Hi all,

I have a 2008 STI JDM hatchback and looking at getting a downpipe for a bit more power

Currently the mods are:
Invidia R400 catback exhaust
HkS panel filter
HKS SSQV BOV
Upgraded fuel pump
Tuned to 330hp at Enginetuner

I understand that in the UK a decat downpipe isn't roadworthy. I have seen some with a divorced wastegate. Eg. https://www.ebay.co.uk/itm/325278800882?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=gUk3Xg9bRIG&sssrc=2349624&ssuid=Dyy9Syh1Sr C&var=&widget_ver=artemis&media=COPY

Does anyone have any recommendations of downpipes? Also any other mods to install to increase power as next steps from my current setup?

Cheers,
J

 

First off the downpipe you show is for the 2.5L engine with single scroll turbo whereas the JDM hatch is 2.0L with a twin scroll turbo which has a different outlet flange

Single scroll

Twin scroll



You would need to look at Japanese manufacturers like
ZeroSports; Avo; Fujitsubo; Tomei Powered; Sard; HKS; Syms Racing, to name but a few.

In the UK, Hayward and Scott do a couple of down pipes to suit the JDM model on this page.

 

Thanks Don. And thanks for spotting that it's for a twin scroll. Do you know of any reputable companies that stock downpipe for twinscrolls in the UK? Or would I need to contact an overseas company?

I know Possum Bourne do a good one in New Zealand. I've heard bad things of H and S...

Any other mods you would recommend to increase power?

 

Other mods that helped me to 357bhp on a standard cat; fuel pressure regulator, uprated actuator to hold boost, 3 port boost solenoid. Martyn at ET said oem exhaust holding it back, although I do have an hks center section and sti back box.
Edit; Sard was the cheapest sports cat available in Japan last year, exchange rate better now but carriage costs higher

 

I have a Miltek on mine
the rear lambda didn’t line up
so we bunged it marked the correct location and local engineering shop drilled and tapped it and that was it

 

Hello Users..
https://www.scoobynet.com/uk49s-newreply.php?do=postreply&gosloto results-t=1066937

 

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