So I'm looking at getting a high flow manifold for my 04 RX8, I've seen this hiflow from npboosted but I'm unfamiliar with the brand but it's only about $100, my other option is the magflow for around $1300, not sure if I should try the cheaper one or go big and get the magflow

 

Save your money. There is limited gains from an exhaust manifold.... especially with a totally stock engine

 

Don't put a 100 bucks worth of who knows what alloy on your car. It will not last.
I'd argue about a good header but I'm in the minority.
Search for the header theory thread, a few good tips in there.
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+1 to what dan said.
Theres effectively a net-zero argument for the manifold (header) on our cars. Even with lots of dyno tests on these manifolds on otherwise stock Rx8's, there is arguably no difference between stock and aftermarket. Even tuned, there wouldnt be much of a measurable difference if any. Most gains are seen as a result of replacing the catalytic converter with a cat-delete/midpipe along with a catback exhaust. And even those dont net for a whole lot of power.

 

but.... my Racing Beat header makes cool noises
and more noise = more power, right???

all kidding aside: I would not put a $100 manifold on your car. This is literally one of those 'you get what you pay for' moments and you don't want to be on the wrong side of it.

 

probably manufactured in a Uyghur concentration camp reeducation assistance center …

 

So this mod is less about power and more about I don't have one the old one had a hole in it and 2 it's more for aesthetics at this point

 

I would buy a used OEM manifold and end up with something functional.

Likelyhood a cheap tubular manifold is going to have sealing issues both at the engine and midpipe end. It's also going to be loud and warp from the heat. The stock cast manifold is very durable... thin wall tubing isn't great on a rotary

 

you can find an OE manifold for cheap without contributing to a government and economy of a country that is the enemy of both God and humanity.
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