Ok, so I won't bore anyone with details like facts, or dyno data.
My goal is better performance without more noise, or looking nonstock.
I am old, and I don't want to deal with shifting, so I have an AT.
Clearly that has some disadvantage moving the power to the wheels
I have been very happy with the car (owed about 14 weeks now)
I thought I'd offer some opinions and observations on mods I have done.

1) Z-Tube (www.everythingG35.com)
Frankly what is the point. It really does nothing but make the car louder.
A wasted effort in my book.
PRO:........... None that I can Identify
CON:........... Makes the car louder, with no useful advantage
COST:.......... About $75
INSTALL TIME:.. 10 - 20 minutes

2) Stillen High Flow Air Box. (www.everythingG35.com)
Frankly the best solution I have seen IF you are going to replace the intake/filter.
At least it isn't sucking anywhere near as much hot engine air as most of the supposed
'Cold Air Intakes'. I modified the housing to seal in the compartment so it only draws
air through the normal intake vents as well as a few other holes to the grill area.
PRO:........... Seems to offer some performance at WOT and/or High end of RPM range.
CON:........... Loud, damn is that thing loud when you floor the gas.
COST:.......... About $180... I am not sure it is woth it.
INSTALL TIME:.. 60 - 90 minutes including the mods I did to it

3) Motordyne Plenum Spacer 3/8" (www.motordyneengineering.com)
This Mod ROCKS !!!, absolutely showed noticable improvment as soon as install
was done. Without a doubt improved pulling and acceleration through the entire
RPM range. It also appears to have improved my gas mileage.
PRO:........... Great performance improvement, absolutely great.
CON:........... NOT A SINGLE DOWNSIDE !!!
COST:.......... Depends on size and if you get in on a group buy ($150 - $240)
INSTALL TIME:.. 40 minutes

4) Grounding Gear 5AT Performance System (pm GordGee on this bulletinboard)
This Mod ROCKS !!!, absolutely showed noticable improvment as soon as install
was done. Without a doubt a win all the way around. I got the full blown 10 wire
(7, +1, ECU, TCU) system. The car is smoother, it shifts like a madman.
Now being that for 25 years I have done microcontroller work with a lot of
sensor inputs, I knew it would improve things like smoothness, shifting etc.
I had no idea how much I would feel the improvement - Jaw Dropping...
PRO:........... Great performance improvement, absolutely great.
CON:........... NOT A SINGLE DOWNSIDE !!!
COST:.......... Depends on kit you buy, if you have an AT, get the full blown
10 wire. Send a message to Gordon for details.
INSTALL TIME:.. 120 minutes (also doing the connect to the tranny is a bitch
but well worth it)

In short....

Don't waste your time or money on a Z-Tube, unless it is worth $80 to you just
to make your car louder.

Likely not worth bothering with a CAI, but if you insist The stillen is likely the
best solution.

Run, don't walk to get your Plenum Spacer from Motordyne... You will be thrilled.

Run, don't walk to get your Grounding Gear system. Don't bother with the others out
there like Stillen, or Nismo, etc. Absolutely don't cheap out. Get the best kit
available (10 wire for an AT, and 8 Wire for the MT).

I will do High flow cats in the next few weeks, and expect a good result given
the additional flow. As soon as TechnoSquare has an ECU update for the '05 I will
do that also.

 

My take:

Z-Tube: Make the engine louder definitely. Not sure about performance improvement.

Plenum: Same as Sickone's observations. Highly recommended.

K&N Filter: Makes whistle sound~ good thing is that if you use synthetic oil you don't have to change the filter every 3000 miles.

 

Gotta disagree about the Z tube being useless.

 

ya some dyno tests have shown a slight increase in the upper RPM band w/ the Z tube, however I believe you lose a little on the low end.

 

thanks for your time and input... much appreciated. u've made my decisions much easier now.

 

My thought exactly!!!


Thanks for the write up.!!!!!!

 

In reference to the Z-Tube... As I said when I started, these are my impressions and observations.

I would be interested in what others think (sorta the point of this thread).
For me, I noticed a lot more noise (obviously, since the only real difference between
the Z-Tube and the stock Infiniti tube is the resonance chamber).

It is certainly possible that the extra bellow section where it attaches to the throttle body and the resonance chamber cause more turbulance and impeed air flow... But I doubt it is a measureable amount.

I would love to hear more feedback on it though.

In any case, my feedback here, and hopefully the feedback of others that post will help guys thinking about some of these mods to spend their time and money on those with the best return.

My wife keeps asking why I spend more time talking too, and caressing my G35 than her.... I keep telling her, if she was that young and sexy I would spend more time with her

 

Thanks for the write up.

The only power mod I have right now is the Z-tube. I was well aware that it did very little for performance, but I wanted a little more induction noise. My last car was a 96 Maxima with a bunch of NA mods and what we called the "hacked stock airbox". If you think the Z-tube is loud, you should have heard the Maxima I was actually a bit disappointed in the induction noise of the Z-tube because it wasn't as loud as I was hoping for. I do love the sound though and it's perfect for the character of the car. My car seemed a bit more responsive with the Z-tube, but I'm also aware that increased engine noise is most often mistaken for increased performance.

 

So what is the consensus about TS flashes bringing the redline up. DO you guys think our cars can handle the higher redline without the internal improvements the 05's have for thier higher revs? THis is becoming an issue for me as I look to mod further and cost effectively.

 

I'm sure that our cars '03-'04 can handle the higher revs, but I haven't seen a dyno yet that indicates you can gain any HP beyond 6500 RPMs. In fact I seem to remember seeing a significant dropoff after 6500 RPMs on some dynos.

I'm searching for the dynos, but I can't seem to find them right now.

 

DaveB - if you want more induction noise, add the Stillen CAI/High flow box - you will get your wish

As to TS's ECU reflash, it bumps the redline cutoff to 7100rpm from the stock 6600 or 6700(I forget) very doubtful that would do any damage... it would make sense to use it just to prevent being bangged right at cutoff, rather take it to 7100 all the time.

As far as power gains at 7100 vs 6600, there are a number of things that come into play. First - how did Nissan implement the revlimiter ??? Some have said that at least part of the process is that they run super rich on the injectors when you hit the limiter. (I have to assume in a drive by wire car they simply kill the throttle), but if it is running really rich, you must correct that first to see what is up in those last few hundred RPMs....

For me, the advanges are obvious...
1) those that have gotten have shown dyno's with improved power across range.
2) With an AT, I only have 5 gears, not 6 like the MT, so If I am in 'Haul *** Mode' and am using MM shifting, the higher I can take it prior to a shift, the better, so that at shift to the next gear I am still in the power band.

 

Where do people get this stuff? Do they make it up? At the CFL dyno day the z-tube did NOT lose hp or torque on the low end, it was the SAME AS STOCK until ~3000-3500 rpm's then it made an average of 5-7rwhp and rwtq all the way to redline.

This is a NISSAN stock intake w/o resonators, it is good.
It removes resonators which slow down the G.
These resonators baffle sound, which restrict air flow.
The z-tube is a good mod for $80.
Finally... no, you cannot feel 5 rwhp!

I wish people would stop posting stuff that is inaccurate. Please show me a dyno where the z-tube loses hp and or tq in the lower rpm range. Please! (BTW, I'm holding 3 dynos that prove otherwise. ) Also the SoCal Dyno Day gave props to the z-tube as did the Golden Gate Dyno Day.

 

Roneski, If you have breathing mods that continue to make hp up to redline, then by raising the rev limiter you can make more hp (torque will be falling off at this point). This is the SOLE reason Doug Stewart of Crawfordzcar put the TS ECU reflash on his Z. His stock intake (z-tube), Crawford Plenum, Crawford Headers, Crawford Cats and Borla TD Exhaust were making so much hp that he wanted to increase the rev limiter. After 8 iterations with Technosquare he gained about 6-8rwhp because his 350Z kept making hp up to redline.

BTW, Doug told me personally that he was not "running lean" with these mods and actually had to keep working with Technosquare to get their reflash from making him "too rich" in some rpm ranges and "too lean" in other rpm ranges.

 

Although I totally agree with you about the Z tube (I love it...it was my first mod in combo with the K&N air filter, and I do feel a power increase in addtion to the much improved sound above 3,500 rpm), what I can't figure out is if "Finally... no, you cannot feel 5 rwhp!" -- then how can all those people who now have a 3/8" MD plenum spacer say they defintely "feel" a difference (including sickone who started this thread and knocked the Z tube)?????

..."Motordyne Plenum Spacer 3/8" (www.motordyneengineering.com)
This Mod ROCKS !!!, absolutely showed noticable improvment as soon as install
was done. Without a doubt improved pulling and acceleration through the entire
RPM range. It also appears to have improved my gas mileage.
PRO:........... Great performance improvement, absolutely great.
CON:........... NOT A SINGLE DOWNSIDE !!!
COST:.......... Depends on size and if you get in on a group buy ($150 - $240)
INSTALL TIME:.. 40 minutes" - sickone

Can an additional 5-7HP be felt or not????

 

If the Hp increase and Torque increase are actually increased throughout the entire rpm band, then yes you will feel 5-7rwhp.

The increased volume plenums (Crawford) and the Motordyne Spacer do increase the Hp and Torque over the entire range, so I'm not surprised that people say they feel the increase.