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What Exactly Is EFI Live, HP Tuners, UDC, or Other Custom Tuning?

After having a couple of conversations this week about custom tuning, I realized that there is much confusion on what exactly things like EFI Live, HP Tuners, and other tuning suites really are.  For the sake of this post, let’s assume we are mostly talking about diesel pickups but much of this applies to the gas world as well.  There are really a few different ways to tune a vehicle.  Let’s see if we can clear it all up.

All vehicle engine computers run on a programming that uses hex language.  It looks much like this:



It is a collection of values that the computer looks up in specific locations for the information about how to adjust the engine for things like timing, fuel quantity, or anything else it has control over it.  As you can see in the picture there is a string highlighted.  This highlighted group might very well be for something like how much fuel the engine is supposed to get at a certain throttle percentage.  If you had to adjust your engine’s parameters using this information as it is, you can see what a challenge it would be for most everyone. 

The first devices that came out to manage this information were regular programmers that we all know like Superchips, Diablosport, Edge, Bullydog, etc.  Their engineers use their in house programs to convert this to a form that they can read easier and then they build performance tunes to put in the programmers.  The programs are kind of a one size fits all approach because they do not take any vehicle modifications into account.  Some will allow you to select what intake you have or perhaps advance the timing slightly, but you really can’t adjust much yourself.  These programmers work well for a stockish truck.

The programmer companies would sell a tuning suite to dealers who wanted to adjust these programs for custom applications.  While they worked ok, the programs were a bit clunky and hard to use.  But it was better than nothing and lots of vehicles were tuned this way.  These programs were not something the average enthusiast would usually feel comfortable using.


EFI Life, HP Tuners, Sniper/Delta Force, Minotaur, and a few others have changed that.  They provide affordable tuning suites that are user friendly.  Their engineers have decoded the hex data and plug it into a software that we can look at that makes perfect sense.  We can adjust the parameters in units that relate to what would expect to see instead of odd two character values in strings.  For example here is a timing table from a Cummins diesel engine:



This table shows us how the computer looks up what value to use for timing.  On the left we have what rpm the engine is running.  Across the top axis we have what torque the engine is or should be producing. (This is calculated from other maps like this that take in account throttle position, boost, etc)  When the truck is running at 1500 rpm and producing a calculated 300 ft/lbs of torque, the computer will look this value up in the map and set the timing at -1.  As you can tell from the menu on the left side there are dozens of these maps that can and need to be adjusted.  You have the ability to adjust nearly any aspect of how your engine performs electronically.   I think most people understand this, but here is where it gets really confusing on several levels. 

First question is, why would we want to use this style of tuning over an off the shelf programmer like we talked about first?  There are a few reasons.  First and foremost, the calibrations in a custom tune are usually much better than a boxed generic tuner.  For example, take a look at this stock Cummins timing map:


Yikes.  If you are able to pull a read from a truck programmed with a generic programmer it doesn’t look too much different.  I won’t say all, but most seem to just adjust the timing tables for more timing in certain areas and do not clean it up.  A good timing table will end up looking something like this when a competent tuner finishes with it:


Which one do you think would run better?  Of course the second one will be a much smoother running and performing engine.  Is this a knock on the generic tuners?  Not really.  A good analogy might be between buying a pair of leather boots off the shelf or ordering them matched to your specific foot measurements.  The custom fitted boots will fit better, be more comfortable, and of course cost more.  If you never experienced the difference, you may be very happy with the off the shelf version.

What needs to be understood is that EFI Live or any of the tuning suites are just a tool.  They give you the ability to adjust the programming.  They are not programming itself.  We get many people coming in who want “to buy an EFI Live”.  They are confusing the generic tuners with a custom tuning suite.  When you buy “EFI Live”, you are buying the tool to adjust your computer's settings.  It would be like going into Home Depot, buying a bunch of tools, and then expecting a house to build itself.  After buying those tools, you still have to put in hours of work and a deep understanding of what you are doing.  It’s not very easy all.

To be honest there are tons of hacks out there who buy a tuning suite and “write tunes”.  While it is fairly easy with a little time to create a tune that can produce some horsepower, it takes a ton of work, knowledge, and dyno testing to produce a tune that is really good.  The great thing about the tuning suites is that a hobbyist can purchase it for a reasonable amount of money and start adjusting their vehicle.  There is nothing wrong with that at all and I encourage it.  It’s fun.  But be careful who you are buying programming from if buying tunes.  Again, just because your brother in law, friend, or guy you have a beer with has the tools, it doesn’t mean he is completely competent to build you a house with them.  So what do you do if you want custom tuning but don’t have the time or ability to learn tuning?


The device above is where I think many people get really confused.  These are called Autocals and are sold by EFI Live.  They are a smaller version of the V2 tuning suite device up above.  They allow a tuner to load them with custom tunes specific for your vehicle and then ship the device to you.   When you get it, you can use it very much like the generic tuners we first talked about.  You really don’t have to know anything about programming.  Just plug it in and load the program on your truck.  Very simple.  You get the ease of installation like the generic programmers with the great performance of a custom tune.  Win win.    


The Autocals above are from the respective tuners who buy them from EFI Live and apply their own decal for the front.  There is a gigantic difference between buying “EFI Live” and buying one of these Autocals from a reputable tuner.  The tuners above have spent many hours developing their tuning.  They are also a level above most users of the software as they will actually go in and edit the hex code to be able to adjust parameters that may not be available to the general public version.   When you buy programming from these tuners, you are not buying “EFI Live”, you are buying their tuning.  The EFI Live or HP Tuners is just the platform they used to create your tuning.  It will hands down be some of the best programming you have ever installed in your truck.   Again be careful, anyone with the tools can load tunes on an Autocal and sell them.  The ability of tuners varies greatly.

I hope this clears up exactly what EFI Live, HP Tuners, UDC, Sniper, or any of the other tuning suites truly are.  For about 50% of the truck owners out there, the generic box tuners work fine.  For about another 48%, they should be looking at buying some custom tunes already built for them.  It’s really the last two percent that should be purchasing the tuning suites to do the programming themselves.  Learning tuning is rewarding and fun, but takes a fair amount of time and understanding of how a vehicle and it’s systems function.  

If you have any questions at all on which tuning is right for your application, you can always give us a call or shoot us an email.  We would be glad to suggest a good solution for you.