Wondering how to go about removing the guts of the bbm, and blocking off vacuum lines to make it run?

Ive heard a couple people doing this and just wanna know specifics

You can remove the internals of the manifold, the six butterflies inside are riveted to the shaft that runs through but where it exits at the front of the manifold you will have to block off somehow so you don't get any vaccuum leaks. The best way to get to it all is to take the upper half of the manifold off, which is a b**ch of a job, but if you cut the end off an allen key and use a socket and ratchet it makes things a heck of alot easier haha.

The vaccuum valve that operates the butterfly actuator (located behind the windscreen washer bottle) just needs to be unplugged.

The only problem with this is if you're keeping the car naturally aspirated you will notice alot of performance loss down low in the rev range and from experience this is where the 4.0L needs power to get moving.

But if you're going for boost applications, this is fine, it's probably one of the better things to do. BA XR6 Turbo's don't have butterflies in the manifolds.

thanks for the detailed info

or just get a hex bit

Well you could do that too hahaha, but i was about 40km away from the nearest place that sold tools and no car to get there at the time lol!

T bar works pretty good also IIRC...


also to block the hole where the butterfly shaft was ive previously just cut the old shaft down and reinstalled with sealant for that stock appearance

if you want to work an intake manifold do it to the log, they are so much better compared to the BBM, but if your interested in the bbm mods then chat to FAST XR, he has already toyed with his a fair bit

ive given up on the idea, as i dont have the tools to port the bottom half, and i even took the manifold to a fabricator and he said he couldnt help me cause none of his tools would fit or something along those lines.

From what ive gathered, you lose torque down low but gain some top end power, but i reckon with a custom tune that the losses might be minimised to an extent