Piston clatter was a loud clack, clack sound.

 

Im gonna say you need to take a close look at your AEM unit.
Ive seen this happen several times, all different odd engine destroying circumstances. Always attributed to the aem ems.
Couple weeks back, friend was tuning an SR20, on ems. 5 dyno pulls, all is looking well. starting to move up the scale and get the boogy goin.
Mid pull....doom! buhbuh buhbuh buhbuh.
Shut it down, WTF! all looked well, datalogs look good happen'd INSTANTLY. Pulled plugs and comp test, then head off. Couple tests.....found out the drivers in the aem failed. 3 and 4 injector drivers peaced out at WOT.
Toasted pistons.
Thanks aem.

 

Gotta love AEM. My whole board was bad and the harness on my Wideband. Fried some AEM techies test bench from what I heard trying to figure out the problem. Didn't even have the unit long but because the whole process of the motor in and out took longer than the warranty I had to pay for the fix. However this was not the cause of the dead motor. That is a story not for public forums.


On another note for the timing. Post the timing values for 5500, 6000, and 6500 from the timing map that is entered into the AEM if you can. One other thing I have learned is that the timing for different manifolds epecially log to tubular is critical in not exploding the motor in some cases.

-Chris

 

I am thinking this problem is something that could not have been prevented and is just an odd issue, as in something with the AEM. The fuel was spot on throughout the run, in the 10's to 11's never over, so if an injector driver failed mid run and the injectors stopped working the AFR's would have shown it. If only one cylinder was melted then I would say that one injector may have been flowing less than the other 3, but the fact that every cylinder is melted proves that the injectors were all working equally, one was not leaner than the rest. I also know that the damage to the pistons happened sometime after the turbo was installed on the car. I do not feel that the motor was damaged while it was NA. The reason I am saying this is because the inside of my turbo exhaust manifold has aluminum on it.

When I first installed the turbo setup I was using a tune from another member's car, but his car had a 2mm HG on it. I figured timing would have been close and I drove the car to make sure there were no boost leaks. The wideband was reading very lean so I knew I needed to add a lot of fuel. I wasn't beating on the car by any means, just checking to make sure everything worked properly without leaks. The car saw maybe 4 lbs of boost at one point. I then finally figured out how to add fuel in the AEM and added a lot of fuel across the board. This fixed the very lean numbers that I was seeing on the wideband. I didn't drive the car after this, except for an hour and a half trip to NRG.
I'm betting some damage happened to the motor sometime between when the turbo was installed and it was driven to the tuner. But I do not feel this was the only damage done to the motor. It was deff. hurt while it was on the dyno, and by what I have no idea...Because the motor would not run normally with the sized crater there is in the #4 cylinder sleeve.
Now that I think back, I remember hearing that rattling noise the whole time, even at light loads sometimes. I thought something was rubbing and making some noise.

 

Stock ECU FTW!

 

doh! LOL

 

Well, there you have it. Id bet it was cooked before the dyno session. You may have thought you only hit 4 psi, but that one little burst and you let off too late. done.
What was your fuel pressure set at? both before, and during the tune? If all looked well during the tune, then it was roasted before. At least you recognize that now.
Sucks. Time to start over.

 

That's not possible is what I'm saying. Yes it could have done some damage, but with a chunk missing out of the cylinder wall, the engine would not run correctly. So the major damage to the cylinder wall had to have happened on the last pull.

 

got the pics up finally

 

wow that is some nice damage