Stock Cold air intake performance upgrades

[TDoc]

I already added dual exhaust to my ‘86 K5 with LE9 305. Stock numbers are 160hp @ 4k rpm and 235tq @ 2k rpm.

I removed the very restrictive metal mesh flame arrestor? Which I immediately felt some hp improvement. I thought about going to the standard open element air cleaner but I like that the stock air intake actually pulls cold air from the grille. I wonder if the stock tube is big enough to supply enough air? I guess I could cut off the plastic debris blocker behind the grill and get more air in but the single stock intake tube may be maxed out anyway due to size.

What have y’all done and have noticed any power improvement?

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[TDoc]

Current paper filter is SA3549
12” round and 5.47” tall

 

[Keith Seymore]

You could add another tube and snorkel to the LH side.

There is a knockout in the rad support to allow the installation of another "birdcage".

I ran this setup on my Chevelle with the flat hood and it was worth .2 sec reduction in ET in the quarter.

K

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[Ricko1966]

HO camaros got a dual snorkel air cleaner with cold air ducts. If you swap in a zz3 to another camaro the air cleaner is a necessary component. As @Keith Seymore said add a second snorkel. Or find a dual snorkel off a camaro,be warned they bring a pretty good price tag.

 

[CalSgt]

Maybe with a higher HP SBC some additional cool air would benefit, but I’d gamble if there was HP left on the table due to the intake snorkel GM would have made it bigger from the factory.

 

[TDoc]

Maybe with a higher HP SBC some additional cool air would benefit, but I’d gamble if there was HP left on the table due to the intake snorkel GM would have made it bigger from the factory.

I may cut off the plastic plate behind the grill so I get sort of a ram air effect. Instead of it pulling air from the sides behind the grill. Guess I’ll leave the metal plate inside the filter so it redirects the incoming air to around the rest of the filter. I was suprised how tall the stock air filter is and how restrictive the metal screen thing behind it was. Guess those two were related, more surface area needed? I think my only restriction now is the single intake tube and the 305 lol

 

[Ricko1966]

I may cut off the plastic plate behind the grill so I get sort of a ram air effect. Instead of it pulling air from the sides behind the grill. Guess I’ll leave the metal plate inside the filter so it redirects the incoming air to around the rest of the filter. I was suprised how tall the stock air filter is and how restrictive the metal screen thing behind it was. Guess those two were related, more surface area needed? I think my only restriction now is the single intake tube and the 305 lol

You aren't going to get enough of a ram air effect to benefit you. The guys doing this for real are less than 1 percent gains on 10 second cars. Gains start around 70mph at .7 and 3. At 150mph . The cold air gains are great,but you aren't going to see a benefit of ram air on a street driven squarebody with a 305.

 

[75gmck25]

You have the tall air filter, which flows plenty for any SBC. Most trucks (like mine) have the standard height filter.

Dual snorkel air cleaners are available in aftermarket and factory reproduction versions. I’ve seen them every year from vendors at Carlisle. However, I’m not sure the driver’s side snorkel will clear the air conditioner compressor and lines.

 

[AuroraGirl]

dual snorkel will be nice thought but im not sure youre going to be adding more potential to your 305 that way, but id recommend it for the 1) cool looking
2) redundant THERMAC means less problems if one fails , if you decicde to use a thermac on both sides
3) if there is any gains to be had, youll get it
4) any upgrades or engine swaps in the future that need more air will be sufficiently supplied as a given

 

[SquareRoot]

Unless that 305 is spinning 7000 rpm the snorkel tube is more than sufficient. Removing the plastic "screen" is also a waste of time. You need to understand the concept of "high pressure air" on the front of the radiator support. Same concept as a cowl hood.

 

[Grit dog]

Ain’t no air cleaner mods going to help a 160hp when it was new 40 years ago 305. I’d be happy all the OE stuff is in tact and keep it that way. Those ESC 305s get real finicky when you start messin with them.
And yes that snorkel and air cleaner would work on a mild 454. You’re not getting any grossly measurable or noticeable free power out of that by hacking up the air cleaner parts.

 

[TotalyHucked]

The best thing I ever did to help the performance of my 305/T350 was throw it in the woods and put a 5.3 LS/4L65 in the truck lol. Seriously, those engines are so weezy, you won't see any gains doing any of that. As said, the little core support insert works off low pressure and is actually a good thing. I'd put it all back and leave it alone. Start saving for a better engine. Definitely don't do the usual "open element" air filter, that's just sucking up hot air

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