So we HR guys are lucky enough to have a good design stock header, likely not worth the hassle of replacing. This was also the case with my previous car, 2000 celica GTS, the headers were pretty good to start with. A popular mod was to clean up the interior welds at the primaries to nearly match the gasket, and also the welds and metal at the collector, and them thermal coat. A member on newcelica.org started a business doing this for GTS celi's and did the flowbench testing with verifiable gains compared to oem and some aftermarket units.
Has anyone (Sharif?) pulled the headers to see if the welds are sloppy and could be contoured to improve flow? Just an idea, I love free/cheap HP.

 

Honestly the hassle of getting to the headers in the first place would probably not be worth it compared to the minuscule gains (if any) that can be had from doing so. Pulling the headers from a Celica GTS is alot easier than ours.

 

I talked with someone from Tomei a couple of weeks ago and know that they are working on headers for the HR, but we probably won't be able to find out anything else until 2008.

 

if youre going to pull the headers, you might as well change them out.

 

Like they said, it's most likely not gonna be worth the trouble to pull the headers just to clean up the welds to improve flow (if any improvement can be made).

 

true but at what point does 1 or 2 hp gain start making a diff, it adds up at the end

 

^ That's true, but at what point is 1-2 whp worth over 10 hours of labor?

 

Yeah, headers on all RWD cars now are a pain. I was curious if anyone had taken a lookie, like those daring who are digging into brands spanking new motors, I know it will not be fun, but a free weekend- it could keep me occupied. BTW, the celi is not easy either, though there is only one, it is cramped against the firewall, and you have to pull the motormounts and loosen the crossmember to get the booger out. If I get daring I will take pics, likely no dyno comparo though.

 

Useless mods never stopped people from designing and selling them...

 

I bet the Turbonator adds more power :P

 

With the 07 headers, you get an equal length tubular design which looks very similar to the DC headers for the 03-06's. It took 7hrs to swap out headers on the vq for me laying on a creeper.