Dodge Ram 2500 diesel engine comp mods...

[steve05ram360]

Truck... 2005 dodge ram 4x4 diesel with 3" lift, 34" tires & AT. Started another thread in the aero forum regarding mods I have in mind to clean up the underside of the truck. [pfth... cant post a link to the other thread... Its over in the aero mod forum if anyone wants to read it, I will up date this once I have 3 more posts ] http://ecomodder.com/forum/showthrea...tml#post336473

Under the hood I have a few other ideas I need feedback on... 1st off there are performance mods that have brought me from 15~16 up to 17~17.5 mpg. Have the stock airbox, AFE Torque tube down to the stock turbo, AFE Arcflo intake horn, smarty programming, stock DP into an Aero 4040 muffler into a 30" magnaflow muffler.

So... mode 1, port the airbox and attach a hose to it in such a way that it would draw air from the back of the engine by the firewall so it is warmer than what it gets from the front... (I'm convinced the motor gets the best performance when ambient air temps are at 80~85F). I have the torque app that I can monitor intake air temps with and am thinking of a 2~3" electric exhaust cutout to control flow in the event it gets hotter than what I'm after.

Second mod would be to draw that warm air across the fuel rail to warm up the rail a tad bit. Going this way as I think it's the best way to use the heat that is under the hood vs adding an electric heating method. On the flip side of the coin...one mod I did a while back on my last gas truck was to cool the fuel. This gave me a 6% average bump in mpg over the 1600 miles I tested the mod on... did approx 800 w/o the cooler than 800 with, cant argue with the data. This plus other mods took that truck from 11.5 mpg up to 14.5, 2000 ram 1500 4x4.

Again the truck is getting about 17.5 mpg on the hiway, this was before swapping out wheels & tires, had 33" 12.5 wide 18's on chrome wheels. Now there are taller, narrower tires on a different wheel that shaved 9# off ea wheel. I have not measured the current mpg yet so I dont know where it sits now. The goal is to get up to 20~21 mpg on the hiway doing approx 65 mph.

Anyways, what do you guys think?

[oil pan 4]

You don't want a warm air intake on a diesel. As long as you can keep your intake manifold temperatures above 30'F to 40'F its all good.
You don't want warm fuel unless you can heat it to about 300'F. There was a study posted on here that showed fuel economy and power dropped off as fuel was heated, until it hit 300'F.
The only time warm air and warmed fuel will help you is winter cold starts. Besides that your injectors are burried inside the cylinder head, the fuel gets plenty hot before it gets injected when the engine is warm. You dont want too hot of fuel going to that expensive CP3 injector pump.

What I think is don't try gas engine eco mods on a diesel and loose that muffler and run the shortest possible straight pipe you can get away with.

[steve05ram360]

hummm interesting. So cooling the fuel to a point would probably be good then...??? Are you aware of anyone actually putting warming fuel to the test?

the idea I have for the air hose plumbing would be that it is flexible so I could go either way with the hose. As for the air temp... while the butt dyno is not ever calibrated performance is noticeably better every time it is in the upper 80's, low 90's. Just cant control it since it's ambient. The goal would be to be able to get better control over the intake air temp and measure fuel economy.

[redpoint5]

Originally Posted by steve05ram360

Truck... 2005 dodge ram 4x4 diesel with 3" lift, 34" tires & AT...

The lift is hurting your FE more than anything else. It seems funny to talk about an underbelly when the truck is standing so tall and has such large tires.

So... mode 1, port the airbox and attach a hose to it in such a way that it would draw air from the back of the engine by the firewall so it is warmer than what it gets from the front... (I'm convinced the motor gets the best performance when ambient air temps are at 80~85F)...

Second mod would be to draw that warm air across the fuel rail to warm up the rail a tad bit... On the flip side of the coin...one mod I did a while back on my last gas truck was to cool the fuel. This gave me a 6% average bump in mpg over the 1600 miles I tested the mod on... did approx 800 w/o the cooler than 800 with, cant argue with the data.

Sure we can argue with the data. We have no idea how you controlled other variables or how you measured anything. In one sentence you say warm fuel will improve FE, the next sentence you say cold fuel improves FE. Which is it?

On what principle of physics does heating or cooling the fuel improve the thermodynamic properties of combustion?

I have not measured the current mpg yet so I dont know where it sits now. The goal is to get up to 20~21 mpg on the hiway doing approx 65 mph.

Anyways, what do you guys think?

I think you should chart your current MPG so that you have a baseline to compare with. Even better yet, do ABA testing with any mod that might affect aero or rolling resistance. Without this, there will be no evidence that any work you do has any benefit.

20mpg at 65mph should be achievable from a stock truck. Stop modifying the truck in ways that hurt FE, and improve the efficiency of the driver; this will help the most.

Originally Posted by steve05ram360

hummm interesting. So cooling the fuel to a point would probably be good then...??? Are you aware of anyone actually putting warming fuel to the test?

Warming or cooling fuel just isn't something worth bothering with. It's not going to make a noticeable difference, and the truck is already designed to operate within a range of temperatures.

[oil pan 4]

Originally Posted by steve05ram360

hummm interesting. So cooling the fuel to a point would probably be good then...??? Are you aware of anyone actually putting warming fuel to the test?

One of the other diesel guys posted a study about fuel heating. I think it was by some university.

The only OEM that tested fuel heating/cooling that I know of was cummins marine, they found that fuel sent to the pump at a tempertuare of 75'F seemed to preform best.

[aliazharshah]

Any one know about the plasma ignition system. I want to make plasma ignition myself, Thanks

[steve05ram360]

Originally Posted by redpoint5

The lift is hurting your FE more than anything else. It seems funny to talk about an underbelly when the truck is standing so tall and has such large tires.

I understand that the lift hurts FE, thus the reason for the other post. Since my truck sees off road enough to bump up the ride height to begin with, it needs to stay. The other post I did was intended to get some feedback on the ideas I had about helping out under there as much as possible.

Sure we can argue with the data. We have no idea how you controlled other variables or how you measured anything. In one sentence you say warm fuel will improve FE, the next sentence you say cold fuel improves FE. Which is it?

Well the data was pretty simple since I did the mod in the middle of the trip... 800 mi going up mpg = x, 800 mi going back, mpg = 8 + 6.5%. It was the posts I read here that are claiming the FE goes up with warmer fuel, all of this relating to gas engines only. I do know that testing I did do on a dyno with a fuel cooler setup on a stock engine yielded a max gain of approx 13% in both hp & tq. Every gas motor I did this mod to had a nice butt dyno felt bump in the low-mid range rpms, only 1 motor did I dyno it before & after on the same dyno on the same day w/o pulling the car off the rollers. I believe there should be an ideal number to get the intake air temp & fuel temp to get the most out of it (diesel). Since when the ambient temps are in the 85~95ish range smoke output drops and motor feels stronger it leads me to believe that at those temps it is getting the best burn in the cylinder.

On what principle of physics does heating or cooling the fuel improve the thermodynamic properties of combustion?

Cant answer that, can only point to the before & after data I collected. I can say though that the "after" data had ambient air temps close to the 90's (gas engine) so if anything the gains might have been higher.

I think you should chart your current MPG so that you have a baseline to compare with. Even better yet, do ABA testing with any mod that might affect aero or rolling resistance. Without this, there will be no evidence that any work you do has any benefit.

20mpg at 65mph should be achievable from a stock truck. Stop modifying the truck in ways that hurt FE, and improve the efficiency of the driver; this will help the most.

Heading up to Washington Thursday morning with a light load so I will be seeing where it sits then. I have seen 20 mpg 2x in this truck, 1st it had 2.5" of lift with a wider well worn set of tires that were heavier than what I have on there now. the other time was with a tire 1" taller than the 34" tire that I have on there now, that had the same 3" lift thats on there now. At 65 mph the motor is spinning right around 1700 rpms which is around where the peak torque is. Another thing I can do is run a loop I"ve run in the past which was something like 100~120 mi and do before & after runs on the mods. Since I'm not working, regular runs like that are out of the question for now.

Warming or cooling fuel just isn't something worth bothering with. It's not going to make a noticeable difference, and the truck is already designed to operate within a range of temperatures.

I disagree on this one... it's an area of opportunity IMO. Someone also suggested straight piping the exhaust, also a bad idea (already did it years back & lost mpg) Free flowing exhaust like that will help develop the most power under WOT conditions.

[steve05ram360]

Originally Posted by oil pan 4

One of the other diesel guys posted a study about fuel heating. I think it was by some university.

The only OEM that tested fuel heating/cooling that I know of was cummins marine, they found that fuel sent to the pump at a tempertuare of 75'F seemed to preform best.

I believe the OEM testing back then wouldnt be targeting the best FE, look at what they are doing today with full size trucks with it being common to be getting over 20 mpg .

Funny thing though about the 75F number you posted, the heater in the fuel filter housing is set to turn off @ 70~80*... I read something like that a few years back which made me think it might be worth looking into. On another diesel forum guys started putting fans on a cooler that was on the return line to the tanks to keep the in-tank temps from climbing to much. Some (but not all) reported back better FE from it.

I will go and do the testing anyways and see what it looks like. If no gains, then at least there will be a thread on it that someone can refer to.

[steve05ram360]

whats ABA testing?

[oil pan 4]

Originally Posted by steve05ram360

whats ABA testing?

Something you cant test unless you are willing to undo a mod after its been put on and tested.