Where is the ACT sensor?

1FSTBRD

Registered User
I've looked on this forum as well on the internet, and perhaps I am missing something, but I can't seem to find any info on this mythical ACT (Air Charge Temperature) sensor. Does anyone have pictures of where it is?
 
Up top/rear, right after where the lower return from the IC bolts up, before the bypass.
SC_ACTLocation.jpg
 
Aha--thanks!

Next question for you or whoever else can weigh in on it.....when doing some more research, i'd read somewhere that the air charge temperature sensor was a problem in performance. Does the ACT need to be in this location in the IC tube, or can you plug it and re-route it to somewhere in the air intake? I would think that if it was re-routed, that it would give an actual realistic temperature reading of the air entering the engine, and that the engine wouldn't pull timing once the IC tube gets heat soaked.
 
I'd think that the ACT stock location would be optimal for preventing pinging in the event of excess intake heat temps (I believe the computer starts pulling timing after 150º). If you try to spoof it, you may risk engine damage? Rather than worrying about moving the sensor, it may be better to simply reduce temps coming out of the IC.

Such steps would typically include: cleaning the inside of your stock IC; installing a narrow A/C condenser; IC fan. Next would be a double-IC, then a FMIC. Of course without tools to monitor intake temps, the effects of mods would be guess-based.

As for the lower IC tube being heat-soaked...we're told the air moves thru it too fast to be affected to the point of being an actionable issue.
 
I'd think that the ACT stock location would be optimal for preventing pinging in the event of excess intake heat temps (I believe the computer starts pulling timing after 150º). If you try to spoof it, you may risk engine damage? Rather than worrying about moving the sensor, it may be better to simply reduce temps coming out of the IC.

Such steps would typically include: cleaning the inside of your stock IC; installing a narrow A/C condenser; IC fan. Next would be a double-IC, then a FMIC. Of course without tools to monitor intake temps, the effects of mods would be guess-based.

As for the lower IC tube being heat-soaked...we're told the air moves thru it too fast to be affected to the point of being an actionable issue.

Yeah, I was wondering if it wasn't a failsafe to pull timing. I run 94 octane (and always will), but I was wondering how much timing the engine pulls. My Mustang has the temperature sensor right in the intake, but then again, it's doesn't have near the amount of heat within the engine that the supercharger does.

I was thinking of putting a fan on the IC as well as cleaning out the IC. Was thinking about double IC, but some have said that it has a cooler air charge, but at the expense of reducing boost.
 
Boost is just a measure of back pressure.

As an example, you can open the exhaust on a stock SC and see a drop in boost (reduced back pressure)...that doesn't mean you lose power - in fact you might gain a bit, or at least move the curve. Add a 5% pulley and the boost comes back up, along with gaining more power at the same time. Add more mods to help the engine breath and boost goes back down while power goes up again. Switch to a 10% pulley and see more boost and more power. Wash/rinse/repeat. This is a simplified example, but you get the idea.

While you can go too big with an IC on any car, I think, I don't see any reason to fear a double core setup for our engines. Cooler is better*

150º IAT = - 60 advance = -3.7º timing

Quoting from [ http://www.modularfords.com/content...-Sensors-Part-2-Air-Intake-Temperature-Sensor ]:

"The higher the air charge temperature, the more timing is being pulled to prevent knock. What is often misunderstood about air intake temperature correction is that it's not about power. If your air intake temperature is 180 degrees Fahrenheit instead of 80 degrees, we need to light the mix off later, to get the cylinder to peak pressure at the same time. So why are we trying to avoid pulling timing due to hot air temps, you ask? Simple. It's not the timing that's the problem. The timing is just a compensation for what's actually happening in the motor. The real power robber is that 180 degree air intake temperature. *Fix the problem, not the symptom! In a boosted application, this typically means an intercooler or water/methanol injection."
 
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If the ECU does indeed pull timing because it's seeing a heat soaked temperature at the ACT (especially in stop and go traffic, where the excess idling isn't probably getting enough airflow through the engine).....wouldn't the knock sensor knock the timing back, anyways? I'm not completely sure how these engines work, exactly, but would the knock sensor be too late to catch some of the detonation that would be pulled by the ACT reading hotter temps?

I'm running 94 octane in my car, so i'm already trying to be preventative with detonation and trying to reduce the heat in the engine/ cylinders as much as possible. I'm just curious as to what the wiggle room was in Ford's design, where they were expecting people to run 91 or so octane back when these cars came out. The exhaust was a restriction, as is the MAF and throttle body, but i'm wondering if the ACT location is a design flaw or not.
 
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...wouldn't the knock sensor knock the timing back, anyways?.

See your other thread on that topic here: http://www.sccoa.com/forums/showthr...oes-the-SC-engine-work&highlight=knock+sensor - basically one is proactive and one is reactive. If you rode around on just the knock sensor, things would fail quickly.

As for design 'flaws', remember we're talking about what was leading edge tech from more than two decades back. Many things have changed, from the demise of leaded fuel to much more advanced engine construction materials and air/fuel management schemes.
 
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See your other thread on that topic here: http://www.sccoa.com/forums/showthr...oes-the-SC-engine-work&highlight=knock+sensor - basically one is proactive and one is reactive. If you rode around on just the knock sensor, things would fail quickly.

As for design 'flaws', remember we're talking about what was leading edge tech from more than two decades back. Many things have changed, from the demise of leaded fuel to much more advanced engine construction materials and air/fuel management schemes.

Yeah, the demise of leaded fuel and things like ethanol fuel and fuel improvements to resist combustion have likely changed things quite drastically.

In researching moving the ACT sensor (or IAT as it is called in other cases) i've checked around on the internet, and it seems more often than not, guys advise to put any air temperature sensor in between the MAF and throttle body.
 
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