Thread: Upgraded Puma Airbox

Turbo blanket added.

Originally Posted by MLD

Measure the filter effective area of the allisport version. If cylinder use the cylinder area formula. If a panel, measure the heightxwidth. A puma panel is 121 in sq. If alisport version is smaller, you are taking a step back. For example, the patrol 4.2 and 79 series V8 filters are measurably smaller than the puma panel (107 in sq).

Here is the feedback from Allisport re surface area, they say their surface area measurement of a standard TDCi air filter is approx. 58.5 inches square: "Our AS293 filter has a surface area of approx. 99.2 inches square."

I'm not sure why there is a difference?

Surface area is a lot more than filter size.

It's the total surface area of the filter material.

Well I have no idea - Allisport sounds a lot better to me than standard.

Originally Posted by Tikka7mm08

Here is the feedback from Allisport re surface area, they say their surface area measurement of a standard TDCi air filter is approx. 58.5 inches square: "Our AS293 filter has a surface area of approx. 99.2 inches square."

I'm not sure why there is a difference?

I'm doing an LS conversion and went through the exercise of comparing air filters. This is my data. I'm sticking with the Puma filter and modifying the box for the LS intake piping.

air filters and air filter boxes


K&N uses this formula


A = effective filtering area (EFA) in square inches
A = (CID x rpm) / 20839


CFM calculator for 402 CID @ 80% effic @ 5500 rpm—> ~525CFM; @ 6,000 rpm ~560CFM. LY6 & 4L80 was programmed to shift at 5,000 rpm. Factory LY6 redline 6,000 rpm.


402 CID at 5500rpm = 106 sq inch; @ 6000 rpm = 115.7 sq in - assumes low dust city driving. Off road and country driving is a multiple of 1.5. thus 157 sq in and 172 sq in


5.3L (323CID) at 5500rpm = 411 CFM or 85 sq inch; @ 6,000 rpm = 450 CFM or 93 sq inch


LS1 commodore 289mm x 229mm x 24mm (158 cm 3) - EFA 103 sq in


Puma 290mm x 270mm x 40mm (313 cm 3) - EFA 121 sq in


Silverado 2500HD (6.0L) 318mm x 251mm x 41mm (327 cm 3)


VDJ (79 series) 307mm x 228mm x 52mm (363 cm 3) EFA 107 sq in


VDJ (200 series) 300mm x 311mm x 60mm (560 cm 3) - EFA 144 sq in


GU patrol (TD4.2) 176mm OD; 92m ID; 126mm H - EFA 107 sq in


Silverado Duramax 335mm x 241mm x 80mm (645 cm 3)


Ford F series 6.7 TD 357.6mm x 171.6mm x 105.5mm (640 cm 3)


LS7 (GM 25940997) for Z01 - donaldson (850 cfm)


2500HD (6.6 duramax) 2017-19 - 279mm x 279mm x 76.2mm (


patrol aftermarket filter box - 24cm diam - 90mm inlet & outlet (360 cfm)


for round filters use:


[table]
[TR]
[TD]H=(A/D*3.14)+0.75
A = effective filtering area
H = height
D = outside diameter of the filter
3.14 = pi
0.75 = the rubber end caps
[/TD]
[/TR]
[/table]
to convert CFM to sq Inch, divide by 4.8.

Having driven mine for a couple of days now after the airbox mod I'm also going to stick to the Puma airbox. My truck is a lot less asthmatic on acceleration (quieter).

Exhaust wrap added. Horrible stuff to work with.

Posted it on the FB puma group and one guy reckons fire risk. I can’t imagine too much of a risk as the wrap is from the turbo back <650.