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Discussion Starter · #1 · (Edited)
So, running quite a big turbo and even with exhaust gas temperatures looking normal I'm getting a hell of a lot of heat soak. I do the tuning myself with datalogit but I'm no expert.

If I drive around on boost, the intake temperatures stay down - 35-43 being the average but stuck in traffic or just motorway driving tends to raise the air temperatures (as one would expect). What seems to happen though is that once it reaches temperatures such as 48+ the air fuel mixture is very unreliable and hard to tune even when the temperatures return to normal. Alternatively, parking up at the supermarket and then leaving the car to stand for 15 minutes results in massive surging at idle.

A bit of research shows that PFC does have quite a few heat soak problems and I've kind of solved the idle surging by changing the water temp adjustments to be quite rich when not at 80degC. This results in quite a rich condition if the heat soak hasn't occurred, i.e. start from cold. I've also tried modifying the air temp vs inj which I've played with but the values, although interpolated are not giving me very much accuracy to play with. I'm not inclined to just heuristically punch numbers in, especially when the values are 30deg and 50deg to enrichen the map.

So, is the solution to just get a better ECU or is it possible to move air intake temperature sensor or insulate it somehow?

Cheers!

Edit: In normal circumstances the tune is perfect for what I need, I've got the TPSvsINJ set up according to my style and the temps vs inj are set overly safe. No problems with the ignition timing
 

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This is the problem of Nissan stock air temp sensor location.
I had same problems with link ECU until i put a sensor right after intercooler exit near the bov and connected it to the ECU, i left the sensor at stock location for plumbing purpose only.
 

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Discussion Starter · #3 ·
Did you just plumb the stock sensor straight after the intercooler? I can probably weld a socket onto the piping straight after the intercooler if so.

I assume another solution would be to run water meth cooling?
 

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Yes ofcause you need to weld a socket for it.
I'm using not stock sensor but it is not matter. Aftermarked sensor recomended buy most tuners just react faster but anyway soack heat from Radiator.
You dont need a cooling because the problem is not in the hot air - as you drive WOT at high speed you get a normal air temp. Problem is that plenum get hot and these temperature affetc sensor. So you end up with correction when it is not needed.
 

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Its not just the location of the stock intake sensor its the fact that its actually a water sensor the same one that the radiator has in the bottom!

It is also very slow to respond and because its metal it will heat soak badly.

I have a Link G4 and a Bosch IAT in mine, which is hugely accurate.
 

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Discussion Starter · #7 ·
D-Ranged, can the Bosche IAT be plumbed in as a replacement for the PFC or is the output incompatible?
 

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I guess for PFC you beter leave stock sensor. But believe me bosh sensor does not solve the problem if left in stock location. I use same LInk G4 now and had an issue with bosh sensor mounted to same location as stock so i had to move it to the place where no heat from radiator.
 

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D-Ranged, can the Bosche IAT be plumbed in as a replacement for the PFC or is the output incompatible?
Im not sure mate, i cant see why you couldnt as all it is sending is a signal through voltage. You could always buy one and hook cut the wiring and then hook it up and see if you get a reading. If not solder the old one back on.

I got a metal box welded on to fit the bosch to my HKS hard pipe going in to the plenum so it is no longer in stock position.
 

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Discussion Starter · #10 ·
I don't have a problem welding. Just out of curiosity, what intake temperatures are you guys seeing? I'm seeing around 35-38 when driving 'spiritedly' and low to mid 40s cruising off boost.
 

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I don't have a problem welding. Just out of curiosity, what intake temperatures are you guys seeing? I'm seeing around 35-38 when driving 'spiritedly' and low to mid 40s cruising off boost.
I haven't looked at it when driving to be honest mate. I will have to plug the laptop in to the ECU next time i'm driving it.

You should be able to see where mine is just above the blue AN fitting on the catchtank. If i find a better pic i will post it.

 
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