Outer Limits 4x4 Board

Hey Fellas and ladies. Im looking at building a stainless snorkel for my Bj70 which runs a 3b NA diesel. just wondering if you guys have any suggestions on how big the tubing should be to give sufficient air to the truck?
Cheers, Heath

To make it look sufficienty hetrosexual i wouldn't go below 3.5"

dogbreath_48 wrote:To make it look sufficienty hetrosexual i wouldn't go below 3.5"

ive got a 3.5 inch on my bundy, any smaller and would look ass, but 3.5in is dear to buy mandrels, 4in will be cheaper

i have a 3" on my 4.5 80 series and its good

I have 3inch on my lux, its good too.

I have a 3 inch on my Hilux any bigger and it would look stupid in my eyes I made mine from aluminum bends from supercheap not as strong as stainless but I couldn't get stainless on the day (last min decision to make it) it cost me 200 at retail and some time to weld it up haven't buckled it yet

mine is alloy to and its been bent as 1 peice. looks good

Mine is stainless, one piece, and was free, just cost a case to get it cut and retigged, as the welds that were on it when I got it were poop. And 50bucks for a snorkel hat.
And its been fine so far.

struth makes mansexual snorkels

Have built 2 for 75's and 0ne for 2.8 lux all from 3" and they look trick. Now building for V3 runner after drowning a mates in the river over the weekend. Water was not deep but the speed sent a bow wave up behind the H light and filled the thing. Pulled the plugs and pumped her out then drove home. lucky not to bend any thing.

Cheers

3" or 4" DO NOT USE 3.5" That sh!t is dear as, plus its uncommon, no joiners, no hoses, no airboxes.

3" Looks great and flows plenty more than stock.

I had a 3" on mine a few years ago, on my new one I went straight to 4"

For a 3B, 3" pipe will provide plenty of air and be plenty sufficient. You may however decide that 4" looks significantly better. Eg. 3" on patrols looks shite, 4" is the go. 3" looks fine on the 40 however.

cheers lads for all your advise.. thinking about going 3" and having it bents up so i dont have any black rubber elbows showing!! i'll probably paint it black tho so i dont think stainless would be the go, do yous think aluminium would do the trick?

i have a 80 series petrol landcruiser would 4in be the go for a costum snorkel or would that look too big??

The cross sectional area of a 3 inch tube is ~7 square inches.. The cross sectional area of a 4 inch tube is ~12.5 square inches, nearly twice.. The bigger the tube, the greater the volume/mass of air in the snorkel that you have to get moving when you put the foot down.. I'd suggest that a 3 inch system will perform better than a 4 inch, but I could be wrong.. Its a diesel so top end requirements aren't going to be much..

I have a 3 inch home made system on my 2F powered 40, it goes well..

vk7ybi wrote:The cross sectional area of a 3 inch tube is ~7 square inches.. The cross sectional area of a 4 inch tube is ~12.5 square inches, nearly twice.. The bigger the tube, the greater the volume/mass of air in the snorkel that you have to get moving when you put the foot down.. I'd suggest that a 3 inch system will perform better than a 4 inch, but I could be wrong.. Its a diesel so top end requirements aren't going to be much..

I have a 3 inch home made system on my 2F powered 40, it goes well..

I challenge that, the greater the volume of air in the snorkel the less that air needs to be condensed or the slower it needs to flow through that snorkel to feed any given engine.

In real simple terms try breathing for a whole day through a straw, then do the same through 50mm PVC pipe. The atmosphere will flow a lot easier into your lungs through the bigger pipe and you will work a lot less to fill your lungs.

If you like do the maths on the required air speed through each diameter snorkel, it will be a lot lower on the 4" vs the 3".

The correct method to measure it is by pressure drop through both diameters, pressure drop will be a lot less in the 4"

Cheers

to easy struth, so for a 4 banger a 4" wouldnt be over kill at all?? looks aside

CruiserFun wrote:to easy struth, so for a 4 banger a 4" wouldnt be over kill at all?? looks aside

Looks aside the bigger the better IMO. But taste has to come into it somewhere

I run a 4" on a 4 Runner and it does not look out of place at all.

Cheers

haha cheers struth!! That's only because your 4runner is the don of all cars

Struth wrote:

vk7ybi wrote:The cross sectional area of a 3 inch tube is ~7 square inches.. The cross sectional area of a 4 inch tube is ~12.5 square inches, nearly twice.. The bigger the tube, the greater the volume/mass of air in the snorkel that you have to get moving when you put the foot down.. I'd suggest that a 3 inch system will perform better than a 4 inch, but I could be wrong.. Its a diesel so top end requirements aren't going to be much..

I have a 3 inch home made system on my 2F powered 40, it goes well..

I challenge that, the greater the volume of air in the snorkel the less that air needs to be condensed or the slower it needs to flow through that snorkel to feed any given engine.

In real simple terms try breathing for a whole day through a straw, then do the same through 50mm PVC pipe. The atmosphere will flow a lot easier into your lungs through the bigger pipe and you will work a lot less to fill your lungs.

If you like do the maths on the required air speed through each diameter snorkel, it will be a lot lower on the 4" vs the 3".

The correct method to measure it is by pressure drop through both diameters, pressure drop will be a lot less in the 4"

Cheers

If its a NA 4 cylinder and its not needing a great deal of flow, picture yourself breathing through 50mmPVC all day long and 100mm PVC all day long. The 50mm is plenty. But PVC and snorkels... LOL that Suzuki territory

CruiserFun wrote:cheers lads for all your advise.. thinking about going 3" and having it bents up so i dont have any black rubber elbows showing!! i'll probably paint it black tho so i dont think stainless would be the go, do yous think aluminium would do the trick?

Just buy the bends and weld them in.

bj on roids wrote:

CruiserFun wrote:cheers lads for all your advise.. thinking about going 3" and having it bents up so i dont have any black rubber elbows showing!! i'll probably paint it black tho so i dont think stainless would be the go, do yous think aluminium would do the trick?

Just buy the bends and weld them in.

Yep if you can weld just buy 3" exhaust pipe bends or 4" if your engine is over 3.0Lt







Cheers

To easy boys, thanks for that info and pics!! great help just waiting for some of the old tax money to come in then ill get into it! ill post some pics up after im finished! ( only if i dont mess up and it doesnt look like a dropped pie)

Struth wrote:

bj on roids wrote:

CruiserFun wrote:cheers lads for all your advise.. thinking about going 3" and having it bents up so i dont have any black rubber elbows showing!! i'll probably paint it black tho so i dont think stainless would be the go, do yous think aluminium would do the trick?

Just buy the bends and weld them in.

Yep if you can weld just buy 3" exhaust pipe bends or 4" if your engine is over 3.0Lt







Cheers

Great job!

Thats pretty nice work... Pity about the patrol stuck to the other side of it

haha bam!

Yep only one thing wrong with Patrols, they make their drivers think they can actually drive

thanks for sharing all your views

Exhaust Systems

Just some pics and info for someone who pm'd me.

The snorkel fits to the standard air box with some corrugated rubber hose and a 4" adaptor I made up,




I fixed a square plate with a round hole and tab to the inner guard that allowed us t ofix the snorkel at the guard end via a large hose clamp,


A couple of standard underbonnet bits had to be slightly relocated to make way but nothing too radical.

Some finished pics of a 3" on a different car,





Hope that helps.

Sure helps, thanks!

Seems like I'll have a lot more "relocation" happening as I have two vacuum bottle, fuel filter and some AC parts partially in the way... But I still love how this "shorty" set up took out a few bends and over a meter of tube from the typical Safari style. Well done!

Yep the safari type fit up to a standard intake but talk about excess length and 180 degree bends that simply slow the airflow down, they also use some pretty small tube sections.

The owner of the Patrol says the performance difference between the 4" snorkel and the original Safari he had on is very pronounced.

Cheers