rolling roads.....how can they tell....

[CaL]

...if my car is rich or lean??or if its running spot on??on a standard ecu how do they get into this information?....i know they hook up to rs turbos etc with out mappable ecus....but ive never actually thought about how they do it.....and where do the connect theyre devices to?cheers.cal

 

[dac69er]

they just stick an afr sensor into either the end of the exhaust or they remove your stock lambda and screw it in there, simple!

 

[CaL]

really??thats it??they must have some hardcore equiptemnt to tell them all these things just off that!!.lol

 

[sx_turbo]

the rollers, test how much torque and power ther is at the wheels, the computer then calculates how much power is at the fly.


to tune the fuelling they put a wideband sensor where the car lambda sensor sits, and they also put a probe in the exhaust aswell.

the guy tuning also has a pair of headphones on that is connected to an earth point on the block, and listens out for knock and inconsistances with the electrical noises for the timing side of things.

 

[Spoonz]

the rollers, test how much torque and power ther is at the wheels, the computer then calculates how much power is at the fly.


to tune the fuelling they put a wideband sensor where the car lambda sensor sits, and they also put a probe in the exhaust aswell.

the guy tuning also has a pair of headphones on that is connected to an earth point on the block, and listens out for knock and inconsistances with the electrical noises for the timing side of things.

didnt know bout the headphones thats very intreasting

 

[dEF]

your stock AFR sensor tells your ECU whether your mixture is rich or lean.
Tuners have wideband sensors which tell them exact value of AFR that they can lower or rise by adding fuel or rising boost (in turbocharged engines).

 

[Smore]

if they take your lamda sensor out and put in thier wideband, how does the ECU know what to do?

 

[ragz]

if they take your lamda sensor out and put in thier wideband, how does the ECU know what to do?

depends if the ecu is in closed loop mode or open loop mode

 

[dac69er]

very rarely does the ecu use the stock narrowband sensor to control fuelling under load conditions such as acceleration, thats when the map takes control.
the stock lambda is used on idle or constant speed running to trim the fuelling and ignition to create the cleanest burn possible and therefore lower emissions and give you go economy. generally it runs it as lean as possible

 

[CaL]

isnt lean very bad though??rich is better isnt it?whats the down sides of rich?and the positive sides?

 

[dac69er]

you generally only come up against problems with leaness under load. when on idle or at constant speed/revs you can lean the engine off alot more as its not under load and thereore wont det as easily.
its not stupidly lean so to cause excessive heat or anything, just enough to be safe but to lower emissions and help economy

 

[sx_turbo]

lean isnt always bad toyota developed an engine specially designed to run lean, i think its the 7a-fe engine nicknamed lean burn, as it says runs very len, and was fitted to corrollas and is extremely reliable.

a car can run lean, it just needs to be done just right as to lean can blow the engine.



when running rich you just wont get the maximum power, depending on how rich it is running. the power could be boggy and missfire, also if the engine runs to rich you could suffer from borewash, which ruins the bores of the block and can cause piston ring failure i beleive.

 

[Spoonz]

^^^^Thats 100% correct on idle and not under load its lean so more eco and on full boost u shud run kinda rich

 

[dac69er]

turbo cars generally run richer than N/As anyway. my mums citreon AX was a lean burn engine.

 

[Timmy]

rich mixes don't produce more power. For power the mix is not rich or lean the afr will be around the 12/13 i think. I know thats not that acurate but you get what i mean. I was always under the impression that if you remove the stock lambda it will go into open loop and no good for tuning, but i guess thats not a problem if you got a standalone.

 

[Arbate]

didnt know bout the headphones thats very intreasting

yes... the tunner need to know how the car react on the change of setting..
those headphones help tunner to understand what the engine really wanted.. every little change of setting can easly stess the engine and causes of detonation that can blow up the engine..

just for the add up
every things it explained very clear by all the member above, nice to have a forum that have member who really know about the answer of the question. not just pretending to know.

 

[dac69er]

rich mixes don't produce more power. For power the mix is not rich or lean the afr will be around the 12/13 i think. I know thats not that acurate but you get what i mean. I was always under the impression that if you remove the stock lambda it will go into open loop and no good for tuning, but i guess thats not a problem if you got a standalone.

you do want it spot on but on a turbo car its generally on the rich side you want it as detonation is more prominent if not.

like previously explained the lambda only comes into effect on idle or continuous rpm. when accelerating under boost etc that is when the map that is preset into the ecu comes into effect and controls everything. the lambda is rarely used under these conditions. it isnt on the 4efte anyway

 

[Jay]

just for the add up
every things it explained very clear by all the member above, nice to have a forum that have member who really know about the answer of the question. not just pretending to know.

Agreed, excellent thread with clear explanations. This one's heading to the resolved section for sure lads - nice work!

 

[CaL]

Agreed, excellent thread with clear explanations. This one's heading to the resolved section for sure lads - nice work!

woohoo i did somethin right!!

 

[thefalls]

And hence when the lambda sensor is buggered then the idling of the car suffers a lot.