I read somewhere on this site that keeping exhaust temperature below 600 degrees F will result in better fuel mileage.  One way to accomplish this would be to set up a water/methanol injection system that activates above 600F and deactivates below 600F.  The nozzle would have to be quite small to avoid extinguishing the combustion fire.  An improvement would be to have a two stage system with a second, slightly larger nozzle that activates at about 700F.  I believe Banks Power offers a new water injection system that has the ability to be temperature activated.  The temperature trigger points I'm suggesting are, of course, subject to change.  A wide array of nozzle aperatures are available.

 

Does anyone have any experience with using water injection to improve fuel mileage?  What I am looking for is real world experience in using water/methanol or water/ethanol injection in a diesel engine.  Opinions may be useful if they are supported by scientific knowledge.  If you want to express your opinion without any experience, be ready to back it up with physics, chemistry and math.  I'm sure there are a lot guys out there in the 80,000 pound club that have been using water injection for years.  Please help us all out with your vast knowledge and experience.

Edited June 29, 20159 yr by CoyoteKiller

Easier yet reduce your drag and the EGT's naturally fall. At 60 MPH I typically float 550*F. No water / methanol. Smaller and lighter wheels and tires. Proper use of gears vs speed will reduce EGT's.

 

Water / Methanol is use typically for high horse power to keeping EGT's in check. But if your running 1-2 PSI at 55-60 MPH for boost so there is no heat in the manifold. So the EGT's at that point would be more so drag related. The other factor is methanol is a mild fuel as well. This is kind of like propane injection. Except the water is a cooling agent when its converts to steam.

 

Calculate your temps...

http://www.stealth316.com/2-turbotemp.htm

 

Set IC Efficiency for about 90%.

 

The water meth wouldn't really help in this case as you would still be fueling the same amount as before, with just the addition of water/meth to bring egts down.  

 

as mopar says, reduce drag.  

 

 

 

 

I really would like to bag all 4 corners of the truck to get it nice and low when I don't need to ground clearance.  

Mopar, there's a lot of flat land in the background of your picture.  I live at 1,400 feet elevation at the base of a 4,000 foot pass, so there is a shortage of flat land around here.  Cruising at 1 PSI at 60 MPH is something I do occasionally after getting well out of the neighborhood. 

 

On a 76 mile round trip commute, I'm seeing temperatures as high as 1,000 degrees.  This is not conducive to good fuel mileage.  The truck is equipped with a high flow stainless steel exhaust manifold from High Tech Turbo, 4" Flowmaster exhaust system, S&B intake system, a big High Tech Turbo intercooler, and a CFM intake manifold.  I don't know what else I can do to improve air flow.  Turbo is a High Tech 64/71/14 with DDP 75HP injectors.   

 

This is not a typical situation, so I thought water injection might help on some of the long, uphill sections.

Mopar, there's a lot of flat land in the background of your picture.

 

    Flat ground where?   Everything is on a grade here and highest local point to me is 9,000 feet with grades exceeded 16% locally.

 

On a 76 mile round trip commute, I'm seeing temperatures as high as 1,000 degrees.  This is not conducive to good fuel mileage.  The truck is equipped with a high flow stainless steel exhaust manifold from High Tech Turbo, 4" Flowmaster exhaust system, S&B intake system, a big High Tech Turbo intercooler, and a CFM intake manifold.  I don't know what else I can do to improve air flow.  Turbo is a High Tech 64/71/14 with DDP 75HP injectors. 

 

Built up-side-down.

 

Now compare me to you. Stock HX35W turbo, Stock 3" exhaust with NAPA 3" muffler, Edge Comp, +50 HP injectors, BHAF, stock intake and exhaust manifold. So most of the stuff you've added creates your issues. Now where my gains are I dumped the stock 16x7.5 stock wheels and got 16x7 wheels. Dumped the stock 265/75 R16 tires and went to 235/85 R16 tires. For every 1 pound of rotational mass you ditch your taking 8 pounds off the frame. The difference between my old 265's and my new 235's is about 96 pounds total or about 768 pounds off the frame.

 

Even myself climb grades I rarely ever see 1,000*F EGT's because typically I drop from 5th to 4th direct (1:1) and torque is improved, boost is elevated, EGT's reduced, and MPG enhanced.

Wanna race?

I'll race you for MPG's not speed.

 

But power wise ask JAG1 my truck has nasty problem with breaking loose in 4th gear. My power band is designed around towing and daily driving not top speed. So racing won't prove much other than who can dump the most fuel. But how about how far can you go on a tank of fuel? My record high mark is 27.2 MPG (corrected) 26.12 MPG (Uncorrected).

Yep it sure does on dry pavement no less. Mike your truck is a wolf in sheeps clothing, but I agree there is a point where power upgrades have a diminishing return. Old guys like less on it for less potential problems so what can I say

Gee, I'm surrounded by the administration and it's board of directors.  Guess I will return my truck to stock and go home.  I'm just grateful I don't have a loose rear end like yours!

all just saying hi.  Nothing to get stressed about.

 

Your issue with temps is due to your turbo and somewhat small injectors for it.  You would be able to drop temps with water/meth, but it won't help your mileage, since you are still injecting x amount of fuel, then using water/meth to drop the temp.  

 

What Mike is saying is you have to change your setup if you want mpg's vs the power a 64 mm turbo will support.  As mike pointed out there is plenty of dd power that can be had with a smaller turbo that will not effect your cruising mileage. 

 

I live at 7000' and regularly head up the pass from the city to well over 8500' and I understand what you are seeing.  You are effectively a NA diesel until the turbo can spool.  Issue is with your truck you wont spool it until you are higher in the revs.

 

Can't have your cake and eat it too.

I read somewhere on this site that keeping exhaust temperature below 600 degrees F will result in better fuel mileage.  One way to accomplish this would be to set up a water/methanol injection system that activates above 600F and deactivates below 600F.  The nozzle would have to be quite small to avoid extinguishing the combustion fire.  An improvement would be to have a two stage system with a second, slightly larger nozzle that activates at about 700F.  I believe Banks Power offers a new water injection system that has the ability to be temperature activated.  The temperature trigger points I'm suggesting are, of course, subject to change.  A wide array of nozzle aperatures are available.

 

Does anyone have any experience with using water injection to improve fuel mileage?  What I am looking for is real world experience in using water/methanol or water/ethanol injection in a diesel engine.  Opinions may be useful if they are supported by scientific knowledge.  If you want to express your opinion without any experience, be ready to back it up with physics, chemistry and math.  I'm sure there are a lot guys out there in the 80,000 pound club that have been using water injection for years.  Please help us all out with your vast knowledge and experience.

Sounds intristing! Some of my thoughts are Banks loves to advertise! [$$$$$$]  i dont have experience, but i'm all eyes if you want to jump in the water/meth. inj. tub! [blub!]

fill in your sig. so we can see your ride!!  

Stick around a while & learn from & teach us a few things too! i have benifited [sorry, my grammar is lower then my Rams boost psi!] from the common sense these fellers pounded [ ] in my head about cold air intakes ,etc..... it's ok,..i'll get over it! i'm glad to have somebody to 'chat' with that shares my interest!

    

  DODGE MAKES IT

 

CUMMINS SHAKES IT

 

MY FOOT BREAKS IT

 

MY WALLET FIXES IT.............

 

DO IT AGAIN!!

 

BY THE WAY...........I'M A SILVER!! [not a director, what ever THAT is,,,]

Edited June 30, 20159 yr by organicfarmer

all just saying hi.  Nothing to get stressed about.

 

Your issue with temps is due to your turbo and somewhat small injectors for it.  You would be able to drop temps with water/meth, but it won't help your mileage, since you are still injecting x amount of fuel, then using water/meth to drop the temp.  

 

What Mike is saying is you have to change your setup if you want mpg's vs the power a 64 mm turbo will support.  As mike pointed out there is plenty of dd power that can be had with a smaller turbo that will not effect your cruising mileage. 

 

I live at 7000' and regularly head up the pass from the city to well over 8500' and I understand what you are seeing.  You are effectively a NA diesel until the turbo can spool.  Issue is with your truck you wont spool it until you are higher in the revs.

 

Can't have your cake and eat it too.

 

Exactly... You can't built for racing power and expect daily driver efficiency. This is the common up-side-down problem. You get everything perfect for racing now your MPG's will be lower. Efficiency is based on quick spool of the turbo so actually a HY35W turbo would be better than my HX35W turbo. Better spool up for daily driving light to light less smoke. Smaller injectors atomize fuel better than bigger ones. Smaller the atomize droplet the quicker it can convert from liquid to vapor and go BOOM. Warmer air is more efficient than cold air. The warmer air aid in the conversion process getting the fuel to ignite quicker. Optimal IAT temps are 100-140*F for every 10*F drop you lose 1 MPG. Using lower cetane fuels have more BTU energy than high cetane fuels. Building for efficiency is different that racing power. You build in the design to be near 0 PSI of boost at cruise but to have quick spool and little smoke.So you use a slightly larger injector to aid in spooling a stock turbo but this is limiting top end power. But your mid range power is massive. I start to lose me efficiency after about 60 MPH but I'm design around the mountain of Idaho and not the interstates of the midwest.

 

This is where people screw up again. They follow someone else designs and expect the road manners and end not getting what the expect. Because driving style and road type is different. Building a diesel for efficiency or for race is just like building V8 gas engine. It should be done 1 step at a time. If you make a step bench test and watch your time logs or MPG logs. Once satisfied with that change do another step watch again. Too many people buy a bunch of part and toss then on blindly not understanding the changes and impact the combo of parts will do.

 

 

On a 76 mile round trip commute, I'm seeing temperatures as high as 1,000 degrees.  This is not conducive to good fuel mileage.  The truck is equipped with a high flow stainless steel exhaust manifold from High Tech Turbo, 4" Flowmaster exhaust system, S&B intake system, a big High Tech Turbo intercooler, and a CFM intake manifold.  I don't know what else I can do to improve air flow.  Turbo is a High Tech 64/71/14 with DDP 75HP injectors. 

 

So like you installed a intercooler and it will actually degrade MPG's great for racing but bad for MPG. Too cold will draw MPG's down. Like I based my design of the efficiency of the stock intercooler. Flow improvements like you done typically will not alter the MPG characteristics. Those are great for 500 HP and above typically where they stand out. But during efficiency you boost should be near zero (0-5 PSI) so flow improvements are not required. S&B intake again cold air does not help MPG's. Then the Turbo is too big for light to light launching to it never spools up to help get the truck moving but once its moving the turbo is great because the boost pressure does fall to near zero PSI. Me78569 and Cowboy is making a VGT controller that would be excellent for you. Still in the Alpha stages of design.

 

So this what I meant about up-side down.

Injectors are too small for turbo or turbo is too big for injectors. I'm running +100 hp injectors and essentially an hx35 turbo (see sig.) with no heat/mpg issues driving normally. 

It sounds like there was a misconception that the truck is running hot all the time.  On flat land, I'm seeing 0-1 PSI at 60 MPH, intake air of 100-140F and exhaust temp of 400-500F.  The temperature only goes up on the long uphill sections, which is entirely expected.  I just thought it would help to lower the temperature on the long ascents.  Bigger injectors will be going in soon, after some other things are done.  Unfortunately, there is more to life than diesel trucks!

There isnt really any way to get egts down or mpg up if you are climbing. I see 1000 all the time climbing the passes here.

Water method might help but I would gear down to get rpms up instead. The truck needs the Boost in that case.

I would gear down to get rpms up instead. The truck needs the Boost in that case.

 

Bingo. That is efficient use of gears and speed vs. EGT's. Like for example I've got a slight grade from Riggins, ID to home which is 15 miles but only climb 1,000 feet of elevation in 15 miles. So if I ran 53 MPH in 4th gear I will drop EGT's to about 650*F vs running 5th gear at 53 MPH where its about 800-900*F EGT's. But I still think your turbo is big on the exhuast housing I would opt back to at least a 12 cm² exhaust housing.

 

 

Bigger injectors will be going in soon, after some other things are done.

 

That's going to add to the EGT's. I would consider doing a fuel module like Edge Juice or Edge Comp being I don't see any fuel module in your current setup. This would give you better control over your fuel management over just straight injectors. Then also gain at least 120 HP on top of the 75 HP injectors you got now. The nice part is you could use the defuel modules to tapper out the fuel so to give turbo time to light up. Like myself with +50 HP and my Edge Comp on 5x3 (120 HP with 67% of stock fuel till 10 PSI and then add fuel from there).

 

Timing is the other factor that will improve the MPG number if used properly.

With a turbo that size it's expected to have some high EGTs, that's just the way it is. As for the fuel mileage that 71mm turbine wheel is pretty big and will take a decent amount of fuel to spool it. That's what's killing your mileage. You're using more fuel to spool the turbo to make the power to go up the hills.

 

As for the water meth, from what I have read it's not worth it if all you want is fuel mileage.

 

Hopefully I didn't offend.... Just trying to offer some advice.

Forgot to add the Juice Touch tuner to the description.  I run it on 5X1 all the time.  The performance of this truck is amazing!  It is, after all, just a big boys' toy that gives me a lot of enjoyment.

 

So it's unanimous that water injection is not going to improve anything.  That's what I needed to know!  Thanks guys.

 

PS - I haven't yet figured out how to add a picture or build signature.

Too low of a sub level. Bring it up. Try 5x2 or 5x3.

 

Sublevels

 

1. 33% of stock fuel till 20 PSI of boost.

2. 50% of stock fuel till 15 PSI of boost.

3. 67% of stock fuel till 10 PSI of boost.

 

4. Some extra fuel at low boost.

5. Full fuel at 0 PSI Boost.

 

So this is partially why you EGT's are high is your lagging out the fuel and not getting turbo spun up. Sublevels 1-3 are like placing the virtual egg under throttle till X amount of boost is made. You problem is your attempting to build boost but got no fuel for your large turbo.

 

PS - I haven't yet figured out how to add a picture or build signature.

 

At the top left of the screen click on your user name then select settings. The select signature or photo and you can change both.

Yep water/meth is to help with heat issues when other paths don't work.  I am with Mike here, I think you are too low on fuelto light the turbo under the powerband.

 

Thus causing heat issues.  If you are climbing any real grade you should be seeing boost levels over 5psi minimum to keep heat down.  

 

 

 

Nick

Like towing I can see 30-32 PSI on 7% grade towing my RV and stay very cool at 1,100*F at 55 MPH. Empty grade climbing like Goose Creek to McCall, ID its another 7% and I regularly see 10-20 PSI of boost and about 800*F worth EGT's with a speed limits of 45 MPH and corners rated for 25 MPH. Again smaller injectors, stock turbo, etc. But now flip that coin over and go for racing. I'd lose.. I man enough to admit I would lose that battle quick because I got the power out of the hole up to about 65-70 MPH and flattens out beyond that where your setup would be just pouring on the power after that large turbo got spun up. Again its about designing the power band where its more useful for you driving style.