What exactly does a tuner do?

RockstarMentality · Jan 31, 2012

I bough my car with an SCT Livewire already installed. Well I was messing with it today and I flashed an ECU that was already present in the tuner. After all that was done, here's what I noticed:

1. An increase in top end power (like 3k-5k)
2. A slightly different sound to my car. Not deeper or louder, just different idk how else to describe it
3. After engaging the clutch, RPMs climb down a LOT slower than normal. This made shifting a breeze
4. Very slight if any increase in low end torque

So I guess my question is what's happening to my ECU to make these changes in the way my car drives? What should I expect in terms of fuel economy after "flashing"? How much of an increase in power should I see from this?

Note: It was a while ago that I bought the car, but I vaguely recall the PO telling me he had it tuned down for MPGs. Only mods are Intake/Exhaust

JerZeyStangz · Jan 31, 2012

I need to get one. Most of the mods we do are in vain to a certain extent because we are not utilizing the extra air flow.

g36 monkey · Jan 31, 2012

It flashes your ecu, adjusts timing, spark, etc.

You will get the best mileage if you set it for performance and drive like a granny.

rz5.0 · Jan 31, 2012

Makes you use 91 or 93 octane gas...

g36 monkey · Jan 31, 2012

Mine runs on 87.

rz5.0 · Jan 31, 2012

87 tune really thats pointless in my opinion so much left out. Performance wise...

Rice_slayer · Feb 1, 2012

My Cluster says "premium fuel only"

Since I've only put premium in my cars, I don't care lol. But as said, it adjusts timing/spark and such to optimize your cars computer for the best performance.

justinschmidt1 · Feb 1, 2012

There are many things a tuner can do...but basically they adjust A/F ratios and timing to increase power.

Certain A/F ratios are better for power and efficiency and added timing means more power...with higher octane fuel, you can run more timing safely.

Most of the gains you feel is most likely from running 93 octane and bumping timing up a few degrees.

Your car is tuned to be "safe" from the factory on 87 octane fuel so just the few degrees of timing bump and 93 octane fuel could be worth 20-30 hp on some engines.

g36 monkey · Feb 1, 2012

Mine will be retuned for 93 soon now that I have the long tubes.

RockstarMentality · Feb 1, 2012

Best fuel we get around here is 91. Only one gas station sells 93 and its has ethanol in it (I won't put ethanol in my car) but there's no ping or anything. Thanks for the info guys!