Click here to
show your support
for the NCM
and C5Forum.

Home Discussion Forums Do It Yourself Articles About Your Corvette About This Site

Topic Options
Rate This Topic
#102959 - 11/19/01 08:42 PM More questions
Barbie Offline
Member

Registered: 07/22/01
Posts: 1029
I have understood that many C4 owners have said they get a performance increase, by relocating their MAT sensor. After all this is how it is on a C5. Correct??

After taking my MAT sensor out I found out it was the same sensor as my coolant sensor. Thinking this was a mistake or a mix up, I went to the dealer and found out that is what is used. I don't know if it was for the speed density system alone on my '90, or not.

[img]http://albums.photopoint.com/j/View?u=1420913&a=13997095&p=56567453[/img]

My question is....how accurate can this MAT sensor be? And, how will relocating it to the air filter housing effect the engine?

Thanks in advance.

Barbie

[ 11-25-2001: Message edited by: Barbie ]

Top
#102960 - 11/19/01 08:55 PM Re: More questions
J.B. Offline
Full Throttle Member

Registered: 12/02/00
Posts: 10504
Loc: North East
I don't know the answer but that photo is very cool! whao!
_________________________
2008 Black/blk C6 Z51 NPP M6
2008 Silver/blk CTS FE2 AWD 304hp

Top
#102961 - 11/19/01 09:17 PM Re: More questions
Buzzer Offline
C5Forum Fanatic

Registered: 12/05/00
Posts: 2194
Loc: Virginia
Wish I knew more about where it was OEM located, but it can be as accrate as any sensor. Locating it to the housing may cause it to read temps to high. I would imagine its located somewhere nearer cooler air. No??

Top
#102962 - 11/20/01 05:46 AM Re: More questions
c4c5specialist Offline
Member

Registered: 07/10/01
Posts: 1612
Loc: conn
Hey Barb,
Hows things??
Lets get technical. First off, the intake air temp is a thermistor, just like you cooling temp sensor, resistance changes within the sensor, based on temperature fluctuation.
Now, engine calibration changes, based on information from several sensors, both of these are a part of the equation.
You see, the lower the air temperature, the higher the oxygen content, this is why dyno runs, and 1.4 miles times improve with lower outside temperatures. This also changes the way spark timing is advanced, and fuel is introduced. The cooler the air, the more timing can be induced to increase power, without detonation.
Lets say that you would like to put the temp sensor to the air cleaner, which is more in front of the radiator, than in the air duct. You would obviously decrease the temperature read by the computer, however, you are not reading the actual air pulled into the engine. As the air is pulled into the engine, it will be heated, by the proximity to the hot engine, and the air duct above the radiator.
So, what this does is give you a slightly tainted reading. This would increase your timing, and fuel curve, because the engine sees cooler temps, and runs accordingly. What is not said, is that you may experience detonation if the difference between actual and indicated temps are large enough.
This is why in the newer Vettes, the IAT is located within the MAF, and it was in the 85-88 L98 motors. A real time temp measurement is critical to overall performance.
You have noted in previous posts about the heat under the hood, Barbie, so you know what we are dealing with here. Convection and conduction of excess heat is everywhere under the hood. The key is control of the heat, as you have stated.
If this is understood, a more effective way of isolation of cold air to the engine is found.
I would follow you instincts as far as venting excess heat.
You know I didnt agree with the hood thing, for the bond reasons, however, your theory is very sound, and should be explored, cuz I aint no body guy. wink
I hope this helps, besttoyou, c4c5 hammer hammersonthecase
_________________________
c4c5 Chevrolet dealership mechanic, ASE Master Technician w/L1. COFFEE ADDICT. A persons judgement is only as good as the information they have, which should be FACT, not fiction.


Top
#102963 - 11/20/01 08:02 AM Re: More questions
Barbie Offline
Member

Registered: 07/22/01
Posts: 1029
Paul, it's a good thing you're not a doctor. I can imagine the words you would use. Thanks for the thorough explaination, it helps me understand. I think I'll leave the sensor in it's original location under the plentum and let the heat extractors do their thing. I am still surprised at the sensor they used. It's not a real air temperature sensor it's more like a heat sensor. Many thanks.

Barbie

Top
#102964 - 11/20/01 10:32 AM Re: More questions
Buzzer Offline
C5Forum Fanatic

Registered: 12/05/00
Posts: 2194
Loc: Virginia
Barbie
You have a PM

Top
#102965 - 11/20/01 08:35 PM Re: More questions
Barbie Offline
Member

Registered: 07/22/01
Posts: 1029
Thanks for the info Buzzer.

Barbie

Top



Moderator:  BruceF, hcvone, J.B., Redshift