It's a lot easier to feel increased torque than horsepower although horsepower is directly derived from torque.

 

hehehe man calm down guys....

I didn't really knock the Z-Tube, I said it was my least favorite.
I certainly would be blown away to see 5 - 7hp with a Z-tube only.
I am not saying I don't believe it, but I am certainly skeptical.

The same 5 - 7 hp is what dynos showed for the motordyne spacer, and you
feel it without a doubt.

So, remember I was offering my 'impressions and observations' and the point is to bring up these discussons.

I would love to see some dyno data on z-tube only mod.

One thing that doesn't add up to me in the comments was the statement that
"These resonators baffle sound, which restrict air flow"
First there is only one resonator hole, and NO BAFFLES in line with the intake tube. It is a hole on one side about 3/4" leading to a resonator. My guess is it is a tuned port... i.e. it is not restricting air flow, it is just producing an antiwave to the sound being generated.

I have great interest in the subject (and all other related issues) so please post the data, results, impressions, etc. If the dynos were done with
a a stock setup, and then with a Z-Tube and K&N drop in, you must also account for how much the K&N did to help breathing.

i.e. are the dynos with no change to anything other than adding a z-tube ?


As far as would you feel 5 - 7 RWHP over 3500RPMs... without a doubt you would.

Also, to be accurate I wasn't the one that said the Z-Tube reduced lowend.
Nor would I believe it would, it makes no sense

 

I have K&N, Z-Tube, and 3/8" Spacer - I'd do all of them all over again. Honestly I can't feel a performance difference from the K&N and Z-Tube, but I enjoy the new roar under the hood. The plenum spacer is a different story - DEFINITE power increase, improved throttle response! D E F I N I T E !

 

I have the exact same setup as you, except I have 7 wire grounding kit bought it from ebay. My mods are in chronological order as it appears from my signature.

After installing 7 wire kit, I felt smoother shifting. The delay I had from 2nd to 3rd was gone after installing 7 wire grounding kit. (I got this kit from ebay not from Gordgee's GG.) Not sure if Gordgee's kit would felt anything different, but I know his kit is definitely a quality piece.

I didn't feel anything with K&N drop in.

After installing Z-tube, I "felt" the air flow is smoother. Definitely added FINE roar in high RPM and no difference during normal driving.

After installing Plenum spacer, I "felt" less air flow restriction, especially during WOT and revving faster to high RPM.

All of these are how I "felt". No numbers to prove if my butt dyno has any real HP or torque increase. Personally, it's only fair for me to post how I "feel" from my daily driving experience and not include any statements relate to say "power increase". This kind of statement is just too controversial because I don't have any numbers to back up what I'm saying. With that said, there are others who had already proven with data on these mods, so it's useless for me to prove how much increase I have in comparing to other's G because I know I won't have the most powerful G.

Sickone: I'm with you. I'm already past the age of adding "noise" to my G. At age of 32, I want performance and quietness. Though, we should all know that modding to increase hp and torque with increasing "noise" is unavoidable most of the time. However, IMO, plenum spacer is the mod that achieved what we are asking for. I also wouldn't mind the z-tube because it didn't add any "noise" during normal driving and sounds pretty sweet during WOT.

 

As Far as Stillen CAI and Z-tube are concerned (I have the UT carbon tube). Just came back from the dyno today and the combo added 3,7 crank hp. I'm pretty happy with it but cannot claim I can butt-feel it.

 

First: The plenum spacer claims to gain MORE than 5-7rwhp. If that's true then I can imagine that people would feel the gains. I'm still waiting for Joe Blow from Idaho to do an independent dyno and not a buddie of a buddie of the guy who makes the spacer. I'm impressed with all of the positive hype, but all of the reviews I've seen are from people in CA who either know the manufacturer or got a "good deal" on their spacer. Not being negative, I'm just waiting for an independent, non-influenced pre and post dyno run to convince myself of the "better than Crawford" gains.

Second: The dynos are all of 2004 5AT's: stock G35, a G35 with the z-tube and popcharger (these are the only mods) and a z-tube with stock airbox and paper filter (these are the only mods). At the top of the dyno chart it tells you that the green line is stock and the red and blue are the stock intake and the pop-charger.

Also, it's difficult to compare the numbers "down low" because most dynos do not show the first few thousand rpms in 4th gear since the shift from 3rd to 4th is near redline and in 4th gear the car is above 2000+ rpm's.

 

SickOne,

I think the biggest single gain you will feel will be the High flow cats!!!

I just tried some resonated test pipes.....car ran like a beast....but I couldn't stand the loudness and gas smell!

I removed them last night and installed a set of the revised Kinetix hi flow cats.
I really can't tell much difference in performance vs the test pipes and they sound much better for my taste.

Plus....I am doing my part to save the ozone layer.....

 

Is the loudness difference big vs stock cats? I'm consiedering installing the high-flows but the car with stock exhaust and z-tube is loud enough for me.

 

Neffster: I certainly understand you desire for 'independant data' on the spacer. I think the same way, and decades in engineering forces you to think that way.

I believe there were some other dynos (I thought) other than the SoCall ones.
Now to be clear, I did meet Tony to pick up my spacer. But I don't know him, am not friends, etc. He is a hell of a nice guy. The price I paid was what I paid, and my review would have been the same had I paid double.

Hopefully some other will post dynos, and aid the need for data.


There are many who think grounding systems are BS, and I would certainly understand, as it is not obvious. Hell I have engineers with 20 years experience who say crap like "It doesn't need a ground plane, it's digital"... wrong...
I would suspect the results are not as dramatic in an Manual Tranny, but in the auto it is a must have...

OldVFRGuy... I will be ordering here in a week or two, then I will figure out if I will install or just have a shop do it. I am gonna go with the crawfords. I want the flow, but I will leave the exhuast stock to reduce noise.

 

I don't think so....but it is hard for me to tell.
I have a Y pipe and Greddy Sp2 exhaust also.

I think the high flow cats may add a little more noise...but not much.

 

Hey Neffster, can you direct me to a dyno plot that runs out pats 6500 RPMs? I know that I've seen a couple before but I can't find them.

The ones that you posted here show a sharp drop off around 6500, but that's probably just because that's where they let off the gas.

 

I haven't seen one... Not sure what you're referring to.

Actually that's where they bounced off of the rev limiter.

 

My bad neffster, I meant the pop charger, not the Z tube. And i'll look for the dyno's that were posted by our members in our regional forum. startertan has a popcharger/ztube combo and posted his dyno on my350z, unfort. the site has been down for a few days. Once its back up i'll post you his dyno results. I want to say w/ his pop charger/ztube he had about 231 rwhp?? Dont quote me on that, the dyno day was about 3 mos ago. Another member ran stock box z tube & kn filter and obtained better numbers and they came to the conclusion that the pop charger was causing very slight loss in low end. That is why most of the intake related posts/threads on this forum that relate to pop charger, people say the pop charger is basically to increase sound and does not really increase performance and why alot of ppl decide to go w/ the ztube/stock/k&n route rather than z tube/popcharger route

 

With my plenum and near 5.0 Airflow on a techtom AF sensor (stockers run around 4.2 at WOT< I believe), I would hope my car could make power above 6600. In fact before mods I used to shift as I felt power drop at around 6000, now I forget to shift as it keep pulling and pulling. I believe if I was at the track I would want a higher redline anyway so I could shift at a higher point into the next gear and put the power band to work quicker.

The Z tube and modified airbox alone may warrant the higher rpm's.

PART II________

Does anyone with the TS flash have comments on what driving a cold car is like. If the safer maps are no longer in the ECU, I would guess you have to be careful on your own and not risk your engine since it effectively is always on a high performance (the only) map.

I've heard alot of people mention the 05's were beefed up internally to handle the higher redline and it worries me a bit. Also Doug Crawford's experience makes me hesitant as well. 6 try's from philly would take me a month probably and I have no dyno in my area. Whatever happened to the piggyback that guy wanted 850 bucks for?

 

My order of mods:
1) Z tube--no butt dyno change, though I could tell that the power did not drop off in the high RPMs as much. Probably worth it.
2) Grounding kit--6 wire kit on my 6 speed coupe. Could not really tell a diff.
3) High flow cats--I could feel a little bit of power increase throughout the RPM range. I think it's worth the $$.
4) Motordyne 3/8" spacer--again, I could feel the power increase throughout the RPM range, and even more noticeably above 4500 RPM or so. Worth the $$.

Next mod: lightweight wheels with lighter tires. That might be all the mods I do.