Well gang... I've been playing with theories and ideas for long enough now its time to put them into a design and see if it actually works. We all know the 24V's seem to take a good tumble in MPG's as the winter sets in well ISX proved that with the 12V engines with static timing that MPG's don't change. Well if you look at it the only thing that could be tossing this out the window is the IAT sensor on the 24V is changing the VP44 performance. Most know that colder air produces better HP/TQ because colder air is denser and requires more fuel to keep balanced. Well if you reverse this and warm the air (in theory) the VP44 should retune and burn according to the manifold temp. So what I've done tonight is fished through my resistor pile and found 3 I'm going to use for test candidates. Orange - White - Red - Gold = 3.9K Ohm = 116*F IATRed - Violet - Red - Gold = 2.7K ohm = 132*F IATRed - Black - Red - Gold = 2.0K ohm = 148*F IAT So now tomorrow I'm going to pull 3 test runs on the same piece of highway... Seeing if the highier the IAT temp increases the MPG or not... I'll can give you something to think about... Grid heaters are NOT controlled directly by the IAT... With the 2.7K Ohm resistor in place before even starting the grid heater still where hitting as normal. So there is more to the grid heater that the IAT temps... ... On the cutting edge again...

As for the temp sensor in the VP44 its phyiscally attached to the electronics and is part of the speed sensor module... [ATTACH=CONFIG]2325[/ATTACH] As you can see there is no way your going to modify that sensor with a ribbon cable inside the VP44...

Just a Q from the peanut gallery... If the IAT Fooler advances the timing... and the various performance boxes alter timing & fuel parameters... Why do we need to IAT Fool? Does the box not do the job? What will the interaction of a box + IAT Fooler be?

Inquiring minds want to know!!

This is fascinating.

Russ

The IAT temp sets the baseline timing that the ECM uses with the VP44 so as weather conditions change then so does the baseline timing. So if the timing is excessive advanced or retarded then the Edge (or addon module) will advance the timing from that point... So if I give the IAT temp a summer temp to play with to give me the leading edge for timing then everything should go up from there...

One of the few reasons I kept my stock fuel filter housing, fuel heater, etc.. Because the fuel heater will come on at temps below 70*F so that is heat source #1... Since my fuel filter housing is aluminum and the coolant passage heats the cast iron manifold rather well... Well now the filter housing will absorb the heat from the manifold heating the fuel heat source #2.

With my winter front I hold a fairly constant 195-197*F worth of coolant so I'm not worried with the ECT temps...

--- Update to the previous post...

Just for ISX and fanless setup... Clutch fans do there job rather well...

http-~~-//www.youtube.com/watch?v=QeKndmCy_yk

How about I pull the wire tap and run only timing from the Edge Comp? Would that fit the bill?

How about I pull the wire tap and run only timing from the Edge Comp? Would that fit the bill?

You said in the summer on a stock truck the thing is wayyy retarded. I am saying if it is wayy retarded in the WINTER, it might be a good thing.. So you fool the IAT so it is retarded, and turn the edge off so it doesn't advance it. I don't know what pulling the wire tap is supposed to do when that only comes into play when you floor it and want more fuel than stock. We need to find out more about where that timing is at. All I keep hearing is advance advance advance well running 55 is only 1600 on most trucks which is the low end of things so you wouldn't need it to be advanced. When I made mine 16* or more it stole power from my low end.

As for the temp sensor in the VP44 its phyiscally attached to the electronics and is part of the speed sensor module... As you can see there is no way your going to modify that sensor with a ribbon cable inside the VP44...

just a thought to possibly consider, with all this advance/retard/hot air/cold air scenarios concerning cylinder temperatures.. Anyone factor in cylinder head 'pressures'? I'm not trying to get too technical at this stage in the game, just a point to consider when tinkering with cold air, timing, fuel, and boost

My wish list... Would be to T the IAT sensor with a line to an in-cab switch. Sensor on... used for starting & maybe hot weather. Sensor off... after starting & cold weather.

just a thought to possibly consider, with all this advance/retard/hot air/cold air scenarios concerning cylinder temperatures.. Anyone factor in cylinder head 'pressures'?

I'm not trying to get too technical at this stage in the game, just a point to consider when tinkering with cold air, timing, fuel, and boost

That is what I have been thinking of the entire time. Advancing it makes head pressure go up but only after the injector has fired. This is why you get a hell of a knock because of all this advancing, mine doesn't knock like that. Up until the point of the injector firing however, the heat of compression is still building and is hotter when the piston is closer to TDC since it is compressing more. Since the incoming air is really cold (since it is winter), you would want more heat in there to detonate the injection better. It wouldn't matter so much in summer. With cold incoming air being more dense, I predict the temperature rises more because there are more air molecules being compressed. By retarding the timing you can wait for the air to get really hot and then fire in the injection and watch it explode more efficiently because there are more air molecules in there.

The VP will still advance timing with engine RPM, but the baseline timing needs to be more retarded in the winter.

I hear ya. I know my '01 is A LOT more noisy when it's cold than my old '96 was.

just a thought to possibly consider, with all this advance/retard/hot air/cold air scenarios concerning cylinder temperatures.. Anyone factor in cylinder head 'pressures'? I'm not trying to get too technical at this stage in the game, just a point to consider when tinkering with cold air, timing, fuel, and boost

Hmmm... Just do the math on the non-running compression of a Cummins with 35 PSI boost is over 1,000 PSI at TDC... I'd be more concered with extremely high cetane fuel (>50 Cetane), propane or water/meth... These fuels act as if the timing timing is increased because they ignite very easy, early, and quickly... Hence why some people have problems with water/meth blowing the head gaskets...

I hear ya. I know my '01 is A LOT more noisy when it's cold than my old '96 was.

You said in the summer on a stock truck the thing is wayyy retarded. I am saying if it is wayy retarded in the WINTER, it might be a good thing.. So you fool the IAT so it is retarded, and turn the edge off so it doesn't advance it. I don't know what pulling the wire tap is supposed to do when that only comes into play when you floor it and want more fuel than stock. We need to find out more about where that timing is at. All I keep hearing is advance advance advance well running 55 is only 1600 on most trucks which is the low end of things so you wouldn't need it to be advanced. When I made mine 16* or more it stole power from my low end.

Test run done... (You don't want ot hear it...) Edge Comp turned OFF! Round trip to New Meadows, ID and back home (40 miles) pulled 12.5 MPG!

12.5? Just what did you do to it? (To be sure I never do the same). OUCH!

12.5? Just what did you do to it? (To be sure I never do the same). OUCH!

He turned his edge off but left the IAT fooler on.

This is just incredible. So with all that crap advancing it, the mileage goes way down, with it retarding it all the way, the mileage goes way down. Are we even sure it is advancing it and retarding it like we think? I know nobody seems 100% sure about what exactly it is doing. At least we know with the edge and the fooler IAT it gets a lot better mileage. But still this is just ate up, I get 16 with the damn 4k lb enclosed trailer at 70mph, big tires cant kill you THAT much. I don't even care how much the timing is screwing you over, something is just way off on those things. I'm gonna figure this out!

I'm gonna see what I can do about logging some parameters this weekend. Seems like we need that for a baseline.

I'm gonna see what I can do about logging some parameters this weekend. Seems like we need that for a baseline.

What can you log? We need some actual timing numbers or something. Or at least to know if it is advancing or retarding. If you can find out anything though that would be great

Other factors on this trip it was late evening... 30*F at home and cooling in New Meadows... By the time I left New Meadows for home again it was down to 24*F and the fog was setting in and getting bad so this was no cruise control trip and varied speed between 45-60 MPH... On top of this there is a fresh oil change Chevron Delo 15W-40, fleetguard oil filter, and new roll of TP in the Frantz filter... I will admit it sucks to drive with the Edge Comp turned on boost is limited to 22 PSI and very doggy getting built up to speed. Other odd factors is the IAT is locked at 132*F... I noticed sometimes the grid heater come on and sometimes they don't... Like this morning start up there was no grid heater at 34*F and started fine... But last night the engine was still warm (120*F) and grid heater came on... Go figure... I was going to make a run today but plans changed last night... (dang!)

wow this is huge now! hard to keep up but doing my best to cant wait to see what comes next:shrug:

--- Update to the previous post...

I'd pass a stone the size of Kansas, if my 24v would break >19mpg on the highway.. Hell, I'd like to see > 14 in town.

My 12V with #10 and 38psi boost got 17-18 in town, and 26 on the highway at 68mph (CC) from VA to NY.

I've used 3/8 tank on this last fuel up, and I've barely reached 120mi.