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O2 Sensor Help Asap


Adz2332
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Yer you guys were right, i got my wires crossed with a game of someone told someone else who got it back to me.

I need to put in a temp sensor... i didnt have time this time but will and get the tune done again. for now the tune goes on/

thanks for the help guys and i do apologise for taking up your time!

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Yer you guys were right, i got my wires crossed with a game of someone told someone else who got it back to me.

I need to put in a temp sensor... i didnt have time this time but will and get the tune done again. for now the tune goes on/

thanks for the help guys and i do apologise for taking up your time!

Tuning a map based ecu without a temp sensor is silly and I am surprised that your tuner would even do it.

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only needs to last one weekend, this weekend, then its back for the snesor and tune again

problem... on a dyno the ambient air is cool and your runs are not back to back... on the track the ambient air isn't cool and you're on/off the throttle.. this means your IAT could go from 20 to 50 degrees and back down to 25 for example..

a big no no...

however if your tuner is switched on (which I hope so) he/she will tune the car not on it's limits so when it does get hot it the motor won't have a spaz attack and knock off its tits.. it will just run extremely rich.

Ideally, as IAT increase timing decreases as well as fuel.. and as IAT decreases, fuel increases and timing is brought back to what it has been dialled as on the dyno... if you want you could add more timing as the IAT gets even cooler

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Well let's say if the charged air going into the motor is 25 degrees Celsius and the motor will happily take 14 degrees of timing, and for each 1 degree of timing the power increase is exponentially decaying in growth then you would assume the motor is near max torque/power for that given load point & rpm.

However say when the intake charge temp is now 45 degrees Celsius due to heat soak and ambient air temp.. the motor now perhaps could only take 11 degrees of timing for that given load point and rpm for that temperature... the 4 degrees lacking is compensated in the intake air temp ignition trim table..

So now say if you're not running one.. regardless of the intake air temp.. once the motor hits that load point & rpm it will just ignite the fuel at 14 degrees before top dead centre.. and yes it would very unhappy.

Not to mention the car would be pig rich.. oxygen density is lower at that temperature and the same amount of fuel is injected resulting in a pretty rich burn.

Hope that makes sense?

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