My opinions and condensed multiple air intake system test results.

You guys may find this information of interest. Take it for what it's worth to you.

First point that's often overlooked. G35 / 350Z ECMs back off timing as coolant and air temps increase above certain levels. (Sources - Infiniti/Nissan Service Manuals & Technosquare.) Edit 2: Also verified by numerous Techtom "timing" runs.

All vehicles tested were G35s.

Primary equipment used:
Techtom CMX-100 N2. Provides the real time info as it's seen by the ECM. It also has a peak-hold feature so you can see the maximum value the ECM has seen. It measures...

Air Flow Meter Voltage (V)
Battery Voltage (V)
Ignition timing (degrees)
Intake temp (F) (at the MAF sensor)
RPM (X10)
Speed (mph)
Water (Coolant) temp (F)


DaveO & Alagolfer's test results.

STILLEN CAI & 350Z AIR DUCT - Insulated
Air Intake System: Stillen CAI w/Popcharger air filter & Z-tube - System, including MAS Air Flow sensor, is fully insulated.
Ambient Temp (dash readout): 98F
A/C System: On
Radiator Fans: On or Cycling
Water (Coolant) Temp: 190F - 210F
Intake Air Temp @ Idle for 2+ minutes: 112-115F
Intake Air Temp @ 60mph: 107-109F
Approximate Cool Down Time: 2+ Minutes

STOCK AIR CASE & 350Z AIR DUCT - Insulated
Air Intake System: Stock Air Case - K&N Drop-in air filter & Z-tube -System, including back of the air case, MAF sensor and Z-tube, is fully insulated.
Ambient Temp (dash readout): 86F
A/C System: On
Radiator Fans: On or Cycling
Water (Coolant) Temp: 190F - 200F
Intake Air Temp @ Idle for 2 minutes: 112F -115F
Intake Air Temp @ 60mph: 96F -100F
Approximate Cool Down Time: 3+ Minutes
Temperatures change more slowly than with the Stillen setup.

POPCHARGER & 350Z AIR DUCT
Air Intake System: JWT Popcharger
Ambient Temp (dash readout): 62F
A/C System: Off
Radiator Fans: Off
Water (Coolant) Temp: 185F - 192F
Intake Air Temp @ Idle for 1 minute: 158F
Intake Air Temp @ 60mph: 84F
Approximate Cool Down Time: 3+ Minutes

POPCHARGER & 350Z AIR DUCT - Insulated
Air Intake System: JWT Popcharger w/heat shield & Z-tube - Back of the velocity ring, MAS Air Flow sensor and Z-tube are fully insulated.
Ambient Temp (dash readout): 97F
A/C System: On
Radiator Fans: On or Cycling.
Water (Coolant) Temp: 190F - 210F
Intake Air Temp @ Idle for 5 minutes: 134-138F
Intake Air Temp @ 60mph: 116F
Approximate Cool Down Time: 2+ Minutes

DaveO & Alagolfer's notes:

Test drive after swaping out the insulated Stillen CAI for the insulated stock air case / K&N drop-in air filter. Initial impressions... where the heck did the mid-range and top end power go!!!! There may be a very, very slight amount of increase in torque at partial throttle, but the car now "boggs" off the line at full throttle.

During back to back insulated Stillen vs insulated Popcharger tests, the Popcharger's temps were about double Stillen's. For example: At idle, when the Stillen system was about 15F above ambient temp, the Popcharger’s temps were 30-35F above ambient. At 60mph the insulated Popcharger system was an average of 10F higher than the insulated Stillen system.


Gsedan35's Techtom Test Results (condensed & edited by DaveO).

K&N 350Z TYPHOON - Modified & Insulated
Air Intake System: A highly reworked K&N 350Z Typhoon System. A totally sealed ram air system with a 3" inlet (vs the original 2.5") and a larger open ended K&N filter. The air box has a carbon fiber lid, but the box itself is metal. The box and upper metal tube are insulated with sheet fiberglass and reflective insulation. The air scoop for the system is located in a high pressure zone in the front bumber.

IMPORTANT!!! The first test was with the airbox lid removed. This allows for a popcharger like setup only with a 3/4 heat shield.

Lid off airbox test
Ambient Temp (dash readout): 99F
A/C System: On
Radiator Fans: On or Cycling.
Water (Coolant) Temp: 183F (@ test start) - 192F
Intake Air Temp @ Idle on initial start: 132F

After 4 blocks, stopped, opened hood, checked intake temp.
Intake Air Temp: 138F
Closed hood and drove off again...
2 blocks at 45mph - 114F air temp
30sec stop - 149F
2 blocks at 45mph - 120F
10 sec stop - 138F
2 blocks at 30mph - 122F
1 minute stop - 149F
4 blocks at 65mph - 109 intake
End lid off testing.

Test with air box lid being re-installed (full ram air system).
Ambient Temp (dash readout): 99F
A/C System: On
Radiator Fans: On or Cycling.
Water (Coolant) Temp: 192F
Intake Air Temp @ Idle: 123F
Test Speed - 65mph

.3 miles - 107F air temp
8.6 miles - 102F
20 sec stop - 109F
After .1 mile - 107F
30 sec stop - 111F
.2 miles - 107F
45 sec stop - 114F
.2 miles - 109F
1:15 sec stop - 116F
.6 miles - 105F

Next day tests.
Ambient Temp (dash readout): 100F - 101F
A/C System: On
Radiator Fans: On or Cycling.
Water (Coolant) Temp: 192F - 195F
Test Speed - 65mph

8 mile pre-test trip - 107F air temp
2 minute soak test - 111F
3 minute soak test - 113F
4 minute soak test - 114F
.4 miles @ 65mph - 111F
1.7 miles @ 65mph - 107F

Second day heat soak test.
2 minutes heat soak - 123F air temp
3 minutes heat soak - 127F
.1 mile @ 45mph - 116F
.4 mile @ 45mph - 113F
1:15 sec stop - 120F
.1 miles @ 45mph - 113F
.8 miles @ 45mph - 109F

Gsedan35's notes:
Perviously, I was running a Z-tube with the setup and no insulation. But when testing in town revealed fast rising heat soak numbers in town and slow cool down's, I elected to insulate the metal tube that the K&N came with and install it in place of the Z-tube. In addition to dramatically lowering heat soak problems, I got a noticible improvement in top end power, wasn't suttle either.

Edit: I found comparing ambient temp and air inlet temp at idle vs idle time to be very interesting. When the ECM's air temp reaches 149F to 158F in under 1 minute at idle it's called heat soak in my book.

Edit 2: If this info isn't scientific enough to meet your standards or there are too many variables for you to follow, then please disregard this post. As I said above, take it for what its worth to you.


DaveO
03 G35 AT Sedan / DP / Willow / Premium / Sport / Aero / Mods / 262 & 260.8 <P ID="edit"><FONT class="small"><EM>Edited by DaveO on 10/07/04 03:00 PM.</EM></FONT></P>

 

From my first read of DaveO and Alagolfer's test, it appears that there are just too many variables for me to come up with a clear winner. Ambient temps varied by quite a bit (by as much as 36 degrees on the extreme), some cars had the A/C on, others were off. Some cars had radiator fans on, others were off.

Good data! I just am not sure what to make of it all.

 

Not sure to make of the data, but interesting none the less. Heres a free hat for your effort

2003 BLK/BLK 6MT Injen, clear corners, Eibach sways and springs, tint
My G on a photo shoot. More to come!


360398-pickle hat.JPG

 

I concur. Good data but I don't see how too much could be concluded yet. Too many variables not controlled for, particularly the wide variety of temperature. Temperature diff is not linear. The temp change over a given period of seconds with happen at a different rate the closer it is to the temperature of the operating temp of the engine, right?

In other words, holding everything constant but the outside temp, going from a stop to 60 mph when it's 30 below zero there will be a big difference in time it takes to cool 10 degrees compared to that same run on a 105 degree day. Thus, unless you're comparing time vs. temperature in the same conditions, one can't really conclude anything.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats

 

very interesting. good job guys. is there a thread where there are instructions on how to insulate? perhaps a DIY? thanks for all the work.

G35s6mt/TSecu/350Z Springs&Struts/K&Nfilter+Z-tube/StillenDualExhaust /6WireGroundKit/KinetixHighFlow

 

Nice work guys.
As my added .02
DaveO used his handy-dandy Techtom on my car at dyno day.
Air temp: ~90
Water temp: 190-210
A/C: On
Intake air temp @ idle: 107


04' G coupe/TB/Prem/Sport/Nav/35% Tint/Injen CAI/Injen Exhaust/Clear corners/V5 Plenum/GroundingGear/Nismo caps/Custom TS ECU/Hotchkis Sways/Volk silver GT-7/Falken Azenis Tires
Plates: 1REVER1

 

I did my amature testing in Aug. at about 93 degrees, high GA humidity.
My heat soak numbers were signifinatly higher after 5 min idle.
Anyways...cooler air is happy air.

"I like you.....You remind me of myself when I was young and foolish"

360554-MVC-011S.JPG

 

i think i would rather have hot air than for my engine compartment to look like that

 

Well you would think the cooler air outside would cause those cars to come with better results but they didn't. On a hot day, with the stillen cai and insulation, it performed the best per the results I see.

2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com

 

"First point that's often overlooked. G35 / 350Z ECMs back off timing as coolant and air temps increase above certain levels. (Sources - Infiniti/Nissan Service Manuals & Technosquare)"

What does the manual say exactly. Q45 said timing is reduced when ambient gets above 90F among other things.

Where would this temp be taken? Is it ambient or intake temp? Seems like intake temp would be over 90F 90 % of the time depending on where you live.

I notice my car sounds a whole lot different before the coolant temp warms up. A lot meaner. But you can't take advantage of it because the coolant temp is not up yet. wtf.

2004 G35C 6MT Black. Killer.

 

Holy Jiffy Pop that's a heck of an intake you have there.

http://www.floridag35.com

 

Looks like a HUGE baked potato! LMAO

 

Based on the data, it reassures me I made somewhat of a right purchase with the Stillen CAI instead of the PopCharger. Of course people can interpret it thier own way, but in my head, I am glad what I bought.


http://members.cardomain.com/lilmauwow

 

lilmauwow,

As you can see I'm still testing different CAI system modifications.

Recently a good friend gave me an extra stock air case. I plan to modify and test it when I get time.


DaveO
03 G35 AT Sedan / DP / Willow / Premium / Sport / Aero / Mods / 262 & 260.8

360876-Stillen - JWT RCS Opening.JPG

 

DaveO, whats that? did you cut a hole in your fiberglass thingamabob ala 350z? how is that working for you? hmm, i like...but im not sure...

G35s6mt/TSecu/350Z Springs&Struts/K&Nfilter+Z-tube/StillenDualExhaust /6WireGroundKit/KinetixHighFlow