albert

Well, I've done my first round of temp testing, and I'm amazed. Amazed and Appaled.

Test appartus. Fluke 54-2 Datalogging Thermometer. Test Probe #1. Stock airbox. Probe next to stock air temp sensor. Test Probe #2. Stock Intake manifold. Probe Inside runner #2. 1" Upstream from port. Probe .75" up from port floor. Probe surrounded by .5" of silocone to insulate probe from metal heat.

It was 60-61F the night of the test. Both probe's read this prior to starting. Probe #1 stayed at 60-61F at the start. Installing the intake manifold to a warm block warmed T2 up 10°F in the time it took us to install it and tighten up all bolts. Not good!

I don't have the "starting" datalogs, but I'll do another set. This datalog set is after driving for 5 miles, letting the engine sit for 8 minutes (off) then driving 5 miles home. (so these readings start "warm"

"max" airbox temp 104.3°F
"max" intake port temp 153.3°F
"max" temp difference 56.9°F

I'll post up the "text" of the datalogs tonight.

This is with at 100% BONE STOCK setup.
Stock airbox
stock resonator
stock TB WITH COOLANT HOSES
stock IM

What I learned....
#1. The intake ports get HOT QUICK, and it doesn't really cool down when you floor the engine
#2. The stock airbox heats up rather slowly, but once hot, doesn't cool down either.
#3. The "temp" at the airbox was easy to affect by doing high RPM (high air flow) driving, however cooler airbox temps didn't equal cooler port temps. SO the incoming air CAN quickly cool down the airbox and the stock IAT reading, but that reading doesn't translate to cooler air at the ports.

I don't know if this is the coolant hoses heating up the air, the stock IM transfering heat from the head, both, or neither. (could be radiant heat from the head/valve affecting the temp probe. I doubt it, but it's possible).

I'll have more photos and data graphs along with (hopefully) a new datalog that goes from 100% cold to 100% hot.

T1 T2 T2-T1
90.4°F 129.9°F 39.5°F
87.9°F 136.6°F 48.7°F
88.5°F 140.5°F 52.0°F
89.5°F 143.7°F 54.2°F
90.5°F 146.2°F 55.7°F
91.7°F 148.3°F 56.6°F
93°F 149.8°F 56.8°F
94.2°F 151.1°F 56.9°F
95.5°F 152.3°F 56.8°F
96.7°F 153.3°F 56.6°F
98.5°F 139.9°F 41.4°F
104.3°F 130.6°F 26.3°F
101.1°F 123.8°F 22.7°F
96.1°F 119.1°F 23.0°F
91.3°F 114.4°F 23.1°F
92.6°F 124.4°F 31.8°F


I'll be eventually removing the resonator and doing this again, also the stock airbox in favor of a CAI. I'll also be removing the coolant hoses and installing a Phenelic Spacer(I'll show folks how to make one) between the IM and the head, each step will be documented, and datalogged. This is just my "preleminary" data, and it was simply too shocking NOT to share.

hyundaijvx

Wow, seems like your one of the guys on Mythbusters

Random, could you put all that into words that I understand? All I get is that the intake port is hotter than the airbox. That leaves me just as smart leaving your post as I was coming into it.

01tibby

round one of testing...how many more lol.gif

Mad-Machine

Interesting to know.. but a lot of it makes sense. The Air box is far enough away from the heat of the engine that it's tempeture can vary quite a bit. The Throttle body is governed by the coolant in the engine, so it would stay fairly constant. And the intake ports are only inches from the heat of combustion. Unfortunatly, with the introduction of Fuel Injection, you no longer have the cooling effects of the fuel to lower it's temps... however, the greater precision offered by injection does outweigh this on a daily and very reliable driver.

albert

conclusions;
The stock airbox sucks. It functions as an air 'pre-heater'.

The average air temp rise from airbox to IM port is 20 degrees. That's 2 HP down. (standard rule is 1 HP for every 10F degrees)

Colder air is better air.

Ways to make/get colder air to follow in later posts.

hyundaijvx

What if I got a genuine cold air intake, I'm guessing that would help. laugh.gif

albert

Most CAI's are metal. Metal heats up much faster than plastic does. That means that the CAI may end up heating up FASTER than the stock airbox does.

The CAI has 2 main advantages.
#1. less surface area vs air flow/volume compared to the Stock air box/resonator. Since there is less surface area, there is less hot metal to transfer heat to the intake air, so the intake air should absorb less heat.

#2. Colder air intake pickup. Since a CAI picks up air outside the engine comparment, but the stock resonator picks up engine compartment air (resonator opening is BEHIND rubber seal on hood, meaning it can ONLY draw in engine comparment air, not fresh air). This should mean that the intake air will be cooler to start with, and thus arrive cooler at the TB.

If the CAI is aluminum, it will heat up very quickly and will transfer that heat just as easily to the intake air. If the CAI is steel or preferably a really poor conductor of heat (plastic, silocone, etc) it will absorb less engine compartment heat, and thus will heat up slower and will also transfer less heat to the intake air. This is one of the reasons that "ICEMAN" intakes are so darn effective. They are 100% Silocone and do not absorb much heat, and they do not transfer much heat.

Mad-Machine

All I can tell you about CAIs.. Mine is steel. I checked on a hot day after driving through town, I popped the hood while the car was running and stuck my hand on the intake.. it was still cool to the touch as compared to the rest of the engine compartment.. and even compared to the rest of the car as it was in the shade of the hood and had air moving through it.

Voiddweller

It is taking a while to get it done because they are finishing the SRT-4 intake first but I am working with Iceman Intakes and they are making one for us out of high temp/heat resistant plastic that is tuned and injection molded. I will call them this week for an update and post (in a different post as to not hijack...this just goes along with temp issue). This should seriously help the issues we are having with getting cooler air.
http://www.icemanmotorsports.com/