So, after going through several threads and plenty of pages of discussion over the last week, I think most of us are of the opinion that the N18 is quite a bit different in the vac/boost department sensor-wise.

After dealing with all of the issues with my boost tap (and then finding out it's not only me having issues), I foolishly ordered a BSH tap for my 2011 not realizing that the N18 no longer has the PCV hose needed for that installation.

Obviously, the boost tap @ the MAP sensor failed miserably for me, and again - that seems normal for N18 users.

So... does anyone have an idea for where to grab a solid vac/boost reading for a mechanical gauge? If not, I'll have to just move to Aeroforce and be done with it.

 

Has the option to drill / tap of the cold-side hard boost pipe come to mind?
That would be a viable option as it's easy to source a direct replacement as a spare to modify.

- Erik

 

Hmm... Hadn't thought of that yet. That should supply a vacuum pressure in addition to the boost, correct?

I'll look at the ETK to see the pipe you're talking about. Then, see how much it costs to buy a replacement!



Which number are you talking about on the left side for reference? Around 7, or around 4? EDIT: Scratch that - the R60 has no noisemaker.

 

Just got under the hood again and saw that there's another MAP sensor on the cold pipe. Plunked the boost tap that I had on there, and it fits fine (along with the MAP sensor).

I'm going to test it and report back tonight.

 

Sadly, this was no better than the intake manifold MAP port. Same behavior - measuring boost but no vacuum.

This darned N18 is screaming for 2 seperate guages for vac and boost!

 

Is that your only concern, ...vacuum?
Both the N14 and N18 *barely* pull any vacuum to begin with based on the engine design.
That's why there's a vacuum pump for the brake system as the engine doesn't have enough draw, especially with Valvetronic.

- Erik

 

Well, I wouldn't say 'barely'. We're talking about 22-26Hg of vacuum created which is certainly enough to keep an eye one with a boost/vac gauge.

The boost isn't a huge problem, but it's great to see both in case of a vac leak, etc.

 

Yeah I can't get any vaccum out of my gauge either only for a split second on cold starts

 

Good to know. It's just an N18 thing, then.

Don't think there is a place to monitor both after checking places for several weeks now. Oh well...

 

Why not just use a Scangauge2 and monitor the OBD2 data?

 

That crossed my mind. I've used Aeroforce Interceptors on every can in the last 8 years, but you just can't beat the speed and instant readability of a mechanical gauge for boost.

 

Theta,

Achillies's car has the same issue and hes got an n18... this is something that isnt a problem but a work around will have to be found.

 

Yup. For right now, we can still read either boost or vacuum. So all is not lost - at least we know it's an N18 thing now.

 

Wait, the N18 uses Valvetronic to set idle instead of the throttle body valve.
If so, that could be why you won't see vacuum readings in the intake system?

- Erik

 

I discovered this as well theta, blue fox is right. N18 uses valvetronic control to set idle.

 

Yep, must choose one reading or another - can't have 'em both ways.

 

+1. I think you can set your boost refresh on the AF Interceptor as fast as 20 Hz on a Gen 2 MINI. Not quite mechanical analog speedy, but pretty much within the time a human can react to the information. Plus, the install is so easy and non-intrusive. Biggest shortfall IMHO is the lack of amber gauge lighting analogous to the OEM instruments.

 

Sorry to bring this back up but was anything found as far as this goes?

 

Erm... yes - in that you can read either boost or vac - but not both on a single gauge.

For boost, just use a standard boost tap @ the MAP sensor.

Best of luck!

 

So has anyone tried this with the NM tap? I'm trying out the MAP sensor in post #4 but the stock sensor is too long to fit into the NM tap. Did anyone else have this problem?

 

Just use the main tap point - it should fit fine.

 

The main tap point as in the image in post #4? The sensor is definitely too long to fit in the hole. It gets to the green O-ring then it won't go in further, it's not that I'm just not pushing hard enough.

If I line up the sensor to the outside of the tap, the sensor is about 1/16" longer than the tap itself.

 

That is not the main tap point - that was just an auxiliary we were trying.

The main MAP sensor point is at the rear of the engine near the middle. That's the point everybody uses, and the manufacturers design for.

 

Ok, so it's supposed to go on the intake manifold MAP port? I can get boost but no vacuum off of that then.

It'll be here? Under the airbox?

 

Yep - exactly!

That's the crummy part about the N18 - I think I was one of the first people to mess with this on the N18, and got all confused in the mean time. The N18 makes you choose - monitor vacuum with tapping into the vac line, or measure boost from the MAP sensor. Either/or.

Or, I guess you could have a pure boost sensor and a pure vac sensor... Kind of a lot of clutter, though!