Chip discussion

[|Maku|]

Can ECU understand the quantity of air which is going to cylinder? With different turbo goes different quantity of air to the cylinder. Let’s compare K24 and RS2 (K24/7200). K24/7200 produces less air at low rpm than K24. Let’s say that I’m using K24 stage1 software with RS2 turbo. Is that software able to take into consideration that there’s not so much air at low rpm and then there’s no need to make air/fuel mixture so rich?

Same questions about ignition angle!?

And please, answer only if you know what you’re talking about..

Thanx,

Marko

[s2dude]

Can ECU understand the quantity of air which is going to cylinder? With different turbo goes different quantity of air to the cylinder. Let’s compare K24 and RS2 (K24/7200). K24/7200 produces less air at low rpm than K24. Let’s say that I’m using K24 stage1 software with RS2 turbo. Is that software able to take into consideration that there’s not so much air at low rpm and then there’s no need to make air/fuel mixture so rich?

Same questions about ignition angle!?

And please, answer only if you know what you’re talking about..

Thanx,

Marko

Well...Im no expert on the S2 but
NO.
The software for a standard S2 turbo (stage 1 software like 280ps ~) will NOT work properly with the RS2 turbo.
The software is programmed with fuel and ignition timing parameters to operate with the K24 turbo....
It cannot "work out" what the new amount of fuel etc should be with a abigger turbo that it does not know has changed!!

So basically it will run richer lower down the rev range and run lean at the higher revs due to the extra amount of air being forced into the engine..
What injectors are you running also?

You really should get a custom remap with changes to the car like this....as opposed to generic chips.

MRC in Oxford, UK are the ones to call....they may be able to do it by post asyour from abroad?

[|Maku|]

I said that K24 and RS2 comparison for example. I just wanted to know does ECU sense somehow that more air is going to cylinder when I’m using wrong chip?

[porkkis]

Yes the ignition timing and fuel amount is linked to the air mass.

If I understood whan you want to know is wether it's ok to use stufe1 sw with RS2 turbo, right?
Basically yes, but in real life probably no. This is because bigger turbine changes the engine efficiency and probably makes it run leaner.
Ignition wise the situation is safer as better flow accepts more advance.

With different setups the maps are usually fully optimised in different locations so again, not so good idea.

And yes the ECU does have limits for air masses.

[|Maku|]

I haven’t tested my car completely yet but I can say what figures we have saw with K26/T04E. Software is programmed for RS2 setup. A bit before it starts to boost, mixture is going to about 9,5 (we use WB lambda). Is it because rs2 turbo starts to boost a little bit sooner and with k26/t04 turbo mixture is going rich? Same at high revs, high end is suffering because of it?

When ECU knows that with 1,5 bar there should be XX value air, but with another turbo there’s different amount of air. Can ECU make the difference and take it in to consideration and correct ignition, or it just does what values are written to the software?

[Micky B]

The s2/rs2... ecu mesures the air flow and boost pressure too. If you do not modify the engine volumetric eff. the ecu can work with the changing parameters of the engine exept of the air humidity( more humidity less O2..) the lambda sensor is narrow band so it is used for par throttle only. So if you change intercooler, boost sensor, cams, compr ratio , exhaust,cyl head or porting,fuel pump flow,turbo....etc you should costum remap the ecu!!!!
Any of these mod or mixture of them makes different change in volumetric eff thru the rpm range, so need different chip. Engine run time also has an effect on vol eff. !!!

If you change the turbo but you dont change anything else (boost level is the same), you don't need to change the chip, you will be on the safe side, which meens you don't use the turbo&engine combo on full potencial. At your combo at part throttle you have a little bit lower eff, at full throt you have a little bit better eff.

As you increase eff of an engine , you should inject more fuel(some time less!), and you need to retard ign, if eff falls you can increase ign,reduce fuel(some times engine wastes fuel so need to increase inj fuel) !!!!!
For a better working of that combo you need to mod the ecu for sure, to keep engine potencial on optimum.

ufff

[Jamo]

I haven’t tested my car completely yet but I can say what figures we have saw with K26/T04E. Software is programmed for RS2 setup. A bit before it starts to boost, mixture is going to about 9,5 (we use WB lambda). Is it because rs2 turbo starts to boost a little bit sooner and with k26/t04 turbo mixture is going rich? Same at high revs, high end is suffering because of it?

When ECU knows that with 1,5 bar there should be XX value air, but with another turbo there’s different amount of air. Can ECU make the difference and take it in to consideration and correct ignition, or it just does what values are written to the software?

No, it wont your basically asking if the ecu will learn to use the new turbo to optimum efficiency without remapping and it's a cheap way out but in the long run will cost you more money if something goes wrong.

Running rich is better than running lean but you'll damage the engine long term.

[|Maku|]

Yesterday we tested my ABY Avant. I use rs2 stage 2 chip, k26/t04E turbo, 391@3bar injectors, big intercooler (as SQ), 3” exhaust, 300kpa map sensor, adjustable fuel pressure regulator. Everything else is stock!
The interesting thing is that when I push the throttle pedal down, mixture goes 9,*. But when full boost reaches, mixture is going around 12 (that I can adjust with fuel pressure regulator). At idle and cruising mixture is 14,6-7. Boost goes to 1,9 max and drops down quickly.

Does mixture goes to 9,* before full boost because it meant to work with RS2 spec´s?

One more thing – multysensor is faulty, maybe that’s causing problems for me too..

[Micky B]

It's hard to say, but i think the problem is that the airflowsensor goes out from his measure capability. The ecu does not rcognize the airflow difference so it goes too rich
.But if you reduce fuel pressure at low rpm to get a normal afr it would be lean on the top.At higher revs most of the time the fuel pump has it limits so your fuel flow reduces so it leans out and you see that on the afr nr

Out of 10 audi which is tuned i have to change 9 fuel pumps to stabilize the flow.

My oppinion is first you change the pump to a high flow one,then you need to custom remap the ecu. Or reduce boost until the afr seems to be ok at all speeds.

One chip is only good for one spec car. I remapped 5cyl audi a few 100 times and none of them need the same inj and timing. I had the same result for vw,opels, peugeots ......

[|Maku|]

Fault code that keeps appearing is:

00561 - Mixture Adaptation
13-00 - Adaptation Limit (Mul) Not Reached


EDIT:
Possible couses of fault
- Fuel system pressure too low or too high - NOT LIKELY
- Failure of spark plugs, ignition coils or ignition output stages - MIGHT BE
- Ingress of air to G70 - MIGHT BE
- Leak in exhaust system up to catalyst - NOT LIKELY
- Incorrest signal from air mass meter G70 - MIGHT BE

[porkkis]

Boost leak most obviously.

I don't agree on most Micky's statements.

[|Maku|]

Porkkis and Micky, this topic was made that we could discuss about chips. How much they understand through sensors and how much they don’t. So please guys, feel free to “find the truth”.

By the way, I just came from a ride and car acted strange again. Just before it starts to boost, it does like “blurr, blurr.. blrrr..” and then goes. Same is when I change gear from second to third, at the beginning it does “blurr, blrr, blrr..” and then goes. I suspect it might be faulty ignition coil.

[Micky B]

Mybe you are right.
If you take the coils out and inspect them invidually you may see brown spots on the black plastic housing of the coils next to the steel core, it is the sign of cracked insulation. The coil fires there,specially under higher boost cond.If all coils nice black, something else is the problem: plugs or leak somewhere after the turbo.
Over fuelling can be if the airmass sensor mesures the right amount of air enters the turbo, but there is a leak after it so not the same amout enters in the cyl. wich is unknown by the ecu, so it gets rich.....