From my reading on the forums better throttle response comes from the larger air filters that are less restrictive for the intakes. That's why many people claim drop-ins and post maf tubes almost equal the aftermarket CAI.
Aftermarket air filter allow the engine to take in more air and quicker, thereby giving the sensation of better throttle response. The car should revs up quicker. I do not know how it actually feels since I'm still running stock.

I think most people on here state you will not feel anything under 10hp. I would expect a 20+hp to be felt. The car should feel more lively.

From my understanding there is not much to tuning this car because they still haven't cracked vvel. Currently I would expect a tune to give around 10 hp if there are not other mods on the car my :twocents:

I don't buy it on the intake filters allowing better throttle response, but that's just my theory as of today. I'd need to see some data or drive one before and after to speak confidently on the subject.

As for a tune only giving 10HP...unless timing can't be modified that has to be inaccurate. Adding only 1 degree would make more of a difference than that.

i believe my car had a noticeable improvement in throttle response after adding the drop in filters.

Try this at home with your vacuum cleaner:

Turn it on, then use the attachments on the hose. You will notice that the more restrictive the attachment, the more "whine" the motor makes as it strains to pull the air through the attachment's opening. The more the motor strains, the more HP is being used to Pull the air into the attachment. In the case of a car, this means there is less HP to drive your wheels.

Same principle applies on the intakes and exhausts of cars as I've noted above.

Give the engine a larger "attachment", and it doesn't have to work as hard on "sucking" the air into the chambers. Free-er air flow = less work the engine has to do just to breathe, the more HP is now left over for the drivetrain.

Why do I know this? I am an engineer - and as such, I have dealt with calculating useable HP for Generator Engines considering pressure drops due to intake and exhaust piping. Piping (both intake and exhaust) have a tremendous effect on useable HP from the engine. This was a major factor in my choosing the FI exhaust system by the way - it has the least bends with the least angles (no 90's) which I know for a fact translates to less back pressure and more useable HP at the engine as a result. Intakes work the same way. The less bends and less pipes, the easier the engine breathes, the more useable HP is available for the drivetrain...

This is not hearsay, nor conjecture, nor abstract theory. This is something I have done as a matter of practical engineering - I make my living this way by the way, with 22 years experience in the industry, if that means anything to anyone out there...

This is simple enough to test. I can just pull the filters out of my air boxes. If you had a noticeable improvement with drop ins, then I should REALLY notice something with no filter at all. I'll check it out this weekend and report back.

I'm also an engineer and have been messing with cars since I was old enough to hold a wrench. Comparing a 332HP motor to a vacuum cleaner...meehhhhhhh.

The question becomes if the intake restriction creates vacuum at the area just behind the throttle body when at WOT. If so, then a larger air filter is warranted, if not....well not so much.

A couple threads regarding how much people get with a tune:

http://www.the370z.com/tuning/47404-...ts-inside.html

http://www.the370z.com/tuning/44538-...o-results.html

http://www.the370z.com/tuning/39883-...y-results.html

There are many more like that if you search in the tuning section. My point is people don't get much hp out of a tune on this car. What a tune helps with is better usable power, corrects the afr, and gives it better feedback when you mash in the pedal. IF you go to an uprev tuner, they will most likely say you will gain between 6-15 hp. That number will depend on multiple factors of course.

No where in my post did I say an internal combustion engine is the same as a vacuum cleaner. The point was the principle of doing a lot of work just to suck the air into the plenum vs not working as hard to do the same. The HP difference is what you use to do the suctioning, or divert to the wheels.

I hope that clarifies it a little?

That was some interesting reading, thanks for the links. To me it looks like most of those cars make over 300RWHP after a tune and a couple of bolt ons. Not too shabby for how light this thing is.

I've been browsing the tuning section of the forum but I'm not really finding any good nuggets of information that would help me know what's capable in these cars from a tune perspective. I may post a thread and see if anyone can chime in, but in my experience most end users have no idea how tuning works and think it's some kind of black magic. In reality it's no different than the old carb and timing light days, but since it's computer controlled people are spooked by it.

What I'd like to see is someone with a stock Z do a data log and see what the AFR is as well as the timing at WOT. It "could" be that Nissan already squeezed most of the available power out of this motor from the factory. OEMs don't normally do that, but it is possible. The fact that it's tuned for 91 tells me there is some on the table. We don't even have 91 in my area...it's all 93 and that'd be worth a bit right there. Normally you tweak the timing adding a bit at a time until the knock sensors show some retard, then you back it off just a tick. Then you start setting up the AFR and find the sweet spot of AFR and timing to avoid any knock retard on the fuel available.

I tuned my supercharged 4Runner myself and it's not really a huge deal. I did it with a Split Second piggy back since there is no tuning available for the 4Runner directly. I tuned it on a dyno, then touched it up on the street. Gained about 120RWHP in that little truck :)

Being able to switch tunes on the fly with the cruise control is VERY slick. I wish my Challenger could do that. I have to carry a tuner with me and I have two tunes. A 93 octane street tune and a 109 octane race tune. The only differences between the two are the race tune has a bit leaner AFR, 4 more degrees of timing, and the adaptives for IAT are dialed back to not pull as much timing as the IAT increases. It was good for about 3/10 and 2MPH at the 1/4 mile track.

I hear what you're trying to say. I look at it differently, but probably comes to the same thought....my point of view isn't that it takes more horses to pull in the air, but allowing an engine to breath more easily makes it more efficient. Probably saying the same thing you are in the end. I'm just not sure a CAI will help this car that much, but I just got mine and have some research to do on the current system to form an educated opinion. On my Challenger, which had a similar stock CAI that pulled air from behind the head light, I only gained about 5RWHP. However once I added the supercharger it really needed it as that blower could use all the air I could give it.

5 Rear Wheel HP is a lot by just changing a simple Intake on the engine.

speedy if you wait until april/may I can get datalog for you afr and timing numbers.

your ECU will need to relearn your new "setup", no? i'm not sure you're going to want to drive the amount of time/distance without filters to recalibrate :ugh2:

That's not a lot to me. Standard dyno deviation between runs can be that much.

Cool, what do you have going on in April/May? Mods planned or ?

Should take too long on a MAF based car. Not like I'm gonna drive around for a week without air filters.

Most of the time on these types of vehicles people clear the adaptives and realize a temporary performance improvement just from that alone, however it does revert back as it relearns how you drive.

I can test some of this stuff when the track opens in March and report back.

Look at the dyno charts, very liitle gain or change in the HP or Torque curves. Real world numbers would be in 1/4 mile times or top speed etc.

You fail to acknowledge that the 370z already comes with a factory tuned cold air intake system.

The other numbers that really count are the ones on a flow bench, connecting the aftermarket CAI system offline to the actual engines heads and measuring the additional air flow, from the intake to the manifold and then to the actual combustion chamber. Comparing the stock to the aftermarket CAI.

That's why I mentioned earlier about drop-ins plus post maf tubes will get close numbers to aftermarket cai becuase the stock system is a cai already. I did look at dyno charts both the manuf. and privately done ones they were similar:
STILLEN 370Z Generation 3 Ultra Long Intake Released! : STILLEN Yes most of the 18 hp gains are up top, but there is a gain still across the board. and if i'm not mistaken, the people running boltons run quicker times than stock per the various discussions on this forum regarding track times.

My car is sleeping until then (chicago). In april I will be putting on the F.I. CBE and maybe CAI.

Nice! I love that FI CBE. I may have to get one myself but I'm having a hard time with the price of a cat back for this car. Over a grand!??

Keep in mind doing the CBE and CAI....you'll gain quite a bit with one or the other...but combined it'll be about the same as one on it's own.

I personally like the idea of drop in filters and the MAF tubes to be cost efficient. I've also had some reservations about those filters hanging out in front of the car getting soaked in the rain.