Category Archives: Tuning

Stratified Tunes, and Tuning Results and Discussions

E85 Blends in the Mazda DISI and Ford EcoBoost

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This is a topic that is very active among automotive enthusiasts and is also relevant to the work we do in the Stratified office. If you do not already know this from experience then you must know: Knock (also known as pinging or incorrectly referred to as pre-ignition/pre-detonation) is a major limiting factor to safely increasing the power output of your motor. Knock occurs after the spark event begins combustion and is the spontaneous combustion of the remaining combustion mixture. Ideally once spark has occurred the intake charge will burn in a smooth manner outwards from the spark plug until the flame front is finally quenched by the cool cylinder walls. When knock occurs your engine experiences a sharp rise in pressure and temperature. If severe knock is occurring at high loads, it may lead to engine damage. Due to this we are limited in how much boost and timing we can safely run. An in depth analysis of knock is a topic for another discussion but it is important that you know of it’s existence and the limitation it imposes on performance. Every motor will eventually knock (with enough compression, timing, boost, etc), however, the goal is to use a fuel that safely and consistently supports your desired power output.

So knock is bad, what can we do about it?

Aside from cooling your intake charge via a bigger intercooler, water-meth injection, or a cold air intake, increasing your fuel’s octane rating is the best way to push your motor’s knock threshold up. High octane fuels are less likely to auto-ignite which is what makes them better for high performance applications. E85 has an octane rating that is much higher than the 93 octane most premium gasoline fuels provide. The octane increase benefits from E85 are applicable to any motor. Running 100% E85 is possible in vehicles where the fuel systems are built for E85 (Flex-Fuel vehicles) and where the fuel system can deliver larger volumes of fuel than what is needed with regular gasoline fuels. This is due to E85’s increased oxygen content and lower energy density. On the Mazdaspeed DISI as well as the Ford EcoBoost motors we do not readily have larger direct injection injectors and the fuel pumps are not designed to handle straight E85. Because of this we blend E85 with premium pump gasoline to achieve a mixture that is both compatible with the OEM fuel system while delivering higher octane. We have seen excellent results from an overall mixture of E30. This mixture is accomplished by mixing premium fuel (which usually contains 10% E85) with E85. The mixture should be 25% E85 by volume to net an overall mixture of around E30 (this is due to the premium fuel’s ethanol content).

Okay, ethanol is great, what kind of gains does it provide?

The gains we see from running ethanol blends in the EcoBoost and DISI motors will vary from case to case, however, they are always significant. The performance gains from an ethanol blended fuel will change depending on the base fuel used and modifications installed. For vehicles running the OEM turbo (K03 Ford, K04 Mazda) the average gains are on the order of 25 WHP and 25 WTQ for the Mazdaspeed DISI motors and 20 WHP and 20 WTQ in the Ford EcoBoost motors when going from a pump gas to E85 tune. If your vehicle has a bigger turbo then it will really shine with an E85 tune. As the airflow increases and temperatures start to climb the added ethanol really works to bring down cylinder temperatures and help keep knock away. Below are a few graphs which highlight the differences between E85 and gasoline tunes.The gains we see in these graphs come from the increased timing and boost we can push thanks to ethanol’s higher octane and increased cooling properties. In order to see these types of gains it is necessary to get a tune which is designed for ethanol blends.

The graph below is a comparison performed in warm weather on a stock Focus ST. The blue line is a pull using straight 91 pump gas and the red is a pull with an overall E30 mixture. Although the gains in the graph below are more extreme than what we normally see due to the high temperatures and poor 91 octane fuel, they do show the increased potential of E85.

Image 1: Stratified 91 Vs Stratified E85 Tune on a Hot Day

Here is another comparison; this time performed on our shop Focus ST while it was bone stock aside from a tune. The difference here (ignore the big torque peak at the beginning) is that the base fuel was of high quality and the pulls were performed in cooler weather (both things are advantageous to the straight gas tune).

Image 2: Stratified 92 Octane Tune VS Stratified E85 Tune On a Cool Day

Finally, here is a comparison on a Mazdaspeed3 vehicle. Again we are comparing 91 octane to an E30 mixture. The results here are quite typical of E85 blends on a strong running Mazdaspeed3.

Image 3: Mazdaspeed3 91 Octane Vs E85 Blend

So how do I get tuned for an E85 blend? 

Compared to gasoline, ethanol has a richer oxygen content, different specific gravity, and other subtleties which do not work well with tunes which are based on gasoline fuels. Ethanol’s increased oxygen content requires a much richer stoichiometric air fuel ratio than gasoline. What this means is that you must put in more ethanol (by volume) per unit mass of air in order to reach a stoichiometric mixture (lambda = 1). In most instances (given an OEM or similar sized turbo) this increased flow is supported by the OEM fuel system (the MazdaSpeed does need upgraded HPFP internals). In big turbo cars where power levels are reaching the 400 WHP / 400 WTQ range fueling will become an issue in both the Mazdaspeed and Focus ST motors. When working near these power levels on bigger turbos, the E85 mixture has to be done carefully such that there is enough fueling headroom left to maximize power on the OEM fuel system. Remember that achieving the most performance requires the correct mix of boost, timing, and fueling. Once you have surpassed the capabilities of the OEM direct injection system, there are aftermarket options to increase fueling such as methanol injections systems, additional port injectors (5th / 6th port fuel injection) and hopefully larger DI fuel injectors in the future. Feel free to discuss these build options with us if you’re preparing for a big power build and tune.

Whether you drive a Mazda or Ford, we offer tunes that support ethanol blends for both cars. If you own a Ford, you can go for either a full custom tune or Stratified E85 Flash Tune for your ethanol tuning needs. For Mazdaspeed DISI motors we also offer both full custom tunes as well as Stratified E85 Flash Tunes which accommodate ethanol blended fuels. Regardless of the vehicle you drive the differences between gasoline and E85 make it necessary to get a tune designated for E85 blends. A lot of our customers opt to have maps for both gasoline pump fuel as well as E85 blends and switch/re-flash between these depending on the fuel they have in the tank.

We hope this clarifies a little bit more how E85 is used in these vehicles and its benefits. If you have further questions feel free to Contact Us!

The Stratified Team

Launch Control, Flat Foot Shift, Primary Rev Limiter

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We get a lot of questions regarding the Launch Control (LC) and Flat Foot Shift (FFS) functionality on the Ford Focus as well as Mazdaspeed vehicles. Hopefully this article can clear some of the ambiguities.

The Ford Focus ST and Mazdaspeed vehicles feature 3 fuel cut rev limiters. The primary rev limit is the same as that which comes from the factory and is designed to prevent your engine from over-rev damage. The LC and FFS limiters are interconnected via a speed threshold. Below the speed threshold (typically 6 MPH) the LC limiter is activated and above the threshold the FFS limiter switches on when both the clutch and accelerator are depressed at the same time.

1. Primary Rev Limit: This is the maximum allowable engine speed. This limiter is generally set at 6700 RPM for the MazdaSpeed vehicles and 7200 for the Focus ST. It can be changed from these values if need be and this can be discussed with your tuner.

2. Launch Control: When activated this limiter is always on at speeds below the LC/FFS threshold, it works by holding the engine at your predetermined RPM via a fuel cut. Where you set launch control will affect how much wheel spin you get off the line. Most of our customers set this between 2500 – 4000 RPM. Focus ST customers with map switching have the luxury of selecting up to four different LC settings. If you are unsure where to set LC we recommend setting the values at least 250RPM apart. Typical Focus ST LC settings are something like this: 2,750, 3,000, 3,250, 3,500. To test if LC is activated simply put your foot to the floor with the car in neutral/with the clutch depressed and below 6 MPH, the engine will hold at your predetermined RPM.

3. Flat Foot Shift: When activated this limiter is always on at speeds above the LC/FFS threshold. To use FFS simply keep your foot floored to the next gear shift point. Without lifting your foot step on the clutch, the revs will drop to the FFS limiter value as you select the next gear. Next drop the clutch with your accelerator still floored. Simple as that.

How to activate these limiters:

Once you’ve received and installed your map there is nothing you need to do to activate these limiters. They are always ready and waiting for you to use them.

Focus ST: When you purchase your S-OTS+ map you will be sent a link to an online tuning form. Use this form to tell us whether you would like LC/FFS activated and, if you do, where you would like them to be set. If you have purchased a custom tune then you can let your tuner know either in the preliminary custom tuning form or via email directly.

Mazdaspeed: COBB has an excellent online utility which allows you to change the LC and FFS settings on locked maps. Follow this link to the COBB website. If you purchased a custom tune then you can let your tuner know via email or the preliminary custom tuning form where you would like FFS and LC set.

Here’s a video of Braden at COBB demonstrating LC, FFS, and map switching on a Focus ST.

Load Based Versus Boost Based Tuning

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This is a question we receive almost weekly and we want to clarify the differences as well as the pros and cons to each methodology. To explain these two tuning techniques we will have to first fully understand load and boost and then analyse the pros/cons of the two techniques.

LOAD: Load can be thought of as the amount of air entering your engine at a certain engine speed. Load is an approximation of your motor’s torque output calculated using the the amount of airflow entering the motor, engine RPM, and a scaling constant. The amount of airflow entering the motor (measured in grams/second or pounds/minute) is measured either directly using a Mass Airflow Sensor (MAF) or calculated using a Manifold Absolute Pressure Sensor (MAP).

By looking at load we have a much more realistic idea of how much torque the engine is producing regardless of turbocharger used, temperatures, and altitude. This is the most important difference between load and boost. While a car making 20psi of boost at 3000 RPM on one turbocharger will make a different amount of power to a car making 20psi at the same engine speed on a different turbocharger; a car making 2.0 load at 3000 RPM will make the same amount of power as another car making 2.0 load at the same RPM (given that the loads are calculated accurately). Because of this important distinction load based tunes are able to provide much more consistent torque across all operating conditions resulting in consistent and reliable vehicle operation. What you will see is that the ECU will vary the boost pressure to target the same load/torque depending on ambient conditions. In hotter weather the ECU will target more boost due to the lower air density and in cooler weather it will command less boost thanks to higher air density. To prevent too much boost in very hot conditions for example, our load based tunes do cap boost at a reasonable level.

A graphical representation below shows the torque and horsepower curves of a MazdaSpeed3 vehicle. Underneath, the load and mass air flow readings from the same car are displayed. Notice how the curves look similar in shape. Indeed load correlates to torque output and mass air flow correlates to horsepower output.

Notice how the calculated load curve matches the torque curve and the measured air flow mimics horsepower.

BOOST: Your vehicle’s MAP sensor measures the absolute pressure in your intake manifold. Boost is the measure of pressure above atmospheric pressure in your intake manifold and is usually shown in Pounds per Square Inch (psi). Boost based tuning is the old school way of tuning boosted vehicles as it is an easy way of knowing what the turbo is doing. However, the mass flow rate of air as well as the amount of oxygen entering your engine at a certain boost pressure vary greatly with ambient temperature, humidity, altitude, intake, turbo used, etc. When temperatures are cooler and you are at a low altitude the ambient air has a much higher density and thus richer oxygen content than air at high altitudes and high temperatures. Because of this a boost based tune will have higher torque in the winter than it will in the summer. Our boost based tunes target boost pressures but can also put a cap on loads for engine safety.

Now that we understand the two concepts the question still remains, which is better?

Although load based tunes maintain fairly constant torque in different ambient conditions, the motor’s ability to produce torque changes. A vehicle which is targeting 2.0 load at 3,000 RPM may demand a boost pressure in the region of 20 psi during the hottest summer day. The same car will require less boost to achieve this load figure during the dead of winter since the air density is greater – let’s say it will be somewhere in the region of 15 psi (still at 3,000 RPM). Although the motor’s torque output will remain fairly constant between the two situations the end user is sometimes surprised when they see their car is suddenly making only 15 pounds of boost. In addition, since the motor has the ability to target higher load values during the winter some feel that the car’s performance is not being maximized (although now we start to worry about connecting rods).

A boost based tune which is done in the summer can have much different results than a low boost figure. Imagine a vehicle which was tuned in the summer and was able to carry 20psi of boost without knocking. This vehicle’s tune will target 20 psi no matter what the ambient conditions may be. So, as the temperatures start to drop and air density goes up, the car will be making more and more power at that 20 psi boost figure. This increases the torque output but also puts more strain on the connecting rods and fuel octane being used due to higher cylinder pressures.

OEM tunes target loads because they want to deliver consistent output year-round (the rated engine output). Because of this the control system has nice features such as load by gear which enhances traction and driveability. While we can switch to a boost targeting strategy, some of these driveaibility enhancing features can’t be used as effectively.

We, at Stratified, choose load based tunes based on their reliability, driveability and the consistent torque delivery which is virtually independent of ambient conditions in the majority of cases. However, some cars and setups are better suited for boost-targeting tunes than others and if we know the user’s goals from the get-go we can choose a strategy that suits them best. Some of these include:

– Cars using E85 or very high octane fuel where knock is not much of an issue.
– Cars with built motors that want to maximize power output all the time and are not worried about damage/breaking components.
– AWD cars that don’t need torque by gear output limitations.
– Cars/people that want to get the absolute maximum power from their setup all the time with less concern for driveability or long term reliability.

Hope this makes the distinction between load based tuning and boost based tuning a little clearer and helps you choose the right strategy for your car. Just like with everything else, choose the tuning method best suited for you and your vehicle.

 

How to perform a compression test on a Ford Focus ST

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Compression tests are a very important tool in assessing your motor’s overall health. An especially convenient time to do this is when you are checking your car’s spark plugs. It’s also good to get a baseline compression test before adding parts or tuning the ST. A weak compression test result is something to be investigated further as it can be an indication of a mechanical failure (worn rings, poorly sealing valves, etc.)

On the Focus ST checking your compression is quite straightforward:

Step One – Prepare for testing:

Preparing your Ford Focus ST for compression testing could not be any easier. First drive the car so that it is decently warm. Park it and carefully pull off the coil packs and remove all four spark plugs.

Step Two – Install the Compression Tester:

You can purchase a number of compression testers and they range in price and quality. Some of the very low quality ones can give poor or erratic readings. So if you get abnormal readings on an engine running well, then it is worth trying another tester. The compression tester simply screws into your spark plug hole. Make sure the O-ring makes contact with the cylinder head in order to prevent a false low compression reading.

Step Three – Test Your Compression:

To do this you simply push both the accelerator and the clutch all the way down. Once the clutch and accelerator are depressed press the start/stop button to begin the cranking process. Wait until you’ve heard about 15 cranks of the motor then press the start/stop button again to stop the process. Keeping the accelerator down the entire time prevents the injectors from firing while testing compression. If you have a friend helping; have them watch the gauge – ideally you want to crank until the needle stops moving up.

Make sure that you allow the same cranking duration for all four cylinders to allow for consistent readings.

Interpreting the Results:

Compression numbers will vary slightly from motor to motor but for a healthy internally stock ST motor expect around 160-170 psi (~11 bar) at sea level on a mild day.

The altitude and internal engine changes (pistons, cams, etc.) will affect compression readings. With altitude, the higher you go in altitude the lower the compression will read and this is perfectly normal. Multiply sea level numbers by the table below corresponding to your altitude to get what you should expect if you are testing at higher altitudes. For example a healthy ST motor with 160psi compression at sea level will have a compression of (160*0.8617) around 138psi.

  • 1000′ = .9711
  • 2000′ = .9428
  • 3000′ = .9151
  • 4000′ = .8881
  • 5000′ = .8617
  • 6000′ = .8359
  • 7000′ = .8106
  • 8000′ = .7860

Another indicator of a healthy motor is that the compression is fairly even across all cylinders. The rule of thumb is that all cylinders should be within +/-10% of each other.

If you suspect there is a problem and repeated compression tests indicate this, you will likely have other running issues such as oil consumption, fouled plugs, misfiring, etc. The compression test can identify the problem cylinder and you can then investigate further. The next step would be a leakdown test to show you where the compression is escaping (past the rings or past the valves). This requires more equipment so the beauty of the compression test is that it is quick and inexpensive with minimal tools needed.

Record the readings in order and keep the records to track the health of the motor and catch any issues if they show up later down the road.

Happy Testing,

The Stratified Team

Spark Plug Tech

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We here at Stratified are often asked what are the best plugs to run in our modified cars. The answer to this question depends largely on the primary use of the vehicle, and the extent to which it has been modified.

TL;DR: Buy your NGK LTR7IX-11 plugs on our website HERE.

When changing spark plugs in your vehicle there are two things to consider:

1. The spark plug gap:

This is the easier of the two considerations; for the Ford Ecoboost engine found in the Focus / Fiesta ST as well as the DISI in the Mazdaspeed vehicles we always recommend a plug gap of 0.025 – 0.026″. It is important that the plug be properly gapped or else the car will miss fire under boost/load. A larger gap produces a larger, hotter, spark which helps increase combustion efficiency, however, the larger the gap the harder it is for the ignition system to send a spark across the gap. This is especially evident in the Ecoboost and Mazdaspeed motors which run high boost levels and sparking resistance increases with increased cylinder pressure. Conversely, if the plug gap is too small then the spark created may be too small/weak to properly ignite the combustion mixture.

Most plugs for the Ford ST and Mazdaspeed vehicles come with a gap that is larger than our recommended 0.025 – 0.026″, thus it is necessary to lessen the plug gap. When checking your gap it is important to use proper feeler gauges; you’ll know you’re at the right gap when the feeler passes through the gap with minimal resistance. When closing your plug gap it is important that you do not push up against the plug’s centre electrode as it is easy to damage. The recommended gaping procedure is to tap the ground electrode against a hard surface such as a vice or sturdy shop table several times and then to recheck the gap. You will quickly get the hang of this.

The proper tool to measure your plug gap:

Tap the ground strap down gently checking the remaining gap often:

When the feeler gauge passes through without catching you know you’re at the right gap:

The spark plug gap will generally widen as the spark plug is used. This is due to the erosion of the ground strap but also due to the strap experiencing heating and cooling cycles. If you start to experience misfires and it’s not time for a plug change yet, pull the plugs out to check and re-adjust the gap as necessary.

2. The spark plug heat range:

This is where your modifications, and primary use of the vehicle come into play. Cold plugs are better for highly modified engines, while hotter plugs are more reliable on a daily driven vehicle. If you primarily use your vehicle for low speed daily driving or allow it to idle for extended periods of time, then a cold plug may foul. If you race your vehicle or repeatedly expose your engine to sustained high loads then a hot plug may cause pre-ignition which often results in a melted piston.

Now you may be wondering to yourself “What does the heat range even represent?” A common misconception is that a hotter plug produces a hotter spark; this is not true. The heat range boils down to how much heat the plug dissipates into the cylinder head. The pictures below provide a good representation of the spark plug heat range:

As you will notice, the hotter plug has a much longer portion of the insulator nose exposed to the combustion chamber. This longer nose goes hand in hand with a reduced surface area for the heat transfer. Since hotter plugs leave less area for this heat transfer to occur the firing end will get much hotter. This reduced heat transfer is necessary when your vehicle is driven slowly or often idled for long periods of time as it helps keep the spark plug at optimal operating temperature (which prevents fouling).  However, if the plug chosen is too hot then the insulator tip may become overheated during spirited driving. Once the insulator tip reaches temperatures of around 800C (1470F) it can (will) act as a pre-ignition source (think of a glow plug on diesels) lighting the mixture long before the ECU initiates the ignition event. Pre-ignition is the silent killer of engines; once it occurs there is no sound (knock sensor does not become triggered), there is no warning, only melted pistons/plugs. Due to advancements in engine design pre-ignition is not very common in modern street vehicles.

On the other hand, if the plug selected is too cold then the insulator will never be able to reach its self-cleaning temperature of around 450C (840F) and carbon deposits will start to accumulate on the insulator nose, leading to a fouled plug. Fouled plugs will misfire causing a loss in power and fuel economy. Furthermore, the built up carbon on a fouled plug could start to ember as insulator tip temperatures begin to rise during spirited driving (for example going to a track day, or a canyon run). This embering carbon build up is again an ideal pre-ignition heat source. As you can see going both too cold and too hot can be detrimental.

Another consideration with the heat ranges is cold starting. A plug that is of a colder heat range may have a harder time starting your vehicle when the temperatures start to drop.

Keep in mind that if you are having any doubts about your spark plug health it is possible to “read” your plugs. The appearance of the firing end can tell you a lot about your plug’s operating temperatures as well as the health of your engine. Below is a graphic showing what it is you need to look for. If you are running a colder than OEM plug and it is carbon fouled then you should return to the OEM heat range. If you manage to overheat a plug and haven’t killed your engine then we recommend going at least a step colder.

Another way to check whether the plug’s heat range is correct for your motor is to check the annealing point on the ground strap. If the heat range is correct the annealing line should be around the beginning of the ground strap bend. If the annealing is occurring too close to the electrode then you know that your plug is too cold. If the annealing occurs far down the ground strap bend then the plug is too hot. Here are a couple of pictures of some healthy OEM plugs with around 3,000 miles on them from the Stratified Focus ST development car that were replaced with a step colder plug along with the downpipe, intercooler, and intake (and some tuning of course!). Notice how the colour of the ground strap starts to change right at the beginning of the bend; looks like Ford did their homework!

In conclusion, too cold or too hot of a plug is detrimental. There is a misconception that a plug will cause knock and this is generally not the case. If a plug is to do long term damage, it is pre-ignition and that is not picked up by any knock sensor but also dangerous and thankfully, fairly rare on both the MazdaSpeed and Focus ST/Ecoboost platforms.

For the DISI motors we recommend running a spark plug that is one step colder than OEM. Generally the Mazdaspeed motors do not like running plugs that are two steps colder than OEM unless very heavily modified. Cars that are running higher compression, large amounts of boost, or are often tracked / driven aggressively for extended periods of time may at times require a plug that is two steps colder than OEM (for example have an extra set of colder plugs for track days).

For the Ford Ecoboost we still recommend a plug that is one step colder than OEM for mildy bolted cars especially since 21+psi of boost is quite common. For highly modified cars that see a lot of heat it is advisable to try a plug which is two steps colder than OEM. The Ecoboost motors seem to be able to manage colder plugs better than the Mazdaspeed motors.

For both the MazdaSpeed DISI and Ford EcoBoost the recommended plugs are either the NGK LTR7IX-11 or Denso ITV-22.

Remember to not forget to change the plugs when worn and to not overtorque them when installing.

Happy Tuning,

The Stratified Team

Photo Credits:

Heat Ranges and plug conditions – NGK TECH 

Hot Vs Cold Plugs – Hot’N’Cold