6.2 GM- CFM req

[hafthpy]

Hi guys,
Im currently running a 6.2 GM diesel in my 75 series Landcruiser. Im attactching a stainless steel snorkel so i need to buy a new inline airbox. Can anyone tell me the CFM requirements of the engine??
Thanks

 

[Will L.]

Depends on your turbo, top rpm, tune, etc. to be exact.

http://www.widman.biz/English/Calculators/CFM.html

1400 cfm should be a safe bet.

The easy answer is the best filter housing from a junkyard is the k47 from a pickup or suburban. Better than that would be the housing from a h1/hmmwv ("hummer parts guy .com" type in minus spaces- or real4wd .com). I dont know if http://leroydiesel.com/ sells air filter set ups or not, but he is great pricin and service.

Love to see some pics of your rig if you get the chance.

 

[FellowTraveler]

First you must know approximate volumetric efficiency VE of the diesel then consider exhaust cfm flow, intake flow and if boosted the pressure ratio at common boost levels and drive pressure aka: backpressure.

Take my 6.5td w/S&B air box opened end or modified like mine the filter flows around 650 cfm +- while the 4" in/out CKO HX40w 18 cm2 super fourty flows around 850 cfm +- the filter cfm flow is the limiting factor next consideration is exhaust flow through whatever diameter the downpipe is. The max cfm flow is at WOT and most never see such cfm requirement in daily driving so my feeling is minimum 5" diameter snorkel and the biggest filter you can fit.

http://centriprecleaner.com/calculate-your-needs

 

[FellowTraveler]

Another link for exhaust pipe flow you will see a straight 3" downpipe can flow 740+ cfm on N/A application however keep in mind any elbow/turn radius reduces this flow but cobra style elbow/turn will prevent flow loss.

http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

 

[FellowTraveler]

Another thought is that BIGGER is better in that you'll have good cfm flow and less PM to do on filter as it would stay cleaner longer especially w/prefilter.