want to install a ram-air filter

[grumpyvette]

http://www.ramairbox.com/

http://www.ramairbox.com/kits.html

viewtopic.php?f=55&t=537&p=16255#p16255

http://www.ramairbox.com/snorkels.html

http://www.powerflowracing.com/catalog/catalog02.pdf

http://www.spectreperformance.com/#CATALOG.9848

http://www.powerflowracing.com/catalog/catalog01.pdf

http://www.sfxperformance.com/parts/Spe ... page_1.htm

http://www.billetspecialties.com/subcategory.asp?cid=1

http://www.mr-gasket.com/pdf/74345G.pdf (pages 4 through 9)

http://www.holley.com/types/Air%20Cleaners.asp

http://www.stylintrucks.com/parts.aspx? ... id=FROOGLE"]Retro Air Cleaner

lots of good info here if you look around
BTW theres a surprising amount of materials you can get at your local HOME DEPOT that can be used to fabricate a very effective ram air set-up

basically the idea is to route cool/denser outside air directly into the engine without subjecting it to under hood temp. increases, you can draw air from the base of the windsheild or in the front grill area as both tend to have slightly higher pressures at speed.
naturally the straightest most direct path with the less restriction will provide the best results and ID suggest a dual vs a single intake source if its plausible due to clearances.

IF youve got the hood clearance a 3"-4" tall filter height helps reduce the restriction to air flow
if you have hood clearance issues a drop base air filter design can give extra hood clearance, while it won,t cure every clearance issue it can be useful if your stock air cleaner design needs an extra inch of hood clearance with your new intake manifold design.

 

[grumpyvette]

when it comes to a carb air filter its basically a case where the larger the filters surface are the lower the resistance to flow will be with any filter medium, naturally some filters do a much better job at trapping crud and dust and most are not easily cleand but must be replaced, when they become partly clogged or mileage and performance suffers.

http://www.ramairbox.com/product.html

Thought I'd post this picture of a substack. it may be new to some of you. This one's for a Holley 4150/4160 with stock height air horn. K&N also makes them for Holleys with milled air horns and Edelbrock/Carter AFBs. its used to smooth the air flow into the carb

http://www.summitracing.com/parts/KNN-85-0200/?rtype=10

the most comon performance air filter for carbs is probably the 2"-3" tall 14" diam. chrome air filters many guys use,

, (cheap and fairly effective)
http://store.summitracing.com/partdetai ... toview=sku
if youve got the hood clearance you can install a longer carb center hold down stud and glue two filter elements

sitting one on top of the other, together with that silicone gasket cement effectively doubling the surface area and reducing the resistance to airflow into the carb and while your at it, and add one of these .

as it further reduced restriction as it adds filter surface area.
YES IM fully aware they make 4" and 5" tall filter elements but the cost is frequently far more than the cost of two of the 2"-3" elements even when a tube of silicones added to the cost.adding a stub stack to reduce turbulent won,t hurt either
http://store.summitracing.com/partdetai ... toview=sku

btw
don,t forget to hook up a PVC it tends to help remove pressure under the rings

 

[grumpyvette]

" heres a rather interesting dyno test result of a different site, if you think the air filter selected or air filter housing has little effect on flow rates....

https://www.wixfilters.com/Lookup/FilterLookup.aspx

"First thing we noticed is that the Air Hat and filter combo I was using was KILLING power... To the tune of 70 WHEEL HP and 80# ft. of torque.. KPA was down to 86 and our calculation showed that to be about 12inches of vacuum. This 2.4" tall carb air hat, unit was choking the motor badly

while its NOT 100% directly related, the resistance to air flow rates , is always a compromise between the air filter's efficiency at removing micro sized particles in the air that cause engine wear and restricting air flow that the engine requires to make power easily , increasing the surface area, number of pleats in the filter medium surface and height all tend to reduce air flow resistance, as the increased surface area reduces the resistance to flow

That unit sits almost and inch taller and isn't as restrictive. However, we still were losing 35HP and 40# torque from our previous baseline... with the taller carb inlet hat over an open unrestricted air filter And still pulling over 8 inches of vacuum.
Moved to this 4" tall air hat and gained 50% of the power back without doing anything other than adding additional fuel back into the mix, and by reducing our vacuum by about 4 inches:


Here are the part numbers for these particular units from Spectra Products:

http://www.summitracing.com/parts/spe-98499/overview/
notice this parts rated at 675cfm and its 2.4" tall that was reducing flow and had the engine down 70hp/80 ft lbs

http://www.summitracing.com/parts/spe-9849/overview/
notice this parts rated at 900cfm and its 4" tall, it got us back 35hp of the 70 we lost with the more restrictive air hat on the carb



this taller air filter/carb hat was worth an extra 35 hp but it was still restricting flow significantly

swapping to a full size 3" tall 18" diameter air cleaner with DUAL 5" diameter cool air feed hoses to outside air will usually show little or no measurable air flow restriction

you might also want to keep in mind that what goes in needs to exit without much restriction to flow,if your interested in impressive peak power. Ive seen a couple times where guys installed radical cams and high flow cylinder heads, on big block chevy engines , that picked up 60 plus hp with a swap to a low restriction exhaust and long tube headers over using a stock exhaust several times in the past