How to tune a car, step by step.

[slider2828]

I was searching around today for how to log knock sensor levels and I came across the BEST guide to tuning I have seen. Although this is for a 3000GT, the principals of it and the collection of ideas is right on and very thorough.

Excerpt from:
How to tune a car, step by step. - 3000GT/Stealth International Message Center

Step 1)

Make sure your vehicle is in proper working condition. Fresh spark plugs with a good gap (and proper heat range). Proper octane fuel for the power level. No boost leaks (especially on a MAS based system), proper supporting mods for the intended power levels.
Do a boost leak test BEFORE you attempt to tune on a MAS based system.
In case you didn't catch that....
CHECK YOUR CAR OVER BEFORE YOU TRY TO TUNE IT. Mechanical problems will fester and destroy your tuning budget.

Now we all know here that an engine is just a giant air pump. Three things are required to make power. Oxygen, Octane, and Ignition. Compression comes naturally due to how the engine should be working, if you don't have compression, see step #1. With more oxygen, more octane is required. When they balance out correctly you get power. Ignition is used to control the burn and make sure you have equal burn across the cylinder. This isn't rocket science guys and the factory was pretty good for optimum ignition timing for a XX amount of air and XX amount of fuel molecules (aka power level), and the factories math holds fairly true for quite some power over stock.


Step 2) What fueling system are you using? MAS or Speed Density? (These are the two options everyone here should be using).

This post I will cover MAS based systems, the next post I will get into speed density and standalones.
Step 2a)
MAS: Mass Airflow Sensor
How a MAS sensor works is purely math. On most systems there is a wire there that physically counts air molecules that hit it. The sensor is programmed with its overall flow area and knows that xx air molecules over xx sq inches= xx flow rate. Until you reach the flow maximum of a sensor, this formula will remain the same. Now it isn't exponential, it is more of a curve that gradually tapers out at a certain HZ value, for arguments sake, lets call it 3000hz.

Now at idle most cars are low on airflow, typically between 10-100hz. Because of this you only need so many fuel molecules to maintain the 14.7molecules of air to: 1 molecule of fuel ratio.

Now there are two types of MAS sensors, hot wire and hot filament. The pretty much function the same.
The sensors in our cars are called Karmen Vortex MAS sensors. They are a bit more advanced as they measure pressure waves/turbulence changes. More airflow=more turbulence. Instead of a heated element/wire catching air molecules the sensor measures waves using a LED, mirror, and photo receptor. Pretty much it uses these together to measure fluctuations in pressure. I would concern myself with how the function differently from a MAS sensor because the principal is pretty much the same and they tune fairly similar.

Important MAF system facts:
A)If you decide to mess/move your MAS sensor remember a few things.

Read more

Once again, these facts are based on my opinion and it is up to you to read and understand what is written. This is a guide and nothing definitive and conditions change all the time, so 3SI and I claim no liability for the information... But I think this helps a lot, especially the second page. I am not promoting the 3SI forum in anyway, but I think this is a great article to read....

[Om1kron]

this is a great post

[slider2828]

Thanks it was the most definitive guide I have ever seen about tuning... It has something for everyone, the beginner and the intermediate tuner, but nothing for SteveShadows though cause he is expert level hahaha!

[A Spec Products]

I just run STOCK

So no need a tune lol

Typically though you should leave tuning to professionals

And when I say professionals, I mean it....so many "tuners" out there

Engine go kaboom

"Tuner" goes missing

[let5l1de]

Originally Posted by A Spec Products

I just run STOCK

So no need a tune lol

Typically though you should leave tuning to professionals

And when I say professionals, I mean it....so many "tuners" out there

Engine go kaboom

"Tuner" goes missing

hahaa. My idea of a tuning is taking our stocker to our local oil change spot. and changing a few filters once in a while...


Nice Writeup! But so many variables...

Bolts-on performance parts are generally plug and play with factory tuning easily capable of handling the upgrades.

Once you have gone past the point of no return, its usually best left to the "real tuners". Meaning large turbo(s) computer upgrades, major Fuel/Delivery change, Cams/Timing and whatever bigger performance parts you throw at may be installed by yourself, but don't let pride and or money get in the way of a professional tune. Its OK. Really... Get it done right and protect your investment. Besides, a good tuner will have the right tools, equipment and knowledge to extract the most power potential from your engine (or air pump as some say) setup. Every engine build is generally unique which means it requires its own special tune.

gl with tuning

[Flicktitty]

Originally Posted by A Spec Products

I just run STOCK

So no need a tune lol

Typically though you should leave tuning to professionals

And when I say professionals, I mean it....so many "tuners" out there

Engine go kaboom

"Tuner" goes missing

Damn straight, People put so much money into there cars, yet so many just skimp on the tuning aspect.

[slider2828]

Lol... this is just to understand the basics, but I think its a great guide.... I mean there is more too it and those are advanced topics, but you can get close..... Just use your smarts..... NO biggy....