What would a P7100, S357, 5x12's, and an A518 get me?

[The_Head]

Yeah I backtracked. My original question was What would a P7100, S357, & 5x12's put to the ground thru my A518 transmission? I got talked out switching to a p pump for now, because it is much easier to swap out injectors.

[RCCUMMINS89]

Doesn't RC carry stiffer springs?

He's running one of my springs (or at least tried it out)

The common misconception (not saying you think this) is that a stiffer afc spring will do away with low end smoke. It CAN help.......but it depends on where the smoke is at. It is more of a tool to help with spooling.

It does slow fueling down..........but only from a boosted standpoint..........so from approx. 2-3# up to 15-20#. But form 0# up to the start of building boost a stronger afc spring does nothing.

A longer afc slide pin can help in this scenario.

HOWEVER, The way our pumps are setup.......there is nothing that can be done without putting in a different afc lever once a pump is maxed.

The afc lever (even with the longer slide pin) does not come in contact with the fulcrum lever until approx. 1/4-1/3 throttle at a cranked up pump position.

Where as on a stock or closer to stock truck, the two meet at almost zero throttle advance.

[The_Head]

Yeah I still have your spring in. It did help a good amount. Another problem I need to deal with is the truck shifts too soon. If I'm not paying attention it will be in too high of a gear and I will stab the throttle, and it will roll the coal a great deal. If I want to roll out with authority, I manually shift it and it does much better. It still makes a nice dark grey storm cloud, it is kind of funny to see it when there is no wind, it just hangs there. I still want less smoke though.

[RCCUMMINS89]

As long as they are of a good quality........5x14s should cure your issues.

5x14 is kind of that crossover point of going smaller is really clean (should be) but going bigger is usually pretty dirty. Also 5x14s move enough fuel to make really good power.

[Remps]

A fuel pin could help post low boost smoke as well, depending on which one. A Denny T would help very little, if at all, compared to a stock pin. But a M&H M2 pin wouldn't allow the afc slide pin to come out very much till the M2 was pushed down a little bit. And smaller injectors more than anything.

[RCCUMMINS89]

Remps - EXCELLENT point.

A factory fuel pin, even turned to its shallowest point allows the slide pin to come out a lot further than a proper aftermarket one.

Point being.........with my valet on, I lost 18 pounds of boost when I went from a factory pin turned to it shallow side to when I went to a BD pin. That shows just how much the aftermarkets push that slide pin back in at zero boost.

I find the M & H pins are really good.

My personal favorite is the BD pin. My truck has ran by far the best with the BD performance pin, they've done a good job with it.

[The_Head]

Yeah I switched back to the stock pin over a year ago. I did have a Denny T stage 1.

My pump just puts out too much fuel for it's own good in the low/mid rpm range.

[Tacoclaw]

If you clearance the cover of the AFC it will let your pin come much farther up in the bore, I think mine is coming clear past where the ramp starts and sitting on the major OD of the pin at the very bottom. Dunno if the aftermarket pins are larger than the factory pi's un-machined OD but if not that may help.

[Tacoclaw]

Here's some pics of mine, as you can see the pin can actually get up to where the actual smoke screw threads start, and also that it allows the pin to come up far enough to sit on it's outside circle at the bottom. I use the coil bind as a stop for pin travel so that's theoretically as much preload as I can get without limiting pin travel. Unless the aftermarket pins have a wider starting diameter before machining they won't cut base smoke any more than this setup.
Not sure what's up with the crooked path my pin is sliding on but whatever.

[RCCUMMINS89]

Taco........... you'll find that with an aftermarket pin, you'll have more control on your lower end.

I've done the same thing as you in the past and it works.......but there's only so much you can do with the stock pin.

[Tacoclaw]

My truck smokes like a whore regardless of what that pin is doing, all it takes is a couple too many degrees of pedal movement at the wrong time.


I just drive it and deal with it, it's a good way to keep people from wanting to use my truck when they can't drive it without looking like an ass every shift.

[Sutter1stgen]

Tacoclaw! Did you chuck the afc top in a lathe to machine that spot? Looks good, I may have to do it on mine.

[Tacoclaw]

I actually used the mill to do that but the lathe would work too. I threw it on a couple parallels and held it lightly with the vice. Just went easy on it, I didn't want to deform it with the vice and get a leak.

A dremel would work as well, just take a little longer.

[Sutter1stgen]

Thanks for the tip. I was concerned about deforming the aluminum as well.

[DodgeFreak]

Rc, Are you having any problems with the pin gouging a groove in the fuel pin? Wasn't it BD fuel pins that had a problem with that??