way around it. Maybe getting the AFC Spring kit from TST on hand before we mess with it might be a god idea as well. I think it's like $35 or something like that. Unless the stock GSK is softer if it is I have my stock springs on the bench and we can try them. You need to get the turbo to light a little faster so we need to get a little more fuel to the engine sooner but not put the flame out. So we'll set the smoke screw and grind the barrel and the washers if you haven't already.
 
#19 ·
The TST springs are softer, but longer than stock. The gov spring is way stiffer, I tried running a gov spring with the starwheel and housing full forward, but it was really doggy and barely put a haze off the line and cleaned right up.
 
#20 ·
Okay. He's coming over on Thursday and we are gonna see what we can get done. I am going to grind the barrel and the washers and set the smoke screw and set the starwheel so the foot is out of the way fully at 30psi or should I go lower?
 
#21 ·
I think 30 psi would be an ideal starting point. I think I have mine set for full fuel at 32 psi??? Need to back out my pre-boost screw a little I think.
 
#22 ·
ok i will be there Thursdays, and i really appreciate the help! and as far as 30psi i have no idea, i only build 38 to 40 psi! man i need some more goodies for this truck!
 
#24 ·
30psi is where we are going to set the starwheel so the AFC foot is out ofthe way and you are riding on the plate. That is if your plate is FF. I might be home a bit early on Thrusday so I'll call you. I have to run to Akron for an interview and I'll call you when I am done.
 
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#25 ·
thanks again Phil for all the help the truck is great now! the turbo light fast now! the last adjustments made it great!! really appreciate it!!!!!!!!
 
#27 ·
I'm glad it's running better. FYI for everyone on something I found in his AFC. We replaced the washers with some from Menards. When I was setting the starwheel and using compressed air to move the foot full forward at 30psi there was an audible clink and the foot would not move all the way forward. I found the rear washer was contacting the housing and not allowing full travel like the stud was short. I shimmed it out with a small washer and that gave it full travel and still allowed the nut to have full thread engagment as well. I ground the barrel 1/8" and set it for full travel at 30 psi. When we took it for a drive when he first got there I couldn't believe what a pig it was off the line.....it was terrible. But it's all fixed now. You might want to turn that smoke screw in another full rotation or two and give it a shot as well. Without using the compressed air to set the starwheel tension on the bench no one would have found the washer contacting the housing and limiting travel. I think I might pull mine off and check it as it has me curious.
 
#28 ·
ya it was just amazing what it went from to what it is!!! i new it was a tuning issue i just was not educated enough to figure it out! thanks again for all the help!
 
#29 ·
Yeah it wasn't anything you messed up with your stuff before it just needed tweeked. Like I said if I wouldn't have pulled the AFC off and noticed that the washer was hitting we would have never figured it out. You could have turned that starwheel all you wanted and it wouldn't have worked right. Now you can update your sig to. It's been Sonzabichez tuned LOL.
 
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