Should I install MAP sensor at manifold or intercooler?

Hasenwerk

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1982 Cabriolet (BEW|VNT17|Stage4), 1989 VW TriStar Syncro soon-to-be CR TDI (CBEA), 2001 Ford Ranger Edge 4x4 (ALH|VNT17|R520|Stage4)
I am installing a MK5 Jetta radiator and intercooler in my Ford Ranger ALH conversion, I need to make a place to install the MAP sensor.

Should I install it on the intake manifold or should I install it closer to the intercooler?
 

TDIMeister

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Farther away from the intake valves will mean less fluctuations, which is desirable.
 

JFettig

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I did not have any issues installing the MAP sensor at the end of the intake plenum on my Passat. IIRC I moved it to the inlet of the plenum, either way it worked fine.
 

TDIMeister

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I didn't say it won't work in the intake plenum, I only said that it is desirable a little away to get a less buzzy pressure signal in in the same way that happens when a boost gauge line is tapped right at the manifold.

QuickTD, very good point about the IAT.
 

Motohead1

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Guys at what point or temp does IAT start to affect fueling and any other parameters?
 

Ol'Rattler

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The A5 has a FMIC and the MAP sensor is above the headlight in the top charge air pipe near the intercooler in a stock A5 installation.
 

Ol'Rattler

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Guys at what point or temp does IAT start to affect fueling and any other parameters?
IDK buy I would suspect that the closer the sensor is located to the stock location, the better. VW could have mounted it on the manifold, but for some reason they didn't.
 

[486]

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Guys at what point or temp does IAT start to affect fueling and any other parameters?
also interested in this

after installing the second air/water my IAT sensor's just dangling by the right headlight.
 

Motohead1

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Im running a MAP only tune and I notice a haze shows up above 115F IAT and it will exponentially increase as IAT goes up. This is during sustained cruise on a 95F OAT day.



Sorry Im thread hi-jacking.

Back on topic.


David this MK5 setup you are putting in will it be a stock plastic tank intercooler or using an all aluminum after market one?
 

[486]

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The IAT is used to correct the MAF data. "MAF correction by temperature" is the name of the map. It's not well labeled but the z-axis appears to be percentage correction. Not sure if IAT is used for anything if you are running a MAP-based smoke limiter.
hm, I thought the temperature correction on that end was done with the MAF's internal IAT sensor, done before the data even hits the 0-5v output pin

The name of the map wouldn't make sense, to adjust the actual reading of the MAF by a sensor which is after the turbo and intercooler wouldn't work. Maybe it's name is a roundabout reference to it scaling the computer's internal MAF reading to curtail high-IAT white smoke.
 

Ol'Rattler

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Perhaps the IAT sensor sets the MAF's zero point. The difference in MAF reading at -40F and +100F might be huge if the MAF sensor wasn't compensated for temperature by the IAT sensor.
 

catbed

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Why should post intercooler temperature correct MAF?

Hot film MAFs inherently(hate that word) factor in air temperature when measuring mass flow. After the air mass is measured, it won't change due to temperature, only air volume.

In my ME7 experience, IATs were monitored to add more boost pressure in hot weather so the same amount of torque is delivered as cooler weather. I have no experience on EDC15 yet, tho.
 

[486]

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In my ME7 experience, IATs were monitored to add more boost pressure in hot weather so the same amount of torque is delivered as cooler weather. I have no experience on EDC15 yet, tho.
and you pull timing in a gasoline application
 

Ol'Rattler

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Post intercooler air temp can't be read by the MAF :)
I don't think anyone said they could be. Post intercooler IAT probably modifies what the ECU does with the MAF data. Just a WAG on my part.
 
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catbed

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and you pull timing in a gasoline application
agreed, which is where the raising boost pressure comes in to counteract the loss of torque output due to timing. High IATs = less timing = more boost for same torque output.

as TDIs have no spark plugs, I don't see where you're going with that?

I can't find any translated FR for EDC15 so without manually translating, I can't be sure exactly where IAT is used. I would assume anywhere after the intercooler is OK for MAP sensor, especially with no potential throttling losses like in a gasser.
 

flee

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2002 Jetta GLS wagon
I am installing a MK5 Jetta radiator and intercooler in my Ford Ranger ALH conversion, I need to make a place to install the MAP sensor.
Should I install it on the intake manifold or should I install it closer to the intercooler?
Since you asked this almost 2 weeks ago I'm curious what you ended up doing.
When I switched to an AWIC, I used an ebay weld-on MAP boss.
The aluminum pipe between the AWIC and IM was the best place to weld it on.
 

Hasenwerk

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Sorry for the late reply - vacation time has come and gone.

The answer to when the ECU derates the power due to too high IAT is 80C - I know this as the MK4 intercooler on my Ranger was *less* than optimal and my seat of the pants dyno would tell me there is a noticeable drop at this temperature. Smoke goes way up... it's just bad! (Malone MAP based / MAF-less Stage 4 tune).

The MK5 intercooler has no MAP sensor hole.

I ended up mounting my MAP sensor on the ALH's anti-shudder valve. I gutted the EGR and used that hole to mount the MAP. I have a PD 130 intake manifold I am going to use here soon, so will just make a flange for it with the MAP sensor opening.

For the "what it's worth" department. The MK5 intercooler is AWESOME. 26C ambient the other day and taking a long uphill IAT hit 35C - can't complain about that!
 
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