Fitted Snokel drop in Performance

[Andy2.4]

Hi All,

After recently fitting a TJM snorkel to my 2007 110 i have noticed a big drop in low end power and torque. When up to speed it seems to go ok but at lower speed seems a big difference than before fitting.

Anybody else noticed a performance drop after fitting any type of Snorkel?

Any replies welcome.

[Psimpson7]

Yes afraid so.

despite what people say about RAM air and stuff its basically nonsense on a LR. Some bikes use it but it only has an effect at high speed.

If you suddenly increase the length of the air intake it is going to make it more difficult to get air in, and less air = less fuel = less power.

My TD5 is notaiceably slower with a snorkle than without.

cheers
Pete.

[waynep]

I guess you've checked there is nothing blocking it ?
e.g. a piice of carboard or foam from shipment.

[Andy2.4]

Must admit did cross my mind although had it fitted by TJM so presumed they would have checked before fitting??

Anyone else noticed a drop in off idle torque?

[incisor]

most snorkels cost some performance in my experience also.

you need to check for anything that maybe obstructing it and also check that it doesnt leak as it is too late when you hit water and it lets it in....

[one_iota]

I'll be the sceptic. I'd like to see the science/engineering behind this.

So I'll throw this speculation into the mosh pit:

The thing that would reduce the rate and volume of air would be a reduction in the cross sectional area of the intake system and the friction caused by the additional length.

A snorkel will add say 1 metre of length and if it is designed properly should not reduce the minimum cross sectional area of the existing intake system. The friction should be negligable.

I'd bet that the existing filter is the greatest restriction not a metre of snorkel...the effect if any should be marginal at worst.

A Donaldson Filter on the end of a snorkel is another matter.

[solmanic]

Funny, I always thought a RAM type snorkel was supposed to actually improve engine performance. Not because of the RAM effect as much as the fact that air being drawn into the engine was that little bit cooler. I also support Mahn's theory that extending the pipe shouldn't do anything but reducing the cross-sectional area of the intake should.

Also, you need to be sure that TJM properly sealed the existing air intake duct-work all the way along inside the engine bay. There have been reports on the Defender2 forum that Land Rover, in their perplexing stupidity, have not actually sealed the pipe at all!

[Psimpson7]

On some cars, where the air intake is under the bonnet, I can see the sense in the comment that the air 'may ' be cooler. It wouldn't be on a Defender, as the intake is on the outside of the car.

The friction wouldn't be neglible either in my opinion. It would definetley have more friction than the standard set up.

There are also 2 more 90 degree bends in the intake.

Its been so long since I studied fluid dynamics and I cant find my text books.... darn it!

Pete

[Psimpson7]

Ha - found them :)

Right, looking through them there are quite a few comments, just in the general flow types that would have an impact on this.

Firstly is that it wouldnt be laminar flow, in my opinion it would be turbulent flow, ie the 'air particles' aren't everywhere in a straight line, they are in a intertwining disorderly manner, in effect I suppose richochetting about inside the snorkle. This means that (at least in a parallel tube) only the average motion of the fluid is parallel to the axis.

Theres the first issue

It would also be a non steady, non uniform flow, for example accelerating and decellarating through a pipe with a varied internal cross section.

I will read up a bit more tonight and see if I can come up with any simple examples..

Interestingly I am on a Cosmos Floworks (flow analysis software) course next week so could maybe do a working example......

cheers
Pete

ps feel free to tell me I am talking rubbish ;)

[incisor]

no idea on the science behind it but i can reproduce it at will on the 300tdi with a safari snorkel esp the gains using a basic donaldson precleaner over a ram head.

[discowhite]

im with mahn also!
take your filter out and have a look at the size of the inlet into the air box and the piping to it, then have a look at the diameter of the snorkel pipe, way bigger. if your that worried take your center muffler out, you'll gain back what you think you've lost and add some more.
the other thing is, ide cop andy2.4's theory if the engine was naturally aspirated. turbos are a different story.

cheers phil

i didnt notice any differance in performance when i fitted my bearmach one.

[vnx205]

Ha - found them :)

Right, looking through them there are quite a few comments, just in the general flow types that would have an impact on this.

Firstly is that it wouldnt be laminar flow, in my opinion it would be turbulent flow, ie the 'air particles' aren't everywhere in a straight line, they are in a intertwining disorderly manner, in effect I suppose richochetting about inside the snorkle. This means that (at least in a parallel tube) only the average motion of the fluid is parallel to the axis.

Theres the first issue

It would also be a non steady, non uniform flow, for example accelerating and decellarating through a pipe with a varied internal cross section.

I will read up a bit more tonight and see if I can come up with any simple examples..

Interestingly I am on a Cosmos Floworks (flow analysis software) course next week so could maybe do a working example......

cheers
Pete

That is easily fixed.
Fit a Hiclone or two in the neck of the snorkel.:p

Seriously though, you would hope that the snorkel manufacturers would have done the same sort of research as you are suggesting.

I suppose the problem is that sometimes they have conflicting factors to consider, such as aesthetics or cost.

So it would still be interesting to see what you come up with when you aren't constrained by such considerations.

[Rugrat]

Also, you need to be sure that TJM properly sealed the existing air intake duct-work all the way along inside the engine bay. There have been reports on the Defender2 forum that Land Rover, in their perplexing stupidity, have not actually sealed the pipe at all!

The Land Rover, Mantec and Airtek (TJM) are supposedly only for dust ( Elevated air Intakes) None to my knowledge state to being water tight. My safari (installed by Safari) is water tight - yes its been tested ;) I would highly recommend checking the seals on any Snorkle as its the last thing you want to have a leak in or should that be with????

I havent noticed an improvement or a degragdation in power to the fender. I have noticed a comfortable warm and fuzzy when i go through water though - now just to get that door seal fixed :mad:

[harry]

ok, i agree with psimpson, on the restriction in the tube etc, but i want to skew slightly to the v8,
on a series 1 disco what happens to the airflow into the engine when we cut the venturi snout off the front of the airbox to fit a second battery?

[dullbird]

The Land Rover, Mantec and Airtek (TJM) are supposedly only for dust ( Elevated air Intakes) None to my knowledge state to being water tight. My safari (installed by Safari) is water tight - yes its been tested ;) I would highly recommend checking the seals on any Snorkle as its the last thing you want to have a leak in or should that be with????

I havent noticed an improvement or a degragdation in power to the fender. I have noticed a comfortable warm and fuzzy when i go through water though - now just to get that door seal fixed :mad:

this is very correct.....and anyone that thinks land rover is fitting a SNORKLE has been very misled, as a snorkle is is already above landorvers maximum wading depth so yes what ever is fitted by landrover is a RAI

as for the safari thing anything you fit i think can be sealed so its water tight its whether you go to the effort of doing it.....if you fit a safari to a new defender you still have to go in and do sometic work the same if you were to make an airtec water tight...

i had my airtec fitted to my disco by the garage and yes they had to go in and seal up lots of things......around the airbox etc

i also cant say that i noticed any loss in performance on my disco or my defender.....although i found water in your fuel doesn't help woth performance so who knows:D

[isuzurover]

Ha - found them :)

Right, looking through them there are quite a few comments, just in the general flow types that would have an impact on this.

Firstly is that it wouldnt be laminar flow, in my opinion it would be turbulent flow, ie the 'air particles' aren't everywhere in a straight line, they are in a intertwining disorderly manner, in effect I suppose richochetting about inside the snorkle. This means that (at least in a parallel tube) only the average motion of the fluid is parallel to the axis.

Theres the first issue

It would also be a non steady, non uniform flow, for example accelerating and decellarating through a pipe with a varied internal cross section.

I will read up a bit more tonight and see if I can come up with any simple examples..

Interestingly I am on a Cosmos Floworks (flow analysis software) course next week so could maybe do a working example......

cheers
Pete

ps feel free to tell me I am talking rubbish ;)

I am pretty sure it would be laminar. I would calculate the Re to prove it, but am about to leave for the airport - will calculate it while waiting when I get there if I have a mo.

Never heard of the package you mentioned. FLUENT is the standard package. OpenFoam isn't bad either, and is FREE! Though MATLAB is often best (when you need a number, not just Colours For Directors).

A few quick and dirty manometer studies have found that the DP in ducting is much more than the DP of a CLEAN air filter. AFMs, Elbows, and Corrugated pipe are the worst offenders.

The "ram effect" really only becomes significant over 100km/h. However a well designed snorkle with large enough piping and properly radiused elbows (and no corro pipe) should not create any (significant) additional pressure drop.

[Psimpson7]

cool. Will be really intesting to see what you come up with, My knowledge on this is both limited and rusty!

[p38arover]

ok, i agree with psimpson, on the restriction in the tube etc, but i want to skew slightly to the v8,
on a series 1 disco what happens to the airflow into the engine when we cut the venturi snout off the front of the airbox to fit a second battery?


Jim Allen in the USA (formerly LRNA) did some tests and found that there is a power drop at the top end when you remove the trumpet.

I remember reading one of his emails that commented on this. It was about 10 (or more) years ago that I received the email.

[p38arover]

Jim Allen in the USA (formerly LRNA) did some tests and found that there is a power drop at the top end when you remove the trumpet.

I remember reading one of his emails that commented on this. It was about 10 (or more) years ago that I received the email.


here we are:


================================================== ====
AIR FILTER HOUSING "HORN":
Good on you for not hacking off the trumpet! Would you believe that doing so aftually costs hp. Did some dyno tests a while back and found that altering (i.e. hacking off) or removing the horn cost between 2&3 hp. Probably couldn't feel it but the drop is there. The effect gets worse as the rpms rise but there appears to be a definite disruption of airflow at about 3000rpm because there is a ripple in the torque curve that goes away with the horn installed.
As an aside, a larger displacement engine might need a larger (but similarly designed) horn but when we flow bench tested the air cleaner assembly, it had more airflow capacity than a 4.2-4.5L engine needs to achieve 5500rpm. It gests dicey airflowwise for a bigger engine but as long as you don't need 5500 rpm often, I wouldn't sweat it.
Jim Allen

See D-90 FAQ - Engine: Air Induction (http://www.d-90.com/faq/Engine/EngInduction.html#Hypo)

[Utemad]

ok, i agree with psimpson, on the restriction in the tube etc, but i want to skew slightly to the v8,
on a series 1 disco what happens to the airflow into the engine when we cut the venturi snout off the front of the airbox to fit a second battery?

I've wondered that too as not only are you cutting off the trumpet but you are putting a battery directly in front of the intake.

The previous owner of my Disco1 used a hole saw on the side of the intake box nearest the engine to let more air in.
I would like to fit a better intake. Can't really justify a snorkel since I shy away from water/mud. I was thinking one of those pod filters like on the rice mobiles.

Hearing that a snorkel reduces power would put a pin in many peoples justifications for getting one. Even if it is a flimsy one.

[scarry]

what about a power & torque curve before & after fitting a snorkle.this would not take into consideration any ram air effect,but would give an idea of what is going on.

if you want to get real hi tech you could get an anamometer &measure airflows,& a manometer to read air pressures.the problem is getting accurate readings.these would also be nothing like real life as airflows in real life would be constantly changing

as for the "horn" on the air filter intake,we use a similar thing on exhaust fans& this will increase airflows around 15 to 20% at least

it is also interesting to note the td5 disco has absolutely no ram air effect on the air intake in the upper guard,there is a piece of foam jammed in the upper guard in between the air intake & the headlight,so air is drawn from the rear of the inner guard.i presume the foam is to stop water going into the air intake during wading.dont have a fender so dont know how they are setup.



what about the dump valve in the air box.some guys say seal it up or water will be sucked in through it....others say leave it how it is so if any water gets in it for whatever reason,it can get out.any ideas?

[harry]

thanks ron, i did think mr lr had spent a lot of time researching this as it is really a small opening at the throat of the venturi.
err, mines hacked off to fit a battery, after long hours thinking about it, also i temp tested intake air in the box and in the inlet to sort the venturi differences, not much, but the engine does get very hot air, which probably has something to do with emissions - a snorkle would improve the intake temps, and therefore improve economy 'perhaps' by allowing more air in. but this is also flawed thinking, as the colder the air, the more the oxygen content, so the more fuel we can mix with it - all good so far, until that air gets sensed by the 'mass air flow meter' which has been set to give predetermined values at the factory.
so no gain.
as for those thinking about the ram effect of snorkels - forget it!
170 mph impact air [ram] has the potential to increase the manifold pressure by 1 inch of mercury.
or to make it a bit simpler -
still air, 60 mph [you work out the kph, i'm not doing it all for you]
pressure increase of air - psi - .065
in hg - .128
in h2o - 1.774
and then you have to factor in the air temp and humidity,
ram air in a truck is not an issue, it doesn't do diddly sqat!!!!!!!!!!!

[one_iota]

thanks ron, i did think mr lr had spent a lot of time researching this as it is really a small opening at the throat of the venturi.
err, mines hacked off to fit a battery, after long hours thinking about it, also i temp tested intake air in the box and in the inlet to sort the venturi differences, not much, but the engine does get very hot air, which probably has something to do with emissions - a snorkle would improve the intake temps, and therefore improve economy 'perhaps' by allowing more air in. but this is also flawed thinking, as the colder the air, the more the oxygen content, so the more fuel we can mix with it - all good so far, until that air gets sensed by the 'mass air flow meter' which has been set to give predetermined values at the factory.
so no gain.
as for those thinking about the ram effect of snorkels - forget it!
170 mph impact air [ram] has the potential to increase the manifold pressure by 1 inch of mercury.
or to make it a bit simpler -
still air, 60 mph [you work out the kph, i'm not doing it all for you]
pressure increase of air - psi - .065
in hg - .128
in h2o - 1.774
and then you have to factor in the air temp and humidity,
ram air in a truck is not an issue, it doesn't do diddly sqat!!!!!!!!!!!

And I would guess that the obverse would be true:

A snorkel will not degrade the engines breathing either.

The Venturi effect is an interesting factor in the defender's case as the intake is on the side of the guard and the air moving over the intake at speed should and probably does induce a negative pressure which if these things are so sensitive the standard setup should result in a decrease in performance.

I think the snorkel performance improvement thing is a furphy as is the dust/cool air thing. It's a spin applied in 4wd magazines to seduce the unsure who think it looks cool.

I will install a snorkel to do what a properly installed snorkel should do on a diesel engine and that is to keep water out of the motor on the odd occasion that I exceed the wading depth.

:)

[discowhite]

And I would guess that the obverse would be true:

A snorkel will not degrade the engines breathing either.

The Venturi effect is an interesting factor in the defender's case as the intake is on the side of the guard and the air moving over the intake at speed should and probably does induce a negative pressure which if these things are so sensitive the standard setup should result in a decrease in performance.

I think the snorkel performance improvement thing is a furphy as is the dust/cool air thing. It's a spin applied in 4wd magazines to seduce the unsure who think it looks cool.

I will install a snorkel to do what a properly installed snorkel should do on a diesel engine and that is to keep water out of the motor on the odd occasion that I exceed the wading depth.

:)

BINGO!
and if you arnt gonna use it as such why fit one:angel:

cheers phil

[scarry]

BINGO!
and if you arnt gonna use it as such why fit one:angel:

cheers phil


bingo 2:D


if ram air increased a vehicles fuel economy or performance,they would be fitted to them from new.

doesnt the d3,RR & RRS,all suck air from the side guard ,similar to the defender?

just my 2 cents worth

[discowhite]

yep they sure do, even the freeloader.

cheers phil

[45tr0]

bingo 2:D


if ram air increased a vehicles fuel economy or performance,they would be fitted to them from new.

doesnt the d3,RR & RRS,all suck air from the side guard ,similar to the defender?

just my 2 cents worth

Just my 2 cents - but a lot of performance vehicles do have "ram air" fitted from new - just have a look at the aggressive looking vents on the bonnets on most sports cars and you'll see what I mean. They already come tuned to take advantage of it.

Before I got my LR I used to be one of the japanese 4-pot brigade. A ram air set up is a valuable modification for performance, but only when complemented with other modifications such as an optimised exhaust system and a reprogrammed ECU. Any one in isolation will offer minimal performance enhancement - in combination with the above can offer quite a bit.

I even put my Nissan Exa over a dyno to prove the point - 107kw from the stock CA18DE, 115kw with 2 1/4 inch maxiflo exhaust added, then 119kw with cold air intake & pod filter added, and 143kw once the ECU was replaced and the breathing mods were able to do their job! Without the ECU I had developed a huge flat spot at about 3000rpm - almost undrivable.

[discowhite]

:eek::Dhow do you get the ram air effect on a dyno?
cheers phil

[solmanic]

:eek::Dhow do you get the ram air effect on a dyno?
cheers phil

Stand a sheep in front of it and make it fart a lot...
:bangin:

[scarry]

:Dhttps://www.aulro.com/afvb/ (http://imageshack.us)

now if a snorkle improves performance,wouldnt this bloke have one:D:D:D;)

note the bonnet scoop faces backwards:eek:

[discowhite]

thats to let the energy polariser breath.....derrr;)

funny thing, there was a guy with a 4cly td cortina that usta run at calliope drags, he experimented via numerous slow runs with and with out a snorkel head (sticking straight out of the bonnet) to find that he actually went faster when it blew off 1/2 track:twisted:

cheers phil

[harry]

:eek::Dhow do you get the ram air effect on a dyno?
cheers phil
good on ya phil,
it's a good question.
answer nup can't.

[scarry]

large axial fan &a big trumpet to get the air in the air box.set up variable speed drive on fan useing calibrated anamometer to get same airflow as already worked out at say 100k"s.make sure have same temperatures& humidity da da da




bloody easy.......i dont think so:(


more likely a genuine waste of time:D

cheers

[justinc]

From the time spent in Fluid mechanics some years ago now, I would have to add that in a motor vehicle application it wouldn't be the surface roughness inside the snorkel tube that would hurt the 'smooth' flow of air, as it is usually quite a lot larger diameter than is required. It would be the various compromises in the shape of the snorkel's plumbing that would dictate its effectiveness. For example, the Defender snorkel (300Tdi in this instance) is far more 'efficient' in my opinion than the early ABS fitment D1 Tdi application, where the plumbing from the snorkel body must squeeze through next to the ABS modulator and then travel around the airbox, entering it from the other side. Meanwhile, it changes diameters and shapes at least 3 times in about 400mm of pipe length.
THAT is a restrictive airflow system if ever I saw one.

Most snorkels will improve a diesel engines breathing though, as some have a intake labrinth from the manufacturer to reduce intake noise intrusion, and the Defender 300Tdi and Td5 have a ridiculous restrictive right angle bend from the side guard air intake to the air filter housing/ airbox.:mad:

I would however suggest that the ram air idea is not really applicable to the average turbo diesel 4x4, as the volume and velocity of the air being demanded by the turbocharger inlet is far more than can be 'rammed' in there at highway speeds.

JC

[John W]

I recently fitted a Safari to my TD5 disco so I could make it back without drowning the engine up Cape York. River crossings included water going over the bonnet more than once.

First I would like to say that it is was fun to fit as it is really well made and fits beautifully.

I did not plug the air box drain ( forgot to do it) and had no problem with water getting in. It has a rubber one way drain valve/flap any way and in the end I figured that the intake was large enough up high compared to any leak down low. Splashes and rain that go straight down the ram intake need to go somewhere so was happy to leave it. I did take some bulldog clips thinking they would seal it for water but did not use them.

In the D2 the standard air intake in the inner guard makes for a lot of dust getting to the air filter from the front wheel arch on dirt roads and in the past I have spent a lot of time blowing out the filter on dirt roads each night. This time there was stuff all to blow out even with a couple of thousand Km of dirt so for the D2 I feel it has made a big difference in getting cleaner air to the filter box.

Fuel used was great on the trip and there was no increase in noise. Don't think there was any obvious increase in power either. Same goes for lower speed did not notice anything. At lower engine load the air flow is not that great so doubt it would be much of a restrictor.

Now to fix those door seals and clean and dry the carpet!

[spudboy]

:Dhttp://img369.imageshack.us/img369/5750/a9x20torana11kg8.jpg (http://imageshack.us)

now if a snorkle improves performance,wouldnt this bloke have one:D:D:D;)

note the bonnet scoop faces backwards:eek:

That's because there is a low pressure (or is it a high pressure?) area at the back of the bonnet, and more air got drawn in with the backwards scoop.

[scarry]

That's because there is a low pressure (or is it a high pressure?) area at the back of the bonnet, and more air got drawn in with the backwards scoop.

i recon the bonnet scoop is on the a9x for two reasons


it looks cool

to make room for carbys,air cleaners etc

i dont believe it would make any increase in performance

as for the polariser thingy.........we wont go there

a question still begs....why do most prime movers have snorkels?
asthetics?,and probably to pick up the coolest cleanest intake air possible,but whether this makes any increase in performance,who knows.it may extend the air cleaner life...

[DirtyDawg]

I'll be the sceptic. I'd like to see the science/engineering behind this.

So I'll throw this speculation into the mosh pit:

The thing that would reduce the rate and volume of air would be a reduction in the cross sectional area of the intake system and the friction caused by the additional length.

A snorkel will add say 1 metre of length and if it is designed properly should not reduce the minimum cross sectional area of the existing intake system. The friction should be negligable.

I'd bet that the existing filter is the greatest restriction not a metre of snorkel...the effect if any should be marginal at worst.

A Donaldson Filter on the end of a snorkel is another matter.
Well said Prof Mahn:D:D

[PAT303]

i recon the bonnet scoop is on the a9x for two reasons


it looks cool

to make room for carbys,air cleaners etc

i dont believe it would make any increase in performance

as for the polariser thingy.........we wont go there

a question still begs....why do most prime movers have snorkels?
asthetics?,and probably to pick up the coolest cleanest intake air possible,but whether this makes any increase in performance,who knows.it may extend the air cleaner life...

I fitted snorkels with pre-cleaners to all the non fitted machines at work in the first week not because of water or power but because I would have to change the filters every day if I didn't.In dusty area's you have to get the intake out of the dust and in Kal dust is one thing we aren't short of.Saying that alot of it could come from toyota's intake next to the headlight's on their vehicles that is garanteed to force water into the engine,the same goes for the amount of suspension kits on the market.Truth to it most people avoid water like the plague and rightly so but my motor is none the worst for having one so it will stay on. Pat

[Rosco]

Any further comments appreciated on the Donaldson Pre-Cleaner....

I've had conflicting reports re speed. eg Some say restriction over 40 KPH,
others say over 80.

So gurus ... what's the consensus of opinion here.

Cheers

[feraldisco]

And I would guess that the obverse would be true:

A snorkel will not degrade the engines breathing either.

The Venturi effect is an interesting factor in the defender's case as the intake is on the side of the guard and the air moving over the intake at speed should and probably does induce a negative pressure which if these things are so sensitive the standard setup should result in a decrease in performance.

I think the snorkel performance improvement thing is a furphy as is the dust/cool air thing. It's a spin applied in 4wd magazines to seduce the unsure who think it looks cool.

I will install a snorkel to do what a properly installed snorkel should do on a diesel engine and that is to keep water out of the motor on the odd occasion that I exceed the wading depth.

:)

not a furphy at all - in fact the primary objective for me fitting a Safari was due to dust rather than water-the standard air intake on a D2 Td5 is ridiculous for two reasons - firstly the size of the hole in the inner guard is puny; secondly it takes air from above the front wheel - great on dirt roads...not...

I've cut out a larger hole in my inner guard and have added my own large diameter flexi pipe connecting the end of the snorkel to the airbox. If anything, the car seems to go better - certainly not worse.

Interestingly, the current 4WD Action mag indicates (as tested) a significant fuel economy improvement with snorkel fitted - but of course this depends on the particular car and how restrictive the original air intake set-up is...

[CaverD3]

Interestingly, the current 4WD Action mag indicates (as tested) a significant fuel economy improvement with snorkel fitted - but of course this depends on the particular car and how restrictive the original air intake set-up is...

Quite high (9.2% inrovement in economy) but it was an 80 series Tojo. :angel:

[scarry]

Quite high (9.2% inrovement in economy) but it was an 80 series Tojo. :angel:

doesnt really mean much...it was highly modified,whatever that means.

[CaverD3]

I took that figure with a lot of salt. ;)
I don't think it should make any difference either way as long as the Snorkel is designed properly and free of obstruction.

[one_iota]

Fitting a snorkel to the Disco didn't make a "measurable" difference to either performance or fuel economy.

What made a difference was whether there was a head or tail wind, whether there was a tent on the roof racks or not or whether it was a hot day or a cold day. I return to my original point the snorkel effect on performance will be marginal if everything else is equal.

As for dust well that is what the filter is for and I suppose yes there might be a difference in the life of the filter but again that depends on the dust and whether the ram was pointing north or south but that is another debate :p;)

[feraldisco]

doesnt really mean much...it was highly modified,whatever that means.

it's irrelevant whether it was highly modified or not...the difference was measured on the same vehicle and the measured fuel consumption difference was purely due to the presence/absence of snorkel - and I was surprised at how big a difference it was.



as for the other comment that air filters are there to stop dust, yes they are, and if you like changing air filters on a regular basis, go for your life! I don't and the other advantage of a snorkel is that you can easily put a foam pre-filter over the snorkel head when heading off road to pretty much eliminate dust getting to your main air filter...

[cripesamighty]

Hi all,

This is a scan of the snorkel bit of the article in September's issue of Australian 4WD Action magazine for those that are interested. Note that it is a Safari snorkel.

[scarry]

[QUOTE=feraldisco;815675]it's irrelevant whether it was highly modified or not...the difference was measured on the same vehicle and the measured fuel consumption difference was purely due to the presence/absence of snorkel - and I was surprised at how big a difference it was.

There is obviously something wrong with the figures,as per this thread & many others on this site,guys who have recorded before & after figures have never got any real change.

[CaverD3]

It would depend upon the design of the snorkel, the air intake and the engine itself snorkel install could well improve the breathing of an engine if these were of poor design.
Well it was a Toyota.:D:angel:

[Scallops]

My 07 has a genuine snorkel - I didn't have any drop in power or torque after it was fitted - but what did improve was my fuel consumption.

Consider this - I have calculated my fuel usage from my recent around Oz trip. This included driving over the Gibson and Simpson deserts in 2nd gear, carrying 750kg of kit and with a roof rack and awning etc.

9.8 l per 100km!!!

Now, I do drive carefully - 90km/h cruising and not really reving it much above 2000rpm unless necessary - but still, it's a great result on the juice.

[slipedisk]

Hi all, I fitted my Safari to the TDi 96 mod with a Finner Air filter. I use to travel back to Mt Barker from the city (Adelaide) and before I'd have to change back to 3rd before going through the Hysen Tunnel now I can cruise through there at 80ks in forth and change back further up, even the missus asked what I'd done.

Cheers

[mark2]

Hi all, I fitted my Safari to the TDi 96 mod with a Finner Air filter. I use to travel back to Mt Barker from the city (Adelaide) and before I'd have to change back to 3rd before going through the Hysen Tunnel now I can cruise through there at 80ks in forth and change back further up, even the missus asked what I'd done.

Cheers

Is it possible that the less restrictive filter made the difference, rather than the snorkel?