Unfortunately, no. We had 15 or 16 cars there and didn't have time to swap out mods. It was bad enough adjusting the boost on the TT set up. We started at 7:30-ish and ran until 5pm that night.

I've heard the argument before about certain cars running differently, however there was less than a 1% difference between EVERY CAR that had the same tranny and mods. Dig up the old post and re-read it, I'm too dumb to make this stuff up.

 

I appreciate the dyno plots Neffster. I believe I have seen those from your Dyno Day in the past. By simply looking at the plot I would have agreed the Z-tube looked to have a slight advantage. However, and with all the respect, it's a tough call being two different cars (AT models no less) and without knowing if the runs were all conducted at similar coolant temp and preferably preceded by an ECU reset. I sight it as being inconclusive only because the delta we're dealing with here is relatively small and well within the dyno's +/- 3% margins of error. The only way to validate such small gains is if the multiple runs were attempted and the majority of the cases shows positive delta. Instead, what I would have read from this is that it does not hurt to use a Z-tube (thus I've got one).

I have two dynos that are pre-post on the same car same day on the same dyno and are 6mt equipped. Both showed on-par numbers, as in no gain). I will dig into my archive and have them posted later.

 

Running the z-tube with a stock paper filter would be pointless, unless you want to hear more intake air noise. All you have done is removed the baffled pipe.
The stock paper filter is far too restrictive.

Though the gains would not be huge, it is not unreasonable to assume some small gain with a z-tube IF you at least have a high flow filter like the K&N

There is a lot of data on various cars showing improvement with reduced turbulance
at the intake(prior to the throttle body).

If you do a plenum mod (spacer or replacement) the high flow filter and the z-tube will play a bigger roll, as more air can be moved in at higher revs, the turbulance of a stock infiniti baffled air tube will reduce volumetric efficiency of the engine.

The question as to how much power can be had has many factors.
i.e. is there enough turbulance in the baffled pipe to create a restriction ?

 

Umm, has there been anything to show this statement as true? I think that's a bit inacurrate.

 

I recall reading that the K&N replacement didn't show any improvement, so the stock filter is as good/bad as the K&N. The popcharger has been shown to have an improvement.

 

I can only speak from my experience with my car.

I replaced the air filter as a matter of course at about 6k I used the K&N simply because I generally buy quality.

I expected nothing in performance, as I was only interested in a clean quality filter.

I was very surprised the first time I got in high revs, it seemed to go through the range from 4 or 4.5k to redline quicker... I thought I was certainly imagining it.
I swapped paper for K&N, and it felt 'normal' (as it had prior) put the K&N back, and zoom, put the paper back again, ... normal.

Now I am not gonna pay to dyno a filter, there is something there

The fact that the 'pop chargers' show improvement, clearly due to air flow.
i.e. lack of restriction, or less restrction. The fact that the K&N is less restrictive, etc etc.

Someone who has a day to kill, and a dyno shop willing to do at a reasonable price could run through the combos.

I have seen/felt something above 4k RPM with that simple change, and the fact that gas mileage has improved nearly 5 -7% since the change certainly indicates the K&N is allowing more flow.

 

yes, popcharger does show improvement on the dyno...but once again.......... i stress that the heat shield is not good enough.

anyone with a popcharger, drive somewhere far, then open up your hood and feel the intake. ill bet it'll be hot. i used to have one and damn straight it was hot after a long drive. and ill also bet that my K&N with stock box will have more hp at that point than your popcharger will.

 

Exactly!
Unless you live where the air is cold and dense in the summer, heat soak is a killer!
That is why mine looks like this!
No....not as pretty as a shiny chrome intake tube w/ CAI.....but a lot more efficient when its 90+ degrees in summer!

 

It would be a better test if you had someone else swap the filters and not tell you which one is installed (and of course sometimes not even swapping it). Do this 10 times and see if you get more than 50% correct.

 

that's a very good advice.

 

that is of course good advice...

As I said, I would hardly waste any time bothering with what the K&N does.
Being that I have been in design engineering for 25 years, I was the first to say/think I was nuts.

Which is why I bothered fiddling with it a bit.

But power or no power, the mileage doesn't lie.
4 tanks since I put it in, and mileage is consistantly better.
Something has to account for that.

More over, the only way a pop charger would go in my car is if a unit was made
with a real box to pull cold air, not hot air, and protect from water.

I can't help but laugh that they call those things 'Cold Air Intakes' when they in fact suck in hotter air than stock.

 

yeah i like the stillen design, but then i found out that the bottom of the box is open as well. that may mess with pressurization or something so i dunno...