Ringland Failure Pictures

Just for reference. This is a piston out of my 2006 LGT Wagon. The motor was well maintained and completely stock when this occurred. Both the first and second ring lands are fractured into several pieces. IIRC this was the number 1 cylinder.

Its pretty much general knowledge, you don't want this cars on the stock map.

what was the mileage?
any obvious symptoms?

Originally Posted by Max Capacity

Its pretty much general knowledge, you don't want this cars on the stock map.

Is this true for all 4th gen? I've had naturally aspirated EJ25s for a while now, but my 08 spec.B is my first turbo. Obviously I'm a total turbo novice, but I'm surprised Subaru would let all the uneducated masses drive around with a bad map that can cause premature engine failure.

I've been reading this forum long enough now to know that you are an advocate for a stage 1 tune, but I'm hoping for some clarification about whether this is a problem for all LGT MYs or a specific MY or range. I don't think I've seen that specific info through all my forum searches, and I definitely want this car to last a while...

Originally Posted by Max Capacity

Its pretty much general knowledge, you don't want this cars on the stock map.

I was on a stage 1 map for years, still cooked some valves.

Just can't win.

Originally Posted by chato

what was the mileage?
any obvious symptoms?

About 80k on that motor according to previous owner. 140k on chassis. Symptoms included flashing cruise light, cel, thirst for oil and no power.

This may have been discussed before, but it is new to me, so I am sharing:

Based on a recent discovery, I am tending to believe that the stock map is not to blame but it is rather the factory map combined with a deteriorating MAF sensor - that over time, will cause the car to run dangerously lean.

I say this because when I bought my car, I had it tuned immediately and have re-tuned it several times over the 80,000 miles I have owned it. My car now has 170,000 miles, and I am still running the original MAF sensor. I also log AFR's often with a wideband.

Discovery : While troubleshooting an issue recently, I installed a brand new MAF sensor. What I found was that the AFR's in Open Loop were nearly 2 points to the rich side (9.5). So....it is possible that cars that have not been re-tuned/calibrated later in their life (life of the MAF sensor) could be running 2 points lean under boost which I suspect could be the culprit here in terms of detonation and ringland failure.

p.s. I have cleaned my MAF sensor, carefully, with MAF sensor cleaner every 30,000 miles or so.

Originally Posted by jimmyjames

Is this true for all 4th gen? I've had naturally aspirated EJ25s for a while now, but my 08 spec.B is my first turbo. Obviously I'm a total turbo novice, but I'm surprised Subaru would let all the uneducated masses drive around with a bad map that can cause premature engine failure.

I've been reading this forum long enough now to know that you are an advocate for a stage 1 tune, but I'm hoping for some clarification about whether this is a problem for all LGT MYs or a specific MY or range. I don't think I've seen that specific info through all my forum searches, and I definitely want this car to last a while...

Here's the thread by my Tuner. Same issue with the 4th gen GT's.

http://legacygt.com/forums/showthrea...ts-193842.html

KC, my first MAF cleaning was in Aug 2011 when I went for the tune for the vf52.

Still running the orginal MAF sensor, It is now cleaned once a year.

My wagon has been on Cobb stage 1 since 8000 miles. I think you know when my heads were rebuilt, they needed on valves at 154,000 miles.

My Spec B came with Cobb stage 1 when I bought it at 22,800 miles.

Finally found more technical reasons on why stock tune blows.

Closed loop delay is the one at main fault, basically your car stay's in closed loop for a few seconds while in boost. It's believe this is emissions related because JDM tunes don't have this delay.

Do we know what cylinder is #4 in Romraider? C?

This can be seen in this graph, notice AFR is very lean for about 2krpm

You could ask my Tuner, but not sure how much he'll say. After all, fixing the problem is what people pay him to do.

Zeroed out my Closed to Open Loop delay, results are impressive (From AFR and power gain standpoint)


More details in my build thread.

Any particular brand of cleaner to use on the MAF? I clean others cars MAF all the time but just figured i would ask??? Same process as others , remove MAF...couple sprays....let dry....reinstall? I currently have no issues with how my car runs but i want to keep it that way.

Originally Posted by IGW

Any particular brand of cleaner to use on the MAF? I clean others cars MAF all the time but just figured i would ask??? Same process as others , remove MAF...couple sprays....let dry....reinstall? I currently have no issues with how my car runs but i want to keep it that way.

CRC MAF cleaner works well. Here is how I cleaned mine.

thanks for the info, this is generally how I clean all models, just wanted to see if there was anything special about this model!