Air Filter Box Upgrade- Help!!

[alkhalifa]

I am working on my Defender 90's engine and have come to a halt with figuring out how to get an upgraded air filter box. I want to avoid using oiled air filters because I will be doing a lot of offroad in dusty conditions. I am trying to figure out the best way and have searched all over for a solution. If someone can help me with the Air filter box for my 3.9 EFI I would really appreciate it.

[mdmccallum]

Some useful info. if this pertains to your mods.
Date: Wed, 23 Sep 1998 10:42:22 -0700
From: Larry Michelon kismet2@erols.com
Subject: [D90] Performance Gains

I did a search to find the losses of cutting of the "horn" on the air filter housing (D90's and Classic RR's). At the same time I stumble across the other notes that Jim Allen had writting to the list. Whether or not you believe Jim as a very knowledgable person, he has documentation (often first hand) of his findings. Sorry if it's so long.

Below are direct quotes from Jim's postings. Find out more about Jim at http://www.fourwheeler.com/techline/lrover/index.html.

ON K&N FILTERS:
Item 1) I have several test (the sources of which I posted yesterday) that puts the K&N at least equal to a paper filter. I'm doing more research on this but so far K&Ns are rated as 96.8-97.8% efficient (K&N claims 97%). The info I have on paper filters rates them from 92-96% efficient (the 92% info is about ten years old)
Item 2) I don't understand how you can deduce that a lower restriction filter equals less power at low rpms? I can't account for a Honda but I have dyno charts (from a Disco, RR 4.0SE and RR Classic) that's how that there is little benifit to K&Ns at low rpm (but no loss) and a 4.5-55hp increase at 5000rpm. I was there during the tests that were being done for a series of articles I was working on. There are other tests in magazines that also show similar results.
The whole game with performance air filters is airflow, so until the engine really starts to wheeze at the upper end, it can work OK with any filter that gives it enough air for a particular speed. Based on the tests I ran, the OE filter starts to wheeze at about 3500rpm because that's when the extra power starts to come in. We ran tests on the air filter housings themselves and found that, with the exception of the RR 4.0SE, they were no restriction to power up to the 5500 rpm redline.
Since few of us see 5000rpm, the 4.5-5.5hp may not be a big deal, though my seat of the pants says the engine is snappier on acceleration. After the dyno tests, I drove the 4.0SE and the Disco from the dyno in California back to Colorado and noted an increase in mileage over the trip out in stock condition, but since there were other mods to the vehicles at that point, I can't attribute it to the filter. A non-Rover magazine project vehicle I am currently working on has noted an increase in mileage that I can definately attribute to the filter, but the vehicle had a particularly inefficient unit as stock.
Item 2A) Upon reflection, a carbureted engine might have a problem going to a free flow filter because it was originally jetted for a restictive filter. If you were to re-jet the carb, power would be restored or increased. I guess I'd need to know the details of the test your mentioned.
The bottom line is that for most folks, the power changes and mileage increase would be minimal - but there! The main benifits would be a higher capacity to carry dirt, the ability to handle water and the option to clean the filter forever instead of replacing it sooner or later.
The debate rages on!
Jim Allen

I found this in the F.A.Q. sections of this site.

[Doug]

I'm very interested in this too. Ideally, I'd like to have a very short cold air path to the throttle body. Necessary are 1. filter, 2. MAF. That long MAF-to-throttle hose has got to heat the air up considerably. Although a snorkel brings in cool air, it has to travel through an addition 3 feet of under-hood hose.

The john lee Expedition Exchange snorkel tech article looks good, but I don't like the small filter solution. I want LOTS of cold air! Ideas welcome!

I am running without the horn. Can't tell if it improves air flow for sure, but I can't believe that horn has any value whatsoever unless it's just to keep the paper dry in wet conditions....

DW

[Hans]

Until other projects came up, I was trying to figure out how to relocate an air filter to just under the wing-top vent. I figured I'd make a custom box to put the filter in, some type of baffle to keep rain/snow off the filter element, and mount the MAF to the filter box. Then it would be close to a straight shot right into the plenum, and give me cold fresh air at the same time. If I ever wanted to add a snorkle, it's just a matter of sealing up the box since the snorkle would feed right into it.

-Hans

[Mike Hippert]

I know it sounds silly, but you could put a snorkel on and a good precleaner, the precleaner will catch most of the sand and then you ca run an oiled air filter allowing some more air flow.

[alkhalifa]

Before starting this project (converting a TD5 to 3.9) I thought it would be very good if I can get cool air into the system. So I decided to buy an air scoop that fits on the right wing vent. Little did I know that the heater has a duct that is linked to it. A thought crossed my mind to change the intake of the heater and get it to go through the side vent and use the right wing vent (w/scoop) for the air filter box. I placed the coils under the left vent in order for it to have access to cooler air. I always been told by rally drivers that paper filters are the best because they don't clog up in dusty conditions. My plan is to either stick to the original filter box, custom make one, or get an upgrade that fits. I read an article in LRO (OCT 2004that said that the wingtop vents do not get a lot air because once the air hits the front of the car very little goes throught the scoop on the wingtop. This makes me think if its worth using the wingtop vent as an air intake of cold air. PersonnalyI have never been too fond of snorkels in terms of the final look I'm trying to achieve.

[ELCIDd90]

Just out of curiosity, why the 3.9? why not something bigger like the 4.6 or a chevy small block? Just wondering.

[alkhalifa]

Well, this is a trial and error project and I want to make sure that everything is running smoothly as I test what I (and a couple of Rally Prep Guys) will end up with once its used a bit on the road. If it goes well for a while with no problems then and only then will I upgrade to a 5.0 TVR engine. With this I hope I could get to 120MPH!!!

I have attached 2 pics one of the car and the other is the engine awaiting completion.

[Art Vigil]

"...If it goes well for a while with no problems then and only then will I upgrade to a 5.0 TVR engine. With this I hope I could get to 120MPH!!!

That's the second time you've mentioned aspiring to 120MPH in a Defender.:rolleyes Why don't you just buy a car designed to go that fast?

[alkhalifa]

Thats why we have choices and I guess thats MY choice. Part of the reason I am in this forum is because I'm a Defender fan....I have seen many owners who want to see something different about their Defenders. I didn't read a rule book saying you can't do what you want to a Defender.

[rover4x4]

yeah but honestly why? There are many more vehicles better suited to that sort of thing. More power to you

[alkhalifa]

Well I always like to see the look of people when they see something they don't expect. I remember once that someone told me he saw a 1984 Range Rover beat a Nissan Maxima in drag race. Its things of that nature that really make it worthwile. I know its not safe to do in a D-90. It give Defenders credit that they can perform as well on road. I won't race the car day in day out. Its when I get the occasional sedan driver that looks down at Defenders to see what a Defender is really made of.

[Art Vigil]

"Thats why we have choices and I guess thats MY choice... I didn't read a rule book saying you can't do what you want to a Defender."
What the hell are you talking about? Of course we have choices; I never said you shouldn't be free to do what you want. It's simply my opinion that some choices make more sense than others, and I was asking why you would want to put the effort into making a Defender go 120MPH. You obviously realize how ridiculous it is otherwise you wouldn't be so defensive about it.

Well I always like to see the look of people when they see something they don't expect....Its things of that nature that really make it worthwhile.
Uh huh, I see. :rolleyes I don't expect to see a boat made from a coffee table, but that doesn't make the one below any less stupid.
You can choose to wear women's clothing and dance around singing in the streets also. That doesn't mean people won't look at you like you're some kind of nut. It also doesn't mean that it hasn't been done before. A 120MPH Defender is about as silly as a 4-wheel drive Corvette, but hey, it your choice. As far as I'm concerned, you can do what you want. I was just asking the question.
MY$.02

[evilfij]

John P I bet has been up to 120 in a D90 . . . I had mine up to 110, and that is a stock 3.9

[alkhalifa]

As you mentioned in your opinion its a waste of time, but I never see that it is a waste of time. People are trying to speed up their Defender and you can see that evilfig mentioned he has hit 110. Comparing a Defender reaching is 120 is like a boat made out of a coffee table or a 4x4 vette shows what you know about Defenders. It was published on LRO 105 MPH in a Defender 90. Your opinion is that it was not a good choice? Or the Overfinch Defender 570 is a waste of time in your opinion. So now we have people who have done it personnaly and companies professionally. And you think its nuts a bit too self opinionated aren't we? And whats with the cross dressing offcourse people will think your a nut.........opnions about choices are still opinions it doesn't make them facts.

Lighten Up.......

[JimC]

Neutral corners everyone :) For some reason, this board is prone to temporary outbursts of 4x4 snobbishness.

I think it comes from the fact that here in the states its so common to see idiots driving their kids around in huge trucks, getting 6mpg, running people off the roads and sidewalks simply because its fashionable. We really get edgy about being categorized with the "SUV drivers."

So dont take too much offense when someone here tells you to "get a real car."

And also, some of the old hands could be a little less quick on the trigger to tell people that they have to enjoy Defenders the same way you do.

Remember, the real enemy is the soccer mom!

[Mike Hippert]

Not trying to add fuel to the fire but, I know of a few Rover owners on this board who like to drive their Rovers fast, and would like to have more HP under the hood and some that do have some more hp that drive fast. I don't see any reason why it would not be cool to have a few more HP, 184 stock really sucks. And even my 90 isn't all that bad up to 90 mph, and like Jim said as long as your not a soccer mom eating dinner and talking on your cell phone while you pull out into the guy driving a blue d-90 then you are probably OK to be doing 120 on the right road. Sure there are cars better suited for it, heck a rock buggy is better off road then my 90, and a diesel VW Jetta would be a lot better on road then my 90, but they lack the feel I get when driving my 90 on or off road.

[TwisteD90]

Art, why do you always like to stir shit up :lol It's funny that are giving this dude hard time about fast D90's. Aren’t you running a Super Charger? Ok ok so you bought your truck like that. Didn't you ask me about putting a 4.6 in your truck? Didn't you ask me about wanting your D90 to haul ass w/o worrying about the engine falling a part. Well, keep your eye on Nasser he could be your answer :lol Having a truck that runs 100 mph over in Persian Gulf countries is nothing new. You gotta see for yourself. Nissan Patrol that beats a Corvette at top speed. Toy Land Cruiser that beats a Viper from start to finish. Guys asking to make their trucks faster is normal get used to it.
I for one would love to go faster in my D90. Ask Mike how was our drive to Moab; we would have loved to go passed that 70 mph speed.

[alkhalifa]

Guys Thanks for understanding.....Supercharge Art????????? I never thought of putting that on my 90....Well, as Twisted just mentioned amazing things happen.....Last I saw Toyota Land Crusier out beat a Porsche Turbo....That was a killer to the porsche dealer......in the Middle East.....The Arabian Gulf is full of amazing stories of fast cars....the only problem is......nobody makes an effort of telling the world about it....200MPH 4x4's...................Personally....Defender is the ultimate 4x4.

[jaherring]

Before starting this project (converting a TD5 to 3.9) I thought it would be very good if I can get cool air into the system. So I decided to buy an air scoop that fits on the right wing vent. Little did I know that the heater has a duct that is linked to it. A thought crossed my mind to change the intake of the heater and get it to go through the side vent and use the right wing vent (w/scoop) for the air filter box. I placed the coils under the left vent in order for it to have access to cooler air. I always been told by rally drivers that paper filters are the best because they don't clog up in dusty conditions. My plan is to either stick to the original filter box, custom make one, or get an upgrade that fits. I read an article in LRO (OCT 2004that said that the wingtop vents do not get a lot air because once the air hits the front of the car very little goes throught the scoop on the wingtop. This makes me think if its worth using the wingtop vent as an air intake of cold air. PersonnalyI have never been too fond of snorkels in terms of the final look I'm trying to achieve.

I've also thought about some type of intake/scoop on the wing vent to grab cold air. Regardless of how much airflow hits the horizontal surface you'll still get *cold* air. My point is that maybe a scoop will not be extremely effective in grabbing *forced* air (because the big square nose of the D90 shields it from a good amount of 'headwind'), but it will still be *cold* compared to the air under the hood.

You could also route the air intake somewhere up front behind the headlights (lots of cars intake there) but for a 4x4 it's best not to *lower* the point of your air intake (water injestion). Also, for dusty conditions, the higher the intake the better (this is where the snorkel comes in handy, but the look is not what you want) from what I've read.

I thought that perhaps a *rearward* opening scoop would be the best solution for cold air inlet, mounted high enough to be out of the bulk of the dust, and the rear opening would prevent sucking in too much water (from random splashes) or other heavier particles that might get 'caught' by the scoop.

Where did you get your vent scoop from?

[Hans]

Thats the same reason I want to run a different air intake also, getting COLD air as opposed to the overly hot under-hood air that we have currently. I'm not too concerned about how much the scoop works as a forced air intake, I just don't want to be sucking down hot air anymore. I was even thinking about using a combo cold air intake box to feed both the engine intake and an additional oil cooler, but that would make for some interesting and long oil lines and I'll probably put some fenderside louvers or something for an oil cooler.

-Hans

[Art Vigil]

Art, why do you always like to stir shit up
I give up, I'm done with this forum.

Later,

Art

[TwisteD90]

I give up, I'm done with this forum.

Later,

Art

Oh come on Art, don't do that. It's only the Internet, you know I love you and I never meant to hurt your feelings :)

Listen, not everyone sees the world like you, you like skinny tires but some people don't. If you think SG is a shitty company some people think not. If the dude wants a fast D90 what's the big deal. At least he's doing something different.

Come on, give me a good reply not that reply you just gave me.

Hope to see you tomorrow at the Solihull meeting. Now should I bring my Ninja sword just incase you are in an attack mode :grin

[artm]

Well...

1. wanting to drive 100 mph in a 90 is plain stupid! 120 mph?! That's just absurd - as are so many auto conversions in the Middle East.

2. supercharger: there's nothing wrong with turbo charging a Tdi for added, NEEDED performance. Supercharging is just a different way of getting there. And that doesn't mean a need to go 100!

3. cold air: why not fit an intercooler? Assuming there's space, that's the way to go I would think.

[Doug]

Having finally resolved all my issues with my TVR 5.0 upgrade (and although it is unlikely that I will drive 120 except on lonely desert blacktop), the invigorating sports car response, the effortlessness of pushing through headwinds at speed and the joy of climbing long summits in the flow of ordinary traffic are just too pleasurable to ever want to give back. Further, I don't believe I'll ever have to mod the exhaust or air intake systems for more power -- this engine gives me a little bit more than I could ever really need. I highly recommend the TVR to anyone that can get their hands on one.

PS: I hold the fastest time in the two most recent speed events in the NVTR, running on stock engines (3.9 and4.2), and believe the Defender is a truly capable and non-dangerous high-speed off roader when in good hands.

PPS: Go to this link: http://www.teamsaluki.com/ and watch the video to see what a properly trimmed Defender is capable of.

DW

[Buckon37s]

What I don't get out of all this is the TD5 is just as capeable if not more of getting up to 120. Why all the effort. A chip, propane, big intercooler, and uprated turbo would eat a 3.9 for breakfast, and get 25mpg while doing it. Man the 3.9 blows, wait, did I say that outloud? :confused

edit: Hey Art, I'm pretty sure most TDi engines come with a turbo :lol

[ELCIDd90]

John P I bet has been up to 120 in a D90 . . . I had mine up to 110, and that is a stock 3.9


damn computer, the governor kicks in at 75. im no speed demon, but it sucks when you've got a semi on your tail and you can't go any faster. Won't a disco chip solve this?

[Mike Hippert]

damn computer, the governor kicks in at 75. im no speed demon, but it sucks when you've got a semi on your tail and you can't go any faster. Won't a disco chip solve this?Yep, ask Ron but I think a 95 cold start eprom will fix it.

[Hans]

What I don't get out of all this is the TD5 is just as capeable if not more of getting up to 120. Why all the effort. A chip, propane, big intercooler, and uprated turbo would eat a 3.9 for breakfast, and get 25mpg while doing it. Man the 3.9 blows, wait, did I say that outloud?

I'd prefer a TDI myself too, but since they came with the 3.9's and a TDI swap can be a bit dollar hungry I have limited options. But I'm just looking for a bit more passing power and some extra mpg's, 80-85mph is plenty fast for me.

-Hans

[jaherring]

I'm saving my extra dollar bills (and tens and twenties) for a TD myself. Low torque and really bad mileage bug me. If a TD5 will pull me along effortlessly at 75-80 uphill then I'd be completely satisfied.

An intercooler would be a pretty darn expensive thing to do just to get cooler air & I'm not sure how much benefit they'd be in a normally aspirated engine (the reason you see them with turbos is that the compression of the air *really* heats it up beyond underhood temp - not to mention being routed through that hot metal housing in close proximity to the exhaust). Those wing vents are just waiting to draw in nice, cold ambient air.

If fording rivers wasn't a problem I'd say that just routing the air intake inlet up by the headlights would greatly solve the air temperature problem.

[ELCIDd90]

Yep, ask Ron but I think a 95 cold start eprom will fix it.

mike,

any idea of what those things run used?

thanks

Joe

[alkhalifa]

This is where I found the air scoop:

http://www.exroad.de/shop/product_info.php?products_id=111

You might find other places that might be closer to you.

Artm...when you say that many auto conversions in the Middle East are absurd, did you see them to make that judgement or are you just being naive or "racist"? It would be a joke if you are saying this without even visiting the area.....People who make assumptions not based on facts are stupid.....So the only way you can make a comment like that you should experience the area first hand.

Buckon37s.....True you can get a TD5 to beat a 3.9 but you can get a 3.9 to beat a TD5, I always wanted to get a V8 D90. Its the engine that I would prefer to use, plus I really like the roar of the V8.

[Mike Hippert]

mike,

any idea of what those things run used?

thanks

Joehttp://www.d-90.com/forum/showthread.php?t=2994


plus I really like the roar of the V8.
Honestly, that would be my biggest reason to keep the V8! :)

[Mike Hippert]

I deleted a few posts from this thread due to unnecessary content.

[jabber]

[QUOTE=jaherring]
Those wing vents are just waiting to draw in nice, cold ambient air.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~

Check out RN, they've got 'em (part # RNA1008 & RNA1008R)

[Trevor Tarr]

My solution is something similar to John Lee's setup (http://www.expeditionexchange.com/D90snorkel/), except instead of the Mantec snorkel, I'm running Home Depot ABS drain-pipe with a centrifugal filter cap. But I also relocated my stock filter box to the wingtop and fitted in inline with the snorkel pipe. It's a little more vulnerable out there, but I retain stock filtration, with all the benefits of shorter cooler routing.

[alkhalifa]

Thanks Trevor that was very helpful.....

[mikeslandrover]

Personally I rate oiled filters (K&N), i've spent a number of weeks in the Sahara and the filter was flowing just fine at the end.
A couple of times back in Blighty the K&N has saved the engine in a water hydraulicing situation because the filter didn't collapse like paper ones do and consequently didn't allow enough water into the combustion chambers all at once to cause a hydraulic lock, bent con rods, and associated unpleasantness. I've seen a number of paper elements collapse, allow a larger quantity of water into the engine and POP, engine rebuild time. that's in petrol and diesel engined LR's too.
K&Ns therefore get my vote.

[Doug]

Trevor,

Do you have any photos of your external solution? Sounds like the best solution I've read so far...

What's a centrifugal filter cap and where does one get one?

THanks,

Doug

[alkhalifa]

Mike,

Do you have a picture of how it is setup?

[Hans]

Centrifuge filtration, now we're talking hard core! They're basically like those cyclone vacuums that they sell these days, they use the cyclonic action to spin the dust out away from the filter element and turn the airflow pattern into it's own prefilter. Never seen one for an automobile, but I have seen them on some German tanks.

-Hans

[RyanS]

I think you're referring to something like the Centri Precleaner. Someday, I'll be relocating my air cleaner outside the engine compartment and probably putting one of these at the end of the snorkel (very similar to Trevor's setup).

http://www.centriprecleaner.com/

[Trevor Tarr]

My centrifugal filter cap is a simpler setup than the Centri precleaners. I got it from JB Landrovers (http://www.jblandrovers.co.uk/) for about $55 5 years ago. It's really just a "stovepipe" cap, with slits around the top edge that create the cyclone effect inside, then exit slits around the outside bottom edges, where material can fall out. (Sorry that picture is blurry.)

I'm using a K&N filter in my relocated filter box. I removed the filter cone, and welded on a section of thick tubing which connects to the snorkel with a rubber coupling. The rigid sections are just ABS drainpipe. Everything is fastened with hose clamps, with improvised adaptors to mate the filter box to the wingtop, and the snorkel tubing to the rollcage.

The engine-compartment routing is based on John Lee's design, illustrated on his Expedition Exchange website, and flows in a direct straight line from the wing through the relocated MAF sensor into the intake plenum.

[Mike Hippert]

NICE Trevor!

[Doug]

Thanks, Trevor. That's the plan. Well done!

DW

[artm]

Well, what is the point of putting the filter outside?

1. Getting cooler air? You still have quite a bit of pipe inside the engine bay which get's warmed up. I bet if you measure the air temp as it enters the plenum the gain is not worth it.

You would get cooler air by fitting an intercooler with the filter in the engine bay.

2. Better filtration? No. Heck, add a second filter internally and you get better filtration.

3. Poseur value? Ah, that's it!

So, what about bottom line gains? Performance gain? I doubt it. Don't forget that the snorkel has a purpose: it speeds up the flow of air at higher revs to meet the demand.

If you remove this you must increase the surface area of the "hole". Well, are you you doing this with this cyclone precleaner? Even if you are, you are introducing a longer, more confining path into the airflow which would slow it down. The snorkel has a very short path to preserve the increaseed airflow. What more do you want?

Probably cooler air. In this case abandon the snorkel with a larger pipe and run an intercooler. Cooler air at all revs. You will be introducing a more difficult path but the larger hole should compensate.

Of course, if gains can be documented then I will gladly admit my ignorance but it seems that noone ever bothers to justify this kind of conversion.

[mikeslandrover]

What's the verdict on K&N air filters?
Good , bad or undecided?

[Doug]

Arthur, you haven't been paying attention. The stated purpose by the originator of this thread is the need for cooler air going into the engine via a 'normal' intake route. I do also.
1. There's no mass of pipe in the engine bay anymore with Trevor's set up -- all there is between the throttle body and wingtop is about 6 inches of pipe and the MAF. Filter box, instead of acting like a heat sink for the engine bay, is outside in the cool air.
2. Not trying to achieve better filtration, rather just keep it standard. Extra filtration is a bonus if it comes along.
3. Humor, no? ;) A little joke directed at us desert rats? Both Trevor and I have won off-road competitions in our rigs. (Trevor -- you did nail that Death Valley Challenge a couple of years ago, right? You should come do the NVTR.)

Mike, as far as K&N, the originator of the thread said he wanted to avoid an oiled filter. I don't particularly want one either -- too easy to just change out paper frequently and not worry about possible fouling of the MAF. But I'm still trying to figure this part out and certainly welcome to ideas. I keep hoping I'll find something between paper and oil that is better than both...

DW

[Hans]

If you are asking about why run a snorkle, the main purpose is usually to get the air intake up above water and avoid injesting anything liquid. It also tends to get up above any dust that gets kicked up, which means cleaner air before the filter even comes into play.

As for putting the filter outside the truck when running the snorkle, the hose routing that comes with the Mantec is absolutely horrid. But there is also really no room to put the filter under the hood without drastic measures. Trevor's setup gives the shortest possible intake routing under the hood, probably about 5 FEET or more shorter than the standard Mantec routing. It's an overall much neater and cleaner setup.

You're right that if we were out dualing at stoplights, ditching the snorkle and running an intercooler would be the better bet. But running at lower speeds in dusty/dirty/muddy conditions you won't get the needed flow over the intercooler and under the hood gets real hot and dirty. Sucking the air from a cooler cleaner source up high above the mess helps quite a lot.

-Hans

[Trevor Tarr]

Arthur, others have addressed most of your questions already, but I'll answer myself as well (and forgive me if I've misinterpreted any of your logic).

The purpose of my snorkel was: (1) keep water out of my engine by raising the intake point above (hopefully) any conceivable water level, and (2) breathe cleaner less-dusty/sandy air by raising the intake point as high off the road as possible. "Raised air intake" says it all. Peformance gains were never a goal for my snorkel.

I've been in water up to about the base of my windshield (not entirely intentionally....), and the snorkel did save the day BIG-TIME. (I hadn't installed raised breathers on my axles and transmission yet, and those turned out to be the weak links.) I drive mostly in very dusty/sandy (Death Valley) conditions, with a lot of material kicked up by my truck and others', so hopefully the extra intake elevation is helping.

As I'm sure you've realized by now, I have almost no air ducting under the hood. In fact, the rubber hose from my wingtop-mounted filter box to the MAF is the stock hose, so I'm running exactly stock distance, but mostly outside the hot engine compartment. That's a LOT less than other snorkel designs like Mantec. The tubing I've added before the filter box (which obviously doesn't exist in the stock setup) is about 4" diameter, less constraining than Mantec's.

Plus with the centrifugal snorkel cap, I'm getting at least somewhat superior filtration to stock.

Poseur value? Well John Lee did once refer to my truck, on the DiscoWeb, as a "pimped-out" disgrace to the Rover cause. So who knows? It works for me, and definitely gets my gear and me there and back, to lots of places I'd never otherwise reach. And the curious looks aren't always a bad thing either.

Doug, I actually didn't win the Death Valley Challenge, but did enjoy participating. Sad to say, my navigator and I ended up so carsick that we bailed about halfway through the course. Human frailty....

Trevor

[artm]

Doug:

1. Only 6" of pipe??? I would think you need at least 2-ft from the wing to the plenum.
3. Yes, I was aware of your "desert rat" status. :)


Hans:

1. I referred to the filter being outside, not the snorkel. I am aware of its function.
2. I am certainly not recommending Mantec's system! It is crappy engineering.
3. You do get good airflow with an intercooler at low rmps - from the fans(s)! So, you're always drawing cold air from the front of the vehicle - assuming your fan(s) are up to it.


Trevor:

1. Again, I was not critisizing the snorkel - just the external filter box.
2. I'll have to measure that wing to plenum distance. I thought you still had quite a run of pipe.
3. "pimped-out disgrace": well, I wouldn't go that far! Oh wait, is that a shovel on the hood? I will go that far then! :)
4. didn't win: I'll still call you a desert rat, unless Doug objects in sharing that title.


I'm looking for a cleaner setup and don't need a snorkel just yet so I would try the intercooler route. I will admit, if a snorkel is used then running pipes to and from the intercooler sure adds some distance.

Considering the various driving styles are you really noticing any improvement? A dyno would surely reveal any but who wants to go that far? If temps can be measured that may tell the story.

[Buckon37s]

Jees guys, I don't mean to be overly a**holish, but for f sakes, over 50 posts on an air box upgrade. Your putting this much effort and consideration into something that will net you 2 H.P. if your lucky? Come on, it doesn't matter, run whatever, a snorkle, K&N, who cares. Leave it stock, take the time you were going to spend assesing the situation, and solve world hunger.

[alkhalifa]

Does anyone know where I can get a flexible hose that I can link the vent from the wingtop to the airbox?

[Trevor Tarr]

Nasser,

For a couple years before relocating my filter box to the wingtop, I routed my snorkel along the circuitous vent-to-stock-filter-location-to-plenum path (same as Mantec). But here's another issue to consider, which hasn't been raised yet in this already-hefty thread. Not only is a long and twisty air-path disadvantageous, but so is the interior "corrugated" surface of flexible tubing. The irregular surface is one more factor impeding airflow. So one alternative solution is to devise a rigid "smooth-bore" ducting layout. That's what I did, with the ubiquitous ABS drain-pipe. It took a lot of adjusting to get all the angles right, but what I ended up with was larger-diameter, non-corrugated, and much more heat/puncture-resistant ducting.

[mdmccallum]

If yo are wondering about the advantages of a snorkel this might help.

http://www.landroveradventure.com/video/snorkel1320x240x10.wmv
click on the video section (left of page). At the bottom of the videos listed is one about snorkels. Click on the 1.5m just to the right.

If this has already been posted then ignore. I didn't have time to read all 4 pgs of this posting.

[Buckon37s]

Keep in mind, that is only possible in a Diesel.

[Hans]

Art, the distance from the plenum to the wingtop is definitely more than 6" but remember that you also need to factor the Mass Air sensor into there, which takes up a good portion of that distance regardless of how you attach it to the plenum.

Buck, honestly I don't care much about the HP gain, I just want to get better air into the engine instead of that 150 degree sauna it's sucking down now. I've calculated about a 1.5mpg difference between summer and winter in my truck driving the same roads to work every day with the same grade gas from the same station. (kept a log of every drop of gas and every mile driven), so I'm hoping for a milage difference between the cooler air and the improved flow. 10% less fuel cost, Yummy!

-Hans

[Buckon37s]

Okay,

I get that, but you must realize that by moving the air box you will never get more than the most infintesimal gain. I promise, you will not notice any gain in fuel economy. In NY you are comparing 80 degrees in the summer to 30 degrees in the winter. If you pull all the tricks, you might see a drop in intake temp of 2 to 10 degrees tops. It will take you 15 years to get back the money you spent just skrewing around. The only way to make a difference is with an intercooler, and if you want to spend $500 for .0005 more miles per gallon of gas, thats your decision. I recommend you let off the gas .01 seconds earlier when cruising to red lights, you will see more of a gain that way.

[Roadsiderob]

I work on a lot of diesel forklifts used in extremely dusty environments. A lot of these have some interesting filtration and precleaner systems that look like they could be adapted to our uses quite easily. Check out www.donaldson.com for more information and ideas.
Rob

[mikeslandrover]

Long pipe runs can actually rob BHP. Restrictive snorkles can actually rob 10bhp from a Tdi I've been told.