Civic EG

Hi guys.

I would like to know if it is advisable for me to port my plennum on my intake manifold or to get a smaller throttle body.

The plennum diameter is 56mm i think and my throttle body is 60 mm.

All advice appreciated.

Port matching would be best.. you want it to flow evenly... so you have to match your Manifold opening to match the TB your using.

No a stock 56mm TB is more than enough. If you use a bigger TB you will loose some torque and you whant a stepp from TB to plenum about 2mm

TB 56mm / Plenum 60mm

to prevent reversion same thing with runner to head.

but his TB is bigger then his plenum its like pushing air from a big str8 to a lil straw. it'll have some kind of restriction... right..

I was thinking the same about restriction. But apparently bigger isnt always better.

What kind of engine do you use D16 or D15?
Eather way 60mm TB is to big get yourself a 56mm TB and port the Plennum to 58-60mm.

It's a JDM D15 vtec engine. I currently have a b20b (60mm) throttle on.

So i must get myself the a smaller throttle and port the plennum.

a bigger tb wont improve much just throttle response... most people i talk to say keep stock... but is the intake many stock?? you shouldn't have to do anything.... but get a stock tb lol!!

Is your D series Naturally Aspirated or boosted? I would think an NA d series is fine from factory at 58mm, but in a turbo setup airflow is your friend so a larger inlet on your intake manifold would be good.