Normally Aspirated?? why tune?
 

So Im a bit new to the Non turbo scene as my question indicates so please dont think Im trying to start some E-battle. In years past I was lead to believe that normally aspirated engines dont gain much if anything when it comes to "Tuning" or as they used to call it chipping. Tell me why this is different with our 370z.

You've been given bad information. It's not exclusive to the Z, it applies to all cars.

If you start modifying your intake/exhaust you can alter the a/f ratio. Sometimes it gets far enough out of range that it needs to be corrected for safe operation.

There are also a host of other parameters that can be tuned to enhance the driving experience.

This ^^^

The OP is right to a certain extent. Tuning a Z is with bolt-ons only yeilds very minor increases in power and driveability. Meanwhile, tuning a car with forced induction or more cylinders usually yeilds substantial increases. For example, Evo X's gain nearly 60 whp with just an intake and a tune.

Well it's less about power and more about driveability and engine safety anyways.

But wont the on board ECM deal with this, or at least warn if its an unsafe condition

Makes a big difference. Tuning will allow to regain loss in some areas power from mods that increase in others...

I.e. you're looking to do AAM short tails... when replacing your muffler with delete pipes you will lose some back pressure ... just doing AAM alone wont hurt or make that much of a difference. However take my upgrades

Stillen G3
Z1 test pipes
And
AAM

I lost tons of back pressure for opening up so much... my take off went way down while my top end got way better...

Also I was running very lean, which if left un attended could damage my engine.

UpRev tune fixed the lean running and regained my low end/take off power.

So, decide how much money you'd like to spend, what you'd like to do and how.
Get your piggy bank out brother... you'll be breaking that bitch open.

ECU can only adjust for so much. There have been instances where people with CAI/HFCs/CBE have been dangerously lean.

Yes and no. During cruise and idle, when the ECU is in closed loop, Fuel Trims are used to keep the AFR "stoich". These fuel trims can vary from positive to negative up to a certain percentage. (I'm not sure what the max percentages are for the Z.) This is mostly affected by changes to the intake tract ie different size MAF housings, new throttlebodies, intake manifolds, etc. However, when getting out of closed loop and into open loop (WOT), Fuel trims are usually NOT used. The ECU is pre-programmed to provide a certain amount of fuel based off TPS and RPM. These are the tables that are greatly affected when more airflow can get in and out of the engine. (mods) This causes a lean issue that cannot self fix and must be taken care of with a tune.

That was allot of Technobabble:icon14:, some of which went over my head.
Im only doing Typhoons and AAM shorts. These wont require a tune will they?

:iagree: With mine; it was running very rich (even at idle). My mods were: short ram intake, HFC's, and CBE. The uprev tune cured the AFR issues and eliminated the o2 sensor issues.

It is well worth the $$.

With the 2 bolt on mods Im doing, Typhoon and the Short tails will I be looking at perameters outside the stock ECMs ability to correct.

You should be OK. The general rule is you can pick two from HFC/CBE/CAI and get away without a tune. If you do all three it's a good idea to get one.

Parts ordered, could be terrorizing the neighborhood in less than 7 days:excited:

What'd you get?