Class 8 Truck modifications

[redpoint5]

I wouldn't want to tilt a radiator unless it was designed to be installed at that angle. In other words, the fins are lined up to pass air straight through at the installed angle. Otherwise, the fins are not at optimal angle, not cooling as efficiently as they could, and creating higher air pressure in front of the radiator. In Australia, I would think it is important to get full cooling capacity out of the radiator.

[craysus]

Issue would be more with the space if installing a V radiator...I can not really extend forward more than around 4-5 inches (Maybe not even that much..I may have to stay behind the bumper line..still trying to decipher the ADR (Australian design Regulations) in relation this..)

The old brass era setup looks sexy though! Disparaging to think in the 1910's they had more conceptual understanding of aerodynamics than a brand new truck manufacturer delivering forward glorified house bricks in 2017!!

[gumby79]

Look into a dual pass radiator. Referenced in this article. Aero-tuning the Championship-Winning NASCAR Dodge Trucks

Julian Randles at J&P Motorsports came up with a good idea, which was a two-pass radiator — it had two cores, one behind the other, but all in one radiator unit. You pass the water in the back part of the radiator, and then you fed that through the front part.

You took as much heat energy out of the cooling water as you could, using the minimum amount of air, so you could run a smaller radiator, which meant you were letting a lot less air into the engine bay. This meant you were not giving as much lift to the engine bay and had less frontal lift in the car.

They reference a shop in the US But any reputable Australian shop should be able to do the work .
For you its more about being able to pack as much cooling into the least space(less air doing the same job=less drag) = the most body mod with out compromised cooling. The custom aero hood has more freedom to take the best shape possible to get more productive results ,less cd.
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redpoint5
The US Army HMMWV has a tilted 45° radiator with conventional core.
Air passes through the radiator because of pressure differential, not ram force. Ram can be counter productive. Diverging/Converging Radiator Ducting - Why?
The sudden change of direction increasing pressure in front and decreases pressure behind resulting in a larger pressure differential.
A neet aerodynamic trick would be to duct the energized air into a low pressure zone behind the wheels, brake of the hood.

http://ecomodder.com/forum/showthrea...e-29689-2.html
A link from that thread I found interesting from FSAE.COM.
Diverging/Converging Radiator Ducting - Why?

[redpoint5]

Originally Posted by gumby79

The US Army HMMWV has a tilted 45° radiator with conventional core.

I've heard great things about Humvee efficiency.

[MJamson]

I would like to second (or third) driver training and incentives.

There is a company in Europe (Germany IIRC) who have focussed primarly on the drivers and have had huge savings.

The other thing would be considering setting a company speed limit, the company who I last drove for had a company speed limit of 80 km/h instead of 90 km/h, that saved them fuel and it was marketed as being for safety, there are numerous companies who have done the same.

Not sure how your company runs, but try and branch out and if your wagons return empty, try and find 'return loads', it wont be a fuel saving but if you have a truck going empty from A to B, and can get a return load, it helps the bank balance. Just make sure that it is a good simple run.

Longer term, consider buying low rolling resistant tyres. Super singles help but as you said conditions may not be right.

Longer term there are (at least in Europe) axels that have been designed with efficiency in mind.

Again longer term - investigate the posibilities of teardrop bodies here is an English company who produce them Aerodynamic Teardrop Trailer

And another long term consider the purchase of alternative trucks, many of the European brands are keen to get out into the rest of the world, and presumably offer a good deals.

[Trucker John]

Originally Posted by craysus

Hi all,
I am looking to enhance a fleet of Class 8 trucks. Predominantly these are 550-600HP cummins engined beasts, that do long distance line haulage towing single or B-Double reefers (Refrigerated box trailers)

I am looking to install fuel flow meters to obtain higher levels of accuracy in testing, however currently we have logs for trucks mileage. I will be testing each improvement with a weeks actual driving, with the same rig on the same route with the same driver..Currently we can measure our fuel burn to 2 decimal places, but with the fuel flow meter this will increase to 5 decimal places.

So far...
I am looking at

1. Supplementary gaseous injection (3 vendors all guaranteeing, with money back of a minimum of 15% fuel gain using their products)
--We have trialed propane (LPG) previously but too many negative effects occured *EGT increases, HP and torque increases, and resulted in a crank shaft failure and drivetrain issues from too much hp..*
--Vendor 1 is using HHO - have provided logs and references to other heavy fleet owners, guarantee with 100% money back a 15% gain, but historically have seen 25%+ with no tuning..With tuning gains up to 45% have been achieved.
-- Vendor 2 is using HHO and WI as a combined unit- I have received a guarantee of a free trial unit to put onto our truck, also guaranteeing 15%+ improvements or return the unit with no charge. This vendor I am not convinced is worthy to even test however, with some fairly vague sales pitches, and poor understandings of physics abounding on their web site..Their basic principles (Including "cracking" the water first (AFAIK simple ionising of the water to reduce the coherent bond..)) appear possible, but they come across as dodgy used car salespeople
-- Vendor 3 is using Stored Hydrogen - have logs across their own fleet of buses and other vehicles showing 20% plus improvements. Have also a newer technology for generating Hydrogen on demand from the exhaust gases using a catalyst. and plazma reformers. They are performing full dyno and onraod testing on their OWN fleet, and sharing full results, prior to us testing..they are also combining tuning, and water injection (As sub set results...so very interesting to see the stackability of the technology)..potentially someone actually doing Hydrogen injection to a diesel CORRECTLY and FULLY...

2. Tuning - I am looking at combining tuning with any gaseous attempt..it is pointless I believe adding a supplementary fuel (Or combustion enhancer) , without then reducing the baseline fuel being put into the engine..This tuning will take place on a dyno to ENSURE we do NOT gain any HP / Torque..Being in heavy trucking, with high hp trucks across the fleet, it is a negative effect to increase HP!. Obviously any maps that are created need to have the ability to default back to stock maps incase of supplementary failure. This will be recorded using fuel flow meters under static ramp loads.

3. Water fumigation / diesel emulsion - Looks very promising , and will be treated similar to the Gaseous supplementary above in point 1. It seems most of the aftermarket have very low quality kits available however, so we may need to create this inhouse to get some reliability in the product using quality stainless fittings etc.

4. Aerodynamics - obviously a critical component. Looking at aerotabs (Vortex generators), eco-flaps (Mudflaps), moon wheels, side farings (Fibreglass add ons to enclose sides of trailers, and also cover fuel tanks etc on the truck), Cheek Bones (For front side edges of trailers / cab over trucks),
--Also considering upgrading some of the older hoods on our fleet to reflect the newer more streamlined hoods and lights on later model trucks..still to find someone who has some "upgrade aero" hoods for sale..
-- Streamlining exhausts - removal of stacks infront /sides of cabs..to either behind the cab, or better exiting behind the wheels down low..
--removal of external air filters, relocating to under hood (Using ducting / airscoops to help funnel air to enhance ram-air effect to the 16 litre diesels..)
--Aero Mirrors to be installed / tested to see if much benefit..
--Possibly under trays to be installed..although this may not be possible.
--NB all trucks already have standard top of cab/sleeper farings etc installed.

5. Parasitic losses - removal of hydraulic engine fans, replacment with electric, power steering conversion to electric, airconditioning has already been transferred to the Aux power unit (Small genset instead of big engine),

6. Frictional losses - synthetic lubes in diffs / gearboxes already in use..marginal improvements. Considering using Super single tyres, but they may be too risky on our long haul routes


Open for any suggestions / thoughts...Please keep any negativity to HHO to a minimum, I am going to test 3 different types of Hydrogen to prove this / disprove this on our fleet at minimal cost/risk to ourselves..If it does work however, the unicorn corral will be upset lol

NB: I am a IT and project management specialist , I do NOT claim to be a mechanical engineer / chemist / biologist / rocket scientist / etc...I am pragmatic, and will chase fuel gains for the company.
Our trucks average around 1.95km/l currently, and I would like to push this to a minimum of 2.4km/l If I can obtain more than that I am very happy (My goal is 50% improvement..or around 3km/l......however all benefits must have a short ROI of less than 6 months to be considered worthwhile.

I am trying to keep costs under $30k per truck / trailer combination if at all possible..although ROI is the key..if it cuts enough fuel burn, we will spend to implement it.


.

To your point on aero dynamics we too have fitted Vortex Generators on both our trucks and trailers, and we have good experience with them (around 100 vehicles). The brand is V-Spoilers and we mainly use their panels (on few of the trucks we had to use their single units due to curves and rivets on some of our tractors). They are cheap.

[Trucker John]

And wheel covers we are considering Flow Below (The V-Spoilers guy suggested that also)

[craysus]

Hi Trucker John,
What kind of gains are you measuring with the VG's?

Are you fitting them to all the places on the trucks recommended? (IE trailer rear, trailer gaps between trailers if B-Double, Rear of the cab / sleeper unit...on top and sides for all those..and then also fitting prior to front wheels, rear of any toolboxes, and on the bonnet(Hood) around 1/3rd in to deflect over the windscreen?)

[Trucker John]

Hi Craysus,
Hard to give precise info on the fuel saving as it various a lot. But somewhere between 2-4%. They are very efficient on stability, less spray and dirt at the rears. Even on 2 tankers that we have. There are some independant road tests on V-Spoilers web page, including one from Australia.
We fit the panels on mostly at the end of each trailer (also double trailers). Also on all the tractors, that helps a lot in strong cross wind. Sometimes the panels don't fit, so we switch to their single units (but takes longer to mount). We dont fit in other locations, as we dont like how it then would look.

[craysus]

Have contacted a radiator specialist to see what can be done..I believe a dual pass radiator approximately 40cm shorter than the original should suffice..we can increase the capacity by encroaching on the space originally used by the mechanical fan, and possibly even increase the volume of the radiator (Along with using a dual pass with the "relocated" capacity pre cooling the hot coolant prior to passing to the front of the radiator)

With twin electric fans behind this should create more than enough cooling..

Of note, this would allow a huge height reduction in the front leading edge of the hood..possibly to only around 7.5cm (3 inches) above the standard fender height on the leading edge.....(Similar to the "airflow bullet truck" if you were to remove the front nosecone..)
We can not emulate the bullet trucks aero shape 100%, but some of the other aero he has used can be replicated on our vehicles fairly readily..such as the flat side panels (We have 50mm clearance to hit maximum width..meaning just over 1" clearance over the tyres is possible). I will be looking to use a hinged design to allow easy changing of tyres.
Side skirts on the trailers are definately a requirement, and i think with using some vortex generators, relocating exhaust stacks (To underneath the truck), aero mirrors, and a few other things we should be able to get a very decent improvement in airflow and therefore mileage..

Who knows...the Airflow Bullet truck with mainly aero and some friction reduction has gone from 5mpg to 13.4mpg...if I emulate 80% of that kit, and then also apply engine improvements..we may end up with very similar improvement levels...