Istan and i decided to take my car out last night and really see what the popcharger does. Well at idle and sitting still , yes the popcharger draws heat from the eng compartment. The highest we saw was 170 degrees IAT on the display from the OT-2. Then the cool part, normal acceleration by the time the car hit 20 mph IAT was down to within 20 degrees of ambient temp. Under normal cruising AIT averaged 12 degrees hotter than ambient (90 degrees out last night)

Next we decided to let it sit in the parking lot with the hood up, IAT was between 115 and 120 depending of if my cooling fans were running. This tells me that for an accurate dyno with the Popcharger you need the hood up and need cooling air to get the IAT to the actual temp you would have for normal driving. Its been proven on here that the Popcharger dyno's heigher with the hood up, and of course plenty of people cry foul cause you don't normally drive with the hood up, then again you don't ever race your car with it sitting still either.

Well next tests will be done on the racetrack under full high heat situations. Willow Springs Time Attack with ambient temps around 115 , see what happens.

 

Thing I've always thought about HP is that if you can't feel it, what's the point?

 

We also saw my highest IAT was 11x last night while sitting idle. Granted, I run the funny looking Mastergrade Venom hood, and I'm running a Vortech, but it was interesting.

 

I've run similar test....data logging IAT's and under cruise I can usually keep it within 2-5 degrees of ambient. I have a crappy, DIY soft box made of pipe insulation and a front scoop. Of course at idle it suffers......

 

Crappy? 2-5 degrees of ambient would hardly be considered crappy.

 

I meant my little insulated half box.

 

I also want to play with the insulation, and throw the stock air box in and do some logging around town.

 

Only reason I don't go back to the 06 box is I run the larger Z1 maf hoursing....the 06 box velocity stack is only 70mm. My pop charger velocity stack is matched to the 80mm inlet of the maf housing. If not for that I would use the 06 box.

 

^ Why? I mean i understand a box is ideal, sure, but the money part of the PC is its larger filter area and larger velocity stack. Only way im using a box is if someone makes one to surround the PC. Other than that, ill take a few lost ponies for the 1-2 seconds it takes me to get air flowing through the bay for a better end result.

 

Btw, in for all results Terra. I love that your revisiting this issue that so many mistakenly think is a 'done deal'.

 

In for results as well.

Hasn't tony already done these types of test though?

 

You're going to be slower at the strip and here's why. You'll be sitting in line to race with underhood temps at 150+ degrees. At this point, 150+ degree intake temps will result in a significant power loss (10 to 15whp). Sure, once you get going, the temps drop close to ambient; however, it takes about 3 to 4 seconds to clear out the heat and get to ambient temps. In a race, that means you're going to be down on power for at least 3 seconds and during the most important of the race....the 330'. A 10 to 15whp loss in power across the whole powerband in 1st and some of second will be hugely deterimental. You'll probably be .15 to .2 seconds and 1 to 2mph slower.

 

Dave speaks the truth. 06 airbox or bust for a 350Z.

 

partially true, the air cleared by the time it hit 20mph. That means it clear well before you shift into second. Also it could actually be faster, not many sending units can accuratly log a suddden temp change.

Having hot air for the first 20mph isn't going to effect my track times at all. The added power of the unrestriscted intake is going to help me more.

 

^ Has anyone tested this theory at the track stock vs pop being the only difference? A few hp difference maybe more, but maybe also a mph in the E/T

 

My bolt-on car traps 84-86mph in the 1/8th.......the lag in airflow isn't as substantial as DaveB states. As I stated though....I would run the 06 box if it weren't for the little velocity stack within. I don't wish to hack up an 06 box to make an 80mm velocity stack fit either.

 

Underhood heat isn't going to clear out that fast seeing that 20mph isn't a whole lot of air movement. I've got a data logger myself and have tested this religiously. It takes a solid 3 to 4 seconds to see a significant drop in IAT values when going WOT from a stop. On a hot day, it could take even longer.

The 0 to 40mph portion of a 1/4 mile race is the most crucial. If the engine is ingesting hot air in 1st, it's going to be slower and won't launch as hard. Now if you're racing on a sub 60 degree day, then having an aftermarket intake probably won't make you any slower at all. But if you're racing in hot temps (80+), you'll be slower.

High intake temps result in reduced timing and a richened fuel mixture to cool the combustion chamber and stop knock. Both adjustments kill power. So, not only does the hot air have less available power, the ECU is compensating to keep itself from pre-detonating itself to death.

As Motordyne as shown, aftermarket intakes do nothing for these cars and in some cases they'll slow you down. The OEM intake setup on the Z is close to ideal. I guess for some, the added noise of an intake is worth having a potentially slower car.

 

3 to 4 seconds, about the same time as if you dropped a thermometer in ice water. The temp changes faster than the sensor can change, and even at 10 mph the eng bay will clear out quickly of hot air. I wouldn't doubt if they bay is clear of hot by the time you hit 10mph.

Also who freaking cares about 1/4 times anyhow, we're driving independent rear suspension sports cars that are made to turn corners.

 

The ECU is going to go off of the values from the IAT. Seeing how sealed the engine bays are from the top and bottom, I don't see the engine bay clearing the hot air out until you've got significant airflow (40mph+).

As for the drag racing with IRS, lots of Terminator Cobra, Vette, Supra, and Viper owners seem to do alright with the IRS. Same goes for Z owners. Pulling 1.7 60 foots with just slicks in an NA Z is pretty dang good....for any car regardless of suspension setup.

 

I don't like the idea of having to start out from lights etc.. with the ecu retarding the timing because it's seeing a high IAT reading.

I'd give up whatever preceived high end that people think the stock airbox loses than sacrifice my lowend. The 06 airbox is what I'm running. But I've run the stillen. These are the only two intakes worth running at all IMHO