So I have been doing a lot of research in order to build myself a custom intake for my s14 (the one where u change battery location). my question is, since the throttle body is 65mm (2.5") and the air filter and n60 maf are 3", would it be better to run a 3"-2.5" adapter at the maf to tubing intersection (so you use 2.5" tubing), or at the tubing to tb intersections (so you use 3" tubing)?

thanks for all the help guys, i'll post a write up with pics when i do it next month since no one really seems to have a write up for this mod.

 

If you want to get technical the S14 G70 Maf is 2.85"...

But I would stay at 3" at the way to the TB, I would also think about getting the TB bored out to 65mm, cause it's 65mm at the mouth and 60mm at the btterfly...

 

its been done.. and unless you have a need for extra air over a stock build ( cams etc ), you will really see no gains.

 

^Well The Honda and 2ZZ Toyota guys have seen avg ~5whp w/ I/H/E and getting TB ported, I would assume the KA being such a beast that loves to breathe I would assume it would love that extra 5mm of breathe space...

 

the ka has an issue breathing with the stock intake manifold design and head.

the KA has very small intake ports and large exahsut ports ( opposite of SR)

which is why we can spool large turbos yet.. get chocked out on the smalled T25/28's

 

True...


I was thinking about pairing an 65mm Bore TB with the Stock Mani runners honed/ported out to 46mm (stock is 44mm) and then have a good N/A P&P job on the head (Talked to the guys at Endyn) w/ Crower Vavletrain and PDM 272 cams...

 

Shorter intakes are better than long intakes.