August 28, 2006
lvbndad, no offense taken. Yes, I am one of a handful of members on here calling this mod bunk, and no, I have not personally tried it. I have not personally tried installing a supercharger either, but that doesn't mean I think forced induction is a hoax too.
The difference is that the theory behind forced induction makes sense too. The theory behind the Tornado or throttle body spacer in a carbeurated engine also makes sense. On a fuel injected engine, it just doesn't make sense. Given my somewhat limited knowledge of fluid flow and fluid dynamics, inducing turbulence in the airstream only reduces the airflow. Reducing the airflow can't possibly increase power. It's just not possible. TB Spacers make sense on a carbeurated engine where you need the extra intake length to mix the air and fuel, and a Tornado could help aid that mixing, at the expense of reduced airflow. However, I can see the potential trade-off of reduced airflow versus increased power due to the additional mixing of the fuel with the air yielding better combustion. That same potential for better mixing doesn't exist in port-fuel-injected engine.
Dissociative, yes, the mustang guys have been doing that mod since the early 80s. The key difference, however, is in how the 80s and 90s OBD-I equipped vehicles interpreted the TPS signal compared to how the OBD-II equipped vehicles interpret the signal. OBD-I vehicles with the TFI modules and EEC-IV modules used the specific voltage as an input. If that base voltage was off, it affected the fuel delivery rate. However, with an OBD-II equipped vehicle, as quoted above from the service manual, just cares about the STATE of the voltage, not the actual voltage itself. i.e. the Ratch (minimum) voltage, part throttle, or wide open throttle, and it monitors the rate of change to determine if you're slowly rolling on power, or flooring it.
So, again, given how the current electronic engine control system interprets the signal, I fail to see how changing the base voltage (which gets re-learned as the new RATCH voltage on the next start-up) can possible affect idle or throttle response. The logic behind it makes no sense. Until someone can explain that to me, I'm still off the bandwagon.
Also, if you were to look at the Throttle Position Voltage (TP V) PID in the ECU, you'd see that it measures the voltage coming into the PCM from the TPS. If the TPS voltage drops below .49 or jumps above 4.65, it'll store a P1124 DTC indicating as such.
I can't argue the 'seat of the pants dyno says ' argument. Seat-of-the-pants dynos don't provide data. I can tell you that I get 5% better fuel economy when I'm driving with my fingers crossed because I know a dozen other people that have had similar results. That doesn't justify my claim.