Any of you guys with an HSRK and a Dashhawk...

[GTPprix]

Might want to add some input here:
http://www.g8board.com/forums/showthread.php?p=92142&posted=1#post92142

[Chewy]

I've got both... Just missing one small detail...:poof:

[G8V8]

Before I post this over there, does this agree with your tests and understanding:

This is what I've been told and my own experience as a EE and with IATS, tuners and scanners seems to bear out the hypothesis. Anybody care to elaborate or set us straight?

"Thermal time constant (T.C. or tau, ): The thermal time constant is the time required for a thermistor to change 63.2 percent of the total difference between its initial and final body temperature when subjected to a step function change in temperature under zero-power conditions and is normally expressed in seconds."

Many automotive sensors have T.C. in the 12-14 sec range (or longer). The HSRK has a faster thermistor with a T.C. that I'm guessing is about 3-5 sec.

What this means is this:
Assume AAT is 75* and you are not moving much air. The IAT readings are, say, 125* or 50* above AAT (ambient air temp). This comes from not moving much air so it is picking up heat from the hot ducts, airbox, MAF and also with the MAF totally heat soaked, the IATS inside it is soaked too. Now go WOT. The heated air in the intake tract is sucked in quickly and cooler air from your perfect CAI flows in to take its place. The IATS (IAT Sensor)readings will start to drop such that in 1 T.C. it is reporting 63.2% of the change or a 32* change (50* x 0.632). It reports 83* and took 12-14 sec to get there even though the incoming air has been near AAT after a couple of seconds. It will take another T.C. to report 63.2% of the remaining temp change. Of the 8* left, it will report 5* of them in another T.C. or another 12-14 sec. The IAT reading is 78* and it will have taken 24-28 sec. to get there from the time you went WOT. With the faster IATS, it would have been reporting 78* after 6 - 10 sec, or less it the HSRK sensor is faster than I think it is.

The ability to relocate it also allows it to be mounted further away from items that get heat soaked.

In my Grand Prix GTP, I had a sealed, insulated CAI and located the HSRK and MAF inside the air box. The MAF did not heat soak as before and the IAT reading were fast and very quickly approached AAT.

I don't know what the exact T.C. is for the G8. I know the GP had a typical, slow one.

I drove around in traffic on a loop that I could easily repeat. It has lights, slow traffic sections and fast traffic (60 mph) sections. It has a place to do WOT to about 70 mph. I drove it with the HSRK plugged in and I repeated it with the OEM IATS plugged in instead. I repeated it several times, alternating after a couple of cycles around the loop. In EVERY case, the cruising IAT numbers were10-15* lower with the HSRK. During the WOT runs the IAT reading dropped much closer to AAT much faster than OEM. I could tell which IATS was active by just looking at the numbers on my DashHawk.

Also, just for reference. In the morning, with a totally cold car/engine both IATS and the dashHawk AAT and the radio display all read the same temp.

Here is a WOT scan with the HSRK. Not sure why AAT dropped but the AAT PID reports a couple of degrees higher on my DH than the radio display temp.

http://img.villagephotos.com/p/2002-11/65524/18307579-wot1-exp-HSRK.JPG

[GTPprix]

You are the man LOL Thats EXACTLY what it should do, with the stock IAT you are lucky to get HALF that timing back during a 1/4 mile pass, let alone speeding up after being stuck in traffic for awhile ect... I'm still trying to understand why some people cant comprehend this its really as simple as:

High intake temps decrease timing which decreases HP.
Getting that number back down to Ambient ASAP is the goal ;)

Really thats about as easy as it gets, shaving the IAT table is common practice but we'd rather have accurate data as the IAT table is typically pretty spot on for what you'd want at WOT unfortunately getting it back to where it should be is the issue.

Also its important to note that just AFTER that run, the IAT's immediately start to climb again; heatsoak! :D

[G8V8]

Posted.

[GTPprix]

Posted.

Where? I might be blind again LOL

[G8V8]

Might want to add some input here:
http://www.g8board.com/forums/showthread.php?p=92142&posted=1#post92142

In the thread you asked for some support in.


Where? I might be blind again LOL
Your moma said that would happen if you didn't stop doing that.:)

Damn, It is not there. ??

It is now.

[GTPprix]

Bwahhahaha yeah Mom was right, thanks :)

[EcoBrick Bob]

I've got both... Just missing one small detail...:poof:


Think I just saw your car in a "salvage lot" in Chicago....

As for HRSK... I have watched my DashHawk IAT #s several times, for comparison to Charlie's. My outside temps have been around 80 deg. F.,about 20 deg. less than Houston. I get immediately lower IAT responses when I move air thru the system, as long as I'm not parked, even at a steady 30 mph. My IAT temp. has never gone below 2 deg above outside temp in part because of lower outside temps and the residual engine heat. My HRSK is located 2 inches closer to engine than Charlie's.

I am convinced it works. Believe the HRSK immediate response time could help mileage in stop and go driving.

RRM

[G8V8]

I think the post may have helped on the other board.