Cowl induction + FJ cyclone pre filter?

Planning on doing the cowl induction modification to my AC Tacoma. The dust was just too extreme on our last off road trip. I'm wondering if anyone combined the FJ prefilter with this cowl intake modification or has any comments or criticism.

If someone has the FJ prefilter, what are the dimensions?
Length?
Inlet diameter?
Outlet diameter?

 

By the way it is a 2.4L so I'll modify the air box with a hole in the bottom so I'll have a bit more distance to work with vs. the V6.

 

I've never seen this before. I'm very interested.

 

Just ordered the FJ cyclonic filter... Will keep you all posted.


Toyota 17730-31030 Precleaner Assy, Air W/Hose

 

$174 is insane! Looking forward to updates.

 

Yeah, the price is fucked, but I DIY'ing something like this would have been a major pain in the ass. Also, modeling it, verifying it, etc.

 

Interesting. I have a cyclone prefilter on my snorkel, but it's not in the engine bay.

https://youtu.be/SIMdjCd1OZY?si=PLzBzd4C_PFb6e0g

 

Ok, the prefilter arrived recently, and I bought several silicone couplers.

the challenge in the engine bay of my 2.7L tacoma is that I don't have appropriate surface area on the cowl side of the airbox to connect between the cowl and the airbox. Now I'm looking at doing something like this:



https://www.youtube.com/watch?v=ajfM6FBqs_8&

 

That looks like a cool mod. Let us know how things turn out and if it helps out your dust situation.
Would a full snorkel setup be too invasive for you?

 

The snorkel could be nice, but I'm seeing if I can achieve something a bit more discreet first. I also don't want it to get torn off on trails.

I think this is a brake part here in the way between my airbox and the cowl. Even if i had a surface to cut into in the airbox i'd be blocked.





Here we see the FJ prefilter in front of the airbox and there is surface area there on the airbox to cut into, but I'd need to cut the radiator mount to route air though.


Its an irregular surface to cut into unfortunately. For a street car, I'd like the ram air effect, but for dust avoidance, might not be the best idea. (Open to thoughts).

Could investigate running forward from the fender mount, like this in the blue:



(noting that I have a 2nd generation)

 

These engines do not particularly benefit from ram air, wider, or shorter intake paths. They are tractor motors, not road smokers, and do just fine with the "suboptimal" factory intake paths. As long as you have space for the trap to empty, and you don't have an astronomically longer than factory intake path, or a lot of severe bends, I believe you will be just fine regarding any kind of lost performance concerns - you will certainly not be adding any power to speak of no matter what you do.

I am very interested to see how that separator works for you - I've been considering plumbing one in for ages but have never had my hands on one. I'd like to do it as part of a "cowl snorkel" - don't know if you have considered that option but it is a tried and true method at this point, a few others above have mentioned it and perhaps linked the original thread(s) on that topic.

Actually, since you have your hands on it, could you please take some pictures of the FJ filter from a couple of angles, so I can get a good look at it? I wonder if it would fit inside the fender?

 

Thanks for this input. I'm waiting on a BAMF front bumper and with that exercise and disassembly maybe I'll figure out another routing approach. (I have my truck stored right now so I haven't dug too deeply.)

What do you all think about the dust aspect of doing a ram air set up? I wonder if putting the FJ prefilter at the front behind the grill, will engage the centrifugal action better forcing dust into the pocket better, or will the prefilter work better with less direct, forced-air location. Note, the prefilter includes a rubber catch pouch to get the dust out that it gathers. If you're in a high dust situation you can just remove the rubber nipple and expose the slot and gathered particulate will just fall out.

 

It is designed to work correctly with relatively low pressure - look at the way they are installed on e.g. the FJ or various international market Toyotas, which is with an "ice cream scoop" head inside the fender, certainly not optimized for the highest pressure available as in a ram intake.

 

I have a thread about the cowl intake mod that might be helpful: https://www.tacomaworld.com/threads/cowl-induction-snorkel.525314/
I've also done this on a Gen III for a friend. I have not done it on a 4cyl. A couple of things to consider. First, looking for a ram effect is a waste of time as others have said. Secondly, one of the videos you referenced shows the use an accordion type "dryer" hose. This is a bad idea. The airflow through such hoses is terrible, and if you have no other choice, you need to increase the diameter by at least an inch. There are so many silicone, stainless, and aluminum components out there that just about anything can be fabricated. Stay smooth for better flow. Lastly The cowl intake is considerably cleaner than pulling air from the fender well. Are you sure you need a prefilter? Honestly, I don't travel in packs all that much, but I do around 5,000 miles a year on dirt. I don't have or need a prefilter. I do remove my filter occasionally to gently blow the dust out. I would suggest not adding complexity for the cool factor. That's one reason I don't want a traditional snorkel. I've never needed one, and frankly never seen anyone who did. If I lived someplace with lots of deep water, and found myself crossing it, well, OK. I avoid deep water situations because of all the possible damage it can do.

 

agreed on the ram air effect. I'm really just looking for inlet options. It will be a pain to route this to the front grill, but its an option.

agreed 100% on avoiding the accordian hose. I plan on going 3.5" tubing.

I'm generally in the back of my three truck convoy when going off road and its a california dust nightmare.

One thing to note in the accordian hose example I posted, that is pulling air from the boundary of the cowl and the fender area, i am not sure it will be much cleaner.

The cowl is the ideal spot, I just can't figure out how to get there.....yet

 

Dude, you need to upgrade your position in the pack, ha ha. Yes, that's a nightmare of dust. Good luck with your project.

 

After many Amazon orders for silicone 90s and 45s and PVC 3.5" tubes I've got a path routed from the stock entry point in the frame back towards the passenger mirror at the cowl. No metal cutting needed yet, but plan on opening up (skeletonizing) the wall between this area and the cowl area below the windshield to increase airflow.

I have the FJ prefilter inline now and because I needed a second car in a pinch on Sunday, I ran the tacoma with just the prefilter intaking above the fender liner.

From just about 40 mins of city driving, I pinched the nipple and found the below debris in the rubber catch bellows. Seems to work, AND this is a dirty area for an intake to be located.

I plan on using expanding foam to seal up (will include a hose to drain water) the cowl area from the fender area when I'm done.

Should be all done this week and will post updates. (sorry my pics are not inline.)

 

This isn't a particularly easy install. I have cut a PVC tube with an angle on it to mount flush against that wall between the fender area and the under-windshield cowl area. My next piece will be a 3.5" to 4" 45deg to connect this pvc tube to the inlet of the prefilter. They're not exactly lining up right, so it will be (yet) a(nother) struggle.

When everything is done, I'll post a final parts list so Amazon can recoup on all of my returns I made on unneeded parts.

 

Here is the PVC tube that I've angle cut to be flush with the wall between the fender area and the under-windshield cowl area. You can see that I'll have my work cut out for me to line up the 3.5" to 4" 45deg elbow. I couldn't just force the 45deg elbow into here because the pinch points at the vertex deformed the opening.

 

Ok pretty much got it hooked up. Wasn't easy

Used:
3.5" 90 silicone elbow
FJ cruiser prefilter
3.5" to 4" 45 silicone elbow
3.5" PVC tube

Still need to seal up the cowl wall with expanding foam and skeletonize the wall.