Normally, my total stock car run at 13.7AFR before 4500rpm and 12.7AFR after that. It makes 152.8hp on dyno. Now, I install an eletric supercharger, just a electric blower which can deliver up to 1000cfm under 1PSI. It make 155.8hp. Not impress enough and found it will not inject more fuel by itself. Make the whole AFR curve only reach 13.7AFR all the way up to redline. Do you think resetting ECU can help the car learning the fuel curve? If so, do I need to disconnect the battery? How long should I disconnect? Please advice.
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Electric Supercharger
- Thread starter Taxi Two
- Start date
Martin_172
ClioSport Club Member
LOL give the poor guy an answer! i would but dont know.
where can i get one of these things? lol
where can i get one of these things? lol
a remap is the only way of getting more fuel in, the ecu has set parameters.
I've come across this guy before, and i'm in HK RIGHT now so if he wants to show me, he can.
http://www.clubpeugeot.org/forum206/viewtopic.php?t=6444&postdays=0&postorder=desc&start=15
If you need to join up, do it....the read is worth it.
The HK car forums dont mince their words when it comes to bullshit claims lol.
http://www.clubpeugeot.org/forum206/viewtopic.php?t=6444&postdays=0&postorder=desc&start=15
If you need to join up, do it....the read is worth it.
The HK car forums dont mince their words when it comes to bullshit claims lol.
I'm asking a question but nobody is answering the question. I do think this really work or else, how it can change by 1 AFR? If you have experience on ECU tuning, you will know how much performance gain if the AFR is corrected properly. If so, why it doesn't work? I will do the test again on dyno tomorrow.
Actually, my question is "How to reset computer?" Thanks
Actually, my question is "How to reset computer?" Thanks
you can reset the computer all you want by leaving it unpluged for a while, but that isnt going to do jack. If your little fan is going to produce any form of 'pressure' then the ecu isnt going to know what to do with relative positive pressure over the ambient it read before you started the engine.
Bad idea number 1, put boost into an engine that cant read boost.
And your saying that your introducing enough extra air to change the AFR by 1 point, but your only getting 3bhp more?
Bad idea number 1, put boost into an engine that cant read boost.
And your saying that your introducing enough extra air to change the AFR by 1 point, but your only getting 3bhp more?
benji&eka said:
pmsl!
Saphire Cosworth
A renault secret - They have built in extra bhp in to the clio cups - all you need to do to release this power is drive with your sun visers down and the passenger window open slightly. This re-sets the ecu in to thinking you have a race car and adds approx 25 bhp. Shhh Renault don't want anyone to know this secret.
^^ Very true!
I know about microprocessor-based computers, but I haven't been able to find anyone who speaks computer jargon who knows about the architecture of the Renault ECU, only people who speak Renault jargon. Tell me if I'm wrong but this is what I've concluded from what they've said.
In a re-programmable ROM in the ECU there is a standard factory programmed "map" of the amount of ignition advance and the amount of fuel to inject according to what the rpms are that's the same for every car of that model. The programmed fuel map gets copied into working "cells" when the ECU is powered up. Whats in the cells is retained whilever the battery is connected, like from day to day use, but lost if the battery is disconnected for any time. Renault can read the values in the cells to see if the engine seems to running OK, and they can write new values into them. But they can't change the programmed map. And if you or they disconnect the battery the cells get set back to the programmed map.
The ECU is closed loop. Ie, it has the oxygen sensor, in fact two of them, in the exhaust, The feedback from the oxygen sensor in the exhaust modifies what's in the cells up or down by a bit to allow for the engine breathing a bit better or worse than the programmed map expects. That's to allow for slightly better and worse engines, hotter and colder days, higher and lower barometric pressure, and higher and lower altitudes. That results in it also being able to cope with minor engine modifications that improve the breathing, like a better intake or exhaust. A few horsepower in each direction. But all it does it keep the AFR in the range Renault chose for low pollution at low engine revs, and power with reasonable pollution at higher revs.
A proper re-mapped ECU can start with a different default fuel map, one that reflects a significantly changed engine, and it can contain a different ignition map that produces more horsepower, and it can tell the ECU to seek an AFR that produces more power.
It occurs to me that an easy way to get a few more horsepower would be to intercept the signal from the oxygen sensor and modify it to the value that indicated the engine was running leaner than it really was, so that the ECU pumped a bit more fuel in. Enough for the AFR ratio to be the optimum for power rather than a compromise between power and emissions.
Tell me if I'm wrong. I'd really like to know.
In a re-programmable ROM in the ECU there is a standard factory programmed "map" of the amount of ignition advance and the amount of fuel to inject according to what the rpms are that's the same for every car of that model. The programmed fuel map gets copied into working "cells" when the ECU is powered up. Whats in the cells is retained whilever the battery is connected, like from day to day use, but lost if the battery is disconnected for any time. Renault can read the values in the cells to see if the engine seems to running OK, and they can write new values into them. But they can't change the programmed map. And if you or they disconnect the battery the cells get set back to the programmed map.
The ECU is closed loop. Ie, it has the oxygen sensor, in fact two of them, in the exhaust, The feedback from the oxygen sensor in the exhaust modifies what's in the cells up or down by a bit to allow for the engine breathing a bit better or worse than the programmed map expects. That's to allow for slightly better and worse engines, hotter and colder days, higher and lower barometric pressure, and higher and lower altitudes. That results in it also being able to cope with minor engine modifications that improve the breathing, like a better intake or exhaust. A few horsepower in each direction. But all it does it keep the AFR in the range Renault chose for low pollution at low engine revs, and power with reasonable pollution at higher revs.
A proper re-mapped ECU can start with a different default fuel map, one that reflects a significantly changed engine, and it can contain a different ignition map that produces more horsepower, and it can tell the ECU to seek an AFR that produces more power.
It occurs to me that an easy way to get a few more horsepower would be to intercept the signal from the oxygen sensor and modify it to the value that indicated the engine was running leaner than it really was, so that the ECU pumped a bit more fuel in. Enough for the AFR ratio to be the optimum for power rather than a compromise between power and emissions.
Tell me if I'm wrong. I'd really like to know.
To do that you would need a pre-programmed relationship between the value the lambda sensor was reading and the desired AFR (usually 12.8:1 for max power). for example, say you calibrated the correction (via your interception box of tricks) on the lambda sensor to give 10% richness...this may not be correct for all load/speed sites.
what may be possible however is to set a target lambda value (0.88) so that you could have the lambda sensor always running closed loop and always adjust to your desired AFR, unlike a standard ecu that would run open loop above say 80% load and only read the map value.
There is a sytem you can buy that basically does this. it connects to your injectors, and you programme in a target lambda value. it then alters fuelling via an extended pulse width on the injector, in accordance with the figure you have set it to. i will see if i can find the details for you...
what may be possible however is to set a target lambda value (0.88) so that you could have the lambda sensor always running closed loop and always adjust to your desired AFR, unlike a standard ecu that would run open loop above say 80% load and only read the map value.
There is a sytem you can buy that basically does this. it connects to your injectors, and you programme in a target lambda value. it then alters fuelling via an extended pulse width on the injector, in accordance with the figure you have set it to. i will see if i can find the details for you...
BenR said:
BenR, thanks for your kind advice.
Actually, 1PSI is nothing, just to breakthrough the restriction within the intake system. Similar to cold air duct, it will provide positive pressure but the engine will run without any problem.
The problem is that even more air is pushed into the intake manifold but the ECU will not inject more fuel make the AFR become 13.7. I will try to reset the ECU today and test ont he dyno again. Stay tuned...
GordonD said:
The ECU does have long and short term trim tables, which are wiped out when power is lost for different amounts of time.
But simply running totally closed loop isnt always a great idea. First the lambdas in the std car arent accurate enough at any great varience from stoich, so they cannot be relied upon to feed the ecu with reliable information on which you base all your fuel calculations. Then the sensors are miles away from the exhaust ports and are not reading for individual cylinders, so your getting a delayed average from all of the cylinders. This will mean that response times will lag behind whiat is actually required for the next complete burn, which could lead to a constant mildly lean burn, but measured 'correct'.
Then there is the problem with lambda sensors not liking high EGT's so they will fail in short time if placed in the primaries, becomming a consumable.....and an expensive one.
The std ecu does not 'check' fueling conditions when your at full throttle, the information is just to unreliable, the whole reason why the ECU contains a whole bunch of maps.....its nowhere near as 'simple' as a standalone ecu.
When you remap, the whole point is to change the maps you use when the system is running off closed loop, because they cant use a richer lambda number to simply 'target' for.
I've not actually met anyone who's relyed solely on afr for ther engine.
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