MS air temp sensor location

[db484bhpv8]

I think my air temp sensor suffers with heat soak being in the same place as the original AFM.
Would it not be a better idea to relocate it nearer the airfilter and outside the engine bay?

[Bassfiend229hp]

Not if the air is heating up above ambient between the air filter and the plenum...

[db484bhpv8]

Bassfiend229hp said:

Not if the air is heating up above ambient between the air filter and the plenum...

Its not going to change much in a split second is it?

Just that according to the laptop my airtemp was reading upto 56 deg c while stationary.
The MS over reacted and went very lean and struggled to keep running.

Was fine at full throttle down the strip.

[carsy]

Probably a good idea. I think Simon, Sardonicus has his positioned near the air filter for this very reason.

Once the engine is running and pulling plenty of air through, i would have thought it will be ok where you have it. Just put mine there.

[Bassfiend229hp]

db484bhpv8 said:

Bassfiend229hp said:

Not if the air is heating up above ambient between the air filter and the plenum...

Its not going to change much in a split second is it?

Dunno - I realise that the surface area is greater but air doesn't spend long going through an intercooler either...

[spend]

Bassfiend229hp said:

Not if the air is heating up above ambient between the air filter and the plenum...

By the time the engine has had a few healthy gulps I think that concept is rubbish.. I would always fit the ATS near the air filter, even if your induction does warm the air a bit so much volume goes through (eg 5l x 3000rpm = 5 * 1500 = 7,500l / min!) the inside of teh induction will be cooled to the ambient temp in no time. More importantly the sampling is going to be far closer to what the engine sees than any sampling where the sensor itself is affected by heat soak (ie not the air temp but the sensor itself being bloody hot).

MS'ers only fit the sensor in place of the AFM because of historic skinflint ideas of having to replace the AFM somehow whilst still using the original induction pipes & utilizing the AFM wiring for the ATS IMHO. ie cheapest way to get it plumbed in quick...

[Pupp]

I run mine adjacent to the filter and it works fine save for literally a second or two after a warm engine start when heat from the rad seems to cause it to trim too lean. If I remember to flick the fan override on for a second or two before starting, that stops it (I usually forget of course)

[Bassfiend229hp]

I guess it depends what's between the air filter and the trumpets ... I've just been looking at superchargers and I definitely wouldn't put my air temp sensor at the filter and then have everything pulled through a hot supercharger and associated pipework and expect the temperature of the intake charge to be anywhere close to what was at the filter.

I was trying to work out how to mount one in the 90 degree flexible elbow that feeds the plenum as that seems to be the best compromise between getting a true intake charge temperature and avoiding heat soak...

[spend]

Bassfiend229hp said:

... I've just been looking at superchargers and I definitely wouldn't put my air temp sensor at the filter and then have everything pulled through a hot supercharger and associated pipework and expect the temperature of the intake charge to be anywhere close to what was at the filter....

You just use the same logic & place the ATS at the intercooler outlet so it's away from exhaust heat soak...

[Sardonicus]

carsy said:

Probably a good idea. I think Simon, Sardonicus has his positioned near the air filter for this very reason.

Once the engine is running and pulling plenty of air through, I would have thought it will be ok where you have it. Just put mine there.

Certainly do the trouble is most have the ATS mounted in a length of stainless steel or alloy pipe which heat soaks like a bd on hot shut down then takes a while to cool down once heat soaked and moving again which friggs about with the low speed already lean AFR on re-starting Spend once mentioned mounting the sensor in a silicone leg/nipple which would of been ideal too seeing as a length of silicone tube does not heat-soak but I tried this route, I do pick up some heat from the rad as Pupp says but its a lot better mounted in the air filter stub in the nose IMO (no lean restarts) bit over the top but I cut a hole in the stub and welded a boss the same thread as the ATS sensor I still have the alloy pipe linking the intake pipes together but no sensor fitted Derek worth doing I reckon Bassfiend/phil as below would be a different location I would be thinking of if forced induction but I am not and not likely too

Edited by Sardonicus on Tuesday 7th May 22:19

[Pupp]

Bassfiend229hp said:

I guess it depends what's between the air filter and the trumpets ... I've just been looking at superchargers and I definitely wouldn't put my air temp sensor at the filter and then have everything pulled through a hot supercharger and associated pipework and expect the temperature of the intake charge to be anywhere close to what was at the filter.

I was trying to work out how to mount one in the 90 degree flexible elbow that feeds the plenum as that seems to be the best compromise between getting a true intake charge temperature and avoiding heat soak...

I think that's absolutely correct... mine's presently NA but I will be moving the ATS if/when I go FI for exactly those reasons (although I long since learned that thinking in terms of accurate absolute measurements from such things is a nonsense; it's all about sensible relatives). There's quite a few self-sealing adaptors for tapping into flexible hoses out there so I imagine one with a 1/8NPT receiver will be easy enough to come by...