Different approach to a snorkel

Just a suggestion about where the tube slides through the rubber donut, have you thought about using one of those things that houses use for roof top vent pipes? They're like a stretchy donut but are water-tight more or less and do not permenantly hold the pipe in place, it will still pull out.

 

Not enough room without doing a cobrahead elbow. Even then, space is still an issue. Plus, the fewer bends and shorter length the better it will breathe -- if I stretch it all the way to the driver's side I will likely be introducing a restriction.

Speaking of which: The idea of running the intake along the frame and to the back of the truck is NOT going to work. The longer the run for the vacuum side of an intake, the more restriction is introduced. Think about the number of high-horsepower vehicles that make an intake as short as possible, even to the point of skipping the filter entirely. Better yet, try this: Suck through a foot-long piece of garden hose; now, suck through a 15-foot-long piece of the same hose.
Now if you're talking pressure, such as a turbo or an exhaust, then length becomes less of an issue. But vacuum needs to be as short as possible.

 

I work at Homey Despot , and am familiar with all the various products. Yes, this roof-mount vent cap could work just as well -- however, it requires some kind of attachment; in our trucks, that would be either rivets or screws, or glue. The rubber donut I'm using simply slides into the hole that has to be cut anyway; plus, the donut softens the edges of the cut sheetmetal so it doesn't rub a hole in the tube (something that would have to be done anyway even if the roof cap was used).
Really what it comes down to is variations on a theme. If you like a roof cap more than a pipe donut, then by all means go that route. One can also use foam rubber weatherstripping (like the factory did), C-channel weatherstripping, two-piece screw-in bulkhead fittings, nothing at all, or any number of other ideas I'm not listing. Dozens of different materials to do the same job.

 

How's it holding up?

 

Had "rain" on Friday. Went through some 33"-tire-top-deep mud holes Saturday. Holds up perfectly. I didn't check how wet any filters were, but there was no suckage of water into the intake. I would not have been able to bomb through the ~33"-deep mud hole like I did had I not done the mod. So in that regard, it's quite the success.

 

the change from 23" vacuum to 27" vacuum at idle seems significant with my limited understanding. From that observed change, my understanding is you should see a noticeable, positive change in your fuel mileage. I'd be interested in your observations on fuel mileage. Great work on the mod OP, and sharing your experience.

 

I won't have much of a chance to get good MPG numbers for a while. Around town DD doesn't count.


Installed a simple, basic wall to separate the two intakes (engine/HVAC). Used rigid plastic board (think plastic cardboard), attached to the two stock holes on the HVAC intake (bent up to be flush with the rest of the wall......see pic #5) with a couple of plastic removable rivets. All parts I had sitting around already.

I also trimmed the donut shorter, so that I have more clearance between the two intakes.

While I've only driven a single one-mile roundtrip since doing it, I suspect it made a difference. I seem to have less drop in airflow in my HVAC when I'm at WOT. In fact, it seems like I have *increased* airflow in my HVAC when I'm at under-40% throttle, improving upon the stock cabin-air intake pressure.

I'll keep y'all posted when I get some better readings. I'll fire up my OBD2 reader sometime and get some actual numbers with the new air dam.

 

sub'd for when i get home from this deployment sounds like an awesome alternative to a snorkel. Has anyone thought of running it under the truck w/PVC and up into the bed? Just curious.

 

sub'd

 

So the two-piece aluminum tube has been replaced with a single piece. Otherwise, no changes.

Accessing the air filter is just about precisely the same ease as stock. I don't have to disconnect anything -- because I designed it as a slip-mount at the wall, the entire tube rotates and slides out to allow me easy access.
At some point I need to wrap it with insulation wrap to try to keep some of the underhood heat from cooking my intake air.

Thus far, the results:
Vacuum: increased by ~2in/hg
Fuel economy: no noticeable change
Noise: slight increase under WOT. But now that I have a FlowMaster on the exhaust, I don't hear it any more.
Airflow: cabin airflow is reduced as throttle increases, but I never have negative flow in the cabin
Power: no noticeable increase or decrease
Codes: nothing. Even had it in to the dealer recently for its last free service, and no mention of the intake (mechanic was complaining of my winch and my tires).
Underhood real estate: Tremendous gain. I was able to fit the overly-large Puma air compressor *and* still have more space left over.
Intake temp: no noticeable increase or decrease, but I *do* notice that the intake air temp heats up faster when idling, and cools faster when moving, than it did as stock. Probably because I'm now routed directly over the exhaust manifold, and also because I'm using heat-conductive aluminum instead of insulative plastic.

Btw: All my claims to numbers are based on my access through the OBD2 system via my Kiwi bluetooth + Torque Pro for Android. So unless the OBD2 is off, these results are quantifiable and verifiable.

Ill try to get pics of the updated (final) setup.

 

Any updated on this, I think I'm going to relocate to the cab.

 

I am going to be doing this. Starting the parts list now.

 

Subd

 

sub

 

Want info on this one piece pipe OP used.

 

Will upload photos tonight.
The aluminum tube I got off FleaBay. I don't remember my search terms, but I'm pretty sure it was "aluminum intake pipe" or "aluminum pipe 4". The place I got it from sold it by the foot, and I got one foot. If I were to do it again, I would not go with as thick a tube wall as I have.
I'll look around and see if I can find more precise info about it.

<edit>
Look! More precise info about the straight aluminum tube I used!
http://www.ebay.com/itm/4-OD-6063-T...Parts_Accessories&hash=item485b2c0187&vxp=mtr

 

So the 90* is not part of the one piece?

 

Correct.
Hard pipe is straight. Rubber (silicone) elbow is 90*, with one end cut close.
Total parts are four (90* rubber elbow, straight aluminum tube, rubber grommet, and hose clamps), seven if you count the diverter wall and two fasteners, eight if you count each hose clamp individually.