Different approach to a snorkel

Yes inclines is when it can get loud. What you can do on long trips is disconnect it from the cab to hang under the fender (like stock does). Then when on the trail with dirt, mud and water - reconnect. Since its a simple hose clamp its a 30 second connect/disconnect.

Maybe not ideal for a DD but for me it works since its mainly a trail/camping truck.

 

Advertising: No, I'm referring to having a giant snorkel on my truck. The wife has made it abundantly clear that it "looks horrible [and she] can't believe anyone would do that." Besides, I like the clean, understated look of a bare truck. This goes double for a hood scoop (which would be in a low-pressure zone anyway, negatively affecting performance).
DD applications: Everybody has their own opinions on this, as well as their own personal noise comfort levels. I personally don't agree with Tyler's approach to running the intake into the cab, though admittedly it would be the single most waterproof area to draw from, because of the incessant noise. See above about my opinions on snorkels. Stock location is fine for me, considering I have no plans for glass......except that the stock intake is taking up valuable under-hood real estate -- which is the entire reason I'm doing this in the first place. I'll address the noise issue of my under-cowl location in the next post.
High enough: Pretty sure that if engine-drowning volumes of water are going to be reaching my under-cowl location, I'm going to have a helluva lot more problems I'm going to be worrying about first, or I'm driving like a 16yo with his dad's Hummer (hitting water so fast it splashes so much over my hood that I'm at risk of drowning).

A wet filter is no issue, imo. It means it was doing its job: blocking stuff that shouldn't be going into your engine. A little water in the engine isn't going to kill anything -- in fact, it's a standard procedure on modified turbocharged vehicles to use water injection. Problems arise when there's so much water that things get hydrolocked, which is likely in a vehicle that does a water crossing wrong without an elevated intake.

Correct. Not in the cab, not in the engine bay. Under the cowl. See next post.

 

Got it in today. Piece of cake.
Took me about three hours, 2.5 of which was me tweaking out on getting the hole juuuust riiiight.

Parts needed:
* 4" ID 90* close elbow ("close" = one leg is just long enough to fit a hose clamp)
* 4" ID x ~12" long metal tubing (ahem, aluminum)
* 4" rubber "donut" for mounting clay pipe (Homey Despot SKU #143-175: PlumbQuik part number P44U-405)
* two hose clamps for the elbow (4"ID)
* a few dabs of paint

Tools needed:
* 10mm socket or #2 phillips screwdriver
* 12mm socket with long extension
* your choice of tools for cutting a 4"++ hole in sheetmetal (hole saw, Dremel, files, die grinder, whatever tickles your fancy)


Here's the stock engine bay:




Stock engine bay with intake tube removed:




View under the cowl:



After cutting the hole (sorry, no pics. Possible I'll snap some when I remove everything to paint the bare metal I forgot to do), assembling the tube, and mounting it all up:



You'll note that I have an extra coupler hose on there. That' temporary, as I was using off-the-shelf parts from Schlep Boys (a 6" and a 4" tube). I will be replacing the two-piece intake tube with a single piece of aluminum. The end result will be the 90* elbow and one long, continuous aluminum tube going into the firewall.


Why I did it -- or -- The real estate I gained -- or -- Check out my bad-ass compressor:
(The compressor is just sitting in there for display purposes. Nothing is mounted or hooked up yet.)





The procedure:
This is really simple enough I shouldn't need to explain it. If you're comfortable cutting the sheetmetal of your truck, you probably don't need me explaining how to do it.

Remove the intake tube. Loosen the 10mm hose clamp, unbolt the two 12mm bolts holding it to the wheel well. Remove from truck.

Attach your new elbow to your new tube, so that it is now a single unit. Use this to test-fit where you will be cutting the hole in the firewall. Note that you will very likely need to push/bend the brake lines out of the way slightly, and also note that you will be working very closely to the brake lines when cutting the hole. Pretty sure I don't need to point out just how careful you need to be to avoid cutting the brake lines. Mark where the hole will be, using your preferred method of marking (X, trace a circle, dimple, whatever). Remember to allow for the thickness of the rubber donut!

Start cutting. Again, be careful with those brake lines! Remember to cut a SMALLER diameter hole at first, as you will need to do some cleaning up of the hole, and you can always enlarge the hole with a die grinder (but can't shrink it if you overcut). I used a Dremel with a cutoff wheel, then hit it with my die grinder to get it just right -- if you have a hole saw that's just the right size, use it.

Squeeze the rubber donut into the hole, adjusting the holes size as needed. It should be a nice tight fit. Now work the tube into the donut, making sure it's also a nice tight fit. Adjust the hole size as necessary with a die grinder.

Once you're happy with the fit, and everything attaches well, pull everything out of the firewall and give the bare metal a coat of paint to protect it from rust (the one step I skipped as of this writing). Once the paint is dry, re-assemble everything, remembering to tighten the hose clamps.


The whole project as you see it in the pics cost me about $60. That will be dropping once I exchange the two aluminum tubes and the coupler (and clamps) for a single aluminum tube......I suspect the final bill will be about $30.
If you want a good source for the elbow and T-bolt clamps, let me know. The 4-ply silicone hose cost me $15, and the T-bolt clamps were $4 each.



My notes thus far on performance:
I drove about eight miles between finishing it and posting here. It was on a surface street commonly used as a bypass for freeway traffic, and it was during rush hour......and with one lane closed. Suffice it to say, I didn't get a good variable experience. I did get to mash the throttle some.
Noise: Not noticeably higher. I do sense a low growl when accelerating, but nothing of any particular note. Cruising and WOT don't seem to have changed at all.
Intake temp: No static change -- it still reads about 10* more than ambient. What I did notice was that the dynamic change improved, with the cool-down period after heat soak being significantly faster -- what I mean is that when sitting still, the engine heat tends to soak into the intake, causing the intake temp to soar as high as 50* more than ambient, but when moving all that soaked-in heat from sitting dissipates much faster to return the intake temp back down to ~10* over ambient. At some point I will likely put in some kind of heat shield along the bottom.
Airflow: I have gotten just a bit more vacuum, from ~23 inHg to ~27 inHg. I interpret this as better airflow.
Butt-o-meter horsepower: No change. I can't tell if I gained an extra 2,000 horses, an extra .002 horses, or things stayed the same. My butt's just not sensitive enough.
I will weigh back in on whether there is any effect on cab ventilation. Likewise with low-end power and upper-end power.

 

No. Not sure if I'm going to go that route, or leave it as-is. Not even sure if I really need one, seeing as how it's pretty well protected.

 

Not all OR are like that. The earlier 2nd gens that didn't have atrac have the abs block over on the pass side

 

Nicely done OP, and thank-you for taking the time to show us how you accomplished the mod. I like it.

 

Looks good and clean!

Definitely wouldnt work for me because I wanted a full waterproof setup - Last time i was fording through water it went over my hood and my cabin filter was soaked so I think this would have sucked water, i'm curious how it will handle a heavy rainfall. Keep your cowl drains clear so water doesn't accumulate up there.

How is the noise on it? Any coming into the cabin with the cabin filter being right there?

 

I really like the under hood real estate that was gained. I am curious to see how it fairs in the rain, though. Keep us updated OP. Nice job!

 

Pretty darn nice. I had my cowl off last year to add a screen over the cabin air inlet. Found rats like to build nests on top of your cabin air filter.

While in that area it became apparent of how much air gets into that area. Air is not only pulled in from the top plastic grille, but also from each end of the cowl area near the fenders upper rear corner.

My truck has run a stock intake, a Volant Scoop plumbed into a stock airbox, and now currently has a Volant Scoop into a Volant CAI with sound deadener lining inside the CAI.

For serious off-road, without a snorkel, this may be the second best location behind the inside cab air intake.

Some of the photos in this topic show just how low mounted the oem intake really is. Not only is it in a very dirty area, but also vulnerable to water crossings.

If I had a concern with this install, it would be that if you don't run a fender liner, all the dust / dirt / water spray off the front tire will find it's way into that area of the cowl. The blessing though is that while moving air should enter at the windsheild base and force the flow of air into the fender wells.

This is very nice.

Has anyone ever consider building a ducted system to run down along the frame rail and have the intake pipe in the bed behind the window.

The frame rail would protect the duct, the filter would be oem, the difficult area would be from the engine compartment to the frame rail. Seeing how others came through the fenderwell, it may not be that bad.

PK

 

Looks good OP. I thought about doing this a while back but was concerned about the rain as well. My brother is an xj guy and a bunch of people have done this on his forum I think. Sub'd for more performance info down the road.

 

Very nice. One thought though is that if you are concerned about rain, might try putting a turndown of some sort on it right as it comes through into the cowl.

 

Yeah you could probably buy a snorkle head for cheap if it would fit.

On another note, do you think the cowl is big enough to do something like this? I like this better than a full-fledged snorkle, especially if it only required cutting a hole the cowl. Not sure if possible though, I feel there may not be enough space in the cowl for 3.5" tube while still retaining space to open the hood. Thoughts?

/Sorry for thread jack

 

The Tacoma hood goes over the plastic cowl, so the only way this would work is if you put it in the hood itself (i've been considering it).

Rain is not a problem. You can suck up quite a bit of rain water even without a filter to stop it, and be just fine. Might even be good for the motor, as it will give the pistons a nice steam cleaning, and actually improves performance by cooling the intake temps

 

Updated pics post with part number for rubber donut.

Performance update:
Drove around in various on-road conditions today. The proximity of the intake to the cabin air intake does do two things: 1) introduces some noise, generally when under load and at least 40% throttle, and 2) affects the amount of fresh air reaching the cabin.
In terms of noise, it's definitely not at the annoying level. It's a very nice, powerful-sounding low note that is really only there when making the engine work (climbing hills, accelerating hard). It's not loud, but it is certainly audible. I can only imagine how loud it would be if it were routed into the cab!
Because the location of the intake is right at the intake for the cabin fresh air, the two do compete with each other for air volume. During low-throttle conditions the air blowing through the vents is like stock. But as the engine's work/throttle increases, so too does the drop in airflow through the vents. When at WOT, unless the blower is on at least speed 3, you will not be getting airflow out of your vents......except perhaps a slight negative flow. With the fan on high, you'll notice when you snap the throttle shut, because the airflow noticeably jumps.

My highly accurate but very insensitive butt-o-meter tells me that I have a slight increase in torque across the band. There doesn't seem to be any particular "sweet spot" where I get substantially more power. I do notice there is an increase in throttle response.

 

So far, it sounds like the only big downfall is the vents competing with the intake for fresh air. I wouldn't want that if I was trying to run the defroster on a cold morning. I really like this idea, I wonder if there would be a way to better separate the intake and the fresh air inlet so they're not competing as much...

 

I would be curious to be able to compare noise levels. With mine plugged into the cab up under the glove box (by the cabin air filter) my guess is the noise level isn't much less than mine - since all that is separating your setup form the cab is a cotton filter.

As I have mentioned from the beginning - my intake make zero noise when I am cruising around, on the highway, etc. Only in the conditions you mentioned - more than 50% throttle, steep grades and WOT - does it make any noise at all. The only time a passenger has commented on it is when I was going up a very steep grade that was several miles long - other than that no one even notices the intake in the cab (my wife included).

If the noise really bothers people, when the weather is nice (not raining) its so easy to disconnect the intake from the cab (1 hose clamp) that if I were going on a long road trip to get to a trail - just disconnect while on the road and reconnect when on the trail.

I'm sure we all have our own tolerance levels - so this is definitely our own opinions. Maybe my truck is more noisy overall and it drowns out any intake noise

I think running into the cab and the cowl both are legitimate options - any intake is going to create more noise (even a cone filter under the hood and even someone mentioned their fender snorkel was noisy). I guess if you want no additional noise - leave your intake stock.

Personally, I wish I could have left my intake stock because I don't like intakes in general, but with the way toyota picks up the air from the fender I had to make a change and one that was 100% waterproof.

Thanks for the info and write up!

 

Wicked, I wonder if you could add some sort of sound dampening to your tubing, similar to how they dampen ducts in a building so sound doesn't transfer from floor to floor or room to room. That would make your setup the ultimate snorkel application with no drawbacks for daily drivers.

 

Yeah, I fell asleep with the computer in my lap last night. Was going to post a bit more......

I designed/built it with the idea that I will be fine-tuning it as time goes on. Now that I see there is a small noise issue, I will be addressing that.

First thing I'm going to do is shorten the rubber donut that mounts the tube through the cowl -- that will give me about 1.5", and likely help with competing air demands between the intakes.
I'll also experiment with various ways of building a wall between the two intakes (engine and cabin). Probably start out with some soundboard pieces I have sitting around, probably end up with a formed sheet of aluminum with DynoMat on either side (or dipped in tar) -- I don't have the space to mount a turndown/out.
The available cubic inches under the cowl are more than enough for both intakes. It's just a matter of figuring out how to get the two to stop fighting for each other's air.

I didn't mention this before, but I think it's worth pointing out. The tube is only slid into the rubber donut. I have no plans to attach them together, such as with caulk. This is very intentional, as I want to allow as much movement as possible between the engine and the body. It also helps with removing the intake, or accessing the filter.

 

Is there enough room to put another 90* in the cowl area and send the intake pickup to the driver side? This may help with noise (getting it away from the filter) and the competition for air.