Hey guys, need some help on the IAT sensor placement on my 73 Nova LS swap. Couple questions.

1. I have the IAT sensor from a 2002 camaro, it uses a grommet to hold the sensor in place...Is there a better sensor to use, or is that one fine? Wiring harness is from the same car.

2. What is the best placement of the sensor? I know on the 2002 Camaro it is right in the air box. I have attached a pic of my intake with 2 possible spots.

Thanks.

 

Or is it just better to swap in a 5 wire MAF with the IAT?

 

Id stick it inside your heat shield for your filter. You could use a threaded senor if your going FI anytime in the future, other than that you should be good

 

Thanks.

What vehicles came with threaded sensors?

 

I would put it in the tube behind the fan. Yes it will artificially heat soak in the aluminum and yes it's behind the radiator fan, but it's a closer representation of the actual air temp the engine is ingesting. I've even seen them inserted and phabbed into the intake manifold.

You don't want it in an overly hot spot, but you also don't want to trick the ECM to think it's cooler than actual.


That said, the heat shield spot will work but consider rebuilding your intake tubing with something other than metal and if you're in for every last drop of performance, longevity and customization, try getting the air from outside the engine bay. High compression LS engines burning 91-93 octane fuel are very intake heat sensitive.

 

I can put it right next to the TB in the tubing, it shouldn't heat soak that bad there.

The air filter is separated from the engine bay, and tucked under the fender. It is fed by ducting from the grill. I may make a box lid or seal it to the hood.

I can always coat the aluminum tubing so that it absorbs less heat.

 

Do some logging before you make any changes. It might not be that bad.

If you are real serious about squeezing the most out of it, search "iat omega thermistor ls1gto" in Google. With an external IAT Fbod sensor you can change out the reading device to a faster reacting, possibly more sensitive (can't remember if it was better than stock on that front) unit.

 

Yeah I'm not interested in squeezing out every bit, I just want a fun driver. This motor will likely be 400hp at the crank max.

 

This is the route I'd take.

 

I've seen it put in the end of the conical filter like you have. Just drill a hole on the metal at the end, use the grommet.

 

From what I can tell based on pics, the truck 5 wire MAF looks like its meant to be bolted to the airbox and not have a hose on both ends. Is that true?

Also from the pics it looks like one end the hose attaches to is 4" and the other side is 3.5". Is this true?

Currently my MAF is 3.5" on both sides. Is there a 5 wire MAF that is the same size on both ends?

 

I don't see why you couldn't use hose on both ends of the 85mm maf, and I'm pretty sure the maf is the same on both ends, I have one laying around so I'd have to check.

 

So I ended up buying a 5 wire MAF. The difference is the 75mm MAF takes a 3.5" coupler on either side. The 85mm MAF takes a 4" coupler on one side and a 3.5" on the other.

The plastic side measures about 3 5/8".



The metal side measures about 3 7/8".

 

Why not drill a hole and weld a 3/8 npt bung into the pipe right before the bend to the throttle body. Thats where I put my IAT sensor. The IAT is where the green arrow is pointing.

Here's the bung... http://www.summitracing.com/parts/sum-220072/overview/