00:00 |
- In this worked example, we're going to look at how to tune a rotary engine using the Adaptronic Modular ECU.
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00:07 |
Specifically the car we're using for this worked example is a series 7 Mazda FD RX7 fitted with a 13B two rotor engine.
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00:17 |
The engine in the car is 100% stock standard and instead of modifying the engine, what we've done is made some changes to the turbocharger system in order to optimise the airflow in and out of that stock engine.
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00:30 |
Specifically the turbo system that we are running is a TurboSource kit.
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00:35 |
This uses an investment cast stainless steel exhaust manifold, incorporating two external TurboSmart wastegates and it's fitted with a BorgWarner EFR 8474 turbocharger.
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00:48 |
At this point the turbo kit is able to produce significantly more horsepower than we could reliably hold together with a stock engine and for this reason we're going to be keeping our boost targets relatively mild, around about the 14-15 psi mark and we're aiming for around about the 400 rear wheel horsepower mark as well in terms of our power output.
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01:11 |
The other supporting modifications we've made to the car are around the fuel system.
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01:16 |
In this case we are running a CJ Motorsports in tank pump setup.
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01:21 |
This is a billet fuel pump hanger that goes in the factory tank, running a pair of Deutschwerks pumps in that hanger.
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01:28 |
And this is running forward to a CJ motorsports fuel rail kit.
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01:33 |
We've converted the factory side feed injectors to top feed using that fuel rail kit and we're running a set of ID1300 cc primary injectors and a set of ID1700 secondary injectors.
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01:48 |
I've also got a V mount intercooler and radiator setup and we've made sure that with that setup, we've also got the air intake for the turbocharger being drawn from in front of the radiator and intercooler, ensuring that we've got cool, clean airflow going into the turbo.
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02:06 |
In terms of the fuel system, we have also incorporated a ethanol content sensor in the wiring package and this is so that in the future we can run flex fuel on this vehicle using ethanol blended fuels.
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02:19 |
However for the purposes of this worked example, we're going to be focusing solely on running the car on pump fuel.
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02:25 |
As part of this as well, the rotary engine does us an oil metering pump to inject oil into the rotor housings for lubrication purposes.
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02:34 |
The Adaptronic Modular ECU can actually control the factory Mazda stepper motor based oil metering pump however, we have chosen to remove that which is quite common with competition or heavily modified rotary engines and instead we are running pre mix in the fuel.
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02:52 |
The worked example here is going to be helpful of course for those who want to learn how to tune rotary engines and the rotary engine is quite unique.
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03:01 |
Obviously a completely different operating principle to the more common piston engine.
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03:06 |
There's some intricacies around the tuning with a rotary engine that we do need to understand, specifically the fact that rotary engines will run staged injection, we need to understand how that works.
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03:17 |
The rotary also uses twin plugs per rotor housing with the leading and trailing plug.
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03:22 |
This means that then in our tuning software, regardless what ECU you are running on, you're going to have a leading and trailing ignition table or a main ignition table and a trailing split table, we need to understand how that works.
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03:37 |
There's also some other considerations with rotary engine tuning around the air/fuel ratio targets that we choose which will be usually a little bit different than a piston engine.
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03:48 |
The fact that the rotary engine is also incredibly intolerant of almost any level of knock or detonation, so firmly pays to tune conservatively when we are tuning a rotary engine if you want to get good reliability out of that engine rather than chasing down every last horsepower.
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04:05 |
Now if you aren't a rotary fanatic but you are running the modular ECU from Adaptronic, then don't worry, you're still going to learn plenty about the inner workings of the Adaptronic ECU and you'll be able to apply that to basically any engine, piston or rotary.
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04:21 |
Now that we know what we're dealing with, let's move onto the first step of our process.
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