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Air Temp Sender
darrens - 3/6/06 at 05:02 PM

Just getting the last things togerther for MS and I'd forgotten all about the air temp sender, anyone got any ideas on the best place to mount this, would drilling and tapping the plenum chamber be adequate.

Engine is a RV8 btw

Regards


BKLOCO - 3/6/06 at 06:10 PM

quote:
Originally posted by darrens
would drilling and tapping the plenum chamber be adequate.

Engine is a RV8 btw

Regards


Thats where mine is on my Zetec.
Seems to be fine


mark chandler - 3/6/06 at 08:21 PM

You want to stick it in the air filter, at least no-where that the heat from the engine can get at it so the plenum is not a good idea.

I raced a v8 landrover with megasquirt, I found that ducting the air well away from the engine to draw in cold air made a big difference. I started off with a big K&N straight off the plenum intake, when I relocated this with a few foot of flexy pipe to a side vent and fenced this off from the ambient underbody air the car ran colder and felt distictly faster. I had the sensor plumbed into the flexy tube just behind the filter. NB/ used v12 jag water sensor and air sensor as you do not need to mod the MS to use these.

Regards Mark


britishtrident - 3/6/06 at 08:23 PM

A lot of modern tin tops now use a Bosch combined MAP and IAT in one unit , fitted straight into the plenum.

[Edited on 3/6/06 by britishtrident]


darrens - 3/6/06 at 09:47 PM

I was thinking also concerned about the heat from the engine but wasn't sure how much it would affect the results, I think I might try and devise a way of positioning in the air intake away from the engine.

Regards


stevebubs - 4/6/06 at 12:47 AM

quote:
Originally posted by darrens
I was thinking also concerned about the heat from the engine but wasn't sure how much it would affect the results, I think I might try and devise a way of positioning in the air intake away from the engine.

Regards


So long as the reading is representative of that of the air coming into the engine, then it doesn't matter where it is installed.

Heatsoak from the engine is a worry, but so long as it's placed directly in the airflow then the reading should be fine.

Stephen

[Edited on 4/6/06 by stevebubs]


BKLOCO - 4/6/06 at 07:30 AM

If you use the "open" sensor type ie. The type where you can see the thermistor bead, then heat soak will not be a problem, as the sensor will be in the airflow and thermistors are sensitive enough that the heat of the plenum itself will have little effect.

If however you use the enclosed type, as used as water temp sensors, you will have big problems as this type of sensor reacts far too slowly for air temp mesurement and is affected by the temperature of the body it is screwed into.

You can prove all is well when the system is up and running.
When the engine is at running temperature the sensor in my plenum is still reading the temperature of the air that is travelling through the intake and as I said it's mounted in the plenum.

If you're running MSII then it doesn't matter a rats fart where the sensors are sourced from, be it Vauxhall Ford, Nissan etc. etc. Re calibrating them is a 10 minute job with a saucepan of water and a thermometer Its then all done in software in megatune.

What is important is to duct the intake to pick up the coolest air possible, as cold air is denser than hot.



[Edited on 4-6-06 by BKLOCO]


britishtrident - 4/6/06 at 11:03 AM

Getting cold air into the engine makes a big difference to power on an injected engine --- less so with a carb engine because of the less efficient fuel mixing.

Rover 200/400 K series IAT sensors are easy to remove in the scrappies -- it is asensor with a green connector located in the side of inlet tract to n04 cylinder (ie nearest the gearbox)


darrens - 4/6/06 at 12:49 PM

Cheers for replies, off to scrappers to find a rover 200/400, prob gonna put it in the plenum chamber. I was going to use the enlosed type of sender (i.e water type) but having read BKLOCO's reply I will use the open type

Regards


britishtrident - 4/6/06 at 01:47 PM

I have the official Rover degree-ohms curve for it somewhere.


darrens - 4/6/06 at 10:00 PM

quote:
Originally posted by britishtrident
I have the official Rover degree-ohms curve for it somewhere.


that would be nice if at hand


BKLOCO - 5/6/06 at 04:17 PM

In case anyone wants them here are the Temp/resistance values for ford sensors:

Manifold sensor (open type)

10 deg C = 56k
40 deg C = 16k
70 deg C = 5k5

Coolant sensor

25 deg C = 30k
50 deg C = 11k2
100 deg C = 2k