Take a look at the attached picture... What is the purpose of the part labelled #8? I realize it says Resonator, and it appears to just be a dead-end in the intake box. Anything we can do with this to improve sound?



157169-intake.jpg

 

get the 350Z tube or the K&N intake or The Injen intake. all of those will remove all the resinators. this probaly were we losse the 7hp vs the 350z. that intake has some crazy plumbing on it stock : /



<a href="mailto:Carlos3186@hotmail....otmail.com</a>

 

I am guessing that #8 is a duct from the lower valince up to the entrance into the stock filter box, or the stillen box...

I don't know the effects it produces in the way of resonance though?

-Eric

'03.5 Silver/Black | Prem | Perf | Aero | Stillen Hi-Flow | Z -Tube | Grounding Kit | Nismo Oil/Radiator Caps | Solid Allum Pedals | Diamond Matts | Tints | Valentine1 | Hide-Away License Plate!

 

#8 is just it's own resevoir that's usually there to to help reduce sound but I believe it's main purpose is to catch any water that gets as far as the air cleaner box. You'll see those resevoirs/canisters on most cars below the air cleaner box, or off the bottom of the intake piping before the cleaner box, for this purpose (to keep water from going up the intake track from the airflow and into the motor). The other baffles inside the rest of the piping are just there to combat sound. The inside of the G35 intake pipe is actually very smooth and clear on the inside. If you cut it open you'll notice it's pretty much the same as the Z pipe on the inside, just has the baffles and stuff on the outside to cut sound. I believe the small hp difference between the Z and Coupe is not in the intake, i'd probably look at the exhaust instead, maybe the ECU tuning, but i don't know about that yet?

Justin McClanahan
Heavily Modified 95 Infiniti G20
www.InfinitiPartsUSA.com

 

It's a resonator; they are very common. It creates an air dwell heel to attenuate the F/A intake profile and exhaust note at high rpms. Check the link in my sig for close ups of that resonator, as well as the other two on the stock G intake system.


Black/Willow 03.5 6MT, Premium, Navi, Aero, SAT
350Z Nismo CAI

 

JustinP10,

Your conclusions from your comparision of the G35 Air Duct and the 350Z Air Duct certainly differ from mine. My comparision was done with both air ducts in-hand. I noted at least three differences not including the air duct resonators.

Did you actually have both air ducts in-hand when you did your comparision? Better yet, have you ever driven a G35 with and without the Z air duct? If so, for how long? How many days or miles?

What's the basis for your statement "I believe the small hp difference between the Z and Coupe is not in the intake, i'd probably look at the exhaust instead, maybe the ECU tuning, but i don't know about that yet?" Since it's not the air duct in your opinion, please tell us where the real difference is. I suggest you start with the 350Z and G35 Coupe exhaust manifold, cat/downpipe, y-pipe and muffler part numbers. The midpipe part number is different due to the difference in wheelbase.

Another point... a 5.7 hp & 4.2 ft/lbs torque gain for $85.00 is not a small increase to me. Especially when you consider the high cost per horsepower of most other G35 modifications.

What have you done to increase the power of your "Heavily Modified 95 Infiniti G20"? Are we to assume that an $85/5.7hp/4.2 ft/lb mod is insignificant when modifying a G20?

Moving to the original subject, I've run both the stock air cleaner case and the Stillen CAI with and without the air case resonator. To me there was no difference power, however there may be a very slight difference in sound with the stock setup. I ended up leaving it in place.

DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

I made the conclusion after reading it on Cheston's car domain site. Were the people From Techno square said that.
I agree that is not just the intake but I think that it has a lot to do with it. Yes the exhaust could be a source of the difference but if you look at the dynos of the different intakes the ones for the G make more HP then the ones from the 350z. There is lots of evidence supporting this but you need to look for it I guess my opinions are simply based on 2nd hand information but it is still correct. There is no need to get angry about it bud.

This is from cheston's site
"As you can see the intake inlet, this is highly restrictive. Probably why the G35 has less HP compared to the Z from the Factory.. "
As well as this
"The Second inlet reduces noise of the intake but subsequently reduces hp as well."

http://www.cardomain.com/memberpage/282525/10

Here is evidence from Injen
On the 350z they made “Maximum HP Gain vs. Stock: +7.6HP at 5500 rpm”
Now on the G35 they made “---Total Gain: +14.2 HP---“
And I got the g35 data from here http://www.i-m-racing.com/incolairing3.html and the 350z data from http://www.i-m-racing.com/inrdcolairin.html

Also you are misinterpreting what I am saying when I said “I believe the small hp difference” When I said small HP I didn’t mean it as in a bang for the buck since I meant it as in there is only a 7HP difference between the to cars. If you were to go and drive a 350Z which I have done for probably 20 miles then go and drive the G you wont really notice all that much difference in the HP or at least I didn’t. 7 HP at the crank will not be noticed all that much. I agree that for the money the 350Z tube is a good mod but I am not saying that it is going to make a night and day change.

So I do have some stuff to back up what I am saying. As far as modding my G that’s not really any of your business what I choose to do and what I choose not to do. But in fact I have the Nismo CAI on order and I am about to order the RS*R exhaust.




<a href="mailto:Carlos3186@hotmail....otmail.com</a>

 

Carlos,

Now I'm really confused. I thought I was basically responding to JustinP10's post above.

But since you responded I'd like to point out that I'm not angry (mad) at anyone. However, I guess my frustration showed through. IMO, those who automatically or selectively accept and quote other peoples' subjective opinions as fact doesn't help our forum members effectively compare, learn or make good buying decisions.

Not to pick on you Carlos, but as an example, you quoted Cheston's statements... "As you can see the intake inlet, this is highly restrictive. Probably why the G35 has less HP compared to the Z from the Factory." And "The Second inlet reduces noise of the intake but subsequently reduces hp as well." Was this quote a fact or Cheston's or Tadahi's or ??? subjective opinion? Did anyone of these guys complete a detailed analysis of each intake or run back to back dynos on the same car?

I also read Cheston's statements when initially posted several months ago. At that time I interpreted the word "Probably" as a subjective opinion based on a general observation.

At the time something didn't seem right about his statement, I decided to compare my G35 Sedan’s entire air inlet system to my buddy's 350Z's. After removing, inspecting and measuring both systems we agreed on the following;

1 - The G35 Sedan and Coupe (by part numbers) air intake systems are identical. The total area for air supply is approximately 13 in/sq above the grill providing for a ram air effect at speed. [Main opening - 4.625' x 1.625" = 8.775 in/sq; aux supply opening - 13.125" x .275" nominal]. The air supply duct from the MAF (Mass Air Flow) Sensor to the Throttle Body has two rubber flex joints and is designed with resonators to minimize noise.

2 - The 350Z air intake system is supplies air through a 3.5" x 3.5" (12.25 in/sq maximum) hole in the radiator core support assembly to the front of the airbox for a ram air effect at speed. The air duct from the MAF (Mass Air Flow) Sensor to the Throttle Body has a larger OD (0.50) and is a straighter tube with one flex joint and no resonators.

My subjective conclusions...

1 - The Z air case design is somewhat better than the G35's.
2 - Don't agree that the G35's air inlet is "highly restrictive".
3 - Remain uncertain - "The Second inlet reduces noise of the intake but subsequently reduces hp as well." How? Why?
4 - Believe the 350Z air duct offers a substantial $$/HP/Torque benefit over the G35s.

You also provided the following... "Here is evidence from Injen -- On the 350z they made “Maximum HP Gain vs. Stock: +7.6HP at 5500 rpm” Now on the G35 they made “---Total Gain: +14.2 HP---“ Do I believe it? Yep! ... as long as you'll join me in believing all other manufacturer's performance quotes and ignore any independent data to the contrary.

Again, I’m not angry but remain frustrated and will try not to post when so in the future.

DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

That 'resonator' has got to be similar to the one at #3. Nothing more than a quietener which may cost a little hp in favour of a little peace and quiet.

<font color=red>G</font color=red>S<font color=green>M</font color=green>
<font color=red>G</font color=red>S<font color=green>M</font color=green> <font color=black>Silverstone Coupe</font color=black>

 

ahhaha yeah sorry DaveO i came off kinda bad in my post. but yeah i agree with what ur saying and thats a super detailed post ; )



<a href="mailto:Carlos3186@hotmail....otmail.com</a>

 

DaveO, I have held both in hand and they do have their differences, don't get me wrong, they are most definitely different. I however don't see the huge discrepancies some others see, on the inside of the tubes. The Z is ever so slightly more straight, and the G tube does have the weird box on the top of the pipe w/ the hidden louvers and hole going to it, and the G tube has those extra ruffles in it. And i didn't measure with a digital caliper for the exact side difference as far as inner diameter, but it's not that much different between the two. I'd guess the other factors affect it more than the change in ID.
I have installed a 350Z tube on a G35 coupe and after driving it, there is a noticeable difference in intake noise, but I couldn't feel a noticeable difference in power, only heard more engine noise and this was probably 2 months ago? I have not seen the mod done on a dyno and that's why I have asked if anyone has back to back dynos, to prove the hp gain. I'm not saying don't do it, i'm not saying it's a bad mod, I'm just curious, that's all. I'm sorry if I seemed negative about the mod.
I have seen Injen's dyno results on their G35 vs 350Z CAI's and while the G does gain more, why do the two G's gain different amounts of power, if the stock intake parts are the same (between the coupe and sedan)? The difference between the automatic g35 and the 6mt G35 is almost the same as the 6mt g35 and 6mt 350z. The auto g35 gained 12.6 at peak, 6mt g35 gained 10.9 and the 350z gained 8.3. yes, the Z gained the least and the automatic G gained the most so you'd think the G's have a more restrictive intake. But, 1.7rwhp difference in gain in the auto vs 6mt g35's vs 2.6rwhp gain between the two 6mt cars isn't much difference at all. Just the variance of each dyno could easily surpass that small amount. You're talking less than 1/2 of 1 percent difference between the difference of the 6mt cars and the auto vs 6mt G35's overall power. That's a VERY small variance, that's what I'm saying. I've had more variance on a dyno by the alignment, how the car was strapped down to the dyno, tire pressures, etc... If the cars were pulled off the dyno then restrapped down, that could have been something that may account for the difference in power? Just a dumb thought...

I'm not new to modding cars, while I'm probably one of the younger people on the board, I've had my G20 on a dyno probably 50+ runs over the past few years, if not more. Right now I'm just shy of 180whp (~115whp stock) and I've done many inexpensive little things to get there along with some bigger things too (still N/A). I actually go to the road course here in AZ and it's always the little stuff that makes it or breaks it for you... That and I'm currently in the process of modding up a coupe, so all the little stuff will be what makes the car a complete package, rather than just throwing money and parts at the car...
I'm just curious about this mod, as it seems like it could be a very inexpensive, simple mod as it takes all of maybe 5-10 minutes to do and is simple enough for anyone to install and is cheap to boot!
The Z intake tube is very similar to our 91 intake cam mod. The 93.5 and newer G20's had a less aggressive intake cam so swapping a 91 cam into them produces about 4-6whp at peak (~6400rpms) and as much as maybe 10-15whp at redline (7450rpms). If you can find a used cam they can go for $50-75, new i want to say the're about $185. This is one of the best "bang for the buck" mods you can do to a G20. Advanced timing is another great mod that's cheap/free (just pay for higher octane gas) that gains similar amounts of power to the intake cam mod, or more depending on where your timing was at before the mod. I'll take inexpensive power gains where ever and when ever I can find them. I most definitely wouldn't be making the power I am now without them.

As for the difference in motors, the G35's and Z's share most all of the internal parts, headers, cat pipes and even the Y pipes are the same. IIRC, the mid pipe right after the y pipe is where the cars start to vary as far as the exhaust goes. I can get part numbers on any Nissan or Infiniti application too, so I can look into any other possible differences. If you're curious about anything I'd be more than happy to reference part numbers for you.

Sorry if I sounded like a dick in my last post, it wasn't my intention.

Thanks!

Justin McClanahan
Heavily Modified 95 Infiniti G20
www.InfinitiPartsUSA.com