I was at the Stillen 350z/G35 customer show last month and grabbed a flyer from the sponsered car there. My first time on the site was great I notice so many things and topics to look at, I was hooked.

I have attached a picture of my 04 G coupe DG/Black (Auto) with Volk GT7's on Toyo T1R Proxies, Stillen Anti-Sway bars and Front facia, Injen cold intake, Blackened front badge and clear side markers. I plan on getting the Stillen Exhaust system and have not decided on the brakes yet.

So I hope to hear and learn from you all and share any knowledge that I might have.

"Drive Fast, Take Chances" but be safe too.

Hey man!

You were parked near me - Good to see you on board!

Welcome, and let us know if there's anything we can do for you!

Nice rims! I would also consider the NISMO exhaust; from what I've read, its one of the better sounding systems out there. For me, brakes aren't really necessary as the G already has excellent brakes; maybe better pads/rotors first?

Congrats on the car, and welcome to NICO!

Nice wheels for sure!

Welcome to NICO!

Z

Welcome to NICO - very nice car!

Welcome to Nico! It's great to see people who attended the Stillen Meet.

Thanks for the info on the Nismo exhaust. But when I was looking at my options I noticed that the Stillen put out almost 16hp and I couldn't find one that was even close to it. I will have to listen to the Nismo exhuast, I am sure it does sound pretty nice. I guess I have more research to do to really make sure I get the right one.

Take care and thanks for the warm welcome.

I really liked what you did with your car too. I have a lot of plans for my car and when I am done I will post some more photos of it. I have some ideas that I am throwing around regarding my wheels and think it will be original and very nice too.

Thanks to your too for the warm welcome, everyone seems like one big family.

See ya'

Didn't see a plenum spacer in your mod list...mines on its way, and from what I've been reading, its good for 10+HP!

What is a plenum spacer?

I wouldnt think that one exhaust woudl give much more HP than one... Its never "apples and apples"!! Assume all exhaust mods will give oyu less than 10HP! which is HARDLY noticeable but it will sound cool, which IMO on most modern cars is the only reason to do exhaust!

Stillen web site shows the dyno with normal and their exhaust and, as they say it no other exhaust system out there comes close. The average hp gain I have seen is 8-10 for a cat back system. So to get an extra 6 or more horsepower for about $400 more is worth it, to me.

The point im trying to make is even with DYNO testing you can easily mess with the numbers..... not everyone uses the same dyno or more importantly the same car! Even completely stock brand new cars can have 10-15HP differences!

On paper, 10HP seems like a lot, but it REALLY isnt. 20HP is about where it becomes noticeable... 10HP you think to yourself "MAYBE i feel a difference!", but for sure your passenger wont feel any difference. 20HP your passenger should feel it and you should as well...

Remember theyre trying to sell parts... Now, if you go and find people on the internet that can prove that it gets 16HP and all the other ones dont, then ill shut up..... But I doubt people even dyno their cars before/after mods.... If it were me, find the one you think SOUNDS the best... The bottom line is unless I see real world data ON THE SAME car i will raise my brow at 16HP unless theres other mods like intake , headers, plenum spacers, etc..

Nissan did a great job from the factory squeezing every last HP, so its pretty hard to find cheap HP!

You are right numbers can be cooked to make a certain product look better then the next, it happens with car manufactures all the time. The number they post as hp and torque are at the engine, they don't tell you you will loose most of that before it gets to the wheel. Each car will have different horsepower and torque readings but the difference is not as much as you think. If you tested 10 Chevy Sprints you would get 10 different readings. But if you test 10 Porsches you will more then likely get 1 to 3 different readings. The tolerence in a Porsche, Ferrari etc. is much less forgiving for errors then a sub standard vehicle. The same will be for many after market products. You can't say a $200 exhaust system will work as effectively on a high performance engine as a $800 or $1200 system that was designed and tested for that vehicle specifications. But back to what you were saying, yes numbers can be cooked to give one product an edge in sales but if the news gets out from the buying public in forums like this they will not sell many exhaust systems.

yzarcur wrote:What is a plenum spacer?

From MotorDyne Engineering:

http://www.motordyneengineering.com/techinfo.asp

How the Motordyne Plenum Spacers Make Horse Power on the 287 HP Engine

The Motordyne plenum spacers alleviate an airflow restriction that exists above the first two intake runner inlets. The inside top of the stock plenum is very close to the top of the lower plenum runner inlets. There is only about 1/8" clearance between the first two inlets and the plenum cover. This creates a significant air flow restriction that reduces engine breathing and power output.

If the height of the flow area above the runner inlets were increased it by 1/8" it would reduce the flow restriction (pressure drop) by a factor of 4. If the height were increased once again by another 1/8" or to a total of 1/4" it would reduce the pressure drop by a factor of 9. If the plenum were lifted by a total of 3/8" it would reduce the pressure drop by a factor of 16. If it lifted by 1/2" it will reduce pressure drop by a factor of 25.

Reduction of pressure drop is asymptotic and inversely proportional to flow area. In other words this means the greatest benefit will be realized within the first 1/8" of added height. Fluid dynamic theory, dyno data and flow bench test data support this.

As an example, assume the pressure drop above the intake is equal to 3 PSID at high RPM. By raising the plenum even 1/8" the pressure drop will decrease to 0.75 PSID. That's a significant inlet pressure recovery that will translate into more horse power!

A 1/4" spacer will reduce that same pressure drop to 0.333 psid.A 3/8" spacer will reduce that same pressure drop to 0.1875 psid.A 1/2" spacer will reduce that same pressure drop to 0.120 psid.

Although pressure drop is continually decreasing, the rate of change rapidly diminishes beyond the first 1/4".The same applies to gained HP. The pressure drop above the runner inlets is so dramatically reduced the added HP gains are also rapidly diminishing.

The attached plots are for three sets of tests 1/2", 1/4" and baseline in that order with three pulls each. The results of the 3 pulls per set were then averaged together. These test conditions were very tightly controlled to provide accurate, repeatable results.

Same dynoSame daySame tank of gasSame ambient temperaturesSame engine temperaturesSame ECU starting conditionsSame fan positionSame fan settingSame everythingThe car wasn't even taken off the dyno.

So even if the absolute values aren't correct, the deltas are. These plots show the largest change in gain comes within the first ¼ ". There is only a 1.664 HP difference between the ¼" spacer and the ½" spacer. And weather the car is NA or FI, the reductions in pressure drop will always be proportional to the air mass flow rate. Thus for a given spacer size, FI applications will see even greater gains due to the higher air mass flow rates.

So for NA or FI, nearly any kind of plenum mod is a significant improvement from the stock configuration.

Motordyne Engineering

Welcome.

Very clean ride. A nice drop will make things look even better.

Thank you, that was some explination. I am very impressed with the results and will need to know on how to get one and install it.

Is there a plenuim that is better then another?

I agree, I had a set of Eibach springs all set up for a comp but that fell through. I plan on getting them after I get the exhaust system.

yzarcur wrote:Thank you, that was some explination. I am very impressed with the results and will need to know on how to get one and install it.

Is there a plenuim that is better then another?

From what I've read/heard the 5/16 one is the best, from Motordyne. There is another company, Skunkworks, that people have not had luck with...Install is strait-forward, remove the engine cover (4 bolts), remove the upper air intake (8 or so bolts), drop in the spacer, and put everything back together. The "spacer" is nothing more than a large metal gasket. Probally takes about 30 min to do (waiting on mine in the mail), and most of the time is spent on taking things apart/putting back together. Do the JWT popCharger/Z-tube at the same time; your car will sound very different! I'll post pics of the install...(adding another 5 min to the install time )