recommend to re-tune NISMO cars after installing a cold intake?
 

i am an owner of a 2009 370z Nismo and just wondering before i invest on the cold air intake... is it recommended to re-tune the car since Nissan tuned it for the Nismo specifications?

It really depends. Its the MAF intake diameter immediately prior to the sensor (air cone side of sensor) that determines impact to the air volume being measured. If the MAF intake immediately prior to the sensor was replaced AND is now of a larger diameter than the stock one that was replaced, then yes a tune is certainly needed as the volume of air being measured at the MAF sensor will now be increased.

However if the MAF intake was replaced AND AND the diameter immediately prior to the sensor remains the sames as the stock one that was replaced, then NO a tune is NOT warranted as the volume of air being measured at the MAF sensor will remain the same as before the substitution.

Understand that again I am saying the diameter of the inlet tube immediately prior to the MAF sensor. It has nothing to do with the intake tube diameter AFTER the MAF sensor going to the plenum.

i understand thanks. i wonder if i buy the Nismo Cold Intake kit at the dealership they will tune it for me? :-)

Just buy the Injen Nismo Edition intake that's already tuned for the Nismo 370z. Part# SP1990P or SP1990BLK +13whp for Nismo

sweet! thanks! ill look into that one

The OP is asking whether or not the addition of CAI to his Nismo would change his car enough to warrant (or need) a custom tune.

The Injen Nismo CAI aren't "tuned" for anything, it just fits the Nismo instead of the base. The ECU will still be programmed with the exact same tune as it was with the stock intakes.

To the OP, sorry, but I'm not an expert on tuning and A/F ratios and whatnot. Here is a link to Tony's (from F.I.) response in another thread:

The thread itself:
http://www.the370z.com/intake-exhaus...-too-lean.html

Tony's informative response:
Retune after intake/cbe/hfc


Others in the thread mentioned you may be ok not retuning if the only mod you have is the intake. Best thing appears to be deciding what mods you're going to do, completing them, and checking the A/F ratios afterwards to determine if you're in the optimum range or not.

awesome! thats perfect! thanks for the great links! im also going to consult with Nissan Techs and see what they say.

Short answer: NO. The ECU will adapt to the minimal differences this will have on your car..

I don't know what the diameters of the tubing at the MAF portion are for various brands of CAI but the "diameter" concept I described is the determining factor and rule as to when to retune when putting on a CAI.

I've discussed this extensively...Off the shelf CAI's are not radical enough to require a "retune"...

I can buy that. Caution though....it takes as little as a 5mm difference in diameter of the intake housing where the MAF sensor sits to make a significant A/F ratio impact. I assume then that most 370Z off-the-shelf CAI's are just about all the same diameter as the stock housing diameter at the MAF then?

Stock MAF tube tapers from 2.34" to 2.36" and the car will run with a rich correction to long term fuel trims. (-9%). Bumping the MAF tube up to ONLY 2.39 seems to pretty much eliminate the rich correction and put the Fuel trims right at 0% correction. Only three one thousands of an inch.

Read about why here: Modshack | Stage 2 MOFO (BAMM)

My new tubes:
http://images54.fotki.com/v551/photo...MG_2351-vi.jpg

People have put intakes on millions of cars for years. A simple intake won't destroy your car because it doesn't match your OEM tune. It's just an intake.