[NotSoFast]

    I have completed the connection from the filter discharge to the turbo inlet. It's a reasonably efficient number of elbows starting with a 6" 22 degree connection at the turbo to a 6" diameter aluminum pipe (8" length) to a 6" 45 degree elbow to a 6" to 7" reducing elbow to a 7" elbow into the filter.  What is not seen is the charge air cooling pipe that has been removed. The inlet port on the radiator where it connects can be seen on the upper portion of the radiator.

The connection to the turbo could really use an elbow of about 32 degrees but thats not easily found. The original connection was a 45 degree reducing elbow that only worked because it went to a smaller 5" SS tube. 

I think, I am as good as I need to be on this assembly. A 3D printed tube would be only marginally better. The real issue is the still to small filter element.  Once I get a feed tube from the filter to cooler outside air I will get a baseline and then be able to build a custom filter housing.

[NotSoFast]

I have finally posted on YouTube the results of the modification made to my air intake system and completed a 3300 mile drive from Phoenix to the Florida Keys with some good results.
It can be found here:
https://www.youtube.com/watch?v=4HfS2GAjPVs&t=809s
Would like to hear your thoughts.

Regards,

Mike

[RobSC]

Nice video, packed with useful information.

Rob

[[email protected]]

Looking at a 2011 with the 625 C15 and 12 Spd ZF that is for sale. Do you like your set up especially the ZF? Anything i should be looking out for?
Is the 2011 C15 have a better Air Intake System or does it need upgrading still?

[NotSoFast]

Hi BP,

According to data available on the web. The last version of the C15 was the SDP and was last produced on March 2009 for year 2010 vehicles. I've never seen one so you will need to inspect the intake system to see if its undersized. I would guess that it uses the same 5" formed SS tube between the turbo and the filter, in which case it would need to be upgraded. Also the engine was pulled from OTR production due to problems with the diesel particulate filter (DPF) regeneration system. Make sure a proper solution to the problem was installed before moving ahead with the purchase.

Regarding the ZF transmission, I think its an excellent unit with a very wide range of gearing that should serve you very well. Just spend the time necessary learning how to use it.

Good luck on your purchase.

Mike

[[email protected]]

Does your Coach have a DPF System as well? I am familiar with DPF system's. I owned a 2011 Renegade Ikon for 10 years with a 2008 Volvo 485 with the Volvo 12 Spd Ishift (which that transmission
is very nice and easy to use). I will be trying to contact you if i buy this to copy your intake system if possible. You really did a great job going through that.

[NotSoFast]

It does not have DPF. One of the reasons I liked the coach was it had the 2006 version of the C15, No Def and No DPF. My coach being a 2008 model year was manufactured in 2007. Newell used 2006 engines in inventory well into 2007. Not sure if it went into 2008 production years.

[Richard]

Mike,

We have all followed this with interest. Do you have any long term data relative to fuel mileage that you are willing to share. Just wondering if the changes resulted in data that you can share?

[NotSoFast]

Hi Richard,

Regarding fuel milage data, thats complicated. The problem that existed was a restricted intake system due to an undersized intake pipe which is similar in some ways to lifting your foot off the accelerator. So it could be argued that a possible increase in fuel milage should be expected as you're engine is making less HP so you're driving slower. I did not notice any better milage, however, I did modify my driving technique and more carefully restricted my speed closer to the optimal 1275 RPM which if I remember correctly gave me about 62 MPH. The problem is this coach is so heavy especially when towing my 4x4 Chevy Silverado that any slight hill really makes a difference and comparisons almost impossible. I was especially surprised on my last big drive from Phoenix to Fairhope, Alabama taking the southernly route I10 that my milage was only a bit better then when driving at the speed limit. Somewhere in the 5.6 to 5.8 MPG vs 5.2 to 5.3 in the past. I have hit the 6's however that really required flat roads like those in Florida.

I should also mention that restricting airflow by having a piece of ducting that is overly restrictive is not the same as lifting your foot off the accelerator. The MAS is what keeps the engine running at the proper air/fuel ratio, other than that all of the pressures within the intake ductwork are running out of specification and in the case of the turbos they can run such high vacuum pressures at the seals that seal failure is a risk. 

If you want to know what the actual number are for these coaches then a Dyno is required. I have been looking to get mine on a dyno but no one I asked was interested it trying to get an RV onto there rig.

Another thought I just had is that my last trip involved some different thinking. First, I kept my fuel tank full fearing I might run into an area that was short on fuel. I also kept my pantry fully stocked and even the toad was fully fueled and loaded. All this effects milage.

The additional positive effects my modification has done is to significantly reduced air intake temperatures by insulating all piping and even the air filter. Pulling cooler fresh air from the passenger side engine louvre and continually monitoring the air intake, oil temp and water temp, also allowed me to modify my driving on the fly depending on the instrument feedback. 

The mod is worth doing as power will come into line with factory specs and the turbos will now be at their proper pressures. You will also eliminate the chance of ingesting water and keep your filter dry.

I will make another video when I have something new to show. 

Best Regards to all.

Mike

[Richard]

Thanks !