Take a note and read this article. Look at the engine pics and you'll see that the top VQ tuners are utilizing the stock airboxes on their 7500-8000rpms 300whp+ VQ35s. I think this truely proves just how unrestrictive the stock airbox is. Granted, the G35 intake is a bit different than the Z's in that the G has an intake pipe with resonators and the lower portion of the G's intake box is connected to a resonator. All of these resonators can be easily bypassed with the Z-tube and a plug in the airbox resonator inlet which will basically give you the same flow characteristics of the Z airbox.

http://www.jdm-option.com/eng/featur...2/z33_v35.html

 

I couldn't tell if they are using manifold spacers either. All seem to have the stock upper manifold. Except for the crazy twin version.

 

Perhaps its a class requirement? (just playing devils advocate )

 

I believe the 1st place car did have a spacer.

 

After a second look, two of cars (some of the slowest) do aftermarket style intakes.

 

I recently removed my version of the popcharger and went back to the ztube & stock air box. I was curious if removing the lower resonator under the airbox would be more beneficial than plugging it up. I figure it would pull air that I would think would be cooler from the hole as opposed to closing it. Any opinions?

 

the hole on the stock box connects to another box, they form a vacuum almost if you remove the lower box make sure you plug up the hole so you dont lose that effect

 

I assumed since the engine is acting as a vacuum through the intake that removing the resonator would allow it another supply of cooler and fresh air. I may be putting too much thought into something that would not make any noticeable difference. Mainly because the stock airbox is connected to the supply over the radiator and the power duct entrance.

 

I took a screw-on cap from a bottle of Goop, wrapped some black electrical tape around it, and jammed it into the lower airbox resonator opening

 

Unfortunately some seem to not comprehend that every engine is supercharged by the earth's atmospheric pressure [14.7 psi].

Flow benches are standardized to use 28" water column or 1.0 psi restriction from the atmosphere to the cylinder. The entire intake system from air, thru maf, thru TB, thru plenum, thru valves only losses 1.0 psi in pressure.

13.7/14.7= 6.8% maximum possible loss.

Automotive engineers usually appropriate individual losses to approximately 1% for air box, 1% for filter, <2% for MAF [usally run 7"W.C.~~1.7%], 1% for TB, so from inside TB thru plenum, thru runners, thru valves leaves 2.1%.

Inexpensive manometer type gauges can measure the pressure loss across any component at peak air flow to prove the EXACT loss of pressure thru any component.

Search Google for "Dwyer Manometer" in inches water column.
Careful about measuring after TB as idle and cruise so called vacuum can suck the diaphram out of sensitive equipment.

People who sell intakes, filters and mods don't really want buyers to understand how little these things accomplish.

Become your own engineer and measure things.

Ebay Dwyer gauge or Dwyer manometer to find 50+ items.............0-10" and 0-30" W.C. would be a good starting set.

http://cgi.ebay.com/Dwyer-Digital-Manometer-475-1-Mark-lll-NEW_W0QQitemZ320069431611QQihZ011QQcategoryZ50965QQrdZ1QQcmdZViewItem

 

It's a conspiracy. Now back in your hole before you **** off everyone with a $300 intake

 

It all started when I bought a K&N cone filter, before it arrived I tested the stock air box and filter [loss before the MAF]............yes the K&N was 4.2" W.C. better than oem ................4.2/27.7= 0.15 yes a glorious 0.15psi improvement 0.15 x 6.8%= 1.03%..............3 flywheel HP at best.

Except in SUMMER when the heated underhood air decreased the power by 1% for each extra 11F above outside ambient..............always use some kind of cool ait ducting or just keep oem cold air system.

Ever wonder why many dyno shops test with hood open, the moment they see some of these non ducted intakes?

An inexpensive remote thermometer [20' wire from radioshack] is invaluable in measuring the underhood air flow temp in traffic or use the integral IAT in the MAF via OBD2 scanner.

All about air pressure into engine and its temperature.

If you study the ecu programming you will see the summer protective program which watch coolant and air temp to start reducing ignition advance to protect the motor when coolant get above 195F and the air temp gets above 90F [at the MAF sensor]..........fuel temperature is also monitored in the tank.

Happy engineering.

 

Yeah, I figured at had to flow a little better because I do notice a bit more induction noise with the K&N filter vs using a paper filter. I can't feel a difference in power, but the induction noise increase is fun.


My thoughts exactly.