Removing manifold butterflies

[diamondstar36]

How difficult is it to remove the intake manifold butterflies? I'm not crazy about the design and all the vac. crap that drives it. I'd rather be rid of it all.

[r34 gtr]

me too, will i gain/lose anything with them out? regardless, its one less thing to go wrong, and that seems to happen alot on my car.

- tim

[NeedCAforS13]

I just took off the round pieces... left the bar in there. I didn't feel like trying to plug the holes it leaves in the manifold. I think it will be ok... there is 2 screws on each round plate, and 4 round plates total! took like 5 minutes tops:)

Sean

[CA19DET]

take the steel rod that holds the butterflies can be taken out and the holes weled..

i would like to see a before and after DYNO with and without the butterflies..

[PacManVR4]

Im curious now. i want to do it. i want to know if it would realley help. I know on a dsm a standard intake vs a Cyclone dual runner the flowed withen 1cfm or each other but the cyclone was more responsive in town.

[diamondstar36]

They flow almost equal to eachother at peak performance. Before then the cyclone restricts a lot of air, robbing bottom-end power in place of responsiveness.

[CA19DET]

i actually think the secondary butterflies would produce more torque than without them...

[paul_s13]

i actually think the secondary butterflies would produce more torque than without them...

It didn't on mine, thats why i didtched the Japanese spec head and used a UK/SA spec head and got LOADS more power with the same boost.

With a T3 @ 13psi I got 226bhp with the Japanese head (granted the engine was a bit tired) but after I switched to the UK head and a few other mods I got 301bhp @ 14psi with the same turbo and chip (standard injectors and MAF).

[r34 gtr]

awesome. i might have to give it a try. if its free, and since i have insane amounts of free time, i dont see any reason not to if there is some miniscule chance that it could do something for my car.

- tim

[diamondstar36]

Now there's an idea. I need to go hit up the junkyards.

[r34 gtr]

and that is a good idea...junkyards rule.

- tim

[paul_s13]

The thing you have to remember is that if you have a JDM clip then your ecu will be mapped for the butterflies, taking them out may cause some underfuelling because you will be flowing more air, a euro spec map may help if you are removing the butterflies because the UK/euro head is 4 port without intake runners and should have similar flow rates to the de-butterflied JDM head.

There is quite a difference between the JDM and Euro maps.

[diamondstar36]

Fuel is easy enough to correct with a piggy-back. But getting a UK map would be much more difficult.

[paul_s13]

Fuel is easy enough to correct with a piggy-back. But getting a UK map would be much more difficult.

Its easy, you can download the map from varoius sites and i'm sure slw240 could burn the chip for a small fee, the am27128c eprom chip can be got for next to nothing.

If you don't want to do that you can probably get a whole UK ecu from http://www.sxoc.com/vbb for £20-30 and there won't be import tax.

But it would have to be a post 92 ecu for the o2 sensor support.

[float_6969]

So was the debate ever settled as to wheather the UK head flowed better than the JDM head? (4port vs 8 port) This is excluding the intake mani, just the head. Anyone?

[Nismo1182]

Paul, im looking to get another CA head and im not to thrilled aobut the 8 port design my CA has. How much is the 4 port head with complete intake manifold,injectors, TB, etc over there?

[paul_s13]

Paul, im looking to get another CA head and im not to thrilled aobut the 8 port design my CA has. How much is the 4 port head with complete intake manifold,injectors, TB, etc over there?

Well lets put it this way, I got given a CA for nothing once! but you can probably pick up a whole engine that has killed the crank due to conrod bearing failure for £100 this will get you everything, but if your just changing from a jdm head all you need is the head and the small inlet manifold to plenum section and the fuel rail, everything else fits.

Check the sxoc for adverts.

[float_6969]

Still didn't answer my question...

[Nismo1182]

Id assume the 4 port head would flow better. After taking apart my intake manfiold and seeing how everything goes, Id rather have a 4 port head. Plus the no butterfly valves are another good benefit.

[paul_s13]

Still didn't answer my question...

Well when i spoke to norris designs about it they didn't rate the jdm head and said it never got the same power as the 4 port head.

[r34 gtr]

well....damn...i want one. im guessing this SWAT ecu will be able to handle the removal of the butterflies as it overfuels the car to death anyway. then im running rich on top of that..and ive got an safcII..i think im covered. anyway, ill give the whole removal stuff a try.

- tim

[float_6969]

wonder how much shipping is from the UK.... Hehehehe.