Snorkle intake backwards, better fuel economy....GU8

[WogsRus]

Well ok just to convince myself, turned the snorkle facing forwards, cold morning like 2 deg C including Black ice, fuel economy according to Ultra Gauge was 12.8, n the way back, turned it back and got to 11.2.

I have not idea WTF is going on ut it works for meeeeeeeeeeeeee

[Robo]

lots of ways to look at this one,
forward facing = lean mixture and the foot goes down to achieve speed, as noted 120kph
backwards = factory settings for mixture,
(assuming factory tune is minus the snorkel).
less right foot for same speed 120kph and improve economy.
engine conditions and tune!!
driving habits from each individual.
then a tail wind can also make a big difference.
lots to get ya thinking, this forum is soooo usefull.

[Rustyboner81]

Wouldnt this be due to the MAF sensors (mass air flow sensor)? It calculates the air flow and corrects the fuel mixtures.. turning the snorkel backwsrds creates negative pressure which reduces the air going into the engine and then adjusts the fuel accordingly.

Be interesting to see how the carbys go. Probably starve of fuel

[threedogs]

Melbourne to the Murray river say 250 Ks What ppl don't know its up hill all the way.
Big fuel difference if you fill at the Murray and drive south, usually with a howling tail wind
and down hill, Just had snorkel fitted and has made no difference so far to economy.
Maybe summer I'll be sourcing cooler air, cant see how it makes a difference as it stops at
the filter. I'm getting about 330k to half tank and 560k when light comes on.

[Wizard52]

Just to see for myself, I turned my genuine Nissan snorkel head sideways as it won't do a full 180 without hitting windscreen.
I was sceptical but last full tank returned 12.8lt per 100k instead of usual 13.25 to 13.75. No change to driving conditions.
Going over to the Island early September so sand driving will distort figures but will check again when I return to normal driving.
It doesn't make sense but appears right.

[Sir Roofy]

melbourne to the murray river say 250 ks what ppl don't know its up hill all the way.
Big fuel difference if you fill at the murray and drive south, usually with a howling tail wind
and down hill, just had snorkel fitted and has made no difference so far to economy.
Maybe summer i'll be sourcing cooler air, cant see how it makes a difference as it stops at
the filter. I'm getting about 330k to half tank and 560k when light comes on.

thats about the same as mine it would vary as driving style is different

[threedogs]

Well my snorkel has improved my economy I now get 360 to
half tank and 12.6 /100 k around town on 305 muddies,
snorkel will remain facing forward

[janderson]

A turbo vehicle will only use the air that is needed, any more and it is expelled out the wast gate. So I would think forced in air is a small factor. As a turbo will suck the air that it needs, so then facing the snorkel to the back should not matter other than supplying cleaner air. Threedogs is also right, coming up to the Murray is all up hill.

[nipagu7]

hi guys , interesting thread .
wogsrus I just had an idea , if you set your ultra gauge to read the MAF sensor then get the patrol upto 100kpa on the highway and see what the maf reading is . do this with the snorkel facing forward , then try it backwards . this would let us know weather or not changing the snorkel direction changes the maf sensor reading , which I assume would change the fuel mixture . over the years I've heard people mention that they get better mileage with a snorkel , but can't remember anyone saying they had better mileage with the head turned backwards until common rail motors came along . ray

[Enthree]

very interesting read.
did anhyone tryt it with a carb yet?