Adjustable 10k quick question - Diesel Forum

johndeerebones · 04-22-2005, 07:52 PM

I am gonna put my 10 on a POT in the cab and wanted some input from you guys.

I tried the 5.6k resistor and off the line was great, but about 16-1700 rpms it flatlined and would hardly gain speep until you backed out of it.

The 10k works fine but want some adjustability.

I'm gonna use a 5k - 15k pot, but was wondering how much extra resistance I should put in. If the 5.6k resistor didn't work, I know the 5k will be worse. I thought about putting about another 2k in the circuit to make a 7 to 17, anyone experimented with this to see what the lowest resistance your trucks would stand is? By the way my truck has a MLE1 computer code and is the 225 hp version, but does not have splitshots.

johndeerebones · 04-22-2005, 08:36 PM

No one?

AggiePSD · 04-22-2005, 09:06 PM

Chris has an 18k in his and it runs like a bat outa hell. Might try that. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

masami · 04-22-2005, 09:07 PM

Try using the 5.6K resistor in series with the 10K potentiometer. Connect resistor to one outside connection of the pot and other side of resistor to sensor. Connect other sensor wire to center connection of pot. This will give you a range of 5.6K to 15.6K adjustment, If you want the pot knob to rotate in the opposite direction for resistance change, just change the outside wire pot connection to the other outside wire pot connection. Do NOT wire the resistor across the pot terminals. So its sensor-wire-resistor-wire-outside connection of pot-middle connection of pot-wire-sensor. The resistor value sets the minimum resistance of the circuit. The vaue of the pot gives the adjustment range.

johndeerebones · 04-22-2005, 11:23 PM

No, if it is a 5 to 15k pot, a 5.6k resistor in series would make it a 10.6k to 20.6k circuit. In this mod, less resistance means more hpop oil pressure. that would be the same or less than what I have now with just the 10k.

In a series circuit, resistances just add.

Larry S. · 04-22-2005, 11:42 PM

Where did you find a 5k to 15k pot? Most go from zero to some high resistance. I use a 10k pot with 5.6k in series as described above. 5.6k flat lines and sets a CEL on mine but 8k works good. The lower the resistance the better it works until you hit the limit of your HPOP and then you flat line. Of course if the resistor is hooked in at idle the idle will be real rough at the low value resistances. If you do have a 5k to 15k pot hook a fixed resistor with a value equal to how much greater than 5k you want the bottom resistance to be in series with the pot. If you want 7k as the bottom add 2k in series, etc. Your post makes it sound like you have this all figured out but I thought I would add my explanation.

johndeerebones · 04-22-2005, 11:50 PM

Ok, we agree on the wiring. I was planning on doing this a while back and swung by radio shack and checked out the electronics drawers. I could swear I saw a 5 to 15, but I may just be thinking of how I was gonna do it, don't remember. But anyway you answered my question, about 8k doesn't flat line? I know with the 5.6 mine falls on its face like you lost about 6 cylinders if you get into the loud pedal too much.

Just out of curiosity does the map sim seem to work good in combination with your other mods? I thought of trying the check valve in the map line thing so my map see max boost all the time, but don't know if that'll make it run like crap at low rpms or not.

BadTrukRisin · 04-23-2005, 08:41 AM

You don't want the computer to see a short in the circuit so that is why you do not use a resistor that goes from 0 to 15k without a safety net resistor in series meaning that if you put a 5k in series then the lowest resistance will be 5k and not 0 ohms. [img]/ubbthreads/images/graemlins/biggrin.gif[/img]
Bud

johndeerebones · 04-23-2005, 04:05 PM

Right, 0k wouldn't work anyway. I just thought I saw a 5 - 15k pot by itself at radioshack.

Larry S. · 04-24-2005, 10:41 PM

8K seems to work good with my Babys. I've seen some trucks where 8k was too low but that is not often and you can turn the knob up a bit if it happens.

[ QUOTE ]
Just out of curiosity does the map sim seem to work good in combination with your other mods?

[/ QUOTE ]
The MAP Sim does work with other mods quite well. I picked up 20 HP above my chipped power with it before my injectors were put in. I had problems with letting the simulated boost go too high and setting a CEL but my latest circuit has a boost limiter that I set at 23 or so simulated PSI. It still brings the simulated boost up fast but stops it at the set limit. I have one of the new units out for testing and it should be installed next weekend. It really looks good on the test bench. The one in my truck doesn't have a limiter so I have to keep it turned down a bit.

johndeerebones · 04-25-2005, 08:40 PM

So with that said, the ol check valve in the map line trick does basically the same? After you get good boost once anyway? All it is doing is letting map see more boost than you actually have, correct? [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Larry S. · 04-25-2005, 11:01 PM

What the simulator does that the check valve doesn't is it fools the PCM into thinking boost is higher than it is at low boost. That allows more fuel to be dumped in at low boost and you get more low end torque. It reduces the turbo lag effect quite a bit. The check valve in the MAP line does a similar thing but doesn't drop back to low boost at idle. The Simulator is smoother and more linear in its operation than the simpler mechanical means of acheiving the same effects but at the cost of being more complex and expensive.