What is a plenum and what does it do?
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Intermediate
Joined: Sep 2003
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From: Carrollton TX
What is a plenum and what does it do?
I'm wondering what the Plenum is, noticed a cover for it in the mid america catalog. Plus I noticed if you get a 58 mm throttle body require port matching of plenum? I'm so confused.
Team Owner
Joined: Mar 2000
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From: Boston, MA
Re: What is a plenum and what does it do? (zoopoptung)
The plenum is pretty much the "box of air" on top of your intake manifold. On an LT1 it is the shoebox looking thing which is behind the throttlebody. The air is sucked into the plenum through the TB and then evenly distributed to the 8 runners in the intake manifold to each cylinder.
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
Melting Slicks
Joined: May 2002
Posts: 3,424
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From: Tucson Az
St. Jude Contributor
Re: What is a plenum and what does it do? (scorp508)
The plenum is pretty much the "box of air" on top of your intake manifold. On an LT1 it is the shoebox looking thing which is behind the throttlebody. The air is sucked into the plenum through the TB and then evenly distributed to the 8 runners in the intake manifold to each cylinder.
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
:thumbs:
Melting Slicks
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From: Construction Sucks! MI
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St. Jude Contributor '03 & '05
Re: What is a plenum and what does it do? (edsalinas)
good description. in general, a plenum is where an enclosure of air has higher pressure then the outside air. a duct for heating and ventilating or in our case the big boxything on the top center of our cars.
Melting Slicks
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From: Construction Sucks! MI
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St. Jude Contributor '03 & '05
Re: What is a plenum and what does it do? (zoopoptung)
Plus I noticed if you get a 58 mm throttle body require port matching of plenum?
Le Mans Master
Joined: Jul 2002
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From: Alive and well in Burlington NC
Re: What is a plenum and what does it do? (scorp508)
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
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From: Fort Knox, KY
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Re: What is a plenum and what does it do? (Steel Blue 91)
On an L98 it is the thing that the 8 curved runners are coming out of on top of the engine.
Affectionately known as "the Lobster". :jester
Affectionately known as "the Lobster". :jester
Melting Slicks
Joined: Jun 2002
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From: Phoenix AZ
Re: What is a plenum and what does it do? (onedef92)
But few intake setups LOOK cooler than an L98 IMO - I'll never forget how cool I thought it was when I first saw it in '85 on my brother's (and later mine) Corvette. Instant tire smoking throttle response. GM was still using carbs up until '82 and then it was the crossfire. Had an '82 Trans Am with that, pretty lackluster on the 305. Anyway, getting back to the subject...
My race motor builder also calls the opening below the carb in my Edelbrock Super Victor a "plenum".
My race motor builder also calls the opening below the carb in my Edelbrock Super Victor a "plenum".
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Race Director
Joined: Sep 2000
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From: The Top of Utah
Re: What is a plenum and what does it do? (vetracer)
My race motor builder also calls the opening below the carb in my Edelbrock Super Victor a "plenum".
Thread Starter
Intermediate
Joined: Sep 2003
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From: Carrollton TX
Re: What is a plenum and what does it do? (CFI-EFI)
that clears things up, thanks guys. would you suggest changing the throttle body, probably a 52mm when I do exhaust, cutout airintake lid and headers? if so, what order should I go in? another thing...what about the mass airflow sensor?
Le Mans Master
Joined: May 1999
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From: Windermere FL
Re: What is a plenum and what does it do? (86_RedRider)
Funny, I just replaced my 52mm TPIS TB because it sucked :lolg: with a 58mm BBK. I guess I wore out the TPIS as the spring would not always completly close the TB and I would end up with a really high idle.
The BBK bolted right up and I did not have to port the TB openings. The 58mm TB went to WOT without hanging up or rubbing.
Just lucky (for once) I guess? :hurray:
The BBK bolted right up and I did not have to port the TB openings. The 58mm TB went to WOT without hanging up or rubbing.
Just lucky (for once) I guess? :hurray:
