Analogue Boost Gauge

[-nexus-]

I'm looking for ideas on where to place an analogue boost gauge in my M4C. Before anyone mentions it, I know about the Awron gauges (and similar) and I know they're great but:

1. I don't like digital gauges
2. I won't sacrifice any of the air vents

Does anyone have pics or has seen an analogue boost gauge on the M4?

[vkolp]

Originally Posted by -nexus-

I'm looking for ideas on where to place an analogue boost gauge in my M4C. Before anyone mentions it, I know about the Awron gauges (and similar) and I know they're great but:

1. I don't like digital gauges
2. I won't sacrifice any of the air vents

Does anyone have pics or has seen an analogue boost gauge on the M4?

https://www.kiesmotorsports.com/prod...33-f36-f80-f82

[b_w.]

This is my water meth controller but could do a boost gauge here

[NSX2M4]

Aside from the ones you mentioned and what others have posted, these are really the only other two that are non digital.
I just run Bimmerlink on my iPhone with a phone mount. Costs like 60 bucks total and is wireless.

https://www.turnermotorsport.com/p-3...UaAnTkEALw_wcB

https://www.evasivemotorsports.com/s...4aAn-kEALw_wcB

[-nexus-]

Originally Posted by vkolp

https://www.kiesmotorsports.com/prod...33-f36-f80-f82

I really like this one but my car is RHD and the site states it's for LHD only.

Originally Posted by b_w.

This is my water meth controller but could do a boost gauge here

Originally Posted by NSX2M4

Aside from the ones you mentioned and what others have posted, these are really the only other two that are non digital.
I just run Bimmerlink on my iPhone with a phone mount. Costs like 60 bucks total and is wireless.

https://www.turnermotorsport.com/p-3...UaAnTkEALw_wcB

https://www.evasivemotorsports.com/s...4aAn-kEALw_wcB

This area seems like it's most popular and that triple gauge pod looks nice. I'll have to think about this one as I'd prefer to keep that storage cubby, as well as have the gauge somewhere in my eyeline, so preferably on top of the dash or near the instruments.
The vent option I haven't seen before and might be a good compromise, thanks for sharing that.

[MineralWhiteF80]

You might be forced to do a standalone "dash cup" that double-sided tapes onto your dash somewhere.

I also want to bring up that the S55 engine does not pull a vacuum, so if you have an analog boost/vacuum gauge, you will only see boost values and not any vacuum since the throttle body plate always stays open a certain amount.

If you want a convenient place to tap into the system for your boost line, you can buy this plate that bolts between the intercooler and MAP sensor with a T fitting to put a hose on.
https://ind-distribution.com/product...metering-block

[-nexus-]

Originally Posted by MineralWhiteF80

You might be forced to do a standalone "dash cup" that double-sided tapes onto your dash somewhere.

I also want to bring up that the S55 engine does not pull a vacuum, so if you have an analog boost/vacuum gauge, you will only see boost values and not any vacuum since the throttle body plate always stays open a certain amount.

If you want a convenient place to tap into the system for your boost line, you can buy this plate that bolts between the intercooler and MAP sensor with a T fitting to put a hose on.
https://ind-distribution.com/product...metering-block

Thanks for that, that looks like a very neat and tidy solution to get the boost line tapped in.

I'm very confused though, how can it not go into vacuum? It shouldn't matter if the throttle body is always open a little (this is how it would be at idle anyway), and it would not be building any boost when off the gas. Coasting off throttle should always produce a vacuum, it would not be producing boost. Where did you get that information from? Happy to be corrected but this really doesn't sound right.

[b_w.]

One thing to be aware of with the boost tap is if you have an aftermarket tmic the screws may not be the same. Just make sure to source longer ones ahead of time.

[MineralWhiteF80]

Originally Posted by -nexus-

Thanks for that, that looks like a very neat and tidy solution to get the boost line tapped in.

I'm very confused though, how can it not go into vacuum? It shouldn't matter if the throttle body is always open a little (this is how it would be at idle anyway), and it would not be building any boost when off the gas. Coasting off throttle should always produce a vacuum, it would not be producing boost. Where did you get that information from? Happy to be corrected but this really doesn't sound right.

This is a very interesting topic. The Valvetronic system that the S55 engine uses does some amazing things. I've looked into this topic a lot and I still feel like I dont have a 100% grasp on how this engine works

edit: took me forever to find this- but here is S55 engine explanation: http://s3.bimmerfile.com.s3.amazonaw...S55-Engine.pdf The engine does have a "naturally aspirated" mode that can be activated (typically at idle?), which can create a vacuum for crankcase ventilation, but it not the primary operating scenario for the engine. During operation, the only part of system that has any vacuum is the intake pipes between air filter and turbo.

1. The S55 does not pull a vacuum.

• This is why you cannot hook up a traditional blow-off valve (HKS SSQV FTW) or external wastegate to the S55 engine without using a MAC solenoid and controller to open the BOV . The S55 does not even have a blow off valve installed and uses the Valvetronic to regulate excess boost pressure off throttle.

• Since the S55 engine does not make vacuum in the intake manifold (after throttle plate), there is an external air pump bolted to the side of the engine and connected by a drive chain to the crankshaft that creates the vacuum required for the brake booster (and also drives the high-pressure fuel pumps).

2. The S55 engine at idle and under off-throttle deceleration will show zero on the gauge (0psi boost/0 in.Hg). The turbos are always spinning and creating airflow through the engine and the valvetronic regulates how much air passes through the intake valves.

3. The throttle pedal does not control the throttle plate in the throttle body. The throttle plate is only there to help regulate air flow for many reasons. I've attached a screenshot of a datalog of my car. Pay attention to the teal line and light blue line. Notice how the throttle (accelerator) pedal stays at 100% yet the throttle (plate) opening is opening and closing at many different angles independently as engine RPM increases. You can see that when my boost pressure exceeds the boost target pressure, the throttle plate closes down a little bit to help regulate boost but the throttle pedal is still always at 100% (floored). Also, you will see the throttle plate never closes below 20% throttle, even when the throttle pedal is not being depressed at all (0% throttle).


PS: Have you ever seen that video of the N52 engine running and idling WITHOUT the intake manifold at all?