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hey guys

having a look over the stagea yesterday and i think there is a thick (~5-10mm) spacer on the lower half of the plenum (plenum to block)

has anyone seen this before? (where the boxed part is)

post-51118-0-70057500-1294466456_thumb.jpg

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hey guys

having a look over the stagea yesterday and i think there is a thick (~5-10mm) spacer on the lower half of the plenum (plenum to block)

has anyone seen this before? (where the boxed part is)

The Inlet manifold gasket?

if it's about 10mm thick then it is probably one of those plastic spacers people put on in the hope of gaining extra power from dropping the amount of heat transfer to the plenum. makes sweet fuck all difference though

To plenum temps or power?

My plenum is cold when driving now, dropped the intake temps by 20-30 degrees.

The way I understand it, the air intake sensor (exact same sensor as the temp probe in the radiator) that is on intake manifold (well GTR ones anyway) takes the physical temperature of the plenum where it's attached to, not the actual temp of the air.. the temperature of the plenum can be much higher than the temp of the air because of heat transfer from the head.

The way I understand it, the air intake sensor (exact same sensor as the temp probe in the radiator) that is on intake manifold (well GTR ones anyway) takes the physical temperature of the plenum where it's attached to, not the actual temp of the air.. the temperature of the plenum can be much higher than the temp of the air because of heat transfer from the head.

so that must also mean the radiator temp probe you're talking about takes the temp of the radiator and not the water. that doesnt make sense to me.

a colder plenum will make minimal difference. the air is traveling at super speeds when entering the combustion chamber, it will still be entering at the temperature of the post-intercooled-air at higher rpm where these things would matter IMO.

so that must also mean the radiator temp probe you're talking about takes the temp of the radiator and not the water. that doesnt make sense to me.

a colder plenum will make minimal difference. the air is traveling at super speeds when entering the combustion chamber, it will still be entering at the temperature of the post-intercooled-air at higher rpm where these things would matter IMO.

that is correct. the air is travelling at such a speed that it absorbs very little heat from the piping it is running through. this is also why it is of no real concern having the cooler pipe running along the top of the radiator with a fmic.

as for the temp prob, it may well take some reading from the plenum rather than the air but i really don't know. either way, i'm not sure if the rb25 has an IAT sensor. pretty sure that the skylines at least, don't.

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