Cutthroat912

Ok so quick background on the car:

1990 VVT swap
China gt2871
GT500 injectors
MS3X
Full Kraken 3" exhaust

Ok so I've had the motor swapped into the car for a year now and boosted it a little over a month ago. Mostly street driving with one autocross. On the way home last week the car developed knock. Pulled over immediately. Let it cool and took the valve cover off and everything looked to be correct as far as the valve train was concerned. Pulled the spark plugs and #3 had the electrode broken off. At this point I'm thinking spun bearing. Anyways, I don't have a lot of time to investigate exactly what happened right now. I've already sourced a new motor to drop in place but before I get this one into boost again I'd like some feedback on the tune I was running. I've attached the tune and a pull from a few weeks ago. I will be switching the to a GT2560r well when the new motor goes in. Any feedback is appreciated!

Mudflap

tune? who cares about the tune. What kind of boost were you running? You can't expect that little crappy motor to just magically handle a ton of boost without some engine work.

Cutthroat912

On wastegate, this turbo was hitting 10.5psi.

Full_Tilt_Boogie

iTrader: (1)

Knock can leak to a spun bearing. The missing spark plug electrode is a pretty good sign it was knocking. What heat range are the plugs?

Cutthroat912

They're BKR5E'S

oregonmon

Thread reads kinda misleading to me, considering I know the actually use of your car. You have done how many autox on the VVT swap, many runs and you are a pretty aggressive driver. You also mentioned it was starting to develop a tick or something leading up to the failure that you never figured out.
Then you did the 1 autox boosted, correct?

Cutthroat912

Probably about 15 autocrosses NA along with daily driving. One boosted autocross. There was something that I thought resembled lifter tick that had been there for as long as I could remember but I can't say it was or wasn't there when I first did the swap. With this head having solid lifters I thought the valves may have been out of adjustment or something wonky with the VVT was going on but no, I hadn't gotten around to diagnosing that sound.

The main change in my tune from NA to FI was the addition of the positive pressure rows of the fuel, ignition, and AFR tables. Everything below 100KPa was essentially what it was before I went FI. So if there is something glaringly wrong with the NA part of my tune now, there was something glaringly wrong about my tune before FI.

ryansmoneypit

iTrader: (6)

10.5 psi on a 2871 could have been around 250 some tq, with det, that's bad.

Full_Tilt_Boogie

iTrader: (1)

Thats not a cold enough plug for boost. You should be running a 7, not a 5.
I cant say anything definitive, but your hot plugs could be what killed your engine.

Cutthroat912

Thanks for the input. I have 7's ready to go into the new engine, they just need to be gapped.

LeoNA

I would reduce your whole afr table by .5 and maybe by 1 in the idle area.