So here is my final review about these dundon headers:
- First of all, these headers are beautiful.... they look so good that I just want to hang them on my wall. A quality product! Comes packaged nicely with a set of K&N filters.
- Install by the shop was smooth like a breeze, no fitment issues at all. Took around 2 hours to install
- Initial startup: car sounds stock!
- Initial drive: Under 3k RPM the car sounds completely stock. Over 3k you could hear something angry lurking waiting to be unleashed, and all the way to redline is described as INSANE, my ears are bleeding!!
- Dyno procedure: I was instructed by jamie to follow their dyno steps. Fans at inlets, blocking off radiator heat, monitoring IATs and do a couple of runs.
My stock run showed a 344whp baseline with a respectful IAT.
After that I drove the car for another 100km and came back 3 days later for a post headers dyno.
The post dyno read around 374whp, which showed a massive 30-32whp gain around 5000rpm and a massive 37whp gain around 7500rpm. IMPRESSIVE on a N/A car.
The car is otherwise on stock tune with just BMC filters and 98 octane fuel.
Car runs smooth with no CEL or any warnings. The sound is exotic! Has a nice and loud bark and the downshifts are just plain brutal.
I would like to thank Jamie from DMS for his constant support and for a quality product from DMS.
Video doesn't do it justice you need to hear it in person holy crap does it sound good! I thought my center bypass sounded good but these race headers blows it out of the water in every way. In my opinion these headers are 30% louder than previous setup and the best part zero drone. Listen to the high pitch and the downshifts. I... ~ Derek, Taiwan: 991 GT3RS Race Headers