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Saw this on Ebay

Discussion in 'Gen 2 Prius Accessories & Modifications' started by PriusInMo, Jun 26, 2005.

  1. PriusInMo

    PriusInMo New Member

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    Just came across this on ebay.

    This simple, yet effective modification will allow you to boost the power output of your vehicle's engine without sacrificing reliability or comfort. It consists of a small electronic device that will be inserted between one of your car's sensor and the ECU. This is also know as a "piggy back" device as it is external to the main processing unit (the ECU). You will feel the gain instantly with no expensive tuning necessary.

    http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=33597

    I'm skeptical. Was wondering what others thought.
     
  2. PriusInMo

    PriusInMo New Member

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    Here's a slightly different, but just as dubious ebay mod.

    The Rapid Velocity Performance Module is designed to add more fuel & horsepower to your stock vehicle’s engine.

    Historically, automakers have been required by law to program their electronic control units (ECU), to sacrifice horsepower for fuel economy. By running a car’s engine leaner, vehicles have gained more miles per gallon (MPG). Proven test results have indicated that by adding more gas to the engine’s fuel/oxygen mixture, an increase of up to 25hp+ can result without giving up MPG’s (1/2 mpg).

    http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=33597
     
  3. BT Tech

    BT Tech New Member

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    Don't waste your time or money on this. What is pictured in the ad is a .05 cent resistor used to "trick" the IAT (Intake Air Temperature) sensor into thinking that the air is cooler than what it actually is.

    This is a very bad idea in that the proper amount of fuel is not being delivered to the engine and the result is usually a very rich fuel condition that wastes fuel and does next to nothing and sometimes even lowers power output of the engine.

    Hope this helps...


    Brian
    BT Tech



     
  4. ymmv

    ymmv New Member

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    The short answer is "don't bother." But here's a few other data points on these various products, all doing similar things.

    * They do "work" insofar as the result can increase horsepower and torque.
    * Some cars, especially forced-induction engines, will benefit more.
    * The net improvement will very likely not be discernible by the driver.
    * Chances of improving fuel efficiency is zero.
    * Chances of improving fuel economy is marginal, maybe in the order of 2-5% gains ... unmeasurable in everyday driving.
    * These modifications are categorically NOT LEGAL unless provided with 50-state emissions certification and CARB certification. ANY mod to the engine that effects engine management (any intake and any exhaust at or "before" the catalytic converters) must have emissions certification.

    Just for the curious, these "mod" techniques change the atmospheric pressure sensor reading to convince the engine management system that the vehicle is around 2000 feet lower in altitude (sometimes meaning below sea-level) and this translates into a "richer" trace through the fuel maps.

    I've worked on "piggy-back" systems that control timing (crank position) fuel (air-fuel ratio) and boost (turbo control) and the gains, for most applications in Porsches, are good in naturally aspirated engines and sensational in turbo-charged engines. The idea of magically recreating those gains with a "one size fits all" change to just air-fuel is laughable.

    It's unlikely you'll actually damage an engine with enrichment, but it is possible to "rinse" the cylinders with too much fuel, removing too much oil, causing over-heating from excessive friction, leading to pre-mature wear, loss of compression and ultimately less performance.

    Cheers,