relocating the corvette Intake Air Temperature sensor

[grumpyvette]

relocating the corvette Intake Air Temperature sensor

http://garage.grumpysperformance.co...otal-panic-over-an-easy-fix.12177/#post-58940

http://garage.grumpysperformance.co...ating-the-mat-manifold-air-temp-sensor.10349/

http://garage.grumpysperformance.co...ng-your-tpi-maf-and-cpu-links.2825/#post-7295

Intake Air Temp sensor. It is located on the bottom of the inlet plenum a few inches ahead of the distributor. It is like right next to the fuel pressure regulator., it can effect fuel flow rates

http://tech.corvettecentral.com/2007/01 ... re-sensor/

Ive done it for a few guys, Ive never seen any real measurable gains, or losses, I never bothered on my personal corvettes as a result.

SD = Speed Density
MAF = Mass Air Flow

How it Works (short and sweet)

Speed Density
Ok speed density system cars do not measure the airflow directly, it is estimated. Your engine has sensors that it uses to try and estimate this airflow. It uses your Engine Size, Engine RPM, Air Inlet Temps, Manifold Air Pressure, and a Volumetric Efficiency table in your PCM.

It pretty much breaks down like.

CFM = Engine RPM * CID / 3456 * V.E.

This will give an estimated CFM of what's going into the engine at standard temp and pressure. You use the air temps and pressure to correct the airflow the current engine conditions.


Mass Air Flow
A mass airflow car measures the airflow into your engine directly. It has a heated wire that is in the airstream. This wire tries to cool when air flows over it and the computer applies more voltage to keep it at a constant temp. This voltage is how it knows how much air is going by.

This is essentially measuring the mass of the air entering the engine. Since mass is conserved (not created or destroyed, unless you drive a nuclear sub), then it is independent of air temp and pressure.


In a nutshell

SD = speed density cars guesses on the VOLUME of air entering the engine. Volume changes with temps and pressure.

MAF = Mass airflow cars measures the MASS of air entering the engine. Mass is independent of temp and pressure.

http://www.ecklers.com/corvette-intake- ... -1991.html

http://garage.grumpysperformance.co...otal-panic-over-an-easy-fix.12177/#post-58940

Corvette Intake Air Temperature Sensor Relocating Kit, 1985-1991
The Air Temperature Relocating Kit repositions your engine's air intake temperature sensor from the hot plenum area to the air filter base where it can sense cooler air. This enables the ECM to adjust the fuel to more accurate air temperatures resulting in increased engine performance. This kit can be used with or without the forced air induction system. The kit includes: IAT sensor, CAD/CAM designed & CNC machined aluminum mount bracket with stainless steel hardware, 78" extension harness, cable ties & installation instructions. Fits all 1985-91's except ZR1 models.

 

[Doodad]

I've seen no measurable Dynos to back up any gains here, but when combined with the throttle body water bypass, smoother idle has been reported, It coiuldnt hurt given the more accurate reading. I've cut the screens on my MAF and saw no difference there, the ECM is going to fight all changes unless you burn your own chip.(PCM 4 LESS) http://www.pcmforless.com/, cool thing about their service is you send them your engine changes and specs and they custom tune for those paramaters not "off the shelf" and if it needs tweaks they'll let you send it back for a re-burn for nothing. I like the Speed dens- set up because it cleans up the engine bay and you can select some mean looking accesories for it. So if you add a cam add bigger injectors, intake heads..etc if you dont tune you wont see the expected gains..and forget the huge throttle body unless you change heads and/or stroke or your wasting money. I'm off track here, you can make your own IAT extension by splicing longer wires routing them to the air cleaner housing and drilling a hole (forgot the size) Use a rubber grommet here. Bingo!