intake air temp...

[Toms306]

[Poodle]

Haven't you got a knob filter on one of these? Could account for the heat-soak.

Tbh if the car's sat for any time the lack of airflow is going to cause temps to go up across the board, common sense really.

[Mr Whippy]

IAT sensor is usually about 2-3deg above ambient air temp, unless you have changed the standard inlet, in which case it's almost always usually higher temp than that.

FMIC acts as an inter-warmer as much as an inter-cooler depending on what is going on...

Monitoring pre/post intercooler charge temps would be interesting.


I won't get into too much to do with intercooling but there is not much advantage in intercooling TOO far unless the ECU knows it's that cool and always will be that cool. Without a charge air temp sensor this ECU/engine can't really benefit as much as it could from really good intercooling.

The best way this ECU/engine can compensate for cooler charge air temps is via the engine coolant temp! Not exactly a great system and that is why intercooling too hard won't gain you anything. Any benefit in charge air density is offset by the engine not changing the injection advance. You get more power with cooler charge air in theory, but it's offset by a later ignition of the charge air and fuel mix in theory.

Beyond a certain amount of intercooling the engine just won't see or care basically as it has no way of doing so.

The IAT on the other hand it CAN see, hence having that value as low as possible (or as close to ambient) is important.

Dave

[DeeTurbo]

IAT sensor is usually about 2-3deg above ambient air temp, unless you have changed the standard inlet, in which case it's almost always usually higher temp than that.

FMIC acts as an inter-warmer as much as an inter-cooler depending on what is going on...

Monitoring pre/post intercooler charge temps would be interesting.


I won't get into too much to do with intercooling but there is not much advantage in intercooling TOO far unless the ECU knows it's that cool and always will be that cool. Without a charge air temp sensor this ECU/engine can't really benefit as much as it could from really good intercooling.

The best way this ECU/engine can compensate for cooler charge air temps is via the engine coolant temp! Not exactly a great system and that is why intercooling too hard won't gain you anything. Any benefit in charge air density is offset by the engine not changing the injection advance. You get more power with cooler charge air in theory, but it's offset by a later ignition of the charge air and fuel mix in theory.

Beyond a certain amount of intercooling the engine just won't see or care basically as it has no way of doing so.

The IAT on the other hand it CAN see, hence having that value as low as possible (or as close to ambient) is important.

Dave

Dave, do you know any cars that run the EDC15 ECU's running a charge temp sensor and if they do would it best possible to map one in?

[Mr Whippy]

I don't know any that run a charge air temp sensor unfortunately.

It's obviously logged in development vs IAT, and for a standardised intercooler or non-intercooled system is probably just sits in a trend line with engine coolant temp or oil temp etc.
Generally you have enough control in other maps to compensate for the higher charge air temps. Ie, at high injection amounts at high rpm, you can assume it must be on boost to make the high injections, and so you can tune in the knowledge that IAT is always within a certain range at that point. If it varies it probably only does at that point due to coolant temp or oil temp etc.

It's not ideal, but it was probably deemed acceptable. It's not ideal for tuning a car because all these basic mappings are kinda built into many tens or hundreds of look up tables.

When you delve deeper and deeper it's surprising how much tuning is done in so many little maps all over the place. They are fine left alone most of the time but as you change too many things then they can become important.

Ie, the mappings all expect that IAT is around 0 - 5 deg above ambient, and it's right in assuming that until you change it.

Who knows what the impact of changing that are... but I'd say anything that increases IAT is just bad full stop. It's de-tuning and there is no other way to sell it.

Dave

[Midnightclub]

Would it be possible to get a separate sensor to use for iats and then tap it into the inlet manifold so the engine is adjusting based on temps post turbo and cooler rather than pre turbo?

[Mattcheese31]

and this is why XUD = so much win, colder air equals bigger charge, coz we all run 'em a bit smokey . .

[Midnightclub]

I don't know about you guys but i prefer my fuel being burnt by the engine.. not being blown out the exhaust..

HDi > Dt.. IMO lol

[Mattcheese31]

I don't know about you guys but i prefer my fuel being burnt by the engine.. not being blown out the exhaust..

HDi > Dt.. IMO lol

thing is though, with a DT you can always hold back a bit on full throttle or mat it when it's freezing and burn the lot . .

[silverzx]

I don't know about you guys but i prefer my fuel being burnt by the engine.. not being blown out the exhaust..

HDi > Dt.. IMO lol

thing is though, with a DT you can always hold back a bit on full throttle or mat it when it's freezing and burn the lot . .

Not this again.

[Midnightclub]

If i recall you agreed with me the other day trent haha

[Mattcheese31]

fight fight . . . . .i should let it be known that i also own a HDI van . . . . lol