Outer Limits 4x4 Board

I'm thinking of getting an Airtek snorkel for my 98 V6 Rodeo.

Years ago a mechanic told me that having air rammed into the manifold can pressurise it and cause fuel mixture and leaking problems without the appropriate mods.

Is this the case with modern EFI engines?
If so, does the computer automatically adjust fuel mixtures to compensate?
Mines on LPG too.

I've read that snorkels can improve power and economy as well as all the other benefits so I'd like to hear about the pro's and con's before I go out and spend my hard earnt money on one.

BTW, how do you Airtek owners rate their snorkels overall?

cheers, sudso

A pressurised manifold can create all kinds of problems, particularly if you have air-fuel mixture leaking from the manifold.

Generating useful manifold pressure from a snorkel isn't that easy. You have nothing to worry about.

Scott

sudso wrote:I'm thinking of getting an Airtek snorkel for my 98 V6 Rodeo.

Years ago a mechanic told me that having air rammed into the manifold can pressurise it and cause fuel mixture and leaking problems without the appropriate mods.

Is this the case with modern EFI engines?
If so, does the computer automatically adjust fuel mixtures to compensate?
Mines on LPG too.

I've read that snorkels can improve power and economy as well as all the other benefits so I'd like to hear about the pro's and con's before I go out and spend my hard earnt money on one.

BTW, how do you Airtek owners rate their snorkels overall?

cheers, sudso

airtek snorkels are very well manufactured and usually fit very well. The the chief benefit of a snorkel is cleaner air in dusty situations. A secondary benefit is engine protection for water crossings of moderate depth, but if and only if the snorkel and entire intake system is waterproofed. Any claims of improved power or economy can only be madefrom a cold-air intake standpoint, however the extra pressure drop across a metre or more of plastic pipe usually wipes out any real benefit. There is no real benefit from pressurising the inlet air from a ram effect.

thanks for that fellas.

There is no real benefit from pressurising the inlet air from a ram effect.

I was actually wondering about adverse affects pressuring a manfold but it sounds like a snorkel doesnt do that. Besides, I just remembered the machanic said that that its a carby that can have probs if pressurised.

Any more tips anyone?

tip ... put one on and seal it up before u drown it ....

tip ... put one on and seal it up before u drown it ....

Not easy done.
It never friggin rains here in South Oz!

I want one more for when we go on our trips away where the creeks actually have water in them and for convoying on dirt roads

cheers

As above, major benefit comes from cooler, denser air.

Usually the engine creates more vacuum than what the snorkel produces in positive pressure (if any).

With EFI, any pressure increase isn't a problem. Usually a MAP sensor, or mass airflow meter to adjust for changes in manifold pressure.

However I have heard of problems of backfiring on gas, on snorkel equipped fourbys on overrun. They rotated the snorkel backwards, and that fixed the problem....

bigpat wrote;

However I have heard of problems of backfiring on gas, on snorkel equipped fourbys on overrun. They rotated the snorkel backwards, and that fixed the problem....

Shit! I run it on LPG most of the time. I've heard what happens to air filter boxes when LPG backfires
Mine has never backfired but I have the latest Gastech fuel processor which at least shows fuel mixture readings at idle, fast idle and acceleration, which allows me to keep an eye on it.

By "overun" do you mean positive pressure in the air intake...not suction?

sudso wrote:bigpat wrote;

However I have heard of problems of backfiring on gas, on snorkel equipped fourbys on overrun. They rotated the snorkel backwards, and that fixed the problem....

Shit! I run it on LPG most of the time. I've heard what happens to air filter boxes when LPG backfires
Mine has never backfired but I have the latest Gastech fuel processor which at least shows fuel mixture readings at idle, fast idle and acceleration, which allows me to keep an eye on it.

By "overun" do you mean positive pressure in the air intake...not suction?

if u run lpg with snorkel just fit a balance pipe from the converter to the inlet it should overcome any faults and i have found after tuning for this MORE POWER
and thay mainly only lean out at speed

Just a thought but i have been told that safari snorkels are designed on a dyno as air tach are not But do not know if this is correct though as i would think the power gained by a snorkel would be very miner and was probly a safari reseller that told me
Just thinking with keyboard
Cheers Jamie H

Sudso, looks like ratboy has a solution.... LPG tech has moved on from the last time I ran it!

By overrun, I mean when you lift off the throttle. I think it would have to due with the high manifold vacuum, extra (pressurised? not right word, but you get the drift) air from the snorkel throws the mixrtures out of kilter, as LPG is very sensitive to prevailing conditions.

I know all about LPG backfires. Destroyed 2 airboxes on my VN calais because of it, until I make up a 'relief valve' to vent the pressure when it happened. Sweet as after that.......

I installed a Safari Snorkel on mine and had a measureable drop in horse power.
Previous I had a K&N Filter and installed a 2.5inch zorst on an RB30 patrol. Installed Snorkel and dropped 10 HP. I'll be doing a 3 inch stainless sytem soon. The problem is, and anyone that designs Commercial Air Conditioning will confirm it, is the bend of the corners and the length of the pipe. Even if you have the same size diameter all the way along, the longer the pipe the more friction so the larger the diameter pipe needed. Combine this with the 90deg on top of the 45deg bend right at the start (above the windscreen) which creates a great deal of turbulance and has a negative impact on the airflow as well.
If Safari designed them on dyno they'd look a hell of a lot different to how they are now.
CJ

thanks for all the replies. Very educating

ratboy;

if u run lpg with snorkel just fit a balance pipe from the converter to the inlet it should overcome any faults and i have found after tuning for this MORE POWER

More details, yes please

and thay mainly only lean out at speed

bigpat

By overrun, I mean when you lift off the throttle. I think it would have to due with the high manifold vacuum, extra (pressurised? not right word, but you get the drift) air from the snorkel throws the mixrtures out of kilter, as LPG is very sensitive to prevailing conditions.

wouldnt the fuel processor detect and compensate? Or I'm hoping thats what would happen

bigpat;

I know all about LPG backfires. Destroyed 2 airboxes on my VN calais because of it, until I make up a 'relief valve' to vent the pressure when it happened. Sweet as after that.......

What size NB and what pressure is it? A mechanic said I could use occy straps in place of the clips but I didnt like that idea as even good ones can snap just when you dont want em to.....and all that engine heat so close to stretched elastic rubber. Hmmmmm.

wouldnt the fuel processor detect and compensate? Or I'm hoping thats what would happen

Like I said, long time since I played with it. The VN rang a glorified "barbie ring" setup (1992 install I think).

What size NB and what pressure is it? A mechanic said I could use occy straps in place of the clips but I didnt like that idea as even good ones can snap just when you dont want em to.....and all that engine heat so close to stretched elastic rubber. Hmmmmm.

It was a 50 mm dia. rubber bung / grommet, positioned opposite to the outlet duct that goes to the engine. Ran a little wire off it so if it blew off during backfire I could find it. When installed, it sealed just fine.

wouldnt the fuel processor detect and compensate? Or I'm hoping thats what would happen

Like I said, long time since I played with it. The VN rang a glorified "barbie ring" setup (1992 install I think).

What size NB and what pressure is it? A mechanic said I could use occy straps in place of the clips but I didnt like that idea as even good ones can snap just when you dont want em to.....and all that engine heat so close to stretched elastic rubber. Hmmmmm.

It was a 50 mm dia. rubber bung / grommet, positioned opposite to the outlet duct that goes to the engine. Ran a little wire off it so if it blew off during backfire I could find it. When installed, it sealed just fine.

use a omvl converter on the back of it u will see a small pipe
take a line from it to the intake side of the air cleaner.It moves the diaphram in the converter to compensate for the air pressure in the air cleaner box


PS back fire on vn is normally the coils (low resitance)
if u gun it and it blows the air box to bits look at coils first then mixture

bigpat wrote:

wouldnt the fuel processor detect and compensate? Or I'm hoping thats what would happen

Like I said, long time since I played with it. The VN rang a glorified "barbie ring" setup (1992 install I think).

What size NB and what pressure is it? A mechanic said I could use occy straps in place of the clips but I didnt like that idea as even good ones can snap just when you dont want em to.....and all that engine heat so close to stretched elastic rubber. Hmmmmm.

It was a 50 mm dia. rubber bung / grommet, positioned opposite to the outlet duct that goes to the engine. Ran a little wire off it so if it blew off during backfire I could find it. When installed, it sealed just fine.

A mechanic said I could use occy straps in place of the clips but I didnt like that idea as even good
first dont use this bloke anymore if he dose that shit what else will he do to your car
u can get a backfire flap there r to types may be a bit hard to find try gas wholesalers u will have better luck

hey trust your mechanics! they're there to help you.

The occy strap isnt such a bad idea, ford had alot more to do witht lpg than holden for years so to prevent the problem of blowing up airboxes the lpg falcon airboxes use springs to hold them down compared to the standard regular airbox which use clips. if you could use this theory somewhere along the lines with your airbox by using little springs with hooks on em.

another thing a mate of mine thought of with his snorkel, its a little trivial but every bit helps. he would get a chux cloth, double it over and tape it to the intake of the snorkel before every trip. not much i know but would restrict the larger heavier dust particles..... an ideas man that staunch(username) is!!!!

Josh n Kat wrote:hey trust your mechanics! they're there to help you.

The occy strap isnt such a bad idea, ford had alot more to do witht lpg than holden for years so to prevent the problem of blowing up airboxes the lpg falcon airboxes use springs to hold them down compared to the standard regular airbox which use clips. if you could use this theory somewhere along the lines with your airbox by using little springs with hooks on em.

another thing a mate of mine thought of with his snorkel, its a little trivial but every bit helps. he would get a chux cloth, double it over and tape it to the intake of the snorkel before every trip. not much i know but would restrict the larger heavier dust particles..... an ideas man that staunch(username) is!!!!

i know if u do this right the first time saves money and repairs dont fuck up in the middle of know where

well thanks for all the info guys
I will get one but will look deeper into the mods for use with LPG before I fit it.
Good to know from others experience what can go wrong and corrective tips

cheers