Charlstw

So recently I went through a real weird issue with my crank snapping during commute, while going a merely 65mph on the highway, as I was slowing down for the exit, it just snap and the car went dead. Took about a whole month to get the engine back together with some high compression builds, pushed the cr up to 12:1, it needed a new exhaust, so I went to see some fabricators to get this done
not sure if its good looking, but it works, custom mid pipe, and muffler, specifically lifted higher for better ground clearance, for shitty roads here in Taiwan.. and custom valve controlled by vacuum with an on and off remote switch, basically I can manually set it open or close, while its open its completely straight thru the tail pipe, while closed it will circle back to go thru a smaller exit with lots of silencing, hence increase back pressure.

I'm not quite a exhaust guru, but that was what the shop explained to me while it was getting done, and it seem to make a difference driving in stop and go traffic with better low end torque, definitely super quiet too，and when its opened, it sounds super loud and mean at WOT.. however, I still get this metal clinging sound at 3-4k rpm range, everything goes away pass 4k.. checked the heat shield, it wasnt it, can a header make that noise?

TommyKing

Is the clinging noise constant through 3k and 4k?

Charlstw

yes, the noise is right around 3-4k and goes away after.. any clue?

TommyKing

So many things come to mind, I had a EK with a Y8 that had a noise that sounded like a heat shield or something loose rattling in the mid rpm range, turns out it was rod bearing and it eventually spun.

Charlstw

ohh.. ****, well it probably wasnt it, since the engine was just rebuilt