Originally Posted by WingsofWar
What kind of power are you thinking about? Its not so much making more power out of a 2.0 N/A, but making it out of the FB20.
Ill give you a few hints from my experience with the EJ22 and EJ25. But the actual scenario may change because of the altered characteristics of the FB20. Especially since it will be different than the current FB20 on the market and vastly different from EJ engines. For this thread, lets label the FB20 on the FR-S, FB20R.
1. Intake - Unfortunately for us, a simple mod such as a air filter or intake pipe will not net any power. Recent Flat-4s intake designs are vastly optimized already with very little flow restriction. BUT what has seen promising power increases on the dyno is cooling the intake charge. Simplest way is the cold air intake mods. Next would be adding Phenolic Intake Gasket to separate the block from the intake manifold allowing the intake manifold to cool. But from my understanding the FB20R will use a thermo plastic intake manifold and probably wont respond to a Phenolic Intake Gasket like the EJ motors do with metal intakes.
2. Exhaust - The FB20R should come with factory EL headers, which are the best for performance. Similar to how all the N/A EJ models have EL headers, however the diameter and flow could be better over OEM. TWE currently makes the only EL 4-2-1 subaru header that has the highest gains seen on the dyno. Next is strangely OBX, due to their pipe design. Cat Back exhausts are a hit and miss on N/A subarus, Iv seen as high as 10hp and as low as 3hp gains. Mated with high flow cats we can see some increases, but the real magic happens at the header.
3. Compression - N/A engines powerband is in the upper registries of the RPM range, and higher compression ratios net the best kind of power the engine can produce. Some EJ251 and EJ252 phaseII tuners use a EJ22 PhaseI head, to bump the compression ratio from 9.7:1 to 11:1. Netting anywhere from 15-23hp. The current FB20 has a 10.5:1 C/R, but at this point we don't know the compression ratio of the FB20R, but its something to look out for when considering mods, anywhere from different pistons to heads.
4. Heads - EJ N/A engines have use a SOHC head design for a long time, but this time around the FB20 will be using a DOHC head. Probably the same for the FB20R. What we are looking for are better exhaust flow characteristics. Some EJ22 tuners enlarge the exhaust ports for better flow and has seen better results vs messing with the intake ports. When we do this its better to do better cams. But my only concern is the if we even need to do anything in the heads to begin with because Yamaha may be doing the work for us.
5. Fuel/Timing and ECU tuning - Here is where it gets a bit tricky, Direct injection theory is we wont ever max out the injectors based on the variation of how they operate. We still get pulse width and duty cycle, but many EFI gurus have had troubles in tuning direct injection. Currently Motec, Megasquirt and AEM are the only Stand alone EMS units that touch direct injection. From there we will probably metering using a MAF, as subaru has favored over MAP when it was changed over in the late 2000s. Id like to see AIT metering implemented in factory ECU settings. Reflashing the ECU using an access port will probably not see major fuel map changes, but timing. But there in lies another problem. Subaru and Toyota both have active learning ECUs in which people have been plauged with because even if you reflash the ECU, it will revert back to its original settings over time. Which is why COBB refuses to make more aggressive maps for N/A accessport guys. This is by far the most important mod for some real gains but we have some major hurdles to overcome.
6. Internals - If Yamaha/Toyota/Subaru is planning on making good power with the car. FB20R should have much better internals overall. Forged crank is likely and could be lightened and balanced. Im not to sure about the piston and rods over the current FB20. But im sure its an area they we need to touch if Yamaha/Toyobaru doesnt.
7. ITBs - This mod is likely among hardcore builders and those who see the track more than anything.
8. Ignition - FB20R will probably use coil-on-plug distributer-less ignition and will feed its power from the electrical system of the car. If we want to see better spark and less ignition break up especially in the higher RPM ranges where we get our power, we need to optimize the electrical output. Higher AMP alternators, maybe a CDI box. We will see when the car actually comes out.
9. Pullies and Flywheel lightened but not overdriven. good for freeing up power we already have.
|