Intake temp. question

[OCDFist]

Not sure if this is in the right section.

I noticed that Intake Temps closely follow Ambient & Charge Air Temps (Cobb AP Stage 1 91 octane, stock IC, Injen intake with completely shielded filter). However, on the highway when coolant temp is normal, Intake Temp will rise and stay approximately 10 degrees higher than Ambient for no apparent reason. This week the temps have been in the teens, and I'm driving at 60-65 mph, so it should be ice cold all the way through.

My question: Is this the EGR system? Obviously I don't mind a little bit warmer intake right now, but when it warms up I'd be interested in keeping everything as cool as possible.

 

[Chuckable]

EGR = exhaust gas recirculation, and it shouldn't have any effect on your intake temp a/k/a Air Charge Temp (ACT). The Injen intake, even though it's shielded, probably draws in warmer air than the factory, Mountune, or Cobb units which draw air from in front of the radiator. Likely when you're on the highway the engine bay temp reaches equilibrium, and the intake is just drawing in that warmer air.

 

[OCDFist]

EGR = exhaust gas recirculation, and it shouldn't have any effect on your intake temp a/k/a Air Charge Temp (ACT). The Injen intake, even though it's shielded, probably draws in warmer air than the factory, Mountune, or Cobb units which draw air from in front of the radiator. Likely when you're on the highway the engine bay temp reaches equilibrium, and the intake is just drawing in that warmer air.

I don't know about the Fist, but many EGR systems send hot exhaust gas back through the intake, hence recirculation. I figured since it was a regular occurrence like clockwork after the car went into closed loop, it was egr or similar.

As far as the intake sucking hot air, with the hood closed it's sealed to original front grill inlet & also a bottom hose going behind the front bumper. The aluminum Injen pipe is cold to the touch after driving all the way to the bend behind the engine.

 

[Chuckable]

I had no idea the Injen came with that hug foam separator! Rather, I thought it was something like this:

I'm up for learning from the more experienced members on the forum. Pretty sure, though, that you're not going to be able to disable the EGR system to eliminate that variable from your testing. Maybe try going back to stock and see if the ACT behaves the same. Then you'll have narrowed it down to the intake.

 

[OCDFist]

I had no idea the Injen came with that hug foam separator! Rather, I thought it was something like this:

I'm up for learning from the more experienced members on the forum. Pretty sure, though, that you're not going to be able to disable the EGR system to eliminate that variable from your testing. Maybe try going back to stock and see if the ACT behaves the same. Then you'll have narrowed it down to the intake.

I re-purposed the box and the foam is from Jegs, originally for sealing carburetors to ram-air hoods.

 

[Chuckable]

Didn't know MacGyver was on the forums!

Seriously, though, can anyone answer OCDFist's question?

 

[dyn085]

Intake temp is measured on the MAF sensor, so it's reading temperature that's basically straight from the air filter. Engine bays get pretty hot during highway travel and unfortunately there's not really going to be any good way to keep that it of an open-element filter. It's not going to be caused by the EGR system.

With all of that being said, what are your charge temps? That's really the only thing I would be concerned with. If you were in constant stop-and-go that 10+ degree intake temp would constantly be taxing the intercooler due to the lack of airflow, but at highway speeds you should be seeing near ambient charge temps regardless of how cool/hot the intake is.

 

[OCDFist]

Intake temp is measured on the MAF sensor, so it's reading temperature that's basically straight from the air filter. Engine bays get pretty hot during highway travel and unfortunately there's not really going to be any good way to keep that it of an open-element filter. It's not going to be caused by the EGR system.

With all of that being said, what are your charge temps? That's really the only thing I would be concerned with. If you were in constant stop-and-go that 10+ degree intake temp would constantly be taxing the intercooler due to the lack of airflow, but at highway speeds you should be seeing near ambient charge temps regardless of how cool/hot the intake is.

I'll agree to disagree on the hot air from the filter. If anything is getting warmer after the engine is warmed up, it's the section of the aluminum intake pipe over the exhaust manifold. I've felt the filter and intake pipe up tp a foot after the filter, after driving for 25 minutes, and it's as cold to the touch as the exterior sheet metal.

I'll take a picture of these gauges tomorrow on the Cobb while on the highway: ambient temp, charge air temp, intake temp, and maybe even compressor inlet & outlet temp.

 

[OCDFist]

I just read on a Focus ST forum that the bypass valve is possibly raising the intake temp, which enters the intake tube just before the mass air sensor. Mystery solved, maybe.

 

[dyn085]

I'll agree to disagree on the hot air from the filter. If anything is getting warmer after the engine is warmed up, it's the section of the aluminum intake pipe over the exhaust manifold. I've felt the filter and intake pipe up tp a foot after the filter, after driving for 25 minutes, and it's as cold to the touch as the exterior sheet metal.

I'll take a picture of these gauges tomorrow on the Cobb while on the highway: ambient temp, charge air temp, intake temp, and maybe even compressor inlet & outlet temp.

Disagree all you want, I'm not here to argue. Your MAF sensor isn't above the exhaust manifold anyways. You're initially saying that the intake gets heated above the manifold, that heat pushes forward in the metal against the incoming air about two feet, then heats the air before your MAF sensor to the point that it's raised 10 degrees. It's not very probable considering where you're saying the metal heats up versus where intake temp is measured.

Also, compressor inlet/outlet are both inferred-not measured, so it's not a relevant reading.

I just read on a Focus ST forum that the bypass valve is possibly raising the intake temp, which enters the intake tube just before the mass air sensor. Mystery solved, maybe.

Maybe, though if that were the case I would assume your intake temp would almost always be at least 10 degrees considering the fact that, under the conditions you've lined out, you're driving at vacuum. It's still a moot point anyways considering the fact that the only intake temperature your engine will really care about is what comes post turbo. I never watch my intake temp due to its irrelevancy, but my CAT is usually only 1 or 2 degrees above ambient at cruise. You won't get any better than that without a separate mechanical device such as an intercooler sprayer.

I think people under-estimate the amount of heat that is transferred into an open-element filter and where it comes from. The heat from the radiator blows almost directly under the OEM box, and when you're cruising at those speeds the engine is significantly warmer than when you're just driving around town. You can put foam between the intake and engine, but are you shielding it from the radiator and underneath? Even Modbargains, which wrote a glowing review of the Injen intake, ultimately ended up sealing the filter into a modified OEM box or something.

 

[MOFiST]

Disagree all you want, I'm not here to argue. Your MAF sensor isn't above the exhaust manifold anyways. You're initially saying that the intake gets heated above the manifold, that heat pushes forward in the metal against the incoming air about two feet, then heats the air before your MAF sensor to the point that it's raised 10 degrees. It's not very probable considering where you're saying the metal heats up versus where intake temp is measured.

Also, compressor inlet/outlet are both inferred-not measured, so it's not a relevant reading.

Maybe, though if that were the case I would assume your intake temp would almost always be at least 10 degrees considering the fact that, under the conditions you've lined out, you're driving at vacuum. It's still a moot point anyways considering the fact that the only intake temperature your engine will really care about is what comes post turbo. I never watch my intake temp due to its irrelevancy, but my CAT is usually only 1 or 2 degrees above ambient at cruise. You won't get any better than that without a separate mechanical device such as an intercooler sprayer.

I think people under-estimate the amount of heat that is transferred into an open-element filter and where it comes from. The heat from the radiator blows almost directly under the OEM box, and when you're cruising at those speeds the engine is significantly warmer than when you're just driving around town. You can put foam between the intake and engine, but are you shielding it from the radiator and underneath? Even Modbargains, which wrote a glowing review of the Injen intake, ultimately ended up sealing the filter into a modified OEM box or something.

Great post. The thing I wonder is the difference in manifold temps with a stock or an open pod filter in like for like conditions. I'm also talking with a better fmic which a lot of us have. I wonder how much difference you'll see at the manifold after a better than OEM fmic in normal cruising and WOT conditions. I'm not in a position to do these logs as I'm tethered to a unique MAF calibration without an Accessport.

 

[dyn085]

Great post. The thing I wonder is the difference in CAT's with stock and open pod filter in like for like conditions. I'm also talking with a better fmic which a lot of us have. I wonder how much difference you'll see at the manifold after a good fmic in normal cruising conditions. I'm not in a position to do these logs as I'm shackled to a certain MAF calibration without an Accessport.

Quite honestly, I don't think you'll see a difference in CAT's at cruise regardless of intake or FMIC. There's tons of airflow and low pre-FMIC temps due to low load while not under boost. I think that if you set four cars up under the different conditions (OEM intake/OEM FMIC, open filter/OEM FMIC, OEM intake/upgraded FMIC, open filter/upgraded FMIC) that they would probably show identical CAT's given the scenario of steady-state interstate cruising. It's essentially the optimal scenario for the FMIC to shed heat.

Obviously that changes drastically during stop-and-go traffic and racing, and each of the four cars would produce wildly different CAT's in each of those scenarios. It's been shown in a few places that the OEM intake is more than plenty for the stock turbo, so aside from looks/sound I just don't see a reason for upgrade and I have yet to see datalogs that substantiate the cost. Nonetheless, if CP-e comes out with a kit similar to the FoST then I will probably get one for looks and datalog compared to stock.

 

[MOFiST]

Quite honestly, I don't think you'll see a difference in CAT's at cruise regardless of intake or FMIC. There's tons of airflow and low pre-FMIC temps due to low load while not under boost. I think that if you set four cars up under the different conditions (OEM intake/OEM FMIC, open filter/OEM FMIC, OEM intake/upgraded FMIC, open filter/upgraded FMIC) that they would probably show identical CAT's given the scenario of steady-state interstate cruising. It's essentially the optimal scenario for the FMIC to shed heat.

Obviously that changes drastically during stop-and-go traffic and racing, and each of the four cars would produce wildly different CAT's in each of those scenarios. It's been shown in a few places that the OEM intake is more than plenty for the stock turbo, so aside from looks/sound I just don't see a reason for upgrade and I have yet to see datalogs that substantiate the cost. Nonetheless, if CP-e comes out with a kit similar to the FoST then I will probably get one for looks and datalog compared to stock.

Sorry i edited my post a couple times for clarity. Yes I agree with you about the stock intake being sufficient for the puny turbo. My reason for upgrading the way I did was multi fold. Mainly to do with no Accessport here and few options. Aside from that my mind tells me the main heat source irrespective of intake is going to be the turbo compressor. Razorlab and probably others have shown the stock fmic is prone to heat soak. Logic would say upgrade that to better cope with that issue and then if you want to run a pod it shouldn't matter all that much as the fmic should be able deal with it.

 

[OCDFist]

I read about the inferred values last night after I posted on here. My Mustang's IAT sensor is in the intake manifold, as are many other cars. I now understand that the Fiesta ST IAT sensor is in the mass air sensor location. I now understand that the hose in the intake tube is supposedly an evap hose, so that's not an issue I'd guess.

Maybe you can't see it in the picture, but there is a plastic box under my air filter, separating it from the engine compartment. It receives air from the original grill snorkel and an additional 3" hose on the bottom of the box that runs behind the fog light. There is foam around the Injen pipe and foam touching most of the hood. I can't see much when the hood is closed, but I'd say 90% is sealed. Without this box, the intake heat was much higher any time there wasn't a mid to high load.

CAT is just above ambient unless sitting idle, then it cools off when the car is moving again. Intake temp is normally similar to CAT, but in this particular question about intake temp, I'm under low load/65 mph/flat highway. I used a temp gun this morning after I drove to work. Outside sheet metal was around 4 degrees F, and the intake filter and tube inside the box was 15 degrees F. It's cold to the touch, but hard to exactly say how cool without the temp gun.

So, you are right, the intake is catching engine heat, about 10 degrees worth this morning, verified by the temp gun.

Temperature = power in these cars, from what I know (which must be limited lol), so any reduction is welcome. I never did hear how the egr system worked in the 1.6L ecoboost.

 

[MOFiST]

I found an explanation of our egr here. (Post 3) http://www.fiestastforum.com/forum...carbon-build-up?p=57501&viewfull=1#post57501

 

[OCDFist]

I read that as well. More possible examples than actual schematics, etc.

 

[OCDFist]

After replacing my Injen intake with a custom 3" plastic & silicone intake yesterday, and not resetting KAM, Ambient Temp on the Cobb was about -35 deg. F. CAT and IAT were within a couple of degrees of outside air while driving in stop & go traffic. I only drove about 20 miles, and during that time Ambient Temp moved closer to normal, but still about -13 deg F on the Cobb.

After sitting a few hours, I reset KAM and Ambient Temp went back to normal. Ambient and CAT were close to outside temp (65 deg F), verified with a heat gun at the filter & charge air tube. IAT displayed about 80 deg F, verified with a heat gun on the engine, so that sensor must be on the engine somewhere.

Anyway, the IAT still heats up about 10 degrees hotter than CAT after the engine is fully warmed up even when moving, while CAT and Ambient are at or below outside air temperature, depending on vehicle movement.

I didn't do it, but I could have unplugged the mass-air/temp sensor and looked at the Cobb Ambient Temp display. Looks like the mass-air sensor is Ambient on my Cobb display.

 

[karlk11]

Not sure if this is in the right section.

I noticed that Intake Temps closely follow Ambient & Charge Air Temps (Cobb AP Stage 1 91 octane, stock IC, Injen intake with completely shielded filter). However, on the highway when coolant temp is normal, Intake Temp will rise and stay approximately 10 degrees higher than Ambient for no apparent reason. This week the temps have been in the teens, and I'm driving at 60-65 mph, so it should be ice cold all the way through.

My question: Is this the EGR system? Obviously I don't mind a little bit warmer intake right now, but when it warms up I'd be interested in keeping everything as cool as possible.

No actual EGR system on variable valve timed Ford cars. The timing is adjusted to allow valve overlap to function similar an actual EGR.