The MazdaSpeed Synapse BPV/BOV

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The OEM MazdaSpeed Bypass Valve/BPV  is well suited for up to 18-20psi of boost. Past this point it starts to leak air and torque drops off even if boost is maintained above 20psi. All big turbo cars should upgrade their BPVs. On some cars even the stock K04 turbo is hindered by a leaking OEM valve. The Synapse Valve is the fastest BPV on the market and you can run it as a BOV as well using our Guardian Angel. For this reason we started to carry it right here in our store.
This Synapse valve won’t leak even up to 60psi of boost and the fast response means excellent driveability as well as fast spool and excellent re-spool between shifts. Our BPV of choice for the MazdaSpeed.
If you want more information on why an upgraded BPV is important read our tech article here.

Stratified Tunes Handle Extreme Conditions

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We often see the dyno as the best place to test and tune a car – but a lot of the time it doesn’t represent the real world very well. Two areas where dynos fall short is in the cooling department (airflow across the intercooler and radiator can’t be replicated with most fans sitting in front of the car) and in how they load the car. Often the car is loaded too little or too much compared to what it sees on the road.

This can skew the results of the dyno tests and put the car under a lot more stress than you would side on the road.

This gives you a unique opportunity to REALLY see how the tune performs under a fairly extreme stress test. I build adaptive protection into all our Stratified tunes because even though most cars don’t experience what you’re about to see; some do on the track or dyno and the last thing we want is a blown up motor. The behaviour of the tune when stress tested like this is where you really get to see the quality of the tune. And this kind of protection is built into all our tunes, from Flash Tunes to the full custom tunes.

This car has very few modifications and I had no idea how the dyno facility was setup or cooled. Nor did I know that they were going to do 3 4th gear pulls back to back or I would have advised against this kind of torture. However, they did, and the graphs below are the results.

Mods:

2013 Focus ST

Cobb filter in stock intake box
Cobb Downpipe (catted)
Muffler delete
Stratified Tune – In Progress

knock prone 91 octane fuel and no other additives.

As you can see the charge air temperature peaked at 212 degrees! The ignition corrections remained mild from pull to pull and the car STILL made consistent power. Customer drove off the dyno and home with no drama not even knowing the kind of stress test his car just experienced.

Name: Extreme Test dyno results.pngViews: 4Size: 950.5 KB

Understanding knock and ignition corrections in your Ecoboost powered Ford

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All engines knock! Ok, now that that’s out of the way :). Knock or detonation is a phenomenon where the combustion process does not start at the spark plug and propagate completely smoothly pushing the piston down. Instead, there are several small flame fronts that usually appear at the edges of the main flame front during the power stroke. These smaller uncontrolled explosions cause pressure spikes in the combustion chamber. High enough pressure spikes for a long duration can cause damage so naturally we want to avoid high intensity knock in our Ecoboost cars … but not completely eliminate  knock … Let me explain why. Or … just jump to the end of the article for a quick list of what to look for.

ford-ecoboost-2-3-knock-detection

Modern cars such as the one above have well tuned “microphones” called knock sensors that pick up on these sounds and react very quickly to stop detonation when it starts. The 4 cylinder Ecoboost has two of these little guys:

When the ECU detects knock it reduces ignition timing advance. Back in the day when the knock sensor technology was not advanced engines knocked all day long without immediately blowing up. You could hear them pinging going up hills. These days, we push small engines to make a lot more power and we realize that maximum power is made right at the knock threshold. Another way to say it is that we want to keep the engine RIGHT at the edge of knock and the modern ECU in the Ecoboost does exactly this through some smart programming.

The ECU always listens to the knock sensors and knows which cylinder is knocking while it keeps adding timing. Once it starts to hear knock it reduces ignition timing on a cylinder by cylinder basis and eventually it learns an ignition trim that scales the entire ignition table up or down depending on how much knock it picks up. This trim is called the OAR – the Octane Adjust Ratio. Over time, the closer this value is to -1, the more timing the ECU is adding to the base timing table since the fuel is good and it is not picking up much knock. The closer it is to +1, the more knock the ECU is picking up meaning either the octane you are using is poor or the tune is too aggressive or both. So having a peek at your OAR using a logging tool such as the COBB AccessPort ever so often will give you an idea of the fuel quality and how the tune is behaving. ***Keep in mind that the tuner has the ability to adjust how the OAR parameter learns so in some cars OAR will sit at one value and in others it will move around more. If you have concerns, bring it to their attention.***

Using a logging tool such as the COBB AccessPort during a wide open throttle (WOT) run can give you further insight. After datalogging such a run you can look at two parameters to get a good idea of how the tune and fuel are performing. These parameters are knock count for each cylinder (how many times the particular cylinder knocked) and knock intensity for each cylinder (how much timing was pulled during each count – called Ign Corr.) When ignition correction is adding timing, that means no knock is heard by the ECU. When it is pulling it back in a step down fashion, it has done so because it heard knock in that one cylinder.

Keep in mind that the way the ECU reacts to knock is tunable. Some tuners will have the ECU pull a good amount of timing when the severity is higher while others are more aggressive. We like to stop knock the first time we hear it so in Stratified tunes the ignition corrections are larger so that knock does not continue happening in that cylinder.

This is something to discuss with your particular tuner. Once you get familiar with what you’re seeing in datalogs you will know what is and isn’t normal. It is also important to choose a tuner that is experienced with the ECU and how it adjusts timing to get the most from this feature without risking the safety of the motor.

In terms of knock counts – remember that when it’s not knocking the ECU is adding timing until it knocks or until it reaches a ceiling for amount of timing added. Because of this, you are likely to get some knock counts during a pull if the tune is built to maximize performance.

Ideally the tune is setup such that knock event intensity is low and that the tune adds timing in a way that doesn’t cause a lot of sudden knock. It’s normal to see the ECU add a little timing and take some away. What you don’t want to see is very large, multiple, and continuous negative ignition corrections.

Let me give you an example. Below are the knock counts on a 4th gear pull for cylinders 1-4. This tells you that some knock has happened during the pull but it doesn’t tell you anything about how severe/intense it was. This is incomplete information. You can see here that Cyl1 knocked 3 times, Cyl2 knocked 3 times, Cyl3 knocked 4 times, and Cyl 4 knocked only once. ecoboost-knock-counts-explained-stratified

To complete the information here are the cylinder ignition corrections for the same pull. As you can see below Cylinder 1 has 3 knock events labelled on the image. The most severe correction was around -1.0 degrees of timing on cylinder 1 and right away that cylinder added more timing and didn’t knock again. You can also see that each cylinder walks ignition up a little, then steps down when it reaches knock. Finally, you can see all the cylinders are well balanced. There isn’t one cylinder that is significantly better or worse than another one. The tune on this car is running well and it is fine tuned for the vehicle’s modifications and fuel.

ecoboost-ignition-correction-explained-stratified

Also note that there will be differences from pull to pull and this is again normal. Always take a couple of pulls to make sure the data is consistent.

Here is a tune that needs attention or the car is using poor quality fuel. You can see that all the cylinders move into the negative ignition correction zone and some with larger steps meaning that the ECU is picking up knock and lowering timing. Also notice that the ECU pulls timing to avoid knock (a step drop in correction); but the engine knocks again (several more steps down). You can also see that they are not recovering like the graph above (not many steps upwards)

Focus ST ecoboost too much knock ignition correction

Here’s a summary on what to keep an eye on. Keep in mind that looking at min/max ign corr. values does not tell you the whole story. Looking at a datalog of a full RPM sweep and looking at knock counts together with the ign corr value. tells you the information you need:

  • Do ignition drops happen regularly at the same RPM and is it consistent at that RPM and boost?
  • The car ADDS timing unless it hears knock. When knocks is heard you will see a DROP in ignition correction. This drop can make ignition correction negative or it can stay positive depending on what the starting value is. If ign corr. is at +3 and there is knock event, it can drop to +1 for example. If it is at 0, it can drop to -2. The knock that it heard is actually the same, the size of the drop tells you how intense the knock event was. The larger the drop, the more intense the knock.
  • Every time you see a drop, it means knock was detected and the ECU dropped timing to protect the engine.
  • Stratified tunes tend to drop ignition timing quite a bit when knock is detected the first time. This is to prevent further knock in the pull and to keep the engine safer. Always look for the NUMBER of drops, (knock counts) not just the Ign Corr. Value.
  • Multiple drops in ignition correction at the same RPM and across multiple cylinders likely mean that you may need the tune touched up or need to use better quality fuel. We can do this remotely for you using your datalogs.

This car does not instantly blow up when it experiences some knock. Far from it. However if you see consistent knock, either higher octane fuel is needed or the tune should be adjusted.

Happy Tuning,

The Stratified Team

Low-Speed Pre-Ignition in the MazdaSpeed DISI and Ford EcoBoost Motors

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Having had a MazdaSpeed3 from 2008 and having been involved with the platform for so many years, one of the most common question that I’ve received – especially in the early days – was why do engines blow on the highway? I went as far as having a collection of broken parts from blown engines all over the country just to see how they failed.

This was a new phenomenon and we saw lots of cars that were bone stock blow up – especially with the first generation MS3 and MS6.

It turns out the Mazda was a pioneer back in 2005-06 when it introduced the DISI – one of the first direct injected spark ignited motors on the market.

Recently (since about 2010-11) the tGDI (turbo gas direct injected) engine has become common so it has received a lot more attention. As more money was spent in downsizing and increasing power output the failure mechanisms in these motors started to become more clear.

And these failures line up exactly with what we are seeing with the DISI.

The root cause is a phenomenon called Low Speed Pre-Ignition (LSPI).

LSPI, which results in Superknock, is auto-ignition before the spark but not early enough to melt the piston. It happens close to the spark event and causes massive knock afterwards. Damaging knock.

The other interesting fact about LSPI is that it happens at low engine speeds and high loads which is a common condition when passing on the highway, for example. Below is a graphic showing the knock in the cylinder just after LSPI occurred:

LSPI is hardest on the rods and pistons in the motor. The rods tend to fail first, and the second ringland follows. This is exactly what we have seen in the MazdaSpeed DISI. Further, most people that lose their motors on the highway or have high knock events on the highway speak about a cloud of black smoke. This is also caused by an LSPI event. From the SAE paper 2011-01-0342:

“From exhaust emission and exhaust port air/fuel ratio measurements it was also recognized that a spike in HC emissions and a significant increase in Lambda (air/fuel ratio enrichment) was associated with LSPI”

Now why does this happen?

There are a number of factors but the biggest are:
– Carbon deposits on pistons and valves, oil fumes, poor quality fuel
– High loads at low RPM
– Valve overlap, EGR

All the causes are still not known. This is still a heavily researched area.

A more complete list below:

 

The OEMs have learned a lot since the DISI. Take the Ford Ecoboost for example, it doesn’t toss rods like the DISI did. However we have seen it damage pistons and ringlands from the same LSPI phenomenon numerous times. The EcoBoost is an evolution of the DISI using the lessons learned from the early days of tGDI engines.

So what can be done to prevent this condition?

– Don’t operate at high loads and low RPM (Instead of loading the motor at a low RPM, downshift into a lower gear)
– Use quality fuel and lubricants (lots of research going on in this area currently)
– A good tune
– Good intercooling (the TMIC really doesn’t help here on the Mazda), WMI if available
– Good operation of the PCV system, clean intake and valves
– Step colder plugs to prevent hot spots
– Keep oil consumption down – use a thicker oil if needed

The manufacturers have greatly improved piston, injector and combustion design since the DISI. You can even see that Mazda redesigned the pistons in the Gen2 (after 2010) and LSPI was less common on the newer cars because fuel was not washing down the walls of the cylinder as much.

Using common sense can keep the DISI together for many miles, but determining WHY cars blew on the highway has been a very interesting journey for me and it feels like the root cause is finally becoming clearer.

Keep in mind that there is never a single variable that will make a motor come apart and every motor will behave slightly differently. This is good because you can attack different areas of your build to prevent LSPI and superknock. Below is a good summary showing some of the engine parameters and their effect on triggering LSPI.

Not all engines fail due to LSPI. The rods do buckle at certain torque levels and knock can be damaging at higher engine speeds, not just at low speeds. However that strange phenomenon with engines letting go on the highway very much lines up with LSPI being a failure mode in DISI engines.

The images are from a good presentation at the link below. There is a lot of SAE literation on the topic if you’d like to learn more about it.

http://www.ukintpress-conferences.co…_Alewjinse.pdf

EcoBoost Focus ST Water Methanol Injection (WMI) Install Review and Results

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Now that we’ve fully completed the installation and optimization of our Water Meth Injection (WMI) system we thought we’d share with you some of the details of the WMI install and tune on our shop Focus ST.

Below is a full list of the modifications we’ve installed so far:
ATP GTX2867 Bolt-on Turbo Kit 0.64 A/R
Catted COBB turbo-back exhaust
Tial Q BPV on CPE METHCharge cold side pipe
CPE Front Mount Intercooler
Stock intake and airbox with COBB filter
Coolingmist Auto-Learn WMI system, 7 Gal/Hr nozzle, 50/50 Water-Methanol mix
92 Octane base fuel

In stock form the biggest power output limitations in the car are airflow, fuel quality, and fuel volume delivered. The stock turbo was swapped out for a GTX2867r on our vehicle to address the airflow problem.

After this the OEM high pressure fuel pump (HPFP) starts to struggle past 360 ft-lbs of torque when using premium pump fuel. The octane limitation of pump fuel itself generally limits power output north of 350hp to the wheels on the 2.0 Ecoboost. To address the octane limitation and fuel pressure drops, the Coolingmist WMI system was used.

WMI has the following advantages:

– It cools down the air charge allowing more ignition timing advance.
– It provides very high octane alcohol (methanol) which increases the fuel octane. The additional alcohol fuel also takes some strain off the OEM fuel system.
– The WMI system helps keep the valves clean in direct injected engines
– The WMI system is only used when needed under high boost meaning the methanol tank won’t need to be constantly filled up.

Adding the WMI system provided around 10% additional fueling with the 7 Gal/Hr nozzle and 50/50 mix. We selected the Coolingmist Auto-learn system which has a built in failsafe. The failsafe system was able to detect our tank running dry as well as a leak that developed at one of the hose fittings.

You can see videos we took of the install here:

Part 1: Under the car

Part 2: Under the hood

Part 3: Inside the car

Results: 

First of all, I should preface that we are very meticulous when taking Virtual Dyno logs to give results that are repeatable and therefore trustworthy. This is very important – you have to trust the data to be able to make sense of it.

The first graph below shows the finalized tune for WMI. The torque curve is very flat from 3000 RPM to redline and the car simply hauls.

Two forth gear pulls in our ATP GTX2867 powered Focus ST after installing WMI.

Below is a comparison showing the gains we made by tuning the ECU to take advantage of the WMI system.

A Virtual Dyno comparison before and after the WMI system was installed.

You can see how the top end benefited the most from the addition of WMI. We were able to safely add timing as well as increase the boost and at the same time keep the pistons nice and happy (no knock). This is what a proper power curve should look like on any car. Our Focus ST now has a flat torque curve with over 300 ft-lbs of torque available at the wheels, from 3,000 RPM right to redline. Notice how linear the horsepower curve is with the maximum power being right near redline.

Now, why no 400whp you ask? There are 2 parts of the car currently holding it back that last 10-15whp. The first is the stock intake which necks down quite a bit just before it joins the coupler on the GTX turbo inlet. The second is the catalytic converter on our COBB downpipe. At 400whp the catalytic converter is easily worth 15-20whp. With these two items swapped out we will be able to get more boost out of the turbo which will take it to 400+whp. The 385-390whp result you see above is done at only 25psi tapering down to 23.5psi. Given that the Focus is used as a daily driver the first upgrade will be the intake. For the intake the plan is to fabricate something that will fit nicely with the GTX turbo inlet. There is something to be said about the OEM intake that  that is that you would never expect this engine bay to be that of a 390whp car.

Although our big turbo Focus ST is making nearly 400 WHP you would never be able to tell by looking under the hood.

Finally, I can’t stress enough how much fun it is to have a flat torque curve and perfectly straight horsepower curve. The car is extremely flexible and just doesn’t stop pulling to redline. With relatively minimal mods and a solid tune this little EcoBoost motor really does deliver. A WMI system is very much a worthwhile modification if you don’t have excellent pump fuel and want to move above 350whp on a big turbo. When purchasing a tune from us a WMI kit does not require and additional fuel map so long as you drive with it everyday.