Air Cleaner Upgrade
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
It seems that would be about right. Plenty for 400hp+
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
I think resdoggie and REELAV8R here were referencing a little drag strip testing I did several years back. (Good memories, guys) I was comparing 1/4 mile times on back to back runs, first with the old, stock L48, single snorkel air cleaner, with all factory pieces in place. The second run was with an open element, 3 X 14 air cleaner. My car was running high 12 second ETs then, very consistently.
For the record, I believe that CAI will always produce more power than under hood air systems, all things being equal. But in this case, my car slowed down by about 3 tenths with the stock CAI unit in place. No doubt this was due to insufficient air flow with the single snorkel which more than cancelled any benefit from the cold air.
Since then I changed intake manifolds to an RPM Air Gap which requires me to use an adapter under my Qjet. Even with a drop base air cleaner I have almost no hood clearance so I couldn't possibly try a stock dual snorkel, with CAI.
For the record, I believe that CAI will always produce more power than under hood air systems, all things being equal. But in this case, my car slowed down by about 3 tenths with the stock CAI unit in place. No doubt this was due to insufficient air flow with the single snorkel which more than cancelled any benefit from the cold air.
Since then I changed intake manifolds to an RPM Air Gap which requires me to use an adapter under my Qjet. Even with a drop base air cleaner I have almost no hood clearance so I couldn't possibly try a stock dual snorkel, with CAI.
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
Personally, I am using one of Pauldana's excellent CAI housings on my 78. It's functional and pretty
Pro
Joined: Nov 2019
Posts: 648
Likes: 353
From: Portland, Oregon
In 1978, GM used the single snorkel on the L-48 and the Dual snorkel on the L-82. In 1979, the dual snorkel became standard on the L-48 and they raised the HP rating by 5hp I believe. Considering the power levels these engines were at, it's noteworthy that the difference was that big.
Personally, I am using one of Pauldana's excellent CAI housings on my 78. It's functional and pretty
Personally, I am using one of Pauldana's excellent CAI housings on my 78. It's functional and pretty
1978 L48 single snorkel vs pauldana CAI
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Pauldana really did a nice job on those. Looks and functionality, great combo. If that can feed his 600+ HP 406 then it's more than adequate for almost everyone else with a SBC Corvette.
He even gets a small pressure rise at speed due to ram air I believe with that set up.
Living the Vette life....
Joined: Mar 2018
Posts: 555
Likes: 221
I can see the single snorkel air cleaner not producing as much hp as the open element setup. With the dual inlet on the later years, you have probably doubled the air flow into the air cleaner. Makes more sense if you compared the area of the throttle blades to the area of the single inlet and dual inlet that the single is restrictive just based on actual area.
Le Mans Master
Joined: Jun 2019
Posts: 7,650
Likes: 2,466
From: Indiana
I can see the single snorkel air cleaner not producing as much hp as the open element setup. With the dual inlet on the later years, you have probably doubled the air flow into the air cleaner. Makes more sense if you compared the area of the throttle blades to the area of the single inlet and dual inlet that the single is restrictive just based on actual area.
Living the Vette life....
Joined: Mar 2018
Posts: 555
Likes: 221
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