difference in KA intakes

long story short, i got 2 KA24DE at home that i’m going to rebuild atleast one engine from the 2 together
and i found that the intakes manifold on the 2 engines are different

one just look like a normal intake, and the other one at the end of each of the runner, theres a flap controled by vacuum, looks like one of those flaps on intakes that has 2 runners, but the problem is KA only have one runner each, and so my questions are

  1. what are they for???
  2. are the 2 interchangeable?
    here’s some picture to explain better
    the 2 intakes side by side
    http://picasaweb.google.com.tw/VQ35DETT/KARebuild/photo?authkey=BL8xJxcbn8M#5097605804595992562

the one w/o the flap
http://picasaweb.google.com.tw/VQ35DETT/KARebuild/photo?authkey=BL8xJxcbn8M#5097605692926842802

the one w/ the flap (normally)
http://picasaweb.google.com.tw/VQ35DETT/KARebuild/photo?authkey=BL8xJxcbn8M#5097605834660763650
when theres vacuum(i don think normal engine vacuum can close them all the way, i don have a vacuum pump at home so i can’t test it)
http://picasaweb.google.com.tw/VQ35DETT/KARebuild/photo?authkey=BL8xJxcbn8M#5097605722991613890

and heres wat i found on one of the engine, the engine doesn’t seems to have too much mileage after it’s last rebuild, but i guess heres the problem why it got pulled out again…
lol
http://picasaweb.google.com.tw/VQ35DETT/KARebuild/photo?authkey=BL8xJxcbn8M#5097605774531221474

Those are the secondary butterfly’s. The 91-94 OBD1 Ka’s uses these swirl control valves, at idle and low rpms the valves close up incresing the velosity of air going into the cylinder, also creating a swirl effect inside the cumbustion chamber.

The one without them has either had them removed (slightly better air flow) or is a 1995+ Ka, 95 and up didnt come with secondary butterfly’s.

o neat…
thx for the info
and i guess they are interchangeable then rite?

Yup, but if your using the one with the scv’s on a 95+ motor, you’d have to find a way to connect the vacuum or just remove them.

is it really worth the trouble removing them? they can’t yeild that much preformance… well at least as long as they are working. I can imagine if those got stuck that would kill your preformance.

they are pretty hard to get stuck
they activate by vacuum and release by spring, and the springs aint soft either

I think you would only notice gains if you’re running high power. Captian Bolt on like me wouldn’t probably notice any differences…