Originally Posted by NJHK

There is tuning...its called a PIGGYBACK.

If you're trying to go turbo, then focus on that cause it's not a overnight operation.

Do your reasearch now so you're prepared in the future.

This is coming from someone who has been there and done that. Take it for what it's worth.

Originally Posted by lil_kano

was that for my NJHK?

i don't want to have to deal with a piggyback system and loose all my power optionability. i'm not planning to turbo unless they come out with a computer tune that i can use to tune my own system and a tune for the auto trannies. so for now im going to do a nitrous system and i just want to know if the engine can handle an extra 85shot/hp.

i can have my friend run it on a dyno and print out my AFR and adjust my fuel or nitrous jets accordingly. i've been asking the quesitons for a while.

NJHK i'm going to send you a PM....

Originally Posted by sick06cobalt

ill share a secret with you... we took a flash of my friends car... 2007 ls and we sent it into hpt they said they would get back to us this week.. so there you go tuning might be coming out, they just needed a flash of someones car to work on it alittle more...

Originally Posted by NJHK

You're thinking of a standalone

Piggybacks retain all stock countermeasures and does not change anything outside voltage signals.

Originally Posted by lil_kano

so its basically a custom tune...just not a refalsh?

Originally Posted by shawn672

i think it just lets u modify a few things by changing the signal that the comuter recieves

Originally Posted by NJHK

What a piggyback does is intercept the voltage signal from your MAF or MAP (depending on your cars setup) and basically tricks your computer into thinking that you need more or less fuel than the sensor is reading and saying that you need.

I know you (redline cobalt) have a MAF sensor, your MAF sensor reads up to a maximum of 5 volts. So say 1.2 volts normally sends a signal to your computer, your computer sends a signal to your fuel injectors to open it for a period of time so it will spray a certain amount of fuel. The amount of fuel you spray from your injectors will ultimately effect your air / fuel ratio.

The higher the volts, the more fuel that your injectors will spray. The less, vice versa.

So say at a period of time in your RPM band, you don't want 1.2 volts, you want 1.4 volts, you use the piggyback to change the signal.

A piggyback is basically a huge controllable resistor.

The problem with piggybacks is that they vary a voltage and control to a maximum point. Remember, piggybacks control from stock settings. 0 setting is stock and negative (-) is less fuel / lower voltage and positive (+) is more fuel / higher voltage.

Now another tip to remember is that too high of a voltage can cause the computer to run a countermeasure to start to retard ignition timing.

Speaking of retarding ignition timing, the AEM FIC ("I" standing for Ignition) can ONLY retard ignition timing. What it does is intercept the signal from the Knock sensor to purposely make the computer think you're having some degree of knock, which a computers counter-measure / defense is to retard ignition timing (this is also known as "knock retard").

Normally, any degree of knock retard means that there is something wrong and causing your computer think there is something wrong with your engine (or in some cases, your knock sensor is faulty). Incase you don't know, your knock sensor listens for abonormal noises caused by an abnormal combustion in the combustion chamber.

So hopefully that makes it a bit more understanding.

Another problem to look into:

PE (Power Enrichment) Delay

PJ (Flying Skwirl) has a thread on here that goes into detail about it on the ECOTECs. http://www.ecotecforum.com/forums/showthread.php?t=105

Using O2 sensor clamping to help decrease the delay.