Class 8 Truck modifications

[craysus]

With exhaust and inlet mods... Are significant gains being found with porting and Port matching along with extrude honing... Or are after market manifolds readily available that could be used?
Does anyone have measured gains with just those mods?
Surely the oem didn't get the manifolds so bad out of the factory that big gains are available?

[gumby79]

Hears a wight paper for you.. if I get the context correct

Influence of Ambient Temperature Conditions
Main engine operation of MAN B&W two-stroke engines
This explains my suggestions to reduce your day/summer and night/ winter IAT changes and shoot for a more narrow operating window. Easyer to tune efficiency fora smaller operating window according to the artical. To cold is just as bad as to hot.
The impact of intake air temperature on performance and exhaust emissions of a diesel methanol dual fuel engine
They ran there test at 1500RRM so comparable to the throttle loading an Ecomodder would use.
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An idea
Air curtains leading the rear tandem driven by the ehxsost. Similar to this http://ecomodder.com/forum/showthrea...ins-34805.html

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Would your authorities have a problem with a removable wind screen with wipers, defrost , leaving the stock in place.
May or may not have to be DOT safety glass. As a solution to rigorous safty laws about redesigning the wind shield. Similarto what Aerohead is mocking up for the wind tunnel

Dreem big chisel down to reality

[ctmaybury@yahoo.com]

Originally Posted by craysus

With exhaust and inlet mods... Are significant gains being found with porting and Port matching along with extrude honing... Or are after market manifolds readily available that could be used?
Does anyone have measured gains with just those mods?
Surely the oem didn't get the manifolds so bad out of the factory that big gains are available?

I'm not going to try to port (changing the shape with a hand grinder imo is a bad idea), but polishing casting imprfections would help airflow. Port matching gasket and manifold conections could help airflow. I don't know about the manifold on the big Cummins motor, but the cast iron exhaust manifold on the isb leaves alot on the table for improvement. Here's a good read.

Exhaust System Technology: Science and Implementation of High Performance Exhaust Systems

[Reg.Airman]

Craysus,
Airman has test results showing 11.9% average increase in miles per gallon (see the AirmanSystems website under Test Summ) of the AirWedge II aerodynamic addition to Class 8 vans and reefers.Testing was done over a two month period. The test was done over the road in all weather conditions. A fairly spectacular demonstration of the difference between skirts and the AirWedge II when running through the snow with another trucker is on the home page. And there are comments in the NEWS page that should be of interest. My Airman email and phone number are on the website.
One important piece: since we use the under trailer airflow to pull the drag off the back doors, the AirWedge is not compatible with skirts. And since the Bernoulli effect also drags airflow from the top of the trailer the AirWedge is not compatible with boat tails although a top kit increases the miles per gallon about another 2%. The nose cone works well with the AirWedge II, too.
If you are interested in running a test let us figure out how to get an AirWedge II to you in Australia.

[ctmaybury@yahoo.com]

The volumetric efficiency section from the same site is also interesting and ties into turbo header design.

Volumetric Efficiency (and the REAL factor: MASS AIRFLOW), by EPI Inc.

[craysus]

Originally Posted by ctmaybury@yahoo.com

The volumetric efficiency section from the same site is also interesting and ties into turbo header design.

Volumetric Efficiency (and the REAL factor: MASS AIRFLOW), by EPI Inc.

These are great in general documents, however I am hesitant to pull a big cummins down to find we would only gain a percent or so at max..
Has anyone modified a big cummins and tested to find firm improvements in fuel efficiency?

A lot of these VE improvements definately do improve horsepower, and sometimes that then has a negative effect on fuel efficiency.
Simple case would be putting a set of extractors on a honda civic..depending on the design you will increase the VE of the engine, and expand the useable rev range by 500rpm, effectively shifting the powerband upwards ..with a corresponding DROP in fuel efficiency due to a sudden torque hole down lower..

I would have thought Cummins would have had this fairly well under control from the factory..(Maybe less so on the earlier engines?)

[craysus]

Originally Posted by Reg.Airman

Craysus,
Airman has test results showing 11.9% average increase in miles per gallon (see the AirmanSystems website under Test Summ) of the AirWedge II aerodynamic addition to Class 8 vans and reefers.Testing was done over a two month period. The test was done over the road in all weather conditions. A fairly spectacular demonstration of the difference between skirts and the AirWedge II when running through the snow with another trucker is on the home page. And there are comments in the NEWS page that should be of interest. My Airman email and phone number are on the website.
One important piece: since we use the under trailer airflow to pull the drag off the back doors, the AirWedge is not compatible with skirts. And since the Bernoulli effect also drags airflow from the top of the trailer the AirWedge is not compatible with boat tails although a top kit increases the miles per gallon about another 2%. The nose cone works well with the AirWedge II, too.
If you are interested in running a test let us figure out how to get an AirWedge II to you in Australia.

Interesting website.
Would definitely simplify the trailer configs, however, I am interested in how you would deal with the extra kit we have under all our trailers (APU's, fuel tanks, tyres, tool boxes, etc.. combined with the tri wheel bogey rear end on our setups?

[ctmaybury@yahoo.com]

The inline 6 cast iron manifold on my 5.9 L Cummins is a mass production unit. There is good benifit to evenly spacing the pulse feeding the turbo. You need equal length tubing for that. Divided turbine housing benifits from feeding half the exhaust to each side. The header I'm designing will send cylinder 1 2 and 3 into half and 4 5 and 6 into the other half making the header a true pulse tuned unit.

The max fe is generally at the same point as max torque. Any increase in ve will drive that point lower on the curve. I don't know if that benifits fe, but it will make more usable hp and torque. I realise this isn't your goal, but if the engine can breathe easier, it must have some fe gain. I can build myself a custom header for next to nothing, but it might cost you more than it's worth to have those built for your whole fleet. It is just food for thought. Another wrench in the fan for a custom header might be downstream emissions equipment like dpf, cat, egr or urea injection. My trucks came with none of that, but yours must be newer than my 98 and 99 models.

You can still do things to gain efficiency with your turbo. Put a blanket over the turbine section to avoid some energy loss (heat).
DodgeRam

[Reg.Airman]

Craysus,
Perhaps sending me pictures of your current configurations would be helpful for us both. You have my Airman email on the website. And you could send a large reply via Dropbox.

Additionally it sounds like you are running doubles or triples (perhaps more). We will need pictures and dimensions to answer your questions specifically. And on the website videos you can see doubles being pulled down a freeway.

Regards,
Reg

[craysus]

Originally Posted by Reg.Airman

Craysus,
Perhaps sending me pictures of your current configurations would be helpful for us both. You have my Airman email on the website. And you could send a large reply via Dropbox.

Additionally it sounds like you are running doubles or triples (perhaps more). We will need pictures and dimensions to answer your questions specifically. And on the website videos you can see doubles being pulled down a freeway.

Regards,
Reg

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