Subaru Group N Rally car that keeps on breaking ringlands

[msgofast]

The first pic is from pinging with lands gone, but the second pic was a lean out, over heated from going too lean and melted. See how you go with the new tune.

[Pascal]

Ohhhhhhh!

Dear Martin, it is fuel! I have very very similar problem from 2003 and 2006 Impreza, restricted 32mm GR. Super N, dog box and bla bla. Same things! FUEL! And ONLY fuel! After few days of suffering we did resolve it with fuel comp's and fuel maping and sensor readings.
Check compensation! Check readings of lambda and delay settings! Check that maybe is a bit wrong readings from sensors. Air, water and so on. Check that they are reading correct value! Maybe is a bit there and here wrong readings and on the end is lean! I did catch my self once with wrong calibration on air temp. sensor and was doing show for me that sensor! Must be there somewhere!

Question: Have water spray device for intercooler?

Regards Pascal

[Martin]

Ohhhhhhh!

Dear Martin, it is fuel! I have very very similar problem from 2003 and 2006 Impreza, restricted 32mm GR. Super N, dog box and bla bla. Same things! FUEL! And ONLY fuel! After few days of suffering we did resolve it with fuel comp's and fuel maping and sensor readings.
Check compensation! Check readings of lambda and delay settings! Check that maybe is a bit wrong readings from sensors. Air, water and so on. Check that they are reading correct value! Maybe is a bit there and here wrong readings and on the end is lean! I did catch my self once with wrong calibration on air temp. sensor and was doing show for me that sensor! Must be there somewhere!

Question: Have water spray device for intercooler?

Regards Pascal

Pascal,

yes there is water sprayed in the Intercooler. When you say fuel you mean the ammount delivered to the engine right? Or are you saying that the fuel quality was bad maybe?

As far as sensor calibration goes the standard Subaru sensors are used, so im pretty sure that the sensors are calibrated correctly. I would like to make sure thought of the Air temp sensor. On the Spec C there is an extra sensor below the Butterfly that is wired to AV8,( not the MAF sensors Air temps sensor) Can anybody maybe post their calibration for that sensor? Id like to make sure mine is correct.

Thanks

Martin


Martin

[msgofast]

I use the delco cal and it is spot on.

Cheers
Michael

[RossB]

THe following calibration should be correct, is this what you are using?
Intercooler Air Temp Sensor – Sti RA (AV8)
Degrees C 1 Decimal place
Temp -50 -40 -30 -20 -10 0 10 20 30 40
Input(V) 5.341 5.302 5.263 5.200 4.833 4.541 4.101 3.759 3.271 2.880
A/D 1094 1086 1078 1065 990 930 940 770 670 590

Temp 50 60 70 80 90 100 110 120 130 140
Input(V) 2.490 2.148 1.904 1.757 1.611 1.376 1.162 0.991 0.849 0.772
A/D 510 440 390 360 330 282 238 203 174 148

Temp 150 160 170 180 190 200
Input(V) 0.629 0.551 0.473 0.411 0.336 0.288
A/D 129 113 97 84 69 59

[Sti]

Martin,

I've got to agree with everything that Michael has said...it is mixture. I've had several EJ's do exactly the same thing when tuned to the specs and fuel you had. Once I changed the tune I've managed to keep the same motor together for a good 2+ years without any issues.

Not sure of the climate you will be running it in but the only other item I can add is to watch the engine temp as on a hot day it will run hot, ie. 100C +, so I generally I put in comps to add fuel and reduce timing once it gets to 100C.

If your after some maps I can help with either VVCT or non VVCT, just email me sjw at bigpond.net.au

Cheers,
Simon.

[Martin]

Hi Ross,

I think I found the problem, the Air temp Calibration is incorrect. Could you please forward me a ECU map with the calibrations for the following sensors?

Air temp ( Incorporated in MAF sensor)
Engine temp
Air temp below butterfly (Sti RA)...connected to AV8



Simon, thanks alot for your reply, ill mail you tonight...
The climate here ranges from about 0 degC to about 30 degC during summer days. The altitude here in Pretoria is about 1500m above sealevel (+-85KpaA ). The cars race at both sealevel up to about 2000m at some races.
What are the suggestions for boost control at high altitudes (32mm restrictor)?

Thanks

Martin

[RossB]

Martin,

I will send you the sensor calibration information.

[Martin]

Hi Ross,

Ive changed the AV8 Input (temp sensor right underneath butterfly) to the cal file in the WRX78 installation note but its way out in my opinion.

AV8 motec cal: 93 deg c
Delco air temp cal 73 degc
subaru engine temp cal 68 degc

These were done right after each other. I know you would like to have the measurements taken at a known ambient temp but i was at the dyno when ive changed the calibration. All 3 were done when temp was stable (its not heatsoak or any other effect). When the car ran it ran with the "subaru engine temp" cal. The Engine temp cal seems to be the closest to correct. Do you have any knowledge of different temp sensors in there cars?

Regards
Martin

[RossB]

Check that the link configuration is correct on the WRX78 adaptor, the following links should be:
Link23 and Link24 Open
Link20, Link22 and Link25 Closed.