Thread: Fitted Snokel drop in Performance

Originally Posted by 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

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

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.

Originally Posted by solmanic

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

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?

Originally Posted by Rugrat

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

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

Originally Posted by 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

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.

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

Originally Posted by 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?

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.

Originally Posted by 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:

Originally Posted by Jim Allen

================================================== ====
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