E30 325is Throttle Body Question (Megasquirt)

[TJF]

Tonight I was test fitting together my intake manifold as part of my Megasquirt conversion. And have a couple questions concerning my throttle body.

The throttle body I have came with the "air pump" and associated hoses discussed in the thread linked below.

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,288516/highlight,325is+throttle+body/

Looking at the Real OEM diagram

http://www.realoem.com/bmw/showparts.do?model=1413&mospid=47322&btnr=11_0861&hg=11&fg=45

I understand the important thing is to supply vacuum to the brake booster. I also get that I need a check valve in that line. That's easy.

Those two lines came from the ports shown here:

But for what was this port originally used? The one under the barb connection for the IAC. It doesn't appear on the Real OEM throttle body pictures that I've looked at. The smaller port I will either use for vacuum sensing or cap off. Just not sure about the larger one..

Thanks,

T.J.

[nbristow01]

What size injectors are you using?

[TJF]

I currently have a set of 19#/hr junkyard injectors from a 4.6L Mustang. Since I have them I'm going to use them and see how they work. (Ford FOTE-D1A is the Ford part number).

[nbristow01]

OK thanks. I am going to use either 21's or 23's. Not sure which yet. I need to hit a wrecking yard and fine some good ones

[Dave_Ganzer]

On my MS2 install (318i manifold)....

I got the brake booster vacuum from the fitting on the top of the aft runner of the manifold. There were 2 small ports in the plenum that I used for MAP and FPReg.

I would just plug all of those ports.....

DaveG

[TJF]

I am planning on using the port on the runner for the brake booster and the little port next to where the IAC is for the FPR vacuum connection. Then I think I will use either the small port on the throttle body or one of the two on the manifold for MAP. It's the big hole that I am wondering what it was originally used for. I am not planning on using it at this point, but toying with the idea of tapping the hole and mounting the IAT sensor there. It is just after the throttle butterfly and I haven't measured to really see if that is an option yet.

[///mChris]

Don't forget the crankcase vent on the valve cover. It's important to make sure you get proper oiling at the top of the head to connect it.

[TJF]

Good point. I'll take a look and figure out the best place for that too.

[TJF]

I'm considering routing the cam cover breather into a catch can instead of back into the intake somewhere. I am putting this together with a mind to a future turbo setup and no reason to do things twice if I don't have to.

[///mChris]

I've wondered what the affect of no vacuum to keep oil pressure in the head would be. Maybe a catch can with a vacuum line to keep pressure in the head.

something like this

http://www.034motorsport.com/engine-components-18t-catch-can-breather-kit-mk4-18t-p-19167.html?osCsid=9o2qu5m7n2giu74oqhet6glvi5

[///mChris]

Does anyone know why a Tii has a jet in the valve cover? The little insert that sits inside the vent is called a jet by the parts book.

[TJF]

I think I remember seeing a C.D. post (with picture) that said it was a flow restrictor. Not sure other than that.

[chipperwerks]

I believe the larger port was part of the idle control system....but was it...I like the intake runners!