mxt_77

Can you expand on your description of "resonance"? Is it resonance like an exhaust? My car resonates at 3-4K because of the CAI, but I wouldn't describe the sound coming from my header as "resonance".

Slows2k

Sounds are always hard to describe, I'll try my best. The header is slightly louder than stock with the hood up, as you can hear the exhaust pulses through the pipe. The Toda has very thin walls, the pipe kind of "rings" on each exhaust pulse. When you're accelerating, the right around 3000-4000 the exhaust note changes to a slightly more "hollow" sound.

If the noise you are hearing is a louder metallic rattle, check the bracket on the bottom header tube to see if it has broken off. Mine made lots more noise when the bracket snapped.

Slows2k

Check here for broken Toda pics, and Toda's warranty policy.

https://www.s2ki.com/forums/index.ph...pic=187462&hl=

Oh yeah, I'm not too pleased with either.

profpin

i dont think its the valves that you hear, but the exhaust pulse that is comming out of your engine...

mikecl713

pulses sound like ticks?

Slows2k

They can to me.

mxt_77

I don't think it's the bracket, because I used spacers so there wouldn't be any significant force on the bracket, and the header has only been installed a few hundred miles. Plus I first noticed the sound just off-idle immediately after installation. It didn't bother me at first, because I assumed it was just the way the header was supposed to sound, but when I came off the autocross course and it was much louder and audible through pretty much the entire RPM range, I got a little worried.

Whatever my noise is, it seems temperature dependent, because it doesn't get worse after normal driving (even after 100 miles). It only got bad immediately after my autocross runs (90 seconds each above 6000 RPM).

It doesn't quite sound metallic (like metal on metal... i.e., the sound my cams made when they failed), but it does sound pingy... if that's a word.
I dunno.

BTW... if I stick my head down by the header, it sounds like the majority of the sound is coming from the cylinder 1 area, but I still can't decide if it's coming from the header, or the header-to-head mating surface, or somewhere inside the head.