12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

need performance help

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  #11  
Old 09-22-2012, 11:56 AM
angelic0-'s Avatar
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your mpgs will be controlled by your skinny pedal...

it doesn't matter how much tuning you do, as long as you don't get hard on it, there will not be any more travel of the rack...

the only thing AFC tuning and a fuel plate do is allow more travel instead of limiting it...

you can gut your AFC and remove the plate, if you're feather light on your pedal you can drive clean
 
  #12  
Old 09-22-2012, 12:01 PM
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What is meant by gutting the AFC ? Just taking out the plate?
 
  #13  
Old 09-22-2012, 12:04 PM
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Originally Posted by angelic0-
your mpgs will be controlled by your skinny pedal...

it doesn't matter how much tuning you do, as long as you don't get hard on it, there will not be any more travel of the rack...

the only thing AFC tuning and a fuel plate do is allow more travel instead of limiting it...

you can gut your AFC and remove the plate, if you're feather light on your pedal you can drive clean
bad info

a properly tuned afc will limit the fuel until the air is there to go with it so that your not putting out the fire. i still have a fully functional AFC on the 13mm ppump on our drag truck
 
  #14  
Old 09-22-2012, 12:17 PM
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Originally Posted by cummin_un_glued
bad info

a properly tuned afc will limit the fuel until the air is there to go with it so that your not putting out the fire. i still have a fully functional AFC on the 13mm ppump on our drag truck
Correct, this was bad info....

Or maybe not entirely bad info, misinformation is a better term...

Tuning your AFC and taking the pressure off the spring will allow more fuel under less boost, thus... more travel...
 
  #15  
Old 09-22-2012, 12:41 PM
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But wouldn't i wanna build boost faster at a lower rpm and gear? Wouldn't that give me the more power at low end ?
 
  #16  
Old 09-22-2012, 12:59 PM
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Originally Posted by javelinamx1974
But wouldn't i wanna build boost faster at a lower rpm and gear? Wouldn't that give me the more power at low end ?
1st gear on a NV4500 is a granny gear.... it will not build much boost unless you're towing HEAVY...

2nd is like 1st gear on a passenger car, but it won't build really much boost either...
 
  #17  
Old 09-22-2012, 01:11 PM
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with larger injectors you will possibly have to put a stiffer spring in the afc housing. mine has a gov spring from a 160 pump in the afc and it is set to not give full fuel until 40psi but with a stock charger i would set it around 15psi the travel will be the same just when it starts to move will be at a different psi
 
  #18  
Old 09-22-2012, 01:28 PM
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Ok thankyou that helped I've asked that a few times if that was normal or not it doesn't start building alot of boost till 3rd. But when should that really start take off? When I shift into 3rd and hold it to the floor she is boggy and smokes alot untiill about between 15 and 20 psi then she really picks up and goes until 30 psi is it normal for it not to pick up until that much boost or does that seem like to much fuel?

---AutoMerged DoublePost---

Ok as far as I kno my p pump and AFC are stock what size would that be ? And I planed on doin either 3k or 4k gov springs I dunno what size injectors I should get?or what fuel plate best suites my needs ?
 

Last edited by javelinamx1974; 09-22-2012 at 01:28 PM. Reason: Automerged Doublepost
  #19  
Old 09-22-2012, 03:56 PM
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a 95 stick shift pump is a 175hp pump. take the allen plug out of the top of the afc and see where the star wheel is located right now, if it is full forward then i would start by backing it up with a screw driver and see if that helps. also note the location of the afc housing on the pump the holes where the bolts that hold it to the top of the pump are sloted see if the housing is pushed full forward if it is back it up to the middle

i would go with 4k springs some 5x14 injectors since its a stock charger then grind your self a 100 style plate
 

Last edited by cummin_un_glued; 09-22-2012 at 03:57 PM. Reason: Automerged Doublepost
  #20  
Old 09-22-2012, 04:02 PM
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Ok how far should I turn that star wheel and thanx for all the info. do u I i need arp head studs and a different turbo for what I want to do?
 


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