Headers or cat delete pipes?

[Steve Tinker]

^^^^ Yes I have ^^^^

BUT its an Australian ROW spec (no cats in the headers) so you may not be able to replicate the same results.

1) I installed a pair of cheap Chinese headers from (you probably know the ones from Texas) to replace my standard ROW headers. Fit was OK, finish excellent and they have been on the car for over 4 years. Not much increase in performance below 3,500 rpm, but over that engine seemed to be crisper & the sound hardened.
Note: I spent quite a bit of time matching up the headers to the cylinder head and gasket.

2) Then a year later I fitted the cat delete pipe from the same supplier - again seat of pants dyno gave another slight improvement, but sound was wonderful over 4,000rpm..
Note II: Recently removed the cat delete pipes as the heat from them damaged my driveshaft CV rubber boots.

3) Refitting the standard pipes altered the torque: standard = better torque below 4,000rpm, cat delete pipes improved torque over 4,000rpm.

4) No drone with either combination.

Looking at the awful headers /cat combo fitted to the US cars, personally I would try the matched headers first.....