Cut And Shut Plenum

[AMR33]

Hey guys

A bloke came over the other day to buy my car. While he was pressure testing it he mentioned something that people do to stock intake plenums called "cut and shut". He briefly explained why people do it but also informed me to avoid a car that has had this done to it.

Can someone explain to me what cutting and shutting the intake plenum is and what it does etc?

Cheers

[Ben C34]

Its moving the throttle body to front of plenum to shorten intercooler piping. pointless as it affects air distribution in the plenum. Nissan spent a while designing it so seems wrong to hack it up

[AMR33]

but doesnt the throttle body sit on the front of the plenum anyway? Or do you mean that when you look at the plenum it will be pointing towards the front of the car?

[AMR33]

as in the throttle body will point towards the front of the car rather than towards the crossover pipe as it does originally?

[ARTZ]

Its moving the throttle body to front of plenum to shorten intercooler piping. pointless as it affects air distribution in the plenum. Nissan spent a while designing it so seems wrong to hack it up

i like this....it "Seems wrong"

is there any anecdotal evidence that it is wrong?

[AMR33]

i like this....it "Seems wrong"

is there any anecdotal evidence that it is wrong?

Well Ive been told that it will lean out your cylinders, 1 and 6 especially. If thats true.....seems pretty wrong ahahhahahaha

[ARTZ]

yeah have heard that...still dont know if i beleive it...people have said the same about greddy plenums..

[jet_r31]

id have to see it to believe it, you could say the same about doing it to a Rb30 sohc intake aswell, yet the fastest car in the country runs that setup

cheers

darren

[AMR33]

id have to see it to believe it, you could say the same about doing it to a Rb30 sohc intake aswell, yet the fastest car in the country runs that setup

cheers

darren

On a stock intake plenum??

[AMR33]

So how is it done anyway? Do you take the throttle body out, make another hole in the plenum and weld the TB in and then weld shut the original hole?

[zebra]

Yup.

Hence cut and shut

[AMR33]

hmmmmm seems like a lot of pain for no gain. I guess a forward facing plenum is the way

Cheers guys

[StevenCJR31]

from what ive read here before the power gains arent that significant on a ffp

[ARTZ]

no...but it does make spark plug changes sooooo much easier

[GTSBoy]

Abdul, if you're interested in my thoughts on the matter, search for posts by me with "plenum" as the search term.

[Soundboyracer]

Example

[WMDC35]

I've seen a number of cars run the chop job, didn't seem to cause any noticeable detriment but they were usually pretty low end setups, 200 ish rwkw or less

the greddy etc were designed as ffp so not really comparable, the people I knew that used to do the chop for people said it still needed the throttle body on an angle towards #1

i'm sure if we had a fluid dynamics tunnel we'd see that the flow is far from ideal, i'd never put one on my car, same as I wouldn't chop the throttle body off the front of the greddy and put it on the side

[XRATED]

Example

... just so much wrong.

[wolverine]

When the AUD was trading at USD55c and Greddy and Nismo plenums were extremely expensive a cut and shut might have made sense to someone.

Today you can buy a buckchoy front facing plenum for a round of drinks.

[Dose Pipe Sutututu]

^ with change

a night at the Ivy will cost more