Factory Forced Induction Philosophy

ZDYNE’s straight forward and factory like forced induction philosophy makes for the cleanest, most reliable and powerful turbo or supercharger installations ever. Please Note: We have put forth an unparalleled effort into ECU modification. We consider ourselves software and electrical engineers foremost but occasionally dabble with hardware out of necessity. Our projects often lead us to generate our own non-ECU, but system critical, engineering data. The Super ECU is a vital part of an equation which enables you to use the Factory Forced Induction Philosophy: Clean installation: factory sensors, harness, no extra boxes, no wire cutting. True 3D engine management with sequential fuel injection and boost sensitivity. (The SECU) Normal fuel pressures (28-48 psi range) Larger injectors in the factory location Off-boost fuel is recurved across all throttle positions (3D) for excellent idle, emissions and drivability with large injectors Recurved ignition advance for boost Manipulate oxygen sensor closed loop operation to take boost into account. The original equipment manufactures (Honda, Toyota, Mitsubishi...) have more development resources than anyone in the aftermarket. They have put in the research dollars and development time to build powerful forced induction street-dynamic driven applications and have made this power reliable. With that in mind, we will ask some questions that we hope will get you thinking. Forget for a moment about what you've heard is required for a forced induction Honda build up. We will compare the naturally aspirated Honda to a car that comes in Factory Forced Induction configuration, the Mitsubishi Eclipse Turbos (which run 15-18 lb/in boost, fuel pressures in the 40lb/in range, a fuel pump which flows under a GSR's in volume, and dynos near 300hp) We realize that this will ruffle some feathers, especially in the light of the educational damage that has been going on for years in the automotive aftermarket (Honda owners in particular). We have simply put this out in order to get you thinking ON YOUR OWN about what is and isn't required to run forced induction. Does the factory forced induction car have a rising rate regulator? Hell no! Stock injectors (above about 60psi) can stick open or leak. Add the fact that injectors "give up" at high pressures - the point of diminishing return - more pressure does not equate to more fuel flow. Our tests (which you can duplicate on your own car using an electrically isolated fuel pressure gauge on your dash), showed that most (the typical round black one) RRRs DO NOT HAVE A RISING RATE. It is an on/off switch where the "rate" simply specifies the on ramp slope. Worse yet, was seeing that it simply did nothing until about 2-3 psi boost! Note that there are a few expensive regulators that function a bit better, but the high pressures are still hurting your factory injectors. Nor will such a configuration ever approach the adjustability of a large injectors/3D tune system. Does the factory forced induction car have a large fuel pump? No, in fact its volumetric flow falls below that of a GSR. Note that the volume and pressure ratings of pumps are often confused. In rising rate regulator configurations, pressure is important, with the typical RRR swinging to 60-110psi. Often a large volume pump is used in RRR configurations in the hopes of flowing even more fuel from small injectors by increasing pressure. A pump change is only required if, after replacing the fuel filter, you are seeing a drop in fuel pressure at top end with the injectors near full duty. Changing out the pump will often create cavitation problems at the pickup, and may overpower the fuel system's return line. It is critical to retain the factory fuel system’s ability to return fuel to the tank, and thereby continue to allow the LOW fuel pressures needed for correct high vacuum/short injector pulse width operation (such as at idle). Does the factory forced induction car have a physically retarded distributor? No. The engine management handles spark curve retard in boost. Does the factory forced induction car have a linear boost sensitive retard device? No. The engine management RECURVES the ignition advance. 2D BSR devices only advance and retard the factory curve. Does the factory forced induction car have additional injectors mounted before the throttle body? No. The manifold as designed was not intended to evenly distribute fuel, just air. Such techniques may lead to fuel pudding in the manifold and uneven cylinder distribution. Upon closing the throttle plate, you may experience fuel-enriched air backing out the blow off valve or dripping down to the intercooler. Such systems are often unable to compensate themselves for changes in air temperature and atmospheric pressure - thus requiring frequent retuning. Does the factory forced induction car have rods made of titanium or forged pistons? No. DSM cast piston image. Obviously as the intention for use of the engine lay on the engineer’s drawing board, he had the opportunity to "beef up" these components, but they are manufactured from materials identical or very similar to the naturally aspirated cars. Further Reading/Research/Contemplation: Hypereutectic Aluminum Pistons. Does the factory forced induction car have an open deck block design? It does differ from the design of the Honda. DSM block image. Obviously the block inserts and welding comes to mind here, but there are questions about their effect on cooling - which may raise head temperatures thereby inducing detonation. Further Reading/Research/Contemplation: Toyota/300Z/Pre88Honda Iron blocks. Does the factory forced induction car have a piggy-back device spliced into the wiring harness to control fuel and spark? No. Obviously a patchwork the factory would never utilize! Such a device can only work on top of what the factory ECU is supplying - which is NOT optimized for forced induction. There are two distinct types of piggy-back devices: one which manipulates the ECU's OUTPUTS, and a second which fakes out the ECU's INPUT signals. We discuss the first type in the following text. (There is a short discussion of the second type in the FAQ. ) Take a look at fueling for a moment. The piggy-back device can only elongate or shorten the fueling pulsewidths from the factory ECU. This greatly limits it worth. The ECU may be supplying fuel in a closed loop mode, open loop mode, throttle enrichment, cold enrichment, or start enrichment. It does not know what the mode of the factory ECU is, and what it is supplying additional fuel on top of. Take for instance the factory’s closed loop or open loop fueling modes. Imagine your turbo Honda driving along on a freeway. You depress the pedal to about 60%. The piggy-back sees boost developing and tries to lengthen the fuel pulse width (add more fuel). The two devices are now fighting. The ECU, being in closed loop and seeing an air fuel ratio richer than 14.7:1 from the oxygen sensor, will shorten its fuel pulse, in turn reducing the input that was originally supplied to the piggyback. End result: a mixture that is likely lean in part throttle / boost situations. Other problems arise with throttle acceleration enrichment, and limits of adjustability. Keep in mind the SECU already knows the factory's modes, and has over 400 load points of adjustability! Spark is a complex issue as well. Look for our upcoming dissertation on the subject in the February issue of Hybrid.honda-perf.org Does the factory forced induction car have stiff valve springs to "help close the valves because boost pressure is holding them open"? No. This seems to be an engine building thought process brought over from traditional high RPM engine building. It does not apply to forced induction kits, just to high RPM use or engines which already borderline on valve float. Given: Valve spring tension about 500 lb/in and boost pressure about 12 lb/in. Simplified Computation: 500 - 12 + more dense compression stroke itself helping to close valves = NIL effect Does the factory forced induction car have a device to increase the spark to "get the spark to jump the increased pressure in the combustion chamber"? No. See what marketing does? If your mixture, timing and plugs are correct this is a non-issue. Also, a properly placed spark event eliminates a need for repeated attempts. Does the factory forced induction car come with Lucas Disc injectors? No. Laser spray injectors may be suitable for race-only situations (constant high RPMs and intake velocity), but this does not validate their use on street driven cars. They sell those injectors for two reasons: 1. That is what everyone is buying, and what they are selling (a catch 22) 2. They are easily available with many high flow rates, and hold up well at extreme fuel pressures. Why does a factory forced induction car come with pintle injectors? Keep in mind that the Factory Forced Induction Philosophy keeps pressures in the 28-48 psi range, and has to run in all conditions: it certainly isn’t 100% high RPM-high intake velocity- WOT driving. It is what we call the Dynamic Driving Condition: idle, warm up, low/high RPM, low/high intake velocity, wide ranging fuel pressures, with varying throttle and load conditions. Although it is difficult to obtain new high flow pintle injectors, there are several reasons why we like them. 1. Great operation at low intake velocities 2. Excellent delivery and spray pattern at low fuel pressure 3. Small pulse width fuel delivery is respectable when used at normal pressures. Interestingly, our own tests have shown that pintle injectors (at normal pressures) operate at or below the minimum opening time of the disc style (directly contrary to common opinion). 4. The pintle injectors provide a more burnable, atomized plume compared to the laser spray injectors. Side Note: We quickly discovered that dynamic fuel delivery characteristics are not available from the after-market "injector experts". What injectors do at 3 bar fuel pressure when wide open for 15 seconds isn’t particularly usefull for injector recalibration, since this is not how they are used in the car. Information of this type is considered proprietary by injector manufactures and rebuilders because it is the core to their revenue. So we did the injector studies ourselves.