Iam new to diesels, have 95 gmc 2500 6.5T. purchaseing cooling upgrades,remote pmd with cooler. truck has 47350 orginal miles. ran across talk of resistors for better performance,like the idea but i dont know what to get, or where to put it. help please!
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
pmd resisters?
- Thread starter kdntx
- Start date
matuva
Tropical 6.5er
The resistor sits inside the connector of the PMD. There's a notch, so you can't put it wrong if you care.
Standard is #5
#9 is said to be the one wich "tells" the PCM to increase fuel flow to injectors, and so increase power. But it won't make you gaining a full stable of ponies, I will say 5~10 at the best.
Standard is #5
#9 is said to be the one wich "tells" the PCM to increase fuel flow to injectors, and so increase power. But it won't make you gaining a full stable of ponies, I will say 5~10 at the best.
dangerousdave
1994 6.5 Suburban
Welcome.
Please read through the sticky list. It's a great education and resource.
Hmmm... "I love the smell of DIESEL in the morning; it's the smell of victory."
George C. Scott (paraphrase?)
Napalm, diesel, whatever.
Please read through the sticky list. It's a great education and resource.
Hmmm... "I love the smell of DIESEL in the morning; it's the smell of victory."
George C. Scott (paraphrase?)
Napalm, diesel, whatever.
- Staff
- #5
Welcome, kdntx! Please take the time to fill out your signature so we can all see that you're driving.
I hate to disagree with my friend Matuva, but changing a resistor won't give you enough of a performance bump to hardly notice... here's why:
The resistor is designed to 'calibrate' the Injection Pump to a specific standard delivery... when the computer calls for 68mm^3 of fuel, and the pump delivers 68mm^3, then the IP needs no calibrating... it gets a #5 (neutral) resistor.
Each increase or decrease in resistor number makes a change of 0.5mm^3 in fuel output.
If the IP delivers 66mm^3, then it gets a #9 resistor, which bumps it up to the right output level (68mm^3) as requested by the computer.
As you can see, changing resistor number is going to make very little difference to your fuel output. More importantly, YOU don't know what resistor you have right now... it could be a 7 already, meaning the best you could get (by installing a #9) would be an increase of 1mm^3 of fuel. That's at maximum output, with your foot right flat on the floor.
Now, putting a chip in your computer can raise your mazimum fuel output by 10-20 mm^3. THAT is a significant difference, no?
Post your details in your signature, do some reading in the 6.2 and 6.5 Technical reference sections. Feel free to ask questions - there are some VERY sharp people on this site, probably the best you'll find online for your truck!
Jim
I hate to disagree with my friend Matuva, but changing a resistor won't give you enough of a performance bump to hardly notice... here's why:
The resistor is designed to 'calibrate' the Injection Pump to a specific standard delivery... when the computer calls for 68mm^3 of fuel, and the pump delivers 68mm^3, then the IP needs no calibrating... it gets a #5 (neutral) resistor.
Each increase or decrease in resistor number makes a change of 0.5mm^3 in fuel output.
If the IP delivers 66mm^3, then it gets a #9 resistor, which bumps it up to the right output level (68mm^3) as requested by the computer.
As you can see, changing resistor number is going to make very little difference to your fuel output. More importantly, YOU don't know what resistor you have right now... it could be a 7 already, meaning the best you could get (by installing a #9) would be an increase of 1mm^3 of fuel. That's at maximum output, with your foot right flat on the floor.
Now, putting a chip in your computer can raise your mazimum fuel output by 10-20 mm^3. THAT is a significant difference, no?
Post your details in your signature, do some reading in the 6.2 and 6.5 Technical reference sections. Feel free to ask questions - there are some VERY sharp people on this site, probably the best you'll find online for your truck!
Jim
matuva
Tropical 6.5er
You're right Jim.
That's why I was talking about ponies instead of horses
That's why I was talking about ponies instead of horses
matuva
Tropical 6.5er
BTW, correct me if wrong : ponies are "dwarf" horses, aren't they ? :sosp:
- Staff
- #8
LOL... I get it now! My momma raised a slow child...
Turbine Doc
Just Another Diesel Guy
BTW Heath uses a #7 in his remote mount kits, incrimental gains by swapping them is not worth the effort IMO, Bill's data from a HD 6.5 equipped truck ambulance if I recall the story correctly, shows the 7 to be the best fuel provider overall.
Some "balck magic" that happens with the feedback vs the algorythm in the PCM the sets fuel delivery schedule, to where it's not a simple matter of resistance/current coming into play, the PWM also impacted by resistor used.
I've swapped 5s with 9s, I did not see any substantial difference, possibly even an imaginary change, and now have the 7 in both of my trucks and have to take it on faith if Bill says the 7 is the best then I'll take that to the bank and run wiht it.
Some "balck magic" that happens with the feedback vs the algorythm in the PCM the sets fuel delivery schedule, to where it's not a simple matter of resistance/current coming into play, the PWM also impacted by resistor used.
I've swapped 5s with 9s, I did not see any substantial difference, possibly even an imaginary change, and now have the 7 in both of my trucks and have to take it on faith if Bill says the 7 is the best then I'll take that to the bank and run wiht it.
Missy Good Wench
Wild Blonde from Cloud Mt
The resistor swap wont make any difference until the ECM samples the cupboard to see whats there.
If the resistor is too far out of line with what the ecm thinks should be there it will complain.
MGW
If the resistor is too far out of line with what the ecm thinks should be there it will complain.
MGW
JMJNet
Recruit
My common sense on this:
if you have to buy it get a #9,
if you already have one like #5, just keep using it (no need to buy #9).
if you have to buy it get a #9,
if you already have one like #5, just keep using it (no need to buy #9).
HighSierra86
Active Member
If anyone wants to believe otherwise they can call walt, and he will be glad to assure you a huge increase of power
Matt Bachand
Depends on the 6.5
If anyone wants to believe otherwise they can call walt, and he will be glad to assure you a huge increase of power
LOL, yep!! "In fact, most dealerships buy the FSD Heatsync from me" direct quote from that lying bastard.
Turbine Doc
Just Another Diesel Guy
Has to be taught on OBD-IIs no self learn on those like the OBD-I, OBD-II will run on stored value until TDCO learn with scan tool or ko/ko & APP to floor has been initiated, actually OBD-II will run indefinately until learn is commanded without any resistor in the FSD.
I did this on purpose to discredt the premier lying purveyor of "clap trap" devices for the 6.5 A-1 Customs, (aka "steaksauce") and his bogus variable rate fuel control :9898: seek & find his site at your own peril :scared: many pop up/spams from that site.
But if you do feel like searching him out make sure you do a google search, he has to pay for that, and if done enough maybe it will bankrupt him and he will finally be off the web instead of ripping off the unsuspecting 6.5er that stumps across his site and doesn't know any better.
Last edited: