Best Everyday P-7100 tweaks on the cheap

RacinDuallie

RacinDuallie

Black Sheep Racing
:bow: We need a good thread on the great budget p-pump mods that one could do and still have a great everyday muscle truck that pulls or races everynow and then:ylsuper: :woohoo:

What would you suggest??
Grind your own plate?

Springs?

Adjustments?

All of the above ? And what else?

:dead-horse-fast2::woohoo:
 
Where is the previous P-7100 tune up thread ? :dead-horse-fast2:

There was lots of useful information :huh::
 
Seveal of the threads were lost accidentaly due to a database error. Sorry. :doh:
 
Here is picture of Mack truck (with P-7100 fuel pump) front rack plug, it allows more fuel rack travel.

174-7444_IMG.JPG


more fuel= more power :ylsuper:
 
AsTroSS said:
Here is picture of Mack truck (with P-7100 fuel pump) front rack plug, it allows more fuel rack travel.

174-7444_IMG.JPG


more fuel= more power :ylsuper:
Click to expand...

This is a good mod!
 
ok you guys owe me, i hate typing.
first there is nothing wrong with grinding your own plate, very simple and badass power gains to be had. this is not rocket sciencetist stuff, the deeper the groove, the more fuel up to a point.you can chuck the plate if you don't do the front plug or afc mods.
then we get into the afc mods, with the washers switched you get a nice addition of rack travel, as in fuel. and to take advantage of this you can pull the arm out and grind 100k or so off the end to make sure you are getting full travel. and you need the plug to get the most out of it.
there ya go more fuel than any stock tranny or clutch can take.
 
Governer spring washer mod, it's pretty cheap(costs you 2 washers)!
Stretch out the overflow valve spring.
That's all I can remember at the moment
 
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cut your own plate, if you have a dremel, it's not hard at all, just dont mess it up! tighten the gov. springs on click, adjust the star wheel for more fuel at low boost, that about it for not spending a dime.


wes
 
gunracer1 said:
... then we get into the afc mods, with the washers switched you get a nice addition of rack travel, as in fuel. and to take advantage of this you can pull the arm out and grind 100k or so off the end to make sure you are getting full travel. and you need the plug to get the most out of it.
there ya go more fuel than any stock tranny or clutch can take.
Click to expand...

Can we get a little more detail? Which washers to switch and where to grind the arm? and where on the pump does the new plug go?
 
Grind the plate flat, take out the foot lever out of the afc and pinch the boostline. All free and will make a stock clutch slipwithout trying.
 
Remove the plate. Remove the smoke arm. You will have to grind out the top rear of the timing coverplate to install the plug. SM......Look at the front of the pump. You will see the a plug, hex headed. That is removed. Check for full rack travel.

I install a 4000 GSK, no plate, no smoke arm, 180 HP injectors in a 160 pump, and dyno'ed at 397 HP smoke free. On the strip I look like a gasser.

Those are a few things.

..Preston..
 
what all is involved in installing the plug in the front of the pump?? just take it out and put the new one in?????? or what?

what does stretching the spring in the overflow valve do???
 
come on people i know someone in here knows............
what does stretching the spring in the overflow valve do and what is the difference between shimming out the stock rack travel cap with a washer and buying the one from mack???? Whats the difference??
 
Stretch the overflow valve, makes more fuel pressure at the pump! the stiffer the spring, the more pressure it will keep!

From my experience its esencial to do on most older trucks 94 and 95 once they get a plate, and get some more speed (washer mod or wide open throttle screw)! Cuz i have noticed specially on straight pipe, they pop at the exhaust at WOT. Timing and the overflow mod fixes the popping!
 
I'm with OldSmokey, I am a good mechanic, but have yet to learn anything about these diesels, so it would ne very helpful to have the very simplified (totally ignorant) explanations to some of these mods just so us newbies can figure it all out.

BTW< where would be a good place to learn about these pumps??

Thanks,
George
 
is it possible to put the mack plug on the front of the pump with the pump still on the truck. I would think that the timing cover would be too much in the way.
 
you would have to grind some of the timing cover away! it wont come off otherway! been there done that!

gstanfield: a good place to learn about these pumps arew the forums! i got most my knowledge, practicing and reading DTR! and know most or all of the free & easy p7100 pump tweaks now
 
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