AFR value & ECU Prodrive MY99

[viper1982]

Hi, I want to check for the Air Fuel meter values ​​of your Subarus impreza GC8. Currently I have the ECU AE800 and replace it with a Prodrive kit MY99 which is an AE801 (according to Ecuexplorer) which is more aggressive in Fuel and boost. The doubt arises that the AFR value is 10 at most 10.2 but generally in any journey it is maintained there. I do not know if that is good or it is too "Rich" I would like to tell me what values ​​are those that handle these ECUs that are original without any modification.
I have exhaust in 3 inches full decat. TD04 turbo, Higher volume Aftermarket IC Bar&plate. and raise the pressure of Boost by shrinking the Pill Restrictor to 120 to 115. Raising the pressure slightly not much more to avoid problems.
Original air BOX & Kyn panel filter. Silicone Y-Pipe Hoses, and silicone Inlet.

[Red Baron]

Here's my AFR plot from the Dyno it's the second graph down, MY99 with Prodrive ECU and Intercooler pipework, Decat down pipe, second cat still in place, Green Cotton filter on the standard TD04.

[Scott.T]

Originally Posted by viper1982

Hi, I want to check for the Air Fuel meter values ​​of your Subarus impreza GC8. Currently I have the ECU AE800 and replace it with a Prodrive kit MY99 which is an AE801 (according to Ecuexplorer) which is more aggressive in Fuel and boost. The doubt arises that the AFR value is 10 at most 10.2 but generally in any journey it is maintained there. I do not know if that is good or it is too "Rich" I would like to tell me what values ​​are those that handle these ECUs that are original without any modification.
I have exhaust in 3 inches full decat. TD04 turbo, Higher volume Aftermarket IC Bar&plate. and raise the pressure of Boost by shrinking the Pill Restrictor to 120 to 115. Raising the pressure slightly not much more to avoid problems.
Original air BOX & Kyn panel filter. Silicone Y-Pipe Hoses, and silicone Inlet.

AFR may get into the 10's on full boost but should not be there all the time.
How are you measuring this ?
If you have a wideband lambda probe you should see oscillation between around 13.8 and 15 at idle and light cruise due to the ECU trying to control stoich at 14.7 AFR

Above around 3000 rpm and when you start to generate positive boost this AFR should stop oscillating around stoich and go to a more fixed value around 12.5 to 13. As you increase revs and boost the AFR should drop into the 11's and finally into the 10's.

Shanes plot above shows the effect of a WOT 3rd gear pull dropping the AFR from stoich to 10.5.

If you are seeing a constant AFR at idle and cruise I would suspect your cars lambda sensor is dead (not your wideband) and the ECU is running base target AFR.
I've seen this on my own with it sat at about 12.5 during idle/cruise.

Or if you are using a wideband probe it may need a free air calibration to be performed.

[viper1982]

Originally Posted by Red Baron

Here's my AFR plot from the Dyno it's the second graph down, MY99 with Prodrive ECU and Intercooler pipework, Decat down pipe, second cat still in place, Green Cotton filter on the standard TD04.

hello red baron How many PSI do you have charged with the turbo TD04 14.5 PSI or do you have it at higher pressure? to get 250 HP? I think you have the PPP kit MY99 for what you name. and as a high-flow panel filter outside the Prodrive kit. but I wanted to know if you altered the standard working pressure in any way. Thank you! regards

[Red Baron]

That's a good question, it's supposed to be the MY99 PPP ECU which should run at 1.1bar which is just under 16psi, as you can see from the bottom plot it peaked at 1bar which is 14.5psi. Also has the better Intercooler Pipework



The biggest power gains probably come removing the catalytic converter from the downpipe although the high flow panel filter will certainly help things.

[viper1982]

Of course, that is exactly the prodrive kit MY99 the same as I have in my USDM Gc8 1999. only that I changed the Intercooler for a bigger one.
and also place the high flow panel filter. I also do not have the catalyst for the Downpipe descent. It hurts that I have no chance to measure how many HP my car owns, because where I live there is not.
what I see in your graph. in the last one I understand that it reaches 1.5 Bar de Boost. but I see it very high ... will it be correct? or am I misinterpreting the graph?

[viper1982]

Ahhh the pill restrictor original 120 i change for a 115 to rise the Boost 17 PSI

[Red Baron]

When you look at the bottom chart the thicker red line is bhp and is read against the left hand scale and the thinner red line is the boost and id read against the right hand scale.

[Scott.T]

Boost pressure and AFR dropping into the 10's looks spot on in those Graphs for a 'Off The Shelf' ECU.
Boost is a touch low and could probably be nudged up by tightening the actuator or dropping the pill size down. Both would have the same effect.

[viper1982]

Originally Posted by Scott.T

AFR may get into the 10's on full boost but should not be there all the time.
How are you measuring this ?
If you have a wideband lambda probe you should see oscillation between around 13.8 and 15 at idle and light cruise due to the ECU trying to control stoich at 14.7 AFR

Above around 3000 rpm and when you start to generate positive boost this AFR should stop oscillating around stoich and go to a more fixed value around 12.5 to 13. As you increase revs and boost the AFR should drop into the 11's and finally into the 10's.

Shanes plot above shows the effect of a WOT 3rd gear pull dropping the AFR from stoich to 10.5.

If you are seeing a constant AFR at idle and cruise I would suspect your cars lambda sensor is dead (not your wideband) and the ECU is running base target AFR.
I've seen this on my own with it sat at about 12.5 during idle/cruise.

Or if you are using a wideband probe it may need a free air calibration to be performed.

Checking what you had actually told me the problem was the original oxygen sensor of the vehicle that was broken. measuring with a multimeter did not yield values, change it for a new one and the AFR values ​​returned to normal, fulfilling what you describe. thank you. I had forgotten to tell you