Driving normally my Scan Gauge II reads -0.7 BST
Anyone else read negative boost on any of your gauges.
This is normal right?

 

That's normal. It's also why some people think a boost gauge is not very useful because it usually reads zero (or vacuum) unless your really into the throttle.

Personally I like'm :thumbsup

 

Like he said above that is normal. It's called vacuum, you'll see some vacuum at cold idle and in between shifts w/ boost.

 

You're only going to read boost when the turbo is spooled up and producing boost. Not sure how anyone thinks a boost/vac gauge properly showing vac when out of boost could deem it "not very useful" cerenkov?? It's showing exactly what the conditions are. Doing it's job properly.

 

I could have worded it better. I'll try again...When people are installing actual physical gauges in the car and only have room for maybe two gauges, other parameters might be more ?important? (read: very subjective) like coolant temp or oil pressure/temp, etc. I understand that the OP is using a multifunction device so it doesn't pertain to him directly. I was just making an observation.

Also I believe that I said the gauge was working properly.

Like I said above, I personally like boost gauges and when I use DashCommand the skin I display has boost, IAT and coolant temp.

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Gotcha. I'm still baffled by MINI/BMW's blatant disregard for any gauges that just about every car on the road has anymore. It's like they assume their buyers are mindless "wives" who know nothing about the car and just think "when it's too late, we'll throw a light on and hope they know enough to pull over".

So with all that said, the main screen on my Torque app shows coolant temp, IAT, Boost. The unavailability of oil pressure annoys me still, but coolant temp in itself is a gauge I can't, for the life of me, understand why they would ever exclude from the stock cluster.

 

Psh think that's bad....new BMWs don't even have dip sticks anymore!

 

I just read that elsewhere too, but you know our dipsticks are horrible anyway. When you have to consult the owners manual on how to read a dipstick, there's something wrong. I still don't know if I'm reading it correctly!

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Now... I've been a BMW fanatic for quite some time now. And I always laugh at all the oddball, quirky things they do. Most of them are fun to make fun of. Like having a warning light for every single thing on the car, because apparently a lot of wives buy BMW's? :P

But please PLEASE tell me you're joking about not being able to keep tally on your oil. I'm sure there's SOMETHING.

 

Yea, when the light comes on haha......or if you have I-Drive, the computer tells you the oil level.

You can also use the stock to toggle between settings to check on the dash.

They're not thinking with their dip stick Jimmy! Hahahaha. :P

 

vacuum is very useful, you'll know if you have a boost leak that way or a hose popped off..... closer to 0 it reads the less the manifold has of vacuum, that it SHOULD have.

 

N14 and N18 are different. As mentioned above, the N18 only shows vacuum when cold. Once it warms up the throttle plate opens and the VANOS system controls the intake. The N18 will be right around 0 psi most of the time, it only boosts when you're on the throttle hard. I see this both on my boost gauge and data logging with the Torque app.

 

VANOS is the bmw equivelant of variable valve timing isn't it? What would be the point for it to keep vacuum as close to zero as possible?

 

Here is a good example while setting at idle.

 

Just curious... The boost gauge,when its at idle, is it rock steady or does it wiggle a bit ?

 

It does wiggle just slightly.

 

Your RPM is constantly fluctuating as is your vacuum ever so slightly. You don't see it on your tach because a buffer is built into the computer so it shows a smooth, steady number.

 

Yes it is the BMW variable valve timing and lift system.

The point of variable intake valve lift is to eliminate the pumping loss at low RPM caused by the partially opened throttle plate. Intake manifold vacuum is the engine sucking against that restricion - intake valve open, piston going down, and throttle plate closed or partially open. Opening the throttle plate all the way and managing air intake with variable valve lift eliminates the loss and results in very low vacuum. This applies whether the engine is turbo/supercharged or not.

One hypermiling technique for cars with a throttle body is to accelerate using top gear to keep RPMs low and WOT to eliminate the pumping loss, of course this only works with a manual transmission.

 

You can damp out the wiggle in the boost gauge by stuffing a little bit of cotton into the tubing just before the input to the gauge.

 

I am on dash command too and eaven if I'm on hard driving I only get negetive boost

 

@Bnourai so you obviously have a boost leak ... do you read boost through the ECU , or do you have a boost tap and read it via vacuum ..

 

Wow man I am so far off on replying only 4 month lol.no boost tap it is via ecu.
Ben

 

 

Soooo, my 2013 S has been reading -0.7 BST at normal idle for 6 years. This week it started showing 0.0 or 0.1 at idle. At full throttle, instead of peaking around 14 it goes to 16. Would this be the boost sensor? If so, is it the one on the intake?