Throttle balancing meter

Using Arduino Project Guidance
1

Im thinking of making an arduino based throttle balancing meter for my 4 cylinder motorcycle.
I will need to measure vacuum in each throttle intake. The connection pipes for this are already in place so connection is simple but what kind of sensors are out there to use?

Also has anyone else made a similar system?

Cheers

2

Sounds like you need an absolute pressure sensor. Lots of those available. Which one you need depends on the actual level of the vacuum, so you first have to determine that part. The extra volume added by the pipes will influence your vacuum.

3

Hi,
If you google arduino inlet vacuum gauge

This pops up.

Looks like the PDF referenced is no longer available, but its a very informative thread.
Schematic;

I hope it helps... Tom.. :slight_smile:

4

Take a look at this post Built a digital carb sync - General Tech Talk - Venture Rider.
I have built two of these and they work great.
Don't try to use the GM sensors, they are cheap, but I found there accuracy to be pretty crappy.
The MPX sensors are not cheap,but sometimes you can find a pretty good deal on E-Bay.
The only other thing I changed was to use an lcd with a backpack to minimize the wiring.
For the power supply I used one of the cheap step down modules that you find online.

5

The cheap freely available BME280 sensors will measure accurately down to 0.3 atm. The main difficulty will be attaching a tube to the very tiny sensing hole.

Could be done.

Allan

6

allanhurst:
The cheap freely available BME280 sensors will measure accurately down to 0.3 atm. The main difficulty will be attaching a tube to the very tiny sensing hole.

Could be done.

Allan

I used some MPX's that were the same because I got them really cheap. I just machined a little hat with a nipple and carefully epoxied them to the sensor. Worked great.

7

All I ever used was an open ended glass tube ( fixed to graduated backboard) containing a loose fitting " armature/indicator".
Graduation is purely for indication on cross reference as it is the " matching vacuum" you are after rather than any actual measurement.
No Arduino required but if you wanted to it would be one place to start.

8

I've never done this, but , just for curiosity, roughly what is the inlet pressure of an IC engine at tickover?

Allan

9

Thanks folks. Lots of useful info.

As one reply mentioned, accurate vacuum reading is not so important as reading differences between cylinders.

I have mechanical meters but an arduino solution would be neater and can be on the bike permanently. Plus be a neat little device to fox the mechanics at my garage when the bike goes for its yearly service and MOT (uk vehicle safety check). Also as time goes by and my microcontroller skills increase I can integrate it into a more comprehensive bike system monitor. Changes in intake vacuum can be symptomsatic of valve wear and seeing changes could help anticipate service needs.