sluggish off line
 

hey guys i need some advice.i raced my truck the first time this weekend.i got tired of hearing my friends mouth about his 2000 model ford truck.well i blew his doors off!but we dead stopped and when we left he jumped me by a full length,then my turbo spooled up and i went by him like he was in reverse.what can i do to make this thing better right off the line?it's like it really don't start pulling good till the top of 1st or 2nd.i have the star wheel all the way foreward,any suggestions?:humm:

what is your TC stall speed? and when you floored it I'm guessing she was rollin some coal before the turbo spooled? you need to tune your afc and play with your timing.

i'm not sure what it stalls at but it's pretty tight.yes it rolls coal until the turbo spooled.i'm fixin to have the timing set to 16.5*.where would you start on tuning the afc?

well what have you done to it so far? other than slideing it FF and crank the starwheel

that's it,should i loosen it some to make the turbo spool faster?

I would take the afc appart flip washers,change your afc spring, and grind .090 off the back of the barrel. put it back together and hook it up to a supplyed air source ( one where you can adjust your pressure). see what psi the foot stops moving at and use the starwheel as a fine adjustment tool. I have my acf set to fully open @ 40psi with your stock turbo I would try something like 25-30 psi fully open.

---AutoMerged DoublePost---

and you don't want lots of fuel down low ... it slows spooling the turbo down

does moving the wheel foreward increase the pressure or decrease it.and wich washers are you refering to?

when you take the 4 bolts off the back of the housing there are 2 washers one has a lip the other is flat ( its easy to see when you get it appart) the one with the lip hits the inner housing and stops the foot from moveing further foward if you swap the washers the foot can move further foward giveing you more top end fuel. cranking the starwheel to the cab is less pressure on the spring moveing the foot faster and throwing lots of fuel down low.

so if i move toward the cab it will prob.spool even slower?

prob will you would be dumping even more fuel down low

Attachment 52164
here is a pic of the washer swap the washer with the lip is on the other side allowing the foot to travel further foward

do you have any pics of the ground barrel?and i was wondering why does tst say if it smokes excessivly to turn the wheel back?

I may have some I'll have to look and they are telling you to put more press on the spring

---AutoMerged DoublePost---

one way puts press on the spring the other takes press off the spring thats how the starwheel works

But smoke makes power... lol Take some fuel out of it down low you should have a little less trouble getting it light timing wouldnt hurt tho.

looking at a cut away pic of an afc it looks like moving the wheel toward the cab would decrease the pressure on the spring.

thats what I said?

lol!i think i kinda understand what's goin on,did you ever find any pics of the barrel?

---AutoMerged DoublePost---

and one more thing,i remember when i first put my plate in that the star wheel seemed to be frozen up so i left it,any suggesions?

Attachment 52149
Attachment 52150

the top one is stock the bottom one I got a little grinder happy with it but you can see where I took bout .090 off the barrel

hm i was told to grind the foot, should i grind the barrel too even after i ground the foot flat?

you can your prob not gonna see much difference. I don't like grinding the foot because it fuels way to much down low, I did this on my first foot I had and never liked it. Ground the barrel on the 2nd and have liked it ever since.

thanks alot man you're a big help.

no prob :U:

:rocking:

is it gonna hurt anything to do all the tuning mods to the afc if i don't change the spring right away?

when you flip the washers the stock spring will be very lose and your still gonna have tons of low fuel. I would wait till you get some springs either from tst or use an old gov spring if you have one they work very well

would it hurt to stretch that one,i think i've heard of people doing this.i'm pulling in a truck pull this weekend so i can order a spring and have it here soon i'm just wanting to tune this thing before sat.also do you know the dimensions on the spring so i can look for one here at work,i build machinery,may have something laying around.

I do not know the dimensions of the spring. I don't know if stretching it is gonna help I would mod it put it back together for the pull and when you get a spring put it in, after you take it appart the first time the second is a cakewalk.

looking at a cut-away pic of the afc,it looks like there is a small piece of sheet metal against the star wheel,maybe to keep it from turning by it's self?or am i seeing things?

---AutoMerged DoublePost---

and if the spring is a little short,can i not get enough adjustment out of the star wheel to make up for this?

if you crank the wheel to much you could cause the spring to bind, up not sure bout the sheet metal I'll have to look when I get off work

https://www.dieselbombers.com/12-val...p-7100-ip.html here's a pic.

oh are you talking about the peice that locks the starwheel in place? when you turn the wheel that peice clicks and locks the wheel so it doesnt turn

i had problems turning mine,i thought it was frozen,is there anything special you have to do to this piece yo get the wheel to turn?

nope should move with a flat head screwdriver ... when you take your afc appart you can see whats wrong it will all be right there

alright just making sure i don't have any suprises when i get into it

i did what you told me,i flipped the washers,ground .090 off the back of the barrel,and i set the star wheel at 20-25lbs. of pressure.i put it together and all i can get out of it is about 7lbs.of boost and no smoke at all!what do i do,this thing is sick!

when you hooked the air up to the afc it was moveing before you put it back in right? what kind of press did it take to make the foot start to move? you may have to loosen the wheel up a little bit.

i just took the housing off and reset it,loos like when i put it on the break-off bolt(which is still in the pump)was under the edge of the afc.pressing the foot hard against the fuel plate.i put it back together and it works fine now,started freaking for a min!does that sound like something that would have caused that?

so the arm was hitting the fuel plate? if the afc can't move it will hold your fuel back

---AutoMerged DoublePost---

also when you set your afc press did you set the arm to start moveing @ 25 psi or go full open @ 25 psi? should be full open @ 25 psi just makeing sure I didn't confuse you

yep,write that down in your little book.you seem like one of the more knowledgeable of our group,but even the best get stumped sometimes:argh:it does spool much faster,but still a god awful cloud,and egt's hit 1500 in 4th gear.

ok so when you first put the hammer down you say it does spool faster? and now with a modded afc and your 0 plate you are almost @ full rack travel therefor you should have more fuel up top ... all you need now is a bigger turbo and the rack plug :U:

cool,one thing i didn't mention,i changed my 0 plate out for an old 100 i had,it gets alot better milage as long as i keep my foot out of it.but it fuels just like a 0 at wot

---AutoMerged DoublePost---

and yes it does spool faster