High MPG work truck

[oil pan 4]

Cross over pipe has been done for a while now, fuel pumps and fuel filters have been relocated to under the truck and the 100% stainless steel T3 to HE351VE adaptor just needs a few inches worth of finishing welds put on it.

[serialk11r]

oil pan 4, sorry to bring this back up even though we couldn't convince you before, but all your beautiful (sounding, I can't see it) work makes me want to try again, since your project is just completely awesome.

So lowering volumetric efficiency...your static compression ratio is currently very high, and the heat ratio decreases at the higher temperatures that you probably have are mostly offsetting the efficiency increases due to compression ratio. For example, they say 17:1 is the limit for gasoline engines where you won't see any gain at all (full throttle, part throttle operation you can go higher since again, dynamic compression is lower). Sure gasoline is different from diesel but air behaves the same way when compressed in either

Anyway, the most efficient part of the engine cycle is going to be the piston's expansion stroke, and that is the only stroke where the engine is making any real power. If you have high volumetric efficiency, what happens is you're leaving more pressure behind at the end of the expansion stroke. Since you have a turbo, the turbo will pick up some of that energy, but as you mentioned it is very inefficient at doing so. However inefficient it is, it is the only way of recovering "mechanical energy" directly from the exhaust, and it does so almost "for free".

If you swap the cams so that you are now losing say 15% of your intake charge, your effective compression ratio drops to like 18:1, but you have the turbocharger increasing manifold pressure so the overall compression that the air sees is much much higher, probably beyond the point where the temperature and thus heat ratio have dropped significantly. Since the turbocharger is being fed less of an excess of gas, you'll have less backpressure, and the turbocharger will be working more off the otherwise wasted blowdown pressure.

Water injection cuts the temperature of the intake charge, but water has lower heat capacity to start with, and dilutes the oxygen concentration of the air so it isn't the best way to reduce temperature.

[Gr8twhite]

Originally Posted by oil pan 4

Water mist injection will lower EGTs by up to 300'F intake temps will show over 100'F reduction depending on starting air temps and how much water I can dump in.

Not to be a "naysayer" but I've got a devils own progressive wi kit on my truck ( 1998 k2500 with a new 6500 Optimizer) using a 10gph nozzle.

Starts at a boost referenced 5 psi and is at full battle cry by 8 psi. I max out at just under 13 psi total for boost.

I only get about 100f drop in egt total. About 30-50 iat drop.

That's if I start spray on the way up in egts. If I wait for them to max out at 1100 and start the spray there is no difference in egt. Maybe a 25-50 f drop once theyre up, if I'm lucky.

Absolutely no improvement in mpg. Perhaps if you used WMI there would be improvement, but you're also adding a fuel source with WMI as opposed to just wi.

Wi works, but it's highly "overhyped" in the add copy. Results of mpg and egt drop seem pretty exaggerated IMHO.

I have no intention of dumping more than 10gph of water into my 20.2:1 engine either....

It's also never sat right with me to be spraying water into the intake stream. I'm in aviation, so I understand the principles behind it. For Otto cycle engines that is. I see the egts benefits in a diesel, but I also soo increased humidity and I know what that does to density also, not a good relationship (google humidity and density altitude).

Once I get my ata intercooler up and running, the wi is coming out of the intake stream and will be retasked to spray on the exterior of the intercooler for additional cooling effectiveness by pulling heat out of the aluminum faster than just the air can.

Ymmv.....

[oil pan 4]

How much water do you use?
I like to use about 2 gallons of water to each gallon of fuel burned. But on long road trips I use closer to 1 gallon of water to 1 gallon of fuel because I just cant carry enough water.
If you start the water injection at 5psi then I bet its hardly ever on.
I run my water all the time when I am at speed.
Before water injection I could never get over 20mpg towing, now with water I consistantly hit 20mpg all the time no problem. Last road trip I had one tank under 20mpg, before water I would get 18-19 most of the time and maybe see one tank over 20mpg.
Last road trip the suburban consumed over 200 gallons of water.

I still plan on running water a 03 duramax intercooler.

EDIT: sold the D-max intercooler and went with a 3 inch in/out universal fit 31x19 inch unit.

[Gr8twhite]

Originally Posted by oil pan 4

How much water do you use?
I like to use about 2 gallons of water to each gallon of fuel burned. But on long road trips I use closer to 1 gallon of water to 1 gallon of fuel because I just cant carry enough water.
If you start the water injection at 5psi then I bet its hardly ever on.
I run my water all the time when I am at speed.
Before water injection I could never get over 20mpg towing, now with water I consistantly hit 20mpg all the time no problem. Last road trip I had one tank under 20mpg, before water I would get 18-19 most of the time and maybe see one tank over 20mpg.
Last road trip the suburban consumed over 200 gallons of water.

I still plan on running water a 03 duramax intercooler.

Dunno how much, but it will drain my 8 gallon tank when towing up a grade and on full spray in less than an hour.

Makes sense when you think about it; 10 GPH, full spray, 8 gallon tank, less than an hour capacity.

My truck cruises at 5-6 psi at highway speed. My spray is just tipping in at that point. Anything besides flat running gets more than 6 psi easily.

I'm glad you see mpg improvement, but I see none....even when at full spray.

As I said, YMMV.

My next move is to rework my calibration ("tune") and return to the stock vacuum system to dump boost at speed, attempting to reduce drive pressure and pumping losses through the turbine when they're not needed.

Well, that's the experiment at least.......

Got a few aero tricks in mind, but mostly for highway running. Pretty mild really, don't want to change the looks of the truck too much.

Time to rig up the magnehelic again and get some fresh pressure readings.....

[oil pan 4]

Having 5-6 PSI at speed sounds a little high. Sounds like the waste gate is staying closed when you dont want it fully closed.

I originally thought more is more with water injection, but my last long trip I went from a 10gph nozzle to a 7ghp and turned the pressure down (I can change the pressure from the drivers seat).
Fuel milage didnt seem to be effected.
I run water all the time for a 3% to 4% boost.
Any thing beyond 3-5gph (the minimum I think it takes to get the FE boost) is just going to help with cooling. Did you know you can easily put an aditional 30,000 to 40,000 BTU/hr out the tail pipe as opposed to through the radiator with water injection?

I can tell the 6.5 likes its water because as soon as I run out of water and hit a hill or try to pick up speed I can tell when its not there.

The HE351VE is so close to being ready to bolted in.
All I need to do is install my 6AN/16x1.5mm coolant fittings, I need to drill them out because they were in my pluming collection and started out life as P/S fittings, so they have a very narrow passage through them.

[oil pan 4]

Update with pic:
Diesel Place : Chevrolet and GMC Diesel Truck Forums - View Single Post - DIY: HE351VE observations, questions and answers

[Varn]

I bought a Renault R10 back in 1978. Rather anemic with it's 1300cc 4 cylinder. I turned up the timing to get better running but encountered a lot of pinging.

I had read about water/alcohol injection with WW2 piston driven fighter aircraft. Using that as a base I made a single stage water/windshield washer injector. I used a small electric windshield washer pump that I plumbed into a fitting on top of the airbox so that it would shoot a stream straight into the 2 barrel Solex Carb, I used a Amal carb jet that I screwed into the air filter. Initially I controlled it with a simple pushbutton switch.

Space was very limited in the car. They even put the spare tire under the hood and the muffler was in the wheel well. I didn't have any space to add a separate water container so I used the windshield washer container with a Y connector.

I used a vacuum solenoid to control a microswitch that drove the pump. It would come on when the manifold vacuum was low. To prevent it from flooding the engine when starting when the vacuum signal was low I used a relay that I set up to latch off of pushbutton switch after I started the car. If I killed the engine I turned the key off and then could restart. Once running I would reengage the relay.

I didn't have the resources to modify the compression ratio but I think I could get a bit more out ot it.

[oil pan 4]

http://ecomodder.com/forum/tool-aero-rolling-resistance.php?Weight=6000&WeightUnits=lbs&CRR=.01 &Cd=.45&FrontalArea=34&FrontalAreaUnits=ft^2&FuelW h=37953&IceEfficiency=.35&DrivetrainEfficiency=.85 &ParasiticOverhead=1400&rho=1.225&FromToStep=5-200-5

[oil pan 4]

The turbocharger is on and driveability has been massivly increased.
If there was 0 or a slight reduction in fuel economy it would still be worth it.