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Air intake modification

We recently finished with making some improvements on the air intake "scoop" that a PO installed on the rear driver side corner above the tail light. The PO made an opening to the compartment above the air separator where the intake pipe makes an offset before going up the corner of the coach to the vent in the mid center where the backup camera is located. The problem with his modification was that there was nothing to keep bugs, leaves and debris out of the air separator. The separator did a fine job of keeping trash out of the filter tho' as little was found when I changed it. It was also possible for water to enter the separator if it was raining hard while driving. Again the separator must have kept water from the filter as I  saw no signs of water damage or stains on it.

I removed the scoop and installed a plastic "funnel' about 4" on the small end and 6" on the top, placed it inside the opening down to the separator and used some foam sealer to keep it in place and prevent water from entering.  To keep "things" out of the compartment I fabricated a small screen out of 1/4" hardware cloth and screwed it to the inside of the opening before replacing the scoop.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Air intake modification

Reply #1 –
Looks like it should work like a dorade vent on a boat. The one thing they have in addition is a small drain from the box for any water that comes in.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Air intake modification

Reply #2 –
Good modification of the modification.  I think the wire screen is a no-brainer...should have been there from day one.

What is the "scoop" made of?  Have you considered painting it white, to better blend with body color?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Air intake modification

Reply #3 –
I would like to do something similar to our U240 but haven't found the time or courage to cut into it.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Air intake modification

Reply #4 –
I may be missing something.....why was the "modification" done in the first place?
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Air intake modification

Reply #5 –
Quote from: mike leary –
I may be missing something.....why was the "modification" done in the first place?
Ram Air Intake?

"A ram-air intake is any intake design which uses the dynamic air pressure created by vehicle motion to increase the static air pressure inside of the intake manifold on an internal combustion engine, thus allowing a greater massflow through the engine and hence increasing engine power."
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Air intake modification

Reply #6 –
Quote from: mike leary –
I may be missing something.....why was the "modification" done in the first place?
My main goal would be a much cleaner source of air.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Air intake modification

Reply #7 –
I have been looking into The Donaldson intake. I have not had time to really look at what kind of room is there but a setup on top of the rear cap would sure be a improvement.
http://www.youtube.com/watch?v=xsaumoXtmSw
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Air intake modification

Reply #8 –
Quote from: stump –
I have been looking into The Donaldson intake.

Interesting, have never heard of it. Makes sense!
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Air intake modification

Reply #9 –
Seems like a lot of work for negligible benefit.  At 70 mph you would get only about 0.18" Mercury pressure boost. Withe the boundary layer separation that far back on the coach, I doubt you get half that much.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Air intake modification

Reply #10 –
I don't travel into the rain country anymore, and my power is plenty. I also wonder how the unit would retro to mine.
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Air intake modification

Reply #11 –
Quote from: sedelange –
Seems like a lot of work for negligible benefit.
Agree.  My comment was tongue-in-cheek.  We are talking, here, about turbocharged engines - true ram air intakes are normally used on naturally aspirated engines.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Air intake modification

Reply #12 –
Yup, very little improvement on a turbocharged engine unless the coach maker did a very poor job with the intake system.

Foretravel did a good job.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air intake modification

Reply #13 –
Quote from: Chuck & Jeannie –
Good modification of the modification.  I think the wire screen is a no-brainer...should have been there from day one.

What is the "scoop" made of?  Have you considered painting it white, to better blend with body color?

Its made of stainless steel, seems to be of good quality and professionally made. Was installed by the second owner sometime between 2002 and 2010, I am the fourth.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota
 

Re: Air intake modification

Reply #14 –
Quote from: mike leary –
I may be missing something.....why was the "modification" done in the first place?

I don't know..... with a turbo the best reason I can come up with is a cleaner source of air. Seems to be a lot of dust that accumulates on the rear of the coach. Often wondered why FT installed the intake where they did. Maybe most don't drive down dirt roads!  :D 
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota