Class 8 Truck modifications

[ctmaybury@yahoo.com]

Would rear wiew cameras instead of mirrors improve your aerodynamics? Interested in your engine mods. Most of the year, my trucks (dodge 2500 isb Cummins) are at 45 mph on dirt roads in the mountains, so I'm focusing on volumetric efficiency and thermal efficiency mostly. Aero mods clearly your best bang for the buck. I wanted to pick your brain about lpg fumigation. You discounted it on the first post claiming engine damage from too much hp. Did you try multi stage injection? Did you limit the lpg to less than 25% of the diesel? If you run in the 10% range, there's very little rick to the motor. My homebuilt system is still in the design phase, but used it for a 4k mile trip with an 8k lbs travel trailer with good results. At the time it was 2 stage injection. Next gen will have 5 stages that key on boost pressure.

Total pre turbo exhaust header is in the works now (bundle of snakes equal length tubes). Combined with port matching and polishing should yield some ve gains. The lpg fumigation should yield thermal efficiency by adding additional cooling to the charge air (probably very helpful with your climate down under).

What about some of the other benefits of lpg fumigation? Longer interval between oil changes, quieter motor, less smoke, less objectionable smell to the exhaust. Some of those are very subtle but noticeable. Did you notice any of those? Lpg is cheap and convenient for me and the motor seems to like it with the right tune (injection timing lpg seems to have an advancing effect).

[ctmaybury@yahoo.com]

I understand natural gas fumigation yields great mileage gains. Not convenient for me so I'll stick to lpg, but it might be a great mod for your fleet.

[dancam]

Hi, a word of caution on changing radiators. If you go too large the velocity decreases and coolant goes from turbulent to laminar flow. You get a stationary film sticking to the walls of the rad and that insulates the coolant thats flowing. Water pump has to be sized to the system volume to keep up velocity. If the rads your looking at flow all the coolant through 1 core and then back through the second it needs to be twice the volume of the original rad to not reduce flow or increase velocity. If half the coolant goes through one core and half through the other that is less efficient than a single core and you need a larger rad but have to watch that you dont get too big.
A water to air intercooler on a truck would add too much heat to the rad, i doubt you want to do that. Anytime you add heat from an intercooler or trans cooler to a rad it becomes less efficient and needs to be larger.
For fans- look for thick fans, slim fans move substantially less air. However the shroud is almost more important than the fan. You can have the best fan there is and with no shroud or a poor one it wont cool properly. It will cool less than a moderatly good fan with a well designed shroud.
- your looking mostly at aero solutions which is good. I cant comment much on them, but here are a few more suggestions. Anytime your oil is thicker than it should be it increases your losses, doesnt matter if its synthetic or not. Find out from the manufacturer what viscosity is best for engine, transmission and diff oils and what acceptable ranges for efficiancy and protection are. Its common here for engine oil to run too cold. In my opinion optimum engine oil temp is 212-220f. Hotter it last less long but you need it to burn off water and some of your fuel dilution. Do you have actual temperature senders in your oil pan or oil gallerys? Some temp gauges are just computer extrapolations based off pressure. If your ideal viscosity is xx.x cst which oem oil reaches at say 220f and say 220f is what they designed it for and the same weight grade but different brand oil you use is a little thicker and your oil only gets to 200f then you have losses. You need to insulate, install a thermostat in your oil cooler or a hotter temp one or run thinner oil so that its the same viscosity at your 200f as oem oil is at 220.
Same goes for the trans and diffs. Get good temperature gauges if you dont have them. Find what operating viscosity should be, what temperature it takes for oem oil to match that and what temp your oil meets that. You may need insulation, thinner oil, thicker oil, heat sinks.... depending what the readings are. I find oil runs too cold most of the time. Maybe not in your case but you should find out.
This would be dependant on each truck and what weights of loads they haul and the terrain and ambient temps. But if you have a bigger truck thats typically hauling smaller loads and the engine and diff oils dont get warm enough you will see gains by changing things.

For cost measures- have you looked into bypass oil filtration, oil analysis and extended oil drain intervals? Big potential savings there.
How about tire pressure monitors? It was asked before but i didnt see you reply to it. You dont want underinflated tires but on truck and single axle trailers a tpms with 6 sensors costing $150 will pay for itself if it saves you from one blowout. They have audible alarms if a tire starts loosing air fast. I havent looked at costs for systems for rigs but it cant be cheap to have a blowout, rip a fender off, treads/fender going through windshield of car behind you, downtime of truck and driver...

[DynoCobra]

Why are you using 16L engines? They are only needed in the Rocky Mountains. If you are thinking of aero ideas, then you first look smaller displacement engines like 12or 13L. Change final drive gearing to max speed versus engine torque needed to maintain speed on level ground with max load. When you get to that point, you can start fine tuning your aero and oil additives. I drove otr for years, was the top driver in my company for fuel mileage and built race cars and fuel economy vehicles that I drove for years. Took 1st place in the Iowa State Fuel Challenge getting 82.0 mpg from my VW diesel pickup in 1981. Subsequently I increased the mileage to 105 mpg as my daily driver by fine tuning with oil and aero adds. Btw, I averaged 7.2 mpg with my 13L 2009 Volvo 780 series.

[freebeard]

coachgeo — It was phrased colloquially to call attention to the three words, airdynamics, genertors and turbulance.

But to respond to your post, the reducto ad adsurdem is to put a generator with a propeller on the hood and use it to recharge the battery.

It's much easier to make turbulence than to reabsorb it. The only thing that really works is fineness ratio, like on a 40ft trailer.

Kevin Cooper — Comment away. Have you been lurking since 2008, or did you just come back?

Okay, now I'm thoroughly confused. DynoCobra also has a 2008 join date and 1 post today.

[craysus]

Originally Posted by DynoCobra

Why are you using 16L engines? They are only needed in the Rocky Mountains. If you are thinking of aero ideas, then you first look smaller displacement engines like 12or 13L. Change final drive gearing to max speed versus engine torque needed to maintain speed on level ground with max load. When you get to that point, you can start fine tuning your aero and oil additives. I drove otr for years, was the top driver in my company for fuel mileage and built race cars and fuel economy vehicles that I drove for years. Took 1st place in the Iowa State Fuel Challenge getting 82.0 mpg from my VW diesel pickup in 1981. Subsequently I increased the mileage to 105 mpg as my daily driver by fine tuning with oil and aero adds. Btw, I averaged 7.2 mpg with my 13L 2009 Volvo 780 series.

This fleet is in Australia.. Lots of mountains.. Towing a lot of weight in bdouble format... Our 13l engines just can't get the loads where they need to go in this format.... The big 16l 600hp engines are required unfortunately.. If the supplementary changes we are looking at reduce hp needs it would make sense for newer trucks we buy to be smaller engined however

[craysus]

Originally Posted by ctmaybury@yahoo.com

Would rear wiew cameras instead of mirrors improve your aerodynamics? Interested in your engine mods. Most of the year, my trucks (dodge 2500 isb Cummins) are at 45 mph on dirt roads in the mountains, so I'm focusing on volumetric efficiency and thermal efficiency mostly. Aero mods clearly your best bang for the buck. I wanted to pick your brain about lpg fumigation. You discounted it on the first post claiming engine damage from too much hp. Did you try multi stage injection? Did you limit the lpg to less than 25% of the diesel? If you run in the 10% range, there's very little rick to the motor. My homebuilt system is still in the design phase, but used it for a 4k mile trip with an 8k lbs travel trailer with good results. At the time it was 2 stage injection. Next gen will have 5 stages that key on boost pressure.

Total pre turbo exhaust header is in the works now (bundle of snakes equal length tubes). Combined with port matching and polishing should yield some ve gains. The lpg fumigation should yield thermal efficiency by adding additional cooling to the charge air (probably very helpful with your climate down under).

What about some of the other benefits of lpg fumigation? Longer interval between oil changes, quieter motor, less smoke, less objectionable smell to the exhaust. Some of those are very subtle but noticeable. Did you notice any of those? Lpg is cheap and convenient for me and the motor seems to like it with the right tune (injection timing lpg seems to have an advancing effect).

LPG fumigation nets about the same benefits as hydrogen fumigation.. However... LPG causes higher egt..
LPG in Australia is available everywhere but is about half the price of diesel... Whereas hydrogen in stored Form is harder to get.. But a lot cheaper.
Hydrogen in generated on demand Form is much closer to free... If you can find a way to generate it more cheaply than electrolysis methods (that use a heap of amperage that obviously counteracts the benefits somewhat). I am having 2 different hydrogen on demand methods looked at.. Using the Exhaust gasses and heat... (catalyst and also plasma reformation methods) both are looking promising atm. If we can generate as required with little external.. And take advantage of waste heat and gasses we have nirvana in effect..
Current testing on the non productionised hydrogen on demand systems we have in play show huge benefits around 35 percent fuel savings.. 70 percent reduction in nox, and a huge reduction in particulat matter. Whilst also increasing performance throughout the rev range
Water looks to stack well... It decreases egt further.. Has been tested so far at 25 percent of fuel volume.. And.. Increases performance again except for the top 1/3 of the upper rpm... (which drivers should never be using regardless)

The total costs for all the aero works... And the engine supplement works should be around 2/3rds the cost of an engine upgrade to a Cummins isx e5. (we have performed a few upgrades... And including exhaust stack removal and some intake mods etc during conversion we only get 10 percent improvements to fe)..
Might work out more cost effective to buy older trucks.. Refurbished the engine and add ancillary changes and aero in the long run... Instead of spending big dollars on the latest trucks to gain 10 to 15 percent fuel..
Spending /1/5th the upgrade price modifying old units and getting 50 to 60 percent or more gains might be smarter... At least until hybrid trucks like the Nikola One or equivalent hit the ground...

[ALS]

I think a review of the basics would be a good start.

Once you have that down then start looking for aero mods that will improve your fuel mileage over the long term. This is the best piece I seen on fuel economy for over the road trucking.

cummins_secrets_of_better_fuel_economy.pdf

There are a number of good videos over on Youtube on the subject of better fuel economy in large trucks. The biggest gains can be made with driver improvement.
An example of this can be seen in this short video from Volvo Trucks.

https://www.youtube.com/watch?v=MltrA95Ln7o

[craysus]

Originally Posted by Kevin Cooper

I have a few comments for you regarding truck aerodynamics. I have been involved in the development of virtually all of the aero add-ons used today. The work was done in the wind tunnels of the National Research Council of Canada form 1976 untill today. Current trucks have much lower fuel consumption than several decades ago. The largest contributor to this improvement has been aerodynamic improvements. I would recommend both boat-tails and trailer skirts for your fleet, assuming that you already have the cab-mounted aero packages and cab extenders. For more info download the Society of Automotive Engineers paper SAE 2003-01-3376, entitled "Truck Aerodynamics Reborn – Lessons from the Past" by Kevin R. Cooper, Aerodynamics Laboratory, NRC Ottawa, Canada. For more info contact Kevin@CooperAero.com. Good luck.

Thanks Kevin, been reading a few white papers out of Canada.. Looks like you boys get to play with lots of testing...
I am definitely looking at aero mods to truck and trailer.. Including everything but boat tails due to legal reasons here in Australia

So aero list so far is
Aero bumper
Undertrayfrom bumper to front axle
Air damn under bumper
Aero mudflaps
New super low hood modified from modern hood.. To replace old sar version
Removing exhaust stacks, horns, raised running lights
Changing mirrors
Changing top air deflector to modern single arc for cab and sleeper style
Using tank / chassis fairings
Using drive wheel fairings
Using top of chassis blocking plates
Trailers..
Using side skirts. Using nose Cones
Aero mudflaps

And using airtabs or similar vortex generators on trailer and tractor.. To bridge the gap.. And to create a virtual boat tail.. And also to reduce buffeting problems.

I can't use super wide single tyres unfortunately here..

Things like weight reduction I can't do much with atm..

If I can achieve the fuel reduction of 40 percent overall.. Which looking at multiple white papers showing huge reductions in drag ( divide by 2 for fuel gains) and the testing on engine improvements so far should all be possible, it will be a massive achievement.
Who knows might open a business once I have the proof... And resell all my work to others interested in sensible cost effective savings on their own fleets..

Seems most after market vendors are only focusing on small sections which rarely work well in their own right..

[craysus]

Originally Posted by ALS

I think a review of the basics would be a good start.

Once you have that down then start looking for aero mods that will improve your fuel mileage over the long term. This is the best piece I seen on fuel economy for over the road trucking.

cummins_secrets_of_better_fuel_economy.pdf

Not a bad document.. Very light on details in many areas however.... Was listed in the first few pages.. currently printed and sitting on my desk along with a number of more in-depth independent white papers