This level of modification is the easiest way to get that few more HP and prepare your car for more power as you desire further down the track. It's also the safest way to handle the power and not destroy the engine in the process. The Standard ECU can only handle so much before something bad happens. Use this as a guide and remember there is a limit.
Benchmark FD testing.
A standard older FD makes 265hp so we will use this as the benchmark. The readings I have a re from a Normal RB-Bathurst Model with 48000klms.
POWER: 268.0 ps
Power at the wheels: 225.6 ps
Torque: 31.7kg-m
Boost: 0.7 ~ 0.9
Stage 1.
I have listed the basics for a Stage 1 tuned car. and the Stage 2&3 are just further expense depending on your budget. But the power is there for the taking.
A: Plugs!Tuning an FD and burning more fuel requires that the fuel can be burned and detonation prevented. A good set of plugs guarantees that the power is on tap when you need it. Dont be fooled by the Rotary only (+) looking plugs. NGK RE plugs look like any other. If you test drive a tuned car with a little hesitation at the top of the rev range, then simply replacing the plugs with colder items may be the answer.
For a Boost Up FD you should go for 10-11 range plugs and relace them after 3000~5000klms.
B: Plug Leads!
To make sure the plugs get the spark they need, upgrade the plug leads. Especially if the car is a bit older.
C:Air Filter!
More air into the engine, your new plugs can burn it up. I recommend the K&N mesh style filters for servicablilty. Foam filters can allow small bits of foam to be sucked in as they degrade with time. Blitz SUS, Apexi and a big K&N are the best around and can be cleaned.
D: Hard Intercooler Pipes.
This is more a reliability issue than a power making upgrade. Rubber items are bound to expand and if they aren't already cracked, they will. Get some aluminum pipes to keep the flow where it should go and prevent boost pressure differences. Companies like HKS and Greddy make nice looking pipes that flow ell and look good.
E: Exhaust ( rear Muffler Only )
This will bring a big change to the car even without tuning the ECU, but because it does allow the car to perform better, the demands on the ECU will change. There are so many manufactures and styles that its hard to know what to get. But do this. Get one that is as straight as possible and as light as possible. Up to 80mm internal diameter is cost effective. Exotic materials can save weight which equals improved performance (accelleration etc) but does not change the power curve, so consider that too. Titanium can be 3kg. Normal is 16kg.
F: ECU
Mr Safety says be prepared for your power. This will allow all those expensive bits you just added to your car to work in harmony. Without this change you may destroy all you have. Selecting the engine map is best left to professionals who know about A/F ratios and Boost curves etc. If you don't then dont try. In Japan its the ROM ECU that can offer the best solution. However, as these are mapped for Japanese Fuel and can't be easily remapped in other countries, then a full replacement ECU like the Apexi is a good solution. Apexi and FconV are very tunable. These are also good if you are going to change the engine spec a lot over time. You can adjust the engine maps to get the best from your car.So at the end of stage 1 how much power should you get. Well about 60HP! yep. Not bad for a small amount of cash... time to re-learn how to drive.
POWER: 331.8 ps
Power at the wheels: 286.5 ps
Torque: 37.3kg-m
Boost: 0.9
Power at the wheels: 286.5 ps
Torque: 37.3kg-m
Boost: 0.9
Stage 2.
Happy with Stage 1, well wait there's more. The engine is firing well, but you need to get that fire out. How simply add a free flowing header pipe.
A: Front Pipe
The front pipe from many companies are basically the same design and most are 80mm exit.There are some dual exit pipes but they are more for looks than adding any real performance benefit. This pipe allow gas from the turbo and wastegate to exit smoothly and therefore increases flow though the exhaust. These then allow higher boost levels as you can force more air in and out of the engine.
How much how much.... Well with an engine re-map you'll be looking at about another 8-10hp and about 300rwhp which is great. If your budget stetches then you may want this mod too. Fitting is a bit tricky though so there may be an extra expense if you ask your workshop to do this.
POWER: 339.8 ps
Power at the wheels: 299.8 ps
Torque: 37.3kg-m
Boost: 0.9
Stage 3.
Flow will now be quite resticted buy the standard catalytic converter. So better breathing will bring a power increase.
A: Center Pipe
A change from the restrictive standard exhaust mid pipe which includes the catalytic converter makes sense. BUT this change must be thought about. Removing the Catalytic converter may mean more power, but may also mean failing your next emissions test at your local authority.These days sports cat's are available and do not restrict flow so much. but this test shows the maximum power available.
POWER: 366.6 ps
Power at the wheels: 325.0 ps
Torque: 40.9kg-m
Boost: 0.9
POWER: 366.6 ps
Power at the wheels: 325.0 ps
Torque: 40.9kg-m
Boost: 0.9
This is a massive 37% increase at 100hp over the standard FD. For a limited investment it will make your car a weapon. Mapped correctly it will still be reliable and fun for years to come.
Any further tuning may bring more power, but it becomes a fine line of reliability. The Turbos are now running hot and the intercooler could be upgraded. but this will increase power. The standard range of the FD's turbos are around the 350-370 hp mark. so any more power will be inefficient. Up the boost and you might have more problems.
My car does not have front pipe or center pipe, but it does have a big intercooler. Power is in the same range as listed here. So it's an alternative for the last two options.
But I am the limit of boost up tuning with 1.1 bar of boost.
To go further. (FULL TUNE)
V-Mount Intercooler and either Highflow turbos or switching to a big single are the answer but both will cost big dollars.
So enjoy your car to it's boost up limit.
Russ.
The R-Magic machine could pass at a car show, but somehow the Option Stand is soo boring. cars are displayed without care and they look boring just parked in a line. As you can tell no-one is really standing around this area. A shame because there were some great machines here.
NATS technical colledge displayed Batman's FD. very Hmmmm interesting.
This car is currently the USA Unlimited RWD Time Attack record holder, Recently taken from the GMG Porsche GT3 with pro driver. As you would expect, there are lots of engine mods, not to much on the body, hmmm. Just your standard Pettit style widebody with GTC style front Mazdaspeed style bonnet with custom cutouts for ducting and a huge GT wing. Simple but effective. Dont forget the fully seam-welded chasis and cage. 
The engine set up is a 13B with custom turbo manifold, BorgWarner turbo, 4" dump pipe and a 5" oval, 5" round ex no muffler. MoTec M800 looks after ECU Duties. There are 3 oil heat exchangers, a custom fabricated radiator and ducting with everything hand made. The car makes 500 hp in race trim at 20 psi. 
Eric from Twins Turbo says "We set the record with 14 psi, and then had a small fire that took us out in the second of 5 sessions. next year more to come." 
Free Plug: Contact the builders,
