[bazf]

bazf.

All manufacturers who fit there sensor in the manifold like this will suffer the same so it an't just a vag thing.

Why don't you design & make a better manifold ?

Dell.

 

Yip they do and I've used phenolic spacers on the 1.8t and the IAT drop rapidly once there is decent airflow across the sensor, these things take an age to cool down.   

 

No need to change the entire manifold(these have an interesting internal design to them must be to reduce turbulence in the plenum) it's just the location of the sensor that needs to change.

[bazf]

Surely the sensor will be calibrated so that when its at a physical particular temperature it knows what that equates to in air temp? 

 

I think there might be too many variables to add that kind of correction factors into the calibration of the sensors but it would be interesting to find out for sure.

[JamesBaby]

I think there might be too many variables to add that kind of correction factors into the calibration of the sensors but it would be interesting to find out for sure.

 

Quite possibly yes.

 

Now that I think of it a bit more, IIRC a MAF meter simply takes the air temperature, and calculates flow volume by how much a hot element is cooled by the flow across it. So if a simple air sample is good enough for air temperature in normally aspirated cold air intake fueling, its probably good enough for an IC. ?

[RS3Dell]

Quite possibly yes.
 
Now that I think of it a bit more, IIRC a MAF meter simply takes the air temperature, and calculates flow volume by how much a hot element is cooled by the flow across it. So if a simple air sample is good enough for air temperature in normally aspirated cold air intake fueling, its probably good enough for an IC. ?

James.

Our RSs don't use a MAF meter but does take the air pressure & its temperature either side of the throttle body.

If I'm correct it uses the throttle angle,rpms + the other sensors to calculate fuelling and ignition timing.

Dell.

[JamesBaby]

James.

Our RSs don't use a MAF meter but does take the air pressure & its temperature either side of the throttle body.

If I'm correct it uses the throttle angle,rpms + the other sensors to calculate fuelling and ignition timing.

Dell.

 

Dell, yes I knew that. I was just using the principle of NA MAF's to illustrate my point as to how the air temp can be measured.

[AusTTRS]

Phenolic spacers are great, certainly stop the heat .

 

I found a chap on ebay selling them for the 2.5 but he had no idea if they fitted or not.

 

AusTTRS, instead of altering the sensor outputs i think relocating the sensors would work by getting them away from the oven.  I'm not sure if there would be any implications from moving them or if the sensors are in those particular spots for a reason or just to make use of space.

 

Hi Bazf,

 

I bought one of the phenolic spacers (positive it will be the same chap) & the reason he doesn't know if it will fit or not is because I told him it isn't a bolt on proposition. He had them made for a different application which I'm pretty sure didn't include our high pressure fuel line/s & injectors. Bending the lines & removing the injectors & rail was more than I was prepared to risk right now so it's a project 'for another day'.

[AusTTRS]

A bit of an update on the Wagner Evo3, & IAT's in general, after a visit to the track last weekend.

 

Pre mods setup - Evo1, WMI, engine bay openings in OEM airbox taped over.

The best track IAT I saw was 39 deg C (with fridge cold methanol mix in tank), but more often 45 deg C. Ambient temps 22-25 deg C

 

Post mods setup - EVO3, WMI, engine bay openings in OEM airbox taped over, additional cold air intake, dual nozzle (iced)water spray on the intercooler. The best track IAT I saw was 25 deg C, but more often 28 deg C. Ambient temp on the day was 22-25 deg C.

 

It's worth noting that the lowest IAT's were at WOT, with the largest amount of air possible wizzing past the sensors. Radiant heat from the aluminium manifold was having minimal impact at this time.

 

Certainly spraying iced water on the EVO3 down the straights made a lot of difference. If the 2.5 engine used a plastic manifold instead, I've no doubt I could have seen ambient, or even sub-ambient IATs in the same situation.

 

As it was, the power gain was remarkable. I had traction issues where I never had before. Also took >1sec of my lap time (a quick lap is 60 sec). 

[Mac]

Pretty sure the temperature you see is not the real temp. entering the engine. On the 2.0 tdi engines we have 4bar MAP measure temp 30cm  before it enters the manifold, doesnt suffer from radiating heat or heat sink like the RS3 , and the temps are REAL. 

 

If you wanna measure correct temp. put a sensor and gauge after the IC. You will see real temperature not influenced by the manifold that gets to 70-80 degrees for sure.

Lets say the system is better designed on the latest tdi engines with MAF reading flow up to 2000kg air /h.

[BenTTU]

Pretty sure the temperature you see is not the real temp. entering the engine. On the 2.0 tdi engines we have 4bar MAP measure temp 30cm  before it enters the manifold, doesnt suffer from radiating heat or heat sink like the RS3 , and the temps are REAL. 

 

If you wanna measure correct temp. put a sensor and gauge after the IC. You will see real temperature not influenced by the manifold that gets to 70-80 degrees for sure.

Lets say the system is better designed on the latest tdi engines with MAF reading flow up to 2000kg air /h.

 

 

I'm a bit unsure what you mean by real temp readings??

The temp sensor plays a huge part in The engine to ensure mixture and timing is correct, if the temp was wrong the car wouldn't perform as it should. I am sure Audi wouldn't just chuck the sensor on and hope for the best.

[BenTTU]

I sat down this morning and read this hole thread.

 

Firstly you can't use a reference or an example from a 1.8t or 2.0tdi vs a 2.5tfsi 5pot engine. Heat soak, air intake temp and oil temp is all going to be different. 

  You think a 2.5tfsi is bad for heat, go tune a rs6 c6 or c7...c7 mapped Monday intake temps 60s! On the road not dyno, Had to drive steady for 20minutes to get it to cool down. 

 

Also the air temps are correct, it's simple really if the heat soak is heating up the sensor as you all state don't you think it won't heat up the air?? 

 

Facts are all charged engines suffer with huge heat soak, some more then others. This is why when you aid water meth on certain engines gains aren't that great due to the heat not being so bad. For example 1.8t aid meth on a standard set up and you see very little gain put meth on a rs6 and gain is huge. 

 

If you want to throw temps into the mix, we could also talk about oil temp water temp and also EGT temps which also play a huge part.

 

Just my 2pence worth

 

Ben

Edited by BenTTU, 14 August 2018 - 07:58 AM.

[T-800]

I sat down this morning and read this hole thread.

Firstly you can't use a reference or an example from a 1.8t or 2.0tdi vs a 2.5tfsi 5pot engine. Heat soak, air intake temp and oil temp is all going to be different.
You think a 2.5tfsi is bad for heat, go tune a rs6 c6 or c7...c7 mapped Monday intake temps 60s! On the road not dyno, Had to drive steady for 20minutes to get it to cool down.

Also the air temps are correct, it's simple really if the heat soak is heating up the sensor as you all state don't you think it won't heat up the air??

Facts are all charged engines suffer with huge heat soak, some more then others. This is why when you aid water meth on certain engines gains aren't that great due to the heat not being so bad. For example 1.8t aid meth on a standard set up and you see very little gain put meth on a rs6 and gain is huge.

If you want to throw temps into the mix, we could also talk about oil temp water temp and also EGT temps which also play a huge part.

Just my 2pence worth

Ben

Interesting......

Someone posted this up on another forum

Der RS 3 (2021) bleibt dem Fünfzylinder treu. Mit Otto-Partikelfilter samt diversen innermotorischen Maßnahmen soll die jüngste Ausgabe aber sogar den dann noch nicht final definierten Euro-7-Standard erfüllen. Um die Leistungs- und Drehmomentkurven anzufetten, soll der RS-3-Motor serienmäßig mit Wassereinspritzung vom Band rollen, in der ersten Ausbaustufe stehen 420 PS und 500 Nm im Raum. Mittelfristig soll der Fünfender sogar 450 PS mobilisieren.

When I translated it

[BenTTU]

Now we are talking, us tuners will have a field day

[T-800]

From Autobild.....

[Mac]

Yesterday with 35 temp outside i drove for 300+ km, mountains, normal road. The IAT was always 4-5 deg above ambient temp with the WT EVO 3 IC, so i am very happy with that. The more i pushed the cooler it got going closer to ambient temp. I have DEFI display .

 

Reached the city and iat went to 50deg, when i got home it was 60 degrees (heat soak, not enough speed to cool everything down) lo i left it running with heat on to cool down engine as well for 5 minutes before shutting it off.