M30B35 Intake Manifold differences?

[Jean]

Hello,

I am in the final stages of finishing up my 91 b35 engine and I've learned that some of these manifolds have only one connection/nipple on the bottom for a thin vacuum line (for fpr for example), and some have two?




I bought my engine with this manifold on it, it came out of a 735i, and I don't understand why/how it's only got one nipple on the bottom of it for the vacuum line? Do I need a different elbow (13) from the throttle body boot to the valve cover (C) without an extension for a vacuum line? I searched realeom and item #13 in the digram is 11151276485 comes up as the one I currently have in the photo below, it does have a nipple on it, it's not like in the diagram above.



When/why did this change?

Mine has only one, this is how it came like on the 91 m30b35:





Specifically where would the vacuum line from the throttle body to the valve cover rubber connection connect to, item C? Since the lower nipple needs to connect to the FPR.



Help?

[Duct_Taper]

Did your 735i manifold come from a car with EML? Not sure if that would be the issue, but I know EML cars have a completely different vacuum setup from standard cars (my E34 has EML).

[Jean]

It did originally have an EML throttle body. So the actual manifold is different, that sucks :( So now I'll have to remove the manifold and tap a fitting into it OR get another manifold OR look for #13 from an EML car OR use a T fitting to split the line into 2?

I am surprised this has not come up before in various b35 swap threads, I can't be the only person with the engine out of an automatic /eml car, can't imagine that.

[Garageaholic]

Just use a T-Fitting and splice into the one existing vacuum line that you have on the manifold.

[Jean]

I'll give that a try, hopefully it won't throw a red flag with CA BAR :)

[Jean]

Took the manifold off today, will get it drilled and tapped (heading out to R/C shops tomorrow to look for the right fitting) to look 100% oem since I plan on getting a sticker.

[5KWattson]

yea if your planning on gettin it reffed in you need to make it look OE as hell they are dicks, i have gone through bar a few times for BS tickets for missin hard ware cuz i had pulled off a broken piece of air intake boot before the filter, got a new one passed fine, im not sure why your takin it to bar though most cops coulnt tell the difference between a m20 and a m30 anyways, let along a cheap (not racist) mexican smog shop

[Jean]

Because I can't take it to any regular smog shop, 4 cyl car with a 6 cyl engine.

[JoeMadoo]

my n/a m30 passed the visual/functional part of the bar test fine but failed the emmissions badly :(

I think you'll be ok if you have a good cat and its running good.

[Jean]

Joe - since you are also in CA and passed the visual, how is your exhaust setup? Specifically what cat and downpipe/ cat to muffler configuration?

I am not sure if I am ok with running a 2 into 1 cat or if I must run 2 in 2 out etc...

[JoeMadoo]

I had the stock e32 manifolds and downpipes to a single 3" cat. I dont even think they looked under the car... But there was something wrong with my engine causing it to pollute more than usual.

[Jean]

So the cat was 2 in from the e32 manifolds/downpipes and then 1 out to the muffler?
Do you remember who makes the cat/model?

Thanks

[JoeMadoo]

I had a dual 2" to Single 3 splittler before the cat and its 3" all the way back. I dont think exhaust size alters emissions really at all, at least i dont think they do?

[White Nightmare]

Do it right and have it refed. Its not hard when everything is done correctly.

-Chris

[Jean]

That's the plan.