Hi Everyone,

I've decided to embrace my inner modder and make a few changes to my 2017 WRX STI Final Edition.

Will be fitting a performance airfliter, Walbro 255l/hr fuel pump, Cobra 3" down pipe with sports car and getting an ECUTEK remap.

In theory this should release some modest performance gains, whilst keeping the car looking standard as I'm keeping everything behind the cat as standard.

I'd class this as a stage 1.5 upgrade, so hopefully around 330hp

I'm just wondering if I'm walking into any problems with this setup - I'm not looking for big gains or a booming exhaust note, just a subtle increase in performance.

Should I be looking at a cold air intake, should I be considering uprated injectors or doing other things like upgrading the oil tank - biggest concern is reliability and durability.

Any thoughts would be welcome.

 

The biggest concern would be the 2.5 engine eating it's own innards.........

 

Thats what I'm trying to avoid by just keeping it simple and replacing parts that are "known" to be restrictive.

 

Oil changes every 5000 miles or less, with quality oil and filter is best practice; no need for pump or injector changes at 330hp, but what about your warranty? IM, the UK importers, are not renowned for supporting warranty claims where mods are concerned, so always budget for a rebuild on a 2.5l. Some last, some don't.

 

A 3" downpipe into an oem 2.5" cat back is still restrictive, and unnecessary under 350hp. Ask advice from whoever's doing your map for what mods you need for your chosen power level. For 330, a panel filter and 2.5" sports cat should be fine. I doubt you would even need an uprated fuel pump tbh.

 

Oh, and pictures are compulsory.!!

 

I have a 2016 sti and did much the same, changed downpipe to decat, 3" Haywards Scott Centre section and resonator, sensible map and increased boost very slightly and it made a difference but not massive. You won't need to change injectors or filter etc and fuel pump only needed +400 as told by professional who's mapped subaru only for 20+ years. Mine now however is about to go fully forged because I've got bored of it!
Also you be glad to know fuel range went from 250 to 340 after the map!!

 

Many threads on here say an upgraded pump.p is not nessacery but a new pump on an older car won't hurt..
I'm reading that the HRC pump is better for cheaper.
Not tired it but only what I've read here.