Metal on metal noise at 2500 RPM
 

So, I went for a drive In the morning to get open loop logs for MAF scaling and I did a few 2k to redline runs and on the way back I started hearing this metal on metal noise at exactly 2500 RPM. I've done this before as well and no issues.

Any thoughts on what it could be?


https://vimeo.com/105577080

Mods:
- Openflash OTS Stage 2 UEL 91 tune ( on car for 1 month)
- JDL UEL headers (3 months)
- nameless down pipe (front pipe over pipe combo) (3 months)
- Ark DTS Exhaust
- Perrin 2.75" intake with Perrin inlet hose (1 month)

Car details:
2013 FRS
25,000 KMs

I would check all of your header back connections. They can come lose and cause a rattle at the right RPM due to the vibrations. I have one at 1,000 RPM upon initial load and it turns out my header heat shield rattles on the down pipe upon initial torque load. I'm going to use large hose clamps and some heat wrap to insulate the two.

Because you have an aftermarket header you won't have the heat shield problem but my overripe hanger bolt has also come loose before. Might check that.

So I figured it out. Ark DT-S exhaust was the culprit. Attachment 90273

I don't know how this happened but that piece was broken off and making noise lol, and I thought it was my engine ready to go kabooom