Virtual Dyno PRO

Review by eFreeware

If you spend your weekends under a hood, or you build engines for customers, Virtual Dyno PRO is the sort of app that earns a place on your phone. It takes the specifications of an engine and vehicle combination and works out what kind of performance you should expect from it, so you can try changes before you spend money on parts. That is the appeal: a way to answer "what if I fit this cam, this head, this blower?" without ordering anything first.

It has been on Google Play since July 2011 and picked up a 4.0 average from 109 ratings across more than 5,000 installs, which is a reasonable signal for a niche tool that asks you to type in real numbers rather than tap through a game. The developer's own framing is that this is a personal dyno package for Android, and that is exactly how I would treat it.

What it calculates from your specs

You enter details about a particular engine and vehicle combination, and the app works through the figures that follow from them. The output includes true compression, engine CFM, total horsepower, net horsepower, peak torque at a given RPM, quarter mile performance and 60 foot times, among other numbers. For anyone who has stared at a dyno sheet, that is a familiar set of measurements, and seeing them update as you change a spec is the core of the experience.

The comparison to a real dyno run matters here. A chassis dyno measures what an engine actually puts down on the day, with all the losses and conditions that involves. This app instead models the combination from its specifications, which means it can tell you what a build should do before it exists. The developer is upfront that the results are meant to be pessimistic rather than flattering, so that a quarter mile time it produces should be within reach of an experienced driver who knows the car.

That design choice shapes how I would read the numbers. A tool that flatters your build is fun for five minutes and useless afterwards; one that under-promises gives you something to aim at. The developer's stated intention is that you should be able to match or beat the figures, which is a more useful target than a best-case estimate.

Playing what-if with a build

The heart of the app is changing one thing at a time and watching the outcome move. Alter the cam, the compression, the induction, and the calculated power and drag strip figures shift accordingly. For someone planning a winter project, that is a cheap way to find out whether a combination is worth pursuing before any money changes hands. It is also a way to settle arguments, since you can run a friend's setup through the same process.

The developer says the app handles nitrous oxide kits along with turbochargers and superchargers, so forced induction and power adders are part of the calculation rather than something you have to approximate by hand. That widens the range of builds the app is useful for, from a mild street engine to something with a bottle in the trunk.

Not every variable can be modeled this way, and the developer acknowledges as much. Weather and track conditions can swing real results considerably, and altitude plays a part too. The app assumes an altitude of 900 feet and a pressure of 14.7, so keep that in mind if your track sits much higher or lower. Treat the output as a reference point for the combination, not a promise about a particular Saturday.

The engine database and sharing files

You do not have to start from a blank sheet. The app ships with a database of pre-defined engines that you can load, adjust to match your own combination, and then save back to the database for later. That is a sensible arrangement for anyone who works on more than one car, or who wants to keep a record of several versions of the same build without re-entering every figure.

Files can be saved to the internal SD card, and a build can be sent to someone else as a Virtual Dyno file so they can open it in their own copy of the app. There is also an option to email a printable vehicle report to any internet-connected computer, which is what I would reach for when a customer or a friend wants something they can hold rather than view on a screen. Machine shops and engine builders have used the desktop Pro version of this software since 1995, according to the developer, and the report is the part that fits that kind of working relationship.

What you need before you start

This is not an app you can use cold. You need to know the specifications of your engine and car, and those figures come from manuals and repair guides that most owners already have on a shelf. If the camshaft has been changed, you will need the cam card to enter the right numbers. Without real specifications, the calculations have nothing solid to work from.

The developer's point is that you do not need to be an engineer to use it, only to have the right figures to hand. The supplied engine database softens the entry point: pick a pre-defined engine, then adjust the values until they match what is actually in your car. That is a reasonable way to learn which inputs matter, since you can see how far a change moves the result.

On the hardware side, the app runs on Android 2.2 or higher and needs a screen resolution of 480x320 or more, with support for large tablets. The most recent update was in December 2023 and concerned screen resolution, with the developer rolling back to an earlier method while the problem is worked out. If you are installing on an unusual display, that is the one area I would keep an eye on.

Who gets the most from it

The clearest fit is someone who builds or modifies engines and wants to test a combination before committing to parts. That includes the professional trade the desktop version has served since the mid-nineties, and it includes the serious hobbyist with a project car and a folder of specifications. If you enjoy planning a build as much as driving it, the what-if loop is the whole point.

It also suits the person who gets asked for advice. Running a friend's combination through the app, or modeling a rival's setup if they are willing to share the details, is a natural use. The printable report makes that easier to hand over, and the shareable file means the other person can poke at the numbers themselves.

What it is not is a substitute for a dyno session or a day at the strip. It works from specifications rather than measurements, and the developer's own caution about weather, track and altitude applies. If you want a number for the engine that is in the car right now, a dyno will give you one; this app is for the engine you are thinking about building.

A $1.50 tool for planning a build

At $1.50 with no ads and no in-app purchases, the cost of trying Virtual Dyno PRO is small against the price of a single wrong part. The 4.0 average from 109 ratings suggests that most people who install it get something out of it, and the fact that it has been updated as recently as December 2023, more than twelve years after release, is a good sign for a paid tool of this age.

I would point it at engine builders, mechanics and committed enthusiasts who already know where to find their engine specifications and want to explore changes before buying anything. If you have no interest in the numbers behind an engine, there is nothing here for you.

What's new in version 1.6.3

2nd attempt to fix screen resolution. Rolled back to old method until the problem is solved.