Upgrades?

[Georgeh79]

Hi I have recently purchased my first impreza and first impressions great! I also own a 300zx twin turbo manual running 430 bhp, my impreza has a dyno sheet showing 327 bhp. It's a 2003 sti uk with Pro drive. I want to get rid my 300 as the subaru is a nice compromise, not as quick but better on fuel more space and hopefully less tinkering ( iv replaced clutch, wheel bearing, timing belt and water pump and alternator in last month on my 300) my question is I'd like a little more power out my scooby, not massive but around 350 ish , other than exhaust and the pro drive upgrade I have no idea what mods have been done, would a remap be worth while or an Intercoller upgrade? I know cars well but nothing really about imprezas so and advice guidance be appreciated thanks

[Tidgy]

At 330 will already be mapped. Need to upgrade the turbo to get more now.

[Georgeh79]

Ok thanks for quick reply, if I upgrade turbo is it simple case of buy and bolt on or will it need mapping again after? Is it worth taking cat off? Iv heard mixed opinions over the years on de cat . Is the boost adjustable on an sti? Is it just a cause of winding a rod ( as my old escort turbo years ago was) or would just a turbo upgrade and that's it? What bhp gain from upgrade turbo thanks for any help

[Georgeh79]

Sorry for adding another question in quick succession but what is a safe bhp without upgrading internals, it's only my weekend car so won't do many miles cheers

[stants]

Nick on here is running around 360 on the 'stock' uk sti engine & as it's forged with standard i/c I can't remember what other mods it has, he was looking to get to 400 but requires some large amounts of cash throwing at it. Fmic & bigger turbo plus map for starters, fonzey has a build thread here and is on 400 bhp may be worth having a read through to get some idea's

The cat will be restricting the flow a little, I think the prodrive system has the sports cat so it will be less restrictive than standard,

Maybe worth getting it on the dyno to see what's going on, as if you went remap you could push it to safe levels of fueling and upping the boost, plus you could always go for switchable maps, low boost fuel save cruse map and an all out attack full mashings?

[Fastboy67]

My o4 blobye sti is running 355 with only a cat back exhaust a 3 port boost solenoid and remap. I believe every time you add something its best to have the map tweaked to keep it running sweet. Definitely worth doing if you go for a bigger turbo upgrade. 

[Georgeh79]

Thanks for suggestions will definitely be looking into it in the coming months :)

[Tidgy]

If you change the turbo it will need mapping, unless you can find out who mapped it before it will prob end up being a full map.

[stubbsey]

10 years ago I was running an STI which I gave to Zen Performance to up-grade after blowing the original engine.

 

We went for a 2.5 version with larger Garret turbo, 650 top injectors, forged pistons/rods, de-cat pipe and re-map - and it made around the 400bhp mark.

 

That was a pretty quick car!!