question for people with I & E, 1+1=1
 

I remember I read the article on D-sport magazine few years back about their intake and exhaust test and they concluded - OEM ecu limited power gain up to 5%. So if you have intake and exhaust without tune, you won't gain more power (so 1+1=1) . however, i see a lot people here in the forum has I&E and no tune. how do you deal with the issue? or you are not aware of it at all?

Source: http://dsportmag.com/browse/product-...intake-systems

THE 5-PERCENT RULE
Because the ECU in the Scion FR-S has tables built in that essentially limit the amount of additional power that can be made, dyno testing bolt-on products on the vehicle proved extremely challenging. Based on over 250 dyno runs that we conducted, we found that the ECU seems to only allow performance gains on the order of about 5.0 percent. Adding the additional components to allow more additional power production with the factory-programmed ECU still only delivers that 5.0 percent gain.
1+1 = 1
Let’s say that you have an intake that adds about 5.0-percent more power when installed on a stock vehicle. Now, let’s say you have an exhaust system that adds about 5.0 percent of power on a stock vehicle. While you shouldn’t expect to get a 10.0-pecent gain from the two, it’s realistic to expect to see a performance gain with both items in the realm of 6.0-to-9.0 percent. Yet, the factory programmed Scion FR-S ECU says 1+1 = 1. We confirmed the severity of the 5.0-percent rule when we found that the Scion FR-S simply didn’t gain any additional power when an aftermarket exhaust was added after the addition of an aftermarket intake system. On DSPORT’s DynoJet 424xLC Linx dyno, the number that could never be exceeded was about 182 wheel horsepower. Stock horsepower figures checked in between 173 and 176 horsepower when tested on different days.

Rules are made to be broken.. Read the last 2 sentences of that article:

"Unhappy with the inconsistency and performance limits placed on the engine by the factory programming of the ECU, our game plan is to rerun the test again on the same vehicle after implementing the ECUTEK solution. The ECUTEK and other reflash solutions are likely to be the only way to break that 5-percent limit on additional power production. Stay tuned and get ready for the updates next issue."


That's how I broke the 5-percent rule. :thumbsup:

Their is no 5% rule or built in "limit" in the ECU restricting horsepower.

But their are limits to the learning ability of the ECU it only "learns" adjustments to fueling and ignition timing.

The ECU has maps for ignition timing, fueling, cam timing, sensor scaling ect their are hundreds of them.

The ECU also has the ability to adjust or learn for minor differences in sensor calibrations fuel (eg 10% ethanol content) temperature and atmospheric pressure or minor modifications to some components that effect fueling or ignition timing.

However these adjustments are limited and the ecu will adjust fueling and ignition timing in an attempt to run as close as it can to its pre-programmed maps. The adjustment do not attempt to extract maxium power or take advantage of intake or exhaust modification they just try to run the pre-programmed maps.

When you change exhaust and intake components it may make the ECU see a rich or lean condition the ECU will then adjust fueling using learned fuel trims to correct this and bring back the fueling to as close as possible to the pre-programmed maps.

Intake and exhaust mods also effect the volumetric efficiency of the engine and intake mods will usually upset the MAF (mass air flow sensor) scaling the ecu will attempt to correct these with fuel trims but its better if MAF is rescaled to suit the intake to minimize fueling errors.

The ECU has no means to adjust for changes in volumetric efficiency caused by intake or exhaust mods. The intake and exhaust cam tables don't have learning ability they just run the pre-programmed maps according to load/rpm ect.

Same for changes in fuel density ie ethanol content. This will cause a rich or lean condition and the ecu will attempt to correct this by adjusting and remembering fuel trims throughout the rpm/load range to bring the AFR back to what is pre-programmed in the MAPS.

If you run fuel less than 93 octane fuel the ECU will detect knock and REDUCE ignition advance hence reduce power until knock ceases. If you run higher than 93 octane the ecu will just run its pre-programmed map and no further ignition advance will happen.


If you wish to get the maximum benefit from exhaust or intake modification or very high octane fuels you need to adjust the base tables for fueling ignition timing cam timings and many other tables to take the full advantage else the mods are largely wasted or will cause drivability problems.

This is where a competent tuner earns his or her money. They will adjust the many tables to take the maxium advantage from any modification and can also extracy some extra power and torque from a standard car, just don't expect too much on an NA car

see post here with dyno results

stock with tune produces more power than full bolt on intake/exhaust mods and no tune.

http://www.ft86club.com/forums/showp...postcount=1439

5% rule... ROFLMAO!


My last car made 100% more whp without touching the ECU.

I know this may just be a coincidence but after I read that article in DSport last year I only believed 5% of what they publish. Weird huh?