Tuning Q&A by Rob Finkle

The Mazdaspeed platform includes a large demographic. From drivers who just got their license to career engineers who personally help to understand the ecu coding.

Today, I will be answering some basic questions about ECU tuning. This will help to explain the benefits of tuning and sort out some jargon and acronyms used for some of the newer people to modding who may be interested in custom maps and tuning.

What is custom tuning/what does ECU remapping do?

Ecu remapping, a.k.a. tuning are terms used to describe the process of making changes to the instructions that a car’s brain (Engine Control Unit) follows.

Remapping / tuning alters the variables that control the way the car behaves under a variety of conditions, including startup, idle, part throttle and WOT (wide open throttle).

To “remap” a car, different platforms use different software to communicate and alter the directions the ecu follows in order to meet the tuner’s goals. The most dominant and reliable software for the Mazdaspeed platform is made by either COBB or Versatune.

Why would you want to tune your vehicle?

When Mazda engineers tuned the factory variables, they were concerned with many more goals than enthusiasts. The engineers at Mazda know that each of the Mazdaspeeds that leave their manufacturing plant will be used in a variety of weather conditions, under a variety of user demands, and must be repaired under warranty if parts prematurely fail. Mazda is also heavily concerned with emissions, gas mileage and tries to balance the stock map they create with performance and reliability.

The enthusiast usually sees performance as the most important goal, while weighting reliability, gas mileage and emissions much lower in terms of importance. If you want to maximize the performance of a car, especially a factory turbocharged vehicle, many “nannies” or electronic performance limitations need to be removed and overly conservative measures taken in a stock map can usually be maximized to make substantial gains in horsepower and torque.

Who should tune their vehicle?

This is an interesting question, because I think I share an opinion with many people familiar with Mazda’s stock mapping that both reliability and performance can be increased with a well thought out tune. In my opinion, if budget allows, anyone who owns a Mazdaspeed can benefit from a custom tune.

What gains can be expected?

While every car is different across the Mazdaspeed platform, in general, if the 93 octane gasoline in your area is of decent quality, a stock Mazdaspeed usually has about 240 hp / 260-280 tq at the wheels.  On an OTS (off the shelf map), cars with an upgraded fuel pump and common modifications usually make roughly 270 hp / 300 tq at the wheels.

• Custom tuned cars usually dyno in the area of 300 whp, 330-350 tq.
• Custom tuned cars running e85 usually make 320-330 whp and 350-375 wtq.

What is the benefit to a custom tune vs. a chip or power programmer?

Much like Mazda engineers, creators of maps included on custom programmers such as hypertech etc. are responsible for making maps that will run well in all weather conditions, at all altitudes and with many different combinations of hard part modifications. A custom tune on the other hand can take full advantage of every condition and every modification that the car will be subject to, as well as allow the owner of the tune to communicate with the tuner his wants.

Custom tuners on the Mazdaspeed platform can tune the car to perform and feel just about any way the owner wants. Boost onset, boost level, boost level per gear, engine idle speed and pedal feel all can be customized per the owner’s preference.

What are the adjustable parameters?

When utilizing the COBB Accessport or Versatune, just about every aspect of the driving experience can be customized.

At present, tuners have access to the necessary tables to customize idle speed, boost levels, drive-by-wire interpretation by the ECU, air fuel ratios, ignition, and variable valve timing… you name it, it likely can be altered from stock form.

Does it have an effect on your warranty/Hidden costs and drawbacks?

This is a fuzzy question in terms of the relationship to reliability and warranty. As discussed above, I’d argue that a well-tuned Mazdaspeed will be more reliable than one that is running the “canned” Mazda map due to the ability of the tuner to customize a map for driving style, altitude, etc., as well as fuel the car with a performance bias vs. fuel economy.

As far as the Mazda warranty is concerned, the tune is not usually the point of contention with Mazda, as most warranty rejection is due to installed hard parts (which can be uninstalled before dealer visits). In short, after returning the stock ROM onto the ecu, Cobb suggests that the Mazda techs can only tell the ecu has been reset if there are a limited number of miles put on the car since the last reflash.

If you are a Mazdaspeed enthusiast in search for more horsepower for your Mazdaspeed, a custom tune will provide excellent gains for your money.  Having had many factory turbocharged cars before my Mazdaspeed3, I believe that a custom tune is one of the best bangs for your-buck modification that can be done from a performance-per-dollar standpoint.

I’m forever on msf, so if you have questions, feel free to pm me. If I don’t know the answer, I’ll do my best to help you find it.

-Rob Finkle
Username rfinkle2 on Mazdaspeedforums.org