psychic_mechanic
psychic_mechanic Dork
12/3/13 3:02 p.m.

I'm running a microsquirt with a MAF/MAP setup on the 3SGTE and was wondering where I should place the intake air temperature (IAT) sensor. I think that putting it between the intercooler and throttle body would give the engine a precise temperature of the air that is going into the intake but that putting it by the MAF may be required so that it reflects the volume of air going into the engine (as I understand it the MAF measures the amount of air going through it by how much the air flowing past the sensor wires cools them so it needs a reference air temp to calculate air flow). So what do you guys think? Should I plumb it like:

1: Filter -> MAF -> Turbo -> Intercooler -> IAT -> Throttle body

or

2: Filter -> MAF -> IAT -> Turbo -> Intercooler -> Throttle body

Swank Force One
Swank Force One MegaDork
12/3/13 3:05 p.m.

Is it a MAP, MAF, or both setup?

Typically i try to place them close to the throttle body, but i also typically view removing MAF/VAF/AFM/etc as a nice little bonus when using a standalone EMS.

Paul_VR6
Paul_VR6 HalfDork
12/3/13 3:07 p.m.

IAT on a boosted car should be after the IC to get the air temp correct. So the answer is #1, or in the manifold.

psychic_mechanic
psychic_mechanic Dork
12/3/13 3:16 p.m.
Swank Force One wrote: Is it a MAP, MAF, or both setup? Typically i try to place them close to the throttle body, but i also typically view removing MAF/VAF/AFM/etc as a nice little bonus when using a standalone EMS.

I'm using both MAF and MAP which is supposed to make tuning a lot easier since I don't have to work out the VE tables. I'm using GM sensors since they are just about free at the local junkyard and the microsquirt supports the LT1 MAF in the drop down menu.

evildky
evildky Dork
12/3/13 3:30 p.m.

Do yourself a favor and ditch the maf. Loosing the maf is one of the reasons I started messing with megasquirt, was also a nice side benefit to converting to a gen3 3sgte.

MadScientistMatt
MadScientistMatt UltraDork
12/3/13 4:04 p.m.
Paul_VR6 wrote: IAT on a boosted car should be after the IC to get the air temp correct. So the answer is #1, or in the manifold.

Correct. I don't like on the manifold as much myself, as it tends to pick up heat conducted in through the manifold and give a false high reading in some cases.

Paul_VR6
Paul_VR6 HalfDork
12/3/13 4:09 p.m.

I am not a huge fan of the manifold either, the best reason to put it there is that it's already there. The heat soak issues can be tuned out for those with more patience than most.. and the appropriate ECU

psychic_mechanic
psychic_mechanic Dork
12/4/13 11:36 a.m.
Swank Force One wrote: Is it a MAP, MAF, or both setup? Typically i try to place them close to the throttle body, but i also typically view removing MAF/VAF/AFM/etc as a nice little bonus when using a standalone EMS.

What's the benefit of removing the MAF? One less item to fail or a potential flow restriction? I may end up just getting the engine running on a conservative tune with the MAF/MAP setup to shake down the chasis. Then I can remove the MAF before really diving into the engine tune if there's a good reason to.

Swank Force One
Swank Force One MegaDork
12/4/13 11:37 a.m.
psychic_mechanic wrote:
Swank Force One wrote: Is it a MAP, MAF, or both setup? Typically i try to place them close to the throttle body, but i also typically view removing MAF/VAF/AFM/etc as a nice little bonus when using a standalone EMS.
What's the benefit of removing the MAF? One less item to fail or a potential flow restriction? I may end up just getting the engine running on a conservative tune with the MAF/MAP setup to shake down the chasis. Then I can remove the MAF before really diving into the engine tune if there's a good reason to.

Both, and less wiring.

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