Hi All,

Recently just bought a completely standard JDM WRX STi Hawkeye after owning a tuned M135i. Never owned a Subaru but it was always on the bucket list.

The car is fantastic, everything I imagined and everything I want from a car and certainly ticks a lot more boxes than the M135i.

There is a few things I’d like to do, I’ve been down the rabbit hole and there is tonnes of information, but it’s hard to decipher between all the models and the fact I have a JDM is even harder. A lot of info is from years ago too, not sure if there has been any advancements etc since.

Firstly the exhaust, can’t lie it’s very poor from standard. As it’s the a JDM, I know it won’t have the rumble of the UK ones, but is there a specific setup that gets close to the UK rumble? Or even a setup that just sounds really good? Finding it hard to find videos specifically of JDM STi. I’d like to keep MOT legal, the M was decatted and it was a headache come every MOT. Also, I’m not sure if setups for the UK Hawkeye will fit the JDM Hawkeye?

Secondly is power. I understand standard these are 280bhp, having come from a 400 BHP 135i the power is lacking and I do find myself wanting more. What is the best route to go for a JDM STi and what sort of gains will I be looking at? From what I have gathered, 350-360 seems about right, anything after that is bigger turbo, more money etc? Is this correct?

 

you have a JDM "twinscroll" and hence equal length headers and NO rumble.........you will never achieve it with this set-up albeit it is far more efficient than the single scroll / unequal kit
std cat is restrictive but sports cats are not easily available for this style