Engine RPM

Name: Engine RPM
Price: 8.99 USD
Rating: 4 (35 reviews)
Author: Real-Time Specialties

Acoustic Tachometer

Only for iPhone

$8.99

35 Ratings
Age Rating

4+
Years
Category

Utilities
Developer

Real-Time Specialties
Language

EN
English
Size

3.3
MB

iPhone

Measure the RPM of an engine by analyzing the sound it makes. Engine RPM listens to the sound of a running engine and uses advanced signal processing algorithms to extract the frequency of that sound and calculate the RPM. This app is primarily for setup and diagnostics of engines. After setting the the number of cylinders and whether the engine is a 2-stroke or 4-stroke engine, the app can work with any internal combustion engine, from diesel tractors to aircraft engines to motorcycles to chainsaws. To use the app you must set an expected RPM range to guide the analysis algorithms to the correct RPM. A real-time graph of the autocorrelation graph is displayed to help in troubleshooting and adjusting the expected RPM range. The analysis requires a clear sound from the engine without excessive interference from extraneous sounds. Do not expect to read the RPM of an engine while other things are making too much noise at the same time. The analysis also requires that the RPM be stable. It cannot read the RPM of an engine that is rapidly accelerating. For this reason, and because of the need for adjusting the expected RPM range, this app should not be considered a drop-in replacement for an operational tachometer. Setup options include update periods from 93 milliseconds to 1.5 seconds, one to 12 cylinders, 2-stroke or 4-stroke, low-pass filtering, and signal clipping. The overall RPM range is 400 to 90,000 RPM (although at any one time, the operational range is typically +/- 30% around a nominal expected RPM). Precision is usually about +/- 10 RPM.

Ratings & Reviews

4.0

out of 5

35 Ratings

Expensive and complicated but it works....
08/19/2018
EJTVDY
1- Read all the help pages beforehand; it’ll take you about 5-10 minutes but well worth it. 2- I used to set idle on a 2 stroke fuel injected motorcycle where the idle is critical: too high and the bike runs too lean, too low and it bogs down in low RPM starts. 3- At first I had it set up to sample every 3 seconds. That was too long. So I cut to 3/4 of a second and it was less of a hassle. I was able to guesstimate the current RPM’s at 1500, (actual was closer to 1700), so I set up the software that way, kept making small adjustments on idle screw untilI got it just right. 4- Logging the RPMs and times was a nice feature. 5- to get a 5 star price needs to come down materially or ease of use must improve significantly. Overall I’m happy with this given the alternatives.
Expensive and complicated but it works....
08/19/2018
EJTVDY

1- Read all the help pages beforehand; it’ll take you about 5-10 minutes but well worth it. 2- I used to set idle on a 2 stroke fuel injected motorcycle where the idle is critical: too high and the bike runs too lean, too low and it bogs down in low RPM starts. 3- At first I had it set up to sample every 3 seconds. That was too long. So I cut to 3/4 of a second and it was less of a hassle. I was able to guesstimate the current RPM’s at 1500, (actual was closer to 1700), so I set up the software that way, kept making small adjustments on idle screw untilI got it just right. 4- Logging the RPMs and times was a nice feature. 5- to get a 5 star price needs to come down materially or ease of use must improve significantly. Overall I’m happy with this given the alternatives.
Great concept. Great execution. Great price!
03/27/2023
Rein’s Small Engine
The Tiny Tach tachometer I’ve been using in my small engine work wasn’t extremely expensive, but it’s finicky and difficult to use when I’m tuning something like a chainsaw. This app, after a couple minutes glossing over the instructions, was almost intuitive to get to function. It will be really nice to be able to set this down and have both hands free to operate the throttle and adjust carburetor settings on equipment now. Large, easy to see display and controls plus other features I haven’t even gotten to will make my work SO much easier! Thanks guys, for all your hard work. I’m totally happy with the price!
Great concept. Great execution. Great price!
03/27/2023
Rein’s Small Engine

The Tiny Tach tachometer I’ve been using in my small engine work wasn’t extremely expensive, but it’s finicky and difficult to use when I’m tuning something like a chainsaw. This app, after a couple minutes glossing over the instructions, was almost intuitive to get to function. It will be really nice to be able to set this down and have both hands free to operate the throttle and adjust carburetor settings on equipment now. Large, easy to see display and controls plus other features I haven’t even gotten to will make my work SO much easier! Thanks guys, for all your hard work. I’m totally happy with the price!
Pricey but works good.
11/03/2019
blade1693
This was a little more expensive that I would have liked but once I used it I would say it’s defiantly useful. Used it to check low and high speed of my lawnmowers and it’s right on. Just slide around the hint rpm as it’s running and it finds the speed right away. It’s also cool that you can also see the audio waveform. The app doesn’t look to fancy but as long as it keeps working with future iOS updates I’ll be happy.
Pricey but works good.
11/03/2019
blade1693

This was a little more expensive that I would have liked but once I used it I would say it’s defiantly useful. Used it to check low and high speed of my lawnmowers and it’s right on. Just slide around the hint rpm as it’s running and it finds the speed right away. It’s also cool that you can also see the audio waveform. The app doesn’t look to fancy but as long as it keeps working with future iOS updates I’ll be happy.
Got my snowblower working
01/03/2021
MichiKyle
Was able to dial in my snowblower RPMs no problem. I do think the app should have the cycle/number of cylinders option right on the Home Screen, I think that would help out. Also, would be nice if it had good enough response times to react to transient surges, really it’s only useful for steady RPM values. But overall, did what I needed for much cheaper than a small engine tach.
Got my snowblower working
01/03/2021
MichiKyle

Was able to dial in my snowblower RPMs no problem. I do think the app should have the cycle/number of cylinders option right on the Home Screen, I think that would help out. Also, would be nice if it had good enough response times to react to transient surges, really it’s only useful for steady RPM values. But overall, did what I needed for much cheaper than a small engine tach.

1. The app is updated to target iOS 26 requirements. 2. The colors of the engine type selection page are changed to enhance clarity. 3. Size of log of RPM readings is doubled from 512 to 1024. 4. Minimum logging interval lowered from 2 seconds to 1 second.

Version 2.6 Sep 12

Data Not Collected

The developer does not collect any data from this app.

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Accessibility

Information

Seller: Real-Time Specialties, inc.
Size: 3.3 MB
Category: Utilities
Compatibility: Requires iOS 13.0 or later.

iPhone
Requires iOS 13.0 or later.

iPod touch
Requires iOS 13.0 or later.

Apple Vision
Requires visionOS 1.0 or later.
Languages: English
Age Rating: 4+

4+

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