KA24DE Secondary Butterfly

[TOPCOG]

Hello, I am rebuilding my KA24DE and am wondering the function of the secondary butterfly wich is on the manifold. Can someone tell me the function of this item?

Also, If I cap off my egr valve will my ECU have problems? or will it adapt and run normally?

C-ya-bye.

[wanabe240esx]

adapt and run normally no, breathe fresh air, yes

the secondary butterfly valves are there to keep the air "swirling" at idle, basically an emmisions device i guess, yes those can be removed, but i guess you have to fiddle with the throttle body

its in the 240sx.org faq btw

[bj180sx]

I think on the newer ka24de's they removed the secondary butterly. Had to many idle issues with the thing I believe. Check the faq on http://www.240sx.org

[pr240sx]

All KA24DE have the secondary butterflies.Just unscrew the butterflies from the shaft and thats it.Also, if you are unsure on doing this, you can disconnect the red (2 wire) connector at the back of you engine. This controls the opening of these butterflies, leaving them open all the time

[4cefed]

Um, have many of you guys defeated the butterflys? I'm not positive, but gathering from general automotive knowledge, these are also there to give the engine a little more torque at lower rpms. Basically, if you restrict the intake flow it increases the the flow velocity giving the engine a little more torque. If they were removed, you would clear out the passages and gain a little more top end HP, but I'm not sure it's worth the loss in torque.

[Nismo_Freak]

The KA doesnt make a ton of torque below 3k anyways.

[float_6969]

They took them out in the newer KA's. I think it was just left over technology they they didn't see any reason to quit using. Kind of like the tip in retard they used to use in the old computer systems.

[FrEaK]

adapt and run normally no, breathe fresh air, yes

the secondary butterfly valves are there to keep the air "swirling" at idle, basically an emmisions device i guess, yes those can be removed, but i guess you have to fiddle with the throttle body

its in the 240sx.org faq btw

The EGR is there not just to thwart your thrist for power... it helps keep emmisions low (obviously) but it also keeps the combustion temps and therefore the engine temps cooler... cooler engines = prolonged life cooler engine = more performanceSo capping the EGR is not only a bad idea but i do believe it will cause errors on your exhaust sensors at some point..

[d240t2]

SCV aka intake butterflies were in DOHC KAs in S13s until 93. Sometime mid-year 93 they quit putting them in. They aren't in any S14 KAs.

If they are so good, why did the factory pull them out? I haven't seen anyone do any dyno tests before and after...but I don't think they did a whole lot of good on the low end...nor do I really think they hurt things that bad on the high end...except possibly for those of us moving a lot of air past them under boost.

In other words...remove them if you have the intake manifold already off, but don't pull off the intake manifold just to get to them.

Dennis

[RatedR]

Hey guys, I've been debating on whether this could be the problem my car's been having...Here's a link to the thread:http://www.nissaninfiniticlub....erfly

So does anyone know????

-R