I did use Por 15 last year to clean up some surface rust on the underside. Good stuff! The spray can is a lot easier than the rubberized can (brush application)
I think i am due for another coat of Por 15. Most surface rust are located on the rear lower control arms and the area where the muffler hangers are located. Too many on that area compare to the front of the car.
One big spray can is enough. Although, I use the rubberized type on lower control arms for better gravel/sand/rock protection. I never read POR 15 high heat capabilities, what I sprayed on my exhaust joints were the high heat break caliper paint from Walmart. The area where the muffler connects to the midpipe. I painted it red, but changed my mind and blacken it up! Maybe I will paint it red again. It looks sporty! =)
BTW, you mentioned about the high flow cat. This will definitely change the sound signature of the G37 exhaust. You might probably look at the Fast Intentions resonated HFC. Might keep the noise closer to stock G37 coupe , but deeper.
It also lessen your lowend torque, but gain on the top midrange towards the highend. If you drive between 2.5k- 4.5k RPM, you might feel the loss of torque. Dont worry, if you decided to tune (Uprev) the car I got your back. I made changes to the throttle programming and the responsiveness can be be felt down 2k RPM.
Pls. Check thread # 262 and #276.
http://www.the370z.com/tuning/43384-smo ... ev-18.html
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