I herd rumors of taking the flaps out of the intake plenum gives a 4hp gain. Is this true?

 

The "flap" in the lower part of the plenuim? I heard that rumour quite a long time ago...

 

any confimation on this "rumour"

 

is it that flap where the air intake goes into? as far as it being true, i don't know. and i don't know a whole lot about cars, but it might have an upper and lower flap for balance.

if you rev your engine a lot, that will flap a lot, unbalanced it could break off. and i don't think you want that getting stuck in your intake.

it MIGHT give a gain, if there's a delay time sucking in air (delay time would be the time to open the flap to draw air in).

i'd say it's not worth it.

 

i've read it could give up to a 20hp gain i'd like to know for sure, so when i rebuild my engine if it will be worth it or not, to actually remove the flaps.

 

Ok, I need a visual. What're you guys talking about?

 

yes they should give a hp gain, and take away torque and partial throttle operation! at low rpm and under cruise, (vacuum) they are closed or partially closed, and direct air up to the fuel injector, which is very recessed, to atomize the fuel better. then at low vac. a stiff spring opens them up,(they are normally open) .

for those of you not sure what where talking about, there are 4 butterflys in the runners right before the fuel injectors on ka24de engines, ill take a pic tonight if i get a chance.
-sage

 

Oh, ok, I ot it now. But don't thoise help increase torque in the low end? Why would you wanna lose that?

 

arn't they on the E aswell??

 

what about extra-honing the plenum what would that do? what is extra honing anyway? Some corvettes just make everything inside bigger and get bigger flaps and butterflies and what not Then they fly..

 

oh yeah, the ka24e prabably also has butterflies,i just wasnt sure so i i wanted to be specific. i think you are referring to EXTRUDE honing, which is the name a company has applied to the process of forcing a putty like abrasive through passageways which makes them exceptionally smooth and promotes flow as it flows through similar to the air. however the runners are already very large, and i doubt much gains at all could be had by it. sr20de's gain just about nothing by extrude honing their im's, whereas honda's gain anywhere from 5-15hp depending on motor........perhaps nissan is very efficient to start with? or perhaps honda's is just better designed so it takes advantage of the improved flow better?

 

ohh i see i understand why the crossfire vettes do this now... thanks! i was just really confused about what they were doing... hmm so i guess i should just leave the plenum alone. But one more thing. I saw a ka24de with hotshot headers and everything all N/A but his plenum looked different! it was polished and it looked a little bigger...

 

where did you see this? i'd like some info, was it a motor that they was specifically for NA? a ka24de with hotshot headers isnt very specific....
-sage

 

Well actually i was just really confused when i saw this KA... I'm still a newb ahaha so dont flame me! here's his very nice and sexy engine bay...

http://memimage.cardomain.net/member...07_10_full.jpg

http://memimage.cardomain.net/member...07_11_full.jpg

Is it just polished?

 

Don't have much input but I must say that is nice and clean!