First intentions once ztube installed??

V

Viperi

Premium Member
Premium
what did you guys notice after you installed the ztube? Not sure if it is in my head or not so would love to hear from others

Currently my setup is, ztube with stock box with resonator deleted.
after i installed it, took it for a boot and i felt no difference in performance but a tad bit in sound.
couple days later (This morning), after starting it, it sounded like it had a deeper growl, and peppy. i gave it some gas to pass a car and omg... Roar with seemd to be less delay in acceleration!

SO my question is would it take a while for the fx to self tune itself for the af ratio thats why i felt it a week later?
Also is it jsut in my head that has a deeper growl and peppier?
 
Last edited:
I didnt feel much in difference, if so it's minor in both performance and sound.

if you have not done so, clean/change air filter then do an ECU "pedal dance" reset. retest the fx and u might see some improvements.
 
Last edited:
soonster said:
I didnt feel much in difference, if so it's minor in both performance and sound.

if you have not done so, clean/change air filter then do an ECU "pedal dance" reset. retest the fx and u might see some improvements.
Click to expand...
what is this ECU "pedal dance" reset and how do you perform it?
 
I can tell you that I didn't notice much of increase in acceleration at the time I installed it, but I did notice a decrease in acceleration when I took it off.
 
I noticed a little bit of agressive in its responsiveness when you hit the gas. I also have the Stillen CAI installed simultaneously though.
 
Z tube added a growl to the motor, get on it past 4k and it really makes a noise.

There should be hardly any performance gains but the ecu sees nothing. There is not more air going in according to the ecu. The maf determines amount of air flow into the engine, you Z tube is mounted AFTER the MAF so even if it allowed air into it, the ecu doesn't realize it or adapt to the changes. What it does realize is you going past 4k more often to heard that growl. Lol
 
TurTLeG said:
Z tube added a growl to the motor, get on it past 4k and it really makes a noise.

There should be hardly any performance gains but the ecu sees nothing. There is not more air going in according to the ecu. The maf determines amount of air flow into the engine, you Z tube is mounted AFTER the MAF so even if it allowed air into it, the ecu doesn't realize it or adapt to the changes. What it does realize is you going past 4k more often to heard that growl. Lol
Click to expand...

This makes zero sense. So by your logic, if we completely blocked the exhaust pipes, it would not affect airflow because its mounted AFTER the maf...
 
JayKno said:
This makes zero sense. So by your logic, if we completely blocked the exhaust pipes, it would not affect airflow because its mounted AFTER the maf...
Click to expand...

Jayno is right, the Z-tube does impact what the ECU sees because of what it does to the flow of air through the intake. The resonated stock tube creates turbulence inside the tube. The Z-tube ensures smoother flow = faster flow = more air than the stock tube. The ECU sees more air at the same RPMs because of the efficiency of the Z-tube. Not much - but enough to measure on a dyno.

There is a learning function on the ECU that should be reset whenever you make any changes to the intake or exhaust. Easiest way is to disconnect the battery, pump the brake pedal a couple times and wait. If all of your radio station presets are gone, the ECU has been reset. It will then learn how the motor breathes with the new intake.

It has been a while since I have preached the Holy trinity of a Naturally Aspirated FX35.

INTAKE - CAI or high flow, plenum spacer
EXHAUST - cat-back
TUNE - UpRev Osiris

By themselves the intake and exhaust WILL improve response and sound, along with a small bump in power. Once you TUNE the ECU, air to fuel ratios can be adjusted, timing, rev limit, top speed... The combination of intake, exhaust & tune gave me an additional 37whp.
 
JayKno said:
This makes zero sense. So by your logic, if we completely blocked the exhaust pipes, it would not affect airflow because its mounted AFTER the maf...
Click to expand...

Ur mass air flow has nothing to do with your exhaust. A mass airflow measures the amount of airflow going into the engine. It then makes adjustment in fuel with the info it gets. I am going off that theory. Z tube is 75% noise, 20% pretty and 5% MAYBE in gains. I felt nothing when putting it on, i didn't expect anything, just like every intake system out there. If it made more HP, nissan who had the technology would of put them on all the cars because in 03-05 it was a HP war and now we have a MPG war.

I'm in the process of tuning right now. Reading and looking at the ecu inputs with cypher and adjusting target fuel trims.

The main purpose/ difference on the Fx tube and z tube is a resonator, in a sense to make it quieter. Well maybe ur FX tube is different then my G tube.

Its like a funnel, u can not force more air in other then what the diameter of the hole let's u and the diameter is still the same.


http://g35driver.com/forums/intake-exhaust/295784-odd-so-i-removed-my-z-tube.html

This guy knows a lot more then i do when it comes to NA OEM mods.
 
Last edited:
Your second argument doesn't really back up your first. I agree with you that a Z-Tube is useless for power. But it's not because it's after the MAF. Think about your first argument for a second. If you make the intake path after the MAF more efficient, then more air would still pass through the MAF and it would compensate accordingly. If your first argument were true, then plenum spacers wouldn't work, and neither would head work because all of it is after the MAF. We all know that both of those mods result in gains. It doesn't matter if the mod is before or after the MAF, if it allows increased airflow, the MAF will see it. The air flows past the MAF due to the vacuum created by your engine, the MAF is not the reason air is coming down the intake tract. If you make anything from the pistons all the way up to the filter more efficient, the MAF will see it and measure it. Most turbo cars use a draw through MAF, by design the turbo is behind the MAF. Does that mean the MAF doesn't measure the airflow? Of course not, the turbo is sucking air through the MAF and that air will be measured.

DaveB's argument (I remember him from the Maxima days, he knows his stuff) is that the factory intake is already tuned w/ a Hemholtz resonator to optimize airflow (similar concept as Motordyne ART pipes). So taking that out would cut power. That point has absolutely nothing to do with your after the MAF argument.

TurTLeG said:
Ur mass air flow has nothing to do with your exhaust. A mass airflow measures the amount of airflow going into the engine. It then makes adjustment in fuel with the info it gets. I am going off that theory. Z tube is 75% noise, 20% pretty and 5% MAYBE in gains. I felt nothing when putting it on, i didn't expect anything, just like every intake system out there. If it made more HP, nissan who had the technology would of put them on all the cars because in 03-05 it was a HP war and now we have a MPG war.

I'm in the process of tuning right now. Reading and looking at the ecu inputs with cypher and adjusting target fuel trims.

The main purpose/ difference on the Fx tube and z tube is a resonator, in a sense to make it quieter. Well maybe ur FX tube is different then my G tube.

Its like a funnel, u can not force more air in other then what the diameter of the hole let's u and the diameter is still the same.


http://g35driver.com/forums/intake-exhaust/295784-odd-so-i-removed-my-z-tube.html

This guy knows a lot more then i do when it comes to NA OEM mods.
Click to expand...
 
Last edited:
Yea i might of missed some points here and there. But my main point is that Z tubes dont do squat BUT make noise.

DaveB is a great guy, full of knowledge. Maybe i blended his knowledge with my own shade-tree understandings. Sadly he got rid of the G35 and gone to a new WRX.

@jumbo, i wish i had done a baseline dyno to see how much power i would of gained from a HFC, spacer and tune. 37AWHP would be very nice.
 
TurTLeG said:
Yea i might of missed some points here and there. But my main point is that Z tubes dont do squat BUT make noise.

DaveB is a great guy, full of knowledge. Maybe i blended his knowledge with my own shade-tree understandings. Sadly he got rid of the G35 and gone to a new WRX.

@jumbo, i wish i had done a baseline dyno to see how much power i would of gained from a HFC, spacer and tune. 37AWHP would be very nice.
Click to expand...

I'm an engineer so I have a hard time swallowing generalizations. It does do squat. In a measureable way. Dynos show that. Is it a big change? No. But it can be maximized with a tune - optimizing the AFRs for the particular intake setup on your car.

It's not just the MAF that controls fuel - the O2 sensor plays a large part as well - after the motor. It sees what the gasses are made of and makes corrections to get the balance of exhaust gasses optimal.

I did the baseline - here is the before (intake, plenum spacer, Stillen Cat-back) and the after with the UpRev tune. This is just one datapoint - the parts you use and the tuner's experience has a lot to do with what power increases you will see on your own FX.

Jumbodyno021510.jpg
 

Attachments

  • Jumbodyno021510.jpg
    Jumbodyno021510.jpg
    42.2 KB · Views: 22
You must log in or register to reply here.
Back
Top