Guess the boost spike of 2-3 lbs stretches the rod enough to hit plug and close gap? Or significant cylinder crankcase vacuum pulls the plugs in closer hitting the piston? :rock::dontknow:
I'm not a mechanic so I don't know if I can answer this with out sounding like an idiot. When I was driving the piston hit the spark plug on the #3. I changed the plugs and it lasted a little while till the over-boost caused the #3 to let go. My theory was the initial impact weakened the piston and it just held on for a little while longer. I can't say for sure if the turbo caused any of it. Just my opinion.
It broke off a small piece of ringland, hit the plug and went out the exhaust, pretty common on oem junk pistons with big cylinder pressure. It will still run....for a while. Justin
After looking at the dyno graph it seems like the engine lost about 100 hp from 4000 rpm till 4250. That is alot! He blamed the small header outlet size but the boost didn't change nor did the A/F. I think the valves were floating and overheated them. anyone have any thoughts or am I thinking to much?
few years on the update fellas. The truck now has a built 4 gen motor and im loving everything about this but it hits a wall around 3-4k rpms. its like its not getting fuel or pulling timing or something?! I am about to start a new thread with pics and details. i will link this thread in the new one.
Seems to me someone previous spent alot of cash to do the upgrade but didn't get it properly tuned. get rid of the piggy back and get an SCT tuner with a tune. it will get you started . then find a way to data log and get it tuned remotely until you can get it to a tuner.
I say get it emailed tuned by a good tuner with data logs etc. Once final, throw it on the rollers to check proper air/fuel to make sure your wide bands were reading correctly. That's what i did. No reason for dyno numbers. My dyno numbers were garbage and my time slipped proved it. Proper air/fuel and timing and she should be safe.