U-brew SS Snokle

[canucksafari]

Nice write-up here on a u-brew SS Snorkle: http://www.mudrhino.com.au/Docs/DIY3.pdf. Might be a good idea for a tech day in the fall. We could get some other plans and I have some other write-ups which are slightly different. For those guys going with the bigger exhaust on their turboed engines, they need to remember that the exhaust is only 1/2 of the equation in better airflow.

 

[mainlander]

That looks saaawweeeeeeet!

Easy too. And actually if one couldn't afford the SS tube, one could always use PVC.

Dam-kit John, now I have one more thing to add to the list!

 

[canucksafari]

Already inquired about the parts with a friend who works in Abby for Western Star. They carry Donaldson air intake components. No idea on price but if we just buy the Donaldson elbows and spin top filters, it would simplify things.

 

[d0ubledown]

looks awesome john...if you can get supplies together...im in. after last weekends dunk in the drink...i thought hmm. snorkles next. a DIY job that doesnt look mickey moused...

and i think you can get the safari snorkel funnel ends separately, if you want the completed look...

 

[Enigma]

Stumbled across a thread on bc4x4 with this link, good prices!

OffRoadOverstock.com

 

[canucksafari]

Jeff, those are very good prices for a Safari snorkle. However, I understand if you plan on a turbo with a decent boost, then they will not give you enough air. I was told that on my Safari, I should have a 3.5" round tube snorkle with no more than 2 bends before the turbo to move enough air running under 10 psi boost (for the turbo which is still just a dream ). That does not include the air filter box. Over 10 psi, I should have a 4" tube. The fancy top filters apparently are quite restrictive and you are better off with a big primary air filter and no prefilter. Anybody want to punch the numbers, I can post up the formulas the diesel boys in Aus use.

 

[Enigma]

Well I already have a turbo, and don't know jack about boost ( I have a gauge tho!), but anything has to be better than the stock setup.

And according to my funky Blitz Racing boost gauge, I'm usually hovering around 0.5 kg/cm2 and up to 1.0 kg/cm2 when I have my foot into it. This translates into 7.1 PSI and up to 14.2 PSI.

 

[canucksafari]

Here is some math stuff / tech for those who are so inclined. To sum it up, I know I need a minimum 3.5" pipe but better a 4" pipe with an airfilter/box (CAT or F350) which can flow enough air.

The first is the math for a TD4.2 which is similar in cylinder volume to a 1HZ or 1HDT. The guy used it to figure out the compressor side turbo he needed but it also works for figuring out max airflow required.

Boost pressure determines the Pressure Ratio: Pr = (boost + 14.7) / 13.7

then CFM = ( L * RPMmax * Ve * Pr ) / 5660

L = Engine size in Litres
RPMmax = max RPM :ROLL:
Ve = Volumetric Efficiency: I used 60% (0.6) efficiency at max RPM of 4800
5660 = 5660 ??? NFI

so for mine I used CFM = (4.2 * 4800 * 0.6 * 1.95) / 5660 = 416.5CFM @ 4800 RPM with 12PSI boost.....easy

This second part posted by a friend in Aus left me a bit confused but he builds diesel boats so he should know.

John It requires a bit of maths to work correctly eg you cal the engine output power BHP then the VE which gives you the air consumption.

AS you see it is dependent on power output in other words if you have 150hp at the back wheels your 3 inch Donaldson is left wanting just on its advertised spec values add 2 metres of pipe and now you have lots of black smoke as ITS A has stated. The 3.5 inch i dont have the flow rates so i cannot say but it should be fine but i would still fit 4 inch pipe for the snorkel. You need to have the air speed in the snorkel less than 3 metres / sec to be safe. My opinion only here i am not a big fan of DONALDSON cleaners reason is if you look at say a CAT 3 inch cleaner on heavy equipment it is the same design etc but the body and filter assembly is at least twice as large this should tell you something well it does me. And if you measure the exposed filter area it is tiny compared to your standard nissan unit which we know is to small for this engine turboed so mate i recon the nissan engineer know a sh*t load more than donaldson about there engine. Now a bit of logic all elements flow about the same BTU/ square inch no mater what so donaldsons advertised crap with rotating air etc is crap when flow rate is conserned. MY opinion here only.