How Brain Tuning WORKS...
We have been asked on a number of occasions why it is that WORKS
doesn’t offer a quick dyno based custom tune with our popular Brain
Flash products. The public perception seems to be that as good as the
Brain Flash already is, it would be even better if we were to custom
tune it to each individual customer’s car. In order to appreciate why
the WORKS Brain Flash doesn’t require, or in fact, benefit from, any
additional tuning, it is helpful to understand the following.
A common misconception is that there are extreme car-to-car to
variances in the EVO’s power delivery. While it is true that minor variances exist from one car to the next for all makes and models of cars, our analysis indicates that the more dramatic spread in power ratings seen in the EVO community are attributable to dyno-to-dyno variances caused by environmental effects (dyno setup, altitude, weather, fuel). The EVO’s ECU relies on many sensors to continually monitor air volume, air intake temperature, knock, coolant temperature, throttle position, fuel temperature, and other criteria that it uses to continually adjust the engine’s performance. We have seen slight variations in these sensor readings cause dramatic variations in performance on the dyno.
While WORKS uses a dyno in our ECU development program, it is only one
of several tools that goes into the creation of the Brain Flash. The
dyno is, by nature, an artificial environment. It attempts to provide
the tuner with the ability to simulate road conditions in a consistent
and repeatable manner without the usual hazards of attempting to tune
“on the fly” in traffic or on the track. However, as a simulation of
what happens out in the real world, the dyno has its shortcomings –
especially on a forced induction car with a large front mount
intercooler. On the dyno, we have yet to see a fan that can
sufficiently simulate the volume of air that cools the front-mount
intercooler at, say, 90 mph when an EVO is at speed on the open road.
As such, when the EVO is turning 90 mph on the dyno, the engine is calculating the cooling effect of air volume based on air flow that the car typically sees at 30 mph or less depending on the fan. In addition, the dyno fans do not feed in more air as the car gains speed on the dyno. Likewise, most cars in the real world are not driven at speed with their hoods wide open like on the dyno. Dinan Engineering, a leading BMW tuner, has observed the same in the development of their reflash programs for late model BMWs:
“By far the most significant criticism I have for many dyno facilities
is the use of fans that are simply too small for the job at hand. …
In addition, the intake air sensor will read substantially higher
temperatures than that seen on the road with proper airflow. This issue
is particularly important to address when testing high output cars like
the M5 or M3, and even more so on forced induction cars with
intercoolers as the heat exchanger is not able to cool as efficiently
because of the reduced air flow. The engine compartment is normally
flushed with air driving down the road, particularly at speed, cooling
the manifolds and other associated engine components. … In simpler
terms, accurate measurements can only be achieved when the dyno tests
are conducted in a manner that simulates the car driving down the road,
in as much as is possible. … Cars with intercooled forced induction
systems (superchargers or turbo chargers) provide an even bigger
challenge on the dyno. A separate fan must be employed in order to
sufficiently cool the intercooler. Thermal couples must be installed in
the inlet and outlet of the intercooler so that the temperature drop
seen on the road can be measured. Once the temperature drop has been
established, the fan speed must be adjusted until the same drop in
temperature is maintained on the dyno as that was measured on the
road." Dinan, Steve, Dynamometer Testing and the Modern BMW Engine, 2003 (full article at: http://www.dinancars.com ).
While a dyno tuning session is done at a single ambient temperature, at a single fixed altitude, at a set humidity, with a single tank of gas, by contrast, in the real world, cars are driven on both cool and hot days, at different altitudes, on dry and humid days, and with variances in the quality of gas from tank to tank. During data-logging, the data collected on the road often varies widely from the data collected on the dyno. This has proven to us the effects of the variance from the dyno to the road and even from dyno to dyno. The dyno provides us with an educated guess as to what the car will do on the road, but that’s about the extent of the importance we attribute to it. One of our customers who saw only 211 WHP at the dyno with his Brain Flash P1 the next day went through the quarter mile traps at the drag strip with a speed of a 105 mph (trap speed is used as a widely accepted indicator of a car’s acceleration power, and most EVOs generally run much slower trap speeds). Of course, the same situation can be reversed and a car can put down terrific numbers on the dyno and rarely repeat them in the real world. This exemplifies why WORKS tunes for the real world and limits our use of the dyno to providing a reference point as to what the Evo may or may not do on the road.
WORKS Engineers spend long and often tedious tuning sessions over many months developing the Brain Flash maps to ensure a level of consistency in performance that could not otherwise be achieved or, in fact, improved upon, by a handful of quick dyno runs. By developing the maps over a number of different cars, in a number of different real world environments and using different tanks of gas in the process, WORKS is able to tune a car to behave well in a wide range of conditions. WORKS has invested in very sophisticated and expensive data-logging equipment in addition to using the Mitsubishi MUT tool to allow us to capture and monitor every aspect of the EVO’s inner workings while it is being driven both on the street and on the track, including high speed romps as well as bumper-to-bumper traffic (when no moving air is hitting the face of the intercooler and it begins to heat soak) and everything in between. As such, data-logging is a critical ingredient in the creation of the internal mapping behind the Brain Flash.
Many have commented about Air/Fuel ratios. One question that many EVO owners have is what mixture is considered rich (safe but at the cost of some power) and what is considered lean (less safe but better for power)? Adding the confusion is the fact that respected tuners in the community are citing a fixed, static air/fuel ratio target (10/1, 11.5/1, 12/1, etc.) both in promoting their own products/tune and in critiquing competitors’ products. An important note is that most, if not all, of the numbers posted online for EVOs’ A/F ratios are pulled from dyno environments where A/F ratios are usually different than on-road conditions. With our calibrated wideband O2 sensor, A/F is adjusted at all loads and RPMs on the road where we spend the majority of our time tuning and our customers spend the majority of their time driving.
A tuner who promises to tailor a “custom tune” to your car is
essentially offering you the opportunity to make as much power as
possible based on the environment present during two or three pulls on
the dyno on a given day under a given set of conditions, usually in a
single gear (note: the mapping on the EVO is gear/load and RPM dependent so you can imagine how much accuracy a “custom tune” nets in a single gear). Even if the tuner were to invest days of time on the dyno, doing hundreds of pulls in every gear and at every speed (like we do, and a lot more, in creating the Brain Flash) the fact that the tuner hasn’t attempted to repeat the results seen on the dyno in real world conditions would draw into question the accuracy of the tune.
Our goal is to design EVOs that generate consistent performance
every day under every condition for years on end. Our Brain Flash
products are proven to provide consistent results. Finding power that
is "left on the table" is merely finding a spot in the timing and/or
fuel maps that has not been pushed to the limit. The problem with
taking advantage of this hidden performance is what happens when this
portion of the map is used in a less-than-optimal environmental condition. If you are concerned about safety, it is much better to have a margin than to take every bit that remains and ride the car to its very edge. This is a threshold WORKS is not interested in crossing. If we could have each customer’s EVO for a few weeks of dyno tuning, road tuning, and data-logging, then we could offer an unrivaled “custom tuned” ECU program. This amount of tuning is simply not feasible for most tuners, and certainly not within the short window of time offered to customers in a typical group "dyno day" environment. You can hit a big peak on a dyno for a particular moment or you can make consistent power for years to come, the choice is yours.
-- WORKS Team