High idle mod worthy for all?

[joecool911]

I am wondering for us that live in more moderate climates if the high idle kits are worth doing? Not exactly sure if they are for everyone or just those who live in cold areas? Will the mileage feature work for all climates too?

[hex0rz]

Moderate? How moderate? Bay area CA, moderate?

 

IMHO, if the IAT temps see what the resistor value is for the MPG setting most of the time, I probably would not get it. Thats just me though. But even then, how hot does it need to be outside to produce that ohm value?

 

The one good thing about it is that say an 80 degree day only makes an ohm value that reflects the IAT as less than what the MPG setting is. Well, I cannot say how much of a difference it would make, but you would have that much difference.

 

If I lived in AZ or something like that, that did not have weather temps less than 40 on a regular basis during the coldest parts of the year, I probably would not get it, myself.

 

...but then again, I do not live in AZ! I'm sure someone like Mike could chime in and give better reasoning about it than, I.

[Mopar1973Man]

Lets say optimal manifold temperatures are about 140*F outside so outside temperature needs to be about 100*F. So for every 10* below the 140*F IAT you lose roughly 1 MPG.

 

Remember this is economy running not racing.

[joecool911]

Wow, so at 50* we'd theoretically loose 5 mpg? 30* loose 7mpg? If that's true, that's a lot of fuel over the long haul. I assume you're only advocating using the mpg mode while not towing or hauling?

Edited March 23, 2014 by joecool911

[Mopar1973Man]

Wow, so at 50* we'd theoretically loose 5 mpg? 30* loose 7mpg? If that's true, that's a lot of fuel over the long haul. I assume you're only advocating using the mpg mode while not towing or hauling?

 

I use the fooler empty or towing without problem. As IAT temperature falls the VP44 advances timing excessively. Without the fooler I drop considerable through the winter time and the timing rattle is excessive. So when I select the MPG position you can hear the timing shift in about 1-2 seconds and the rattle is gone as well as the ScanGauge II popping up 2-3 MPG roughly. But still in all the colder the temperature actually is the worse the MPG's get. I typically keep winter fronts in my truck well into April to keep the IAT temperature up as much as possible.

 

The thing is the whole cold air intake thing tend to be backwards for MPG's because if you driving conservatively the boost pressure is low so there is no manifold heat really so the liquid diesel fuel takes more time to convert from liquid mist to vapor to ignite. So the extra manifold heat aids in the conversion process shorting the time.

 

As for IAT temperature the colder the more advanced the timing gets and then coupled with high cetane fuel with quick ignition rate and low BTU value the timing get excessively advanced and that is where the heavy timing knock comes from so the high IAT temp value tends to retard the timing which brings it back to reason.

[Me78569]

Without the fooler I never see 143*f for IAT.  I run the fooler no matter what honestly. 

[Mopar1973Man]

???

 

I seen as high as 150*F cruising with 110-115*F summer heat.

[Me78569]

Nope never, highest I have ever seen was 130ish cruising, 

 

Who knows what at WOT as I am not really paying attention. 

[Mopar1973Man]

Usually I see hotter temps at slower speeds like in town cruising speed limit at 25 MPH city or 15 MPH residential. Less wind flow to cool the intercooler.

[Me78569]

yep, agree'd but even 4th lockup going up the pass from 6000' - 8700' doesn't give me IAT temps above 143.  Odd I agree, but that's what I see. 

 

hence why I leave the fooler on. 

[Mopar1973Man]

I typically see about 130-135*F at hghway speed at 100-110*F outside temp. I can see huge spikes of 160*F (or higher) hitting the exhaust brake.

[Me78569]

Yea typically I see temps ambent temps never above 100*F  so that may be the entire issue, and no exhuast brake....yet    VGT here I come

[joecool911]

How are you guys reading these temps?

[Ilikeoldfords]

Usually with either a scan gauge or some programmer that has a live data monitor.

[Mopar1973Man]

Me is using Quadzilla module to read it I'm using a ScanGauge II live data tool. It's a amazing what you can learn about efficiency when you study all the sensors and what is going on.

[Me78569]

there is a huge amount of data that is able to be read. 

 

I can see

 

Voltage to ecm

Fuel temp

iat temp

throttle position ( APPS)

engine load

coolant temp

 

obviously( egt boost trans temp)

 

It makes it significantly easier to diagnois issues. 

 

I can see bad connections via voltage, bad grounds via voltage, bad map via values, bad apps via position jumping etc etc etc

 

I can drive more efficently by watching load vs egt vs throttle postion vs boost. 

 

A tool such as the scan gauge or a tuner that reads the livedata is a great.

[Ilikeoldfords]

Where is the fuel temp sensors on these trucks? Didnt realize there even was one. What would the computer use that value for?

[Mopar1973Man]

Where is the fuel temp sensors on these trucks? Didnt realize there even was one. What would the computer use that value for?

 

 

The black sensor on the end of the ribbon is a tone wheel pickup and fuel temp sensor.

[Me78569]

Yep within the VP44.

 

I supposed fuel temp plays a role in kicking on the fuel bowl heater? 

[Ilikeoldfords]

That would make sense. I figured the fuel heater just came on with the grid heaters.