Which Engine Management Should You Use In Your Honda

One of the most controversial subjects in the Honda community is ‘which ECU should I use in my car’. This question litters car groups daily, and it’s full of either answers from people with no experience and watching youtube channels or people with non-running cars trying to validate their choice of computer.

In this article, I’m going to attempt to shed light on which ECU is right for your build, and the conditions by which you should be judging with platform is right for you.

First and foremost:If you have no desire to learn how to tune, and only want a car delivered, and done. The hard and fast rule is and will always be: find a tuner first and use their recommended ECU they’re most comfortable and experienced with.

Searching for a tuner AFTER buying a computer is a much more difficult task and results in sub-standard results due to necessity.

This article will be primarily aimed at people interested in learning to tune their car, or are wanting to be ‘dangerous’ in regards to knowing enough to play around with settings.How should I be judging the offerings?

A lot of people get hung up on features and never really ask the question about how it works in actuality. Hondata S300 has most of the same features as most modern computers, but to say they work at the same level would be ridiculous. Today, in 2024, there are plenty of key features you should expect from a modern computer, and I’ll break those down below.

1.) Volumetric Efficiency Fuel Tuning

First to understand VE tuning, we need to understand what ‘Injection Timing Based’ fueling is. Injection timing tuning is the old school way of tuning fuel, in which the tuner commands the exact time (aka pulse width) of the injector with no calculation computer side. This is a simple, rudimentary way to tune fuel, and has been the case for over a decade. Injection Timing’s simplicity is both a pro and a con, but in today’s era, it’s mostly a con.

VE tuning should be the bare minimum to start from.

Above is a picture of a Fueltech fuel map using fuel injection timing based tuning. Notice the map is ever increasing to increase pulse-width as load goes up to 60psi.

What is VE Tuning?

In the picture above we see a tuned 900HP K20 Map in VE. Notice how it goes flat and does not increase beyond 15psi all the way to 50psi.

VE is the most modern fueling strategy used on pretty much every standalone ECU. It’s tuning fuel by telling the engine how much air is in the engine at any given time by using known factors like engine displacement, fuel pressure, fuel type, injector sizing, and fuel pressure, the ecu calculates the correct pulse width to hit the target air:fuel ratio. 

The biggest advantage to this fuel model is that it has inherent safeties built in like injector pressure differential, it’s markedly easier to tune, and it allows you to change fuel parts/fuel types without retuning the car.

Where is this beneficial? If I have a car I’m going to be steadily upgrading over years, I don’t want to have to pay for a dyno when I change my injectors to bigger injectors, when i change fuel pressures, or when I change fuel types. In a traditional, injection timing based computer, any of these changes would necessitate a complete retune of the fuel map. Furthermore, because fuel pressure is an inherent part of the fuel calculation in a VE model, the ecu can account for fuel pressure drops and changes pro-actively rather than leaning on the reactive O2 Control system found in all computers nowadays. 

In the picture above, you can see as fuel pressure demand goes up (blue line) and actual fuel pressure drops (red line), the ecu keeps Air/fuel in check saving this customer's engine. Car was targeting 11:1 AFR and was still on target +/- 1% even with almost no fuel pressure.

When talking about the ease of VE tuning, it’s markedly easier than tuning a fuel injection timing ecu. With experience, a tuner can figure out what pulse widths should be where in general on an older stye fueling model. With VE, it’s a known constant that low load/idle a car will want around 40-60% VE, and at WOT, the car will run at 100-120% VE. Because these are known constants, constructing a base fuel map for a VE map that runs close to target is extremely easy. 

VE also naturally has boost compensations built into the table. This means that when a car reaches ~1bar (14.5psi) of boost, typically, the VE table will run flat after that, meaning you can copy your fuel curve at 15psi all the way to max boost and fueling will be on target barring any problems with back pressure or fuel pressure in the system.

Lastly, almost all standalone ECUs nowadays are VE-based. If your end goal is to learn to tune more than just your car and to learn a multitude of systems, starting from a VE ECU puts you at a tremendous advantage. If you were to start from a fuel injection timing computer, you would have to relearn how to tune VE from scratch. So it’s beneficial to start with VE first. Another advantage to a VE-based computer is that most have the option to run injection timing if that’s what your heart desires. The same does not occur the other way around.

2.) Features

Determining which features apply to your build is certainly a personal choice, but there are several key features that separate higher end computers from lower end computers. In general, most ecus will have everything a ‘street car needs’. These are all more important in regards to utilizing the power of the hardware appropriately.a.) Closed Loop Controls

-Closed loop o2 control and closed loop boost control should be standard on any modern computer. Closed loop controls are important as they allow the computer to make onthe fly adjustments and keep everything in line. Without closed loop controls, you’re shooting in the dark.

b.) Engine Protection Features

There are certain guarantees with building performance cars, and one of the absolute certain ones is that something is going to fail eventually. It’s imperative that you’re ready for when the time strikes. Look for an ECU with extensive engine protection setups and functions. The Haltech Elite system for example offers 3 programmable levels of severity for their engine protection strategy allowing you to simply richen up the air:fuel mixture all the way to shutting the engine off before something completely catastrophic happens.

c.) Inputs/Outputs

You need to make sure the ECU has enough Inputs/outputs to support your goals. In general, most ECUs have enough, you really only run into limited input/output issues on the lower end/entry level computers like an Elite 550 or Fueltech FT450.

d.) Customizability/Power

This is a hard one to articulate, but I would be looking for words like ‘4D Tables’ and the ability to change axises on maps. Having the ability to custom define your axis value is an enormous asset to being able to build customized solutions for your car. For me personally 4D tables are a huge seller.

e.) Accessory Ecosystem

Most ECU companies will have their own ecosystem of parts like coils, widebands, screens, etc. Make sure the accessory ecosystem fits your needs. Companies like Haltech have extensive accessories available and are compatible with most generic sensors.

f.) PnP Support

If you want the easiest solution to start your car and run, looking for MANUFACTURER backed PnP Support is huge. ECUs like Fueltech are a generic standalone ecu with no plug and play data nor adapters available from Fueltech themselves. In this regard, you’ll need to purchase an aftermarket adapter, you’ll need to know the pins for the adapter from the aftermarket manufacturer, and you’ll have to spend time calibrating. Furthermore, specifically on the Fueltech, many people have had issues getting the factory trigger system to work without consulting 3rd parties for settings and advice. ECUs like Haltech, Link, Motec, and ECUMasters have basemaps ready for honda platforms that simply require you to upload from the software and go. This can save you hours of frustration trying to start the car for the first time.

In the picture above, we see the included PnP data for K series triggers from the supplied basemap. There's also a drop down that allows you to change your car trigger type to any of the defauls supported platforms or having the ability to custom define a custom trigger setup.

My personal recommendation (and why):

My personal recommendation for anyone wanting to learn how to tune in 2024 is to start with a Haltech system. 

My reasons in particular have been outlined above, but to give a more definitive answer: the haltech is as easy or as hard as you want to make it which makes it extremely versatile for anyone wanting to learn. You get the huge benefits of VE and the ability to change every axis on every table as well as define custom tables, sensors, outputs, inputs, conditionals, etc. The amount of creativity the ecu allows for is enormous. Where other computers are walled gardens in terms of being able to change and manipulate features the way you need them to operate, haltech encourages you to experiment and try something new. 

Disregarding the power of the software side, the ultimate reason is ‘it just works’. You plug in the computer, you upload the supplied basemap, make changes as necessary, and the car is running within 15-30 minutes. There is no configuring every single individual sensor because the ecu didn’t come with the sensors pre-defined. There is no trying to hunt down who made your aftermarket adapter harness because they didn’t supply a pinout. There is no joining a group or asking a more experienced user what their trigger settings are because you cant even get your computer to recognize the 4+1 cam position sensor. The haltech comes with most sensors used in every build pre-defined for you that you can load in at any time. You’re able to use the injector selector and have injector data ready to go in minutes. The trigger settings are in the basemaps or in the drop down ready to go.

The picture above shows the true power of the haltech system using 4D tables. You can see we have our boost target pressure table scaled by Undriven Wheel Speed x Race Time x Fuel Comp. This allows the customer to have the car ready to race no matter what fuel type is in the car with no need to open a laptop.

For me, it’s a no brainer, but if you shop for computers armed with the information and what to look for, you can now make an informed decision.