modifying 2005 sti (blob eye)

[omar2010]

hi guys - i currently have a near standard 2005 sti 265bhp (afterburner back box only on it at the moment). I am thinking of modifying it to about 320bhp (basic mods only nothing too extreme -i am thinking exhaust air filter fuel pump and ecu).

From the more experienced members - will it make a huge difference to the driving experience?

Any regrets from those of you who have done it?

Sorry for the newbie question - I have never modified a car before.

Thanks in advance.

[BerksJack]

That's all you need for your intended figure bud.

Decatted or sportscat downpipe
Decent panel filter (standard airbox is good for way more than your figure)
Fuel pump
Colder spark plugs
Remap.

If all is well with your car you should see more than 320 on your standard turbo.

It'll feel like a completely new car to drive, you'll love it!

[paul555sti]

The only thing you'll regret is not having done it sooner.

[ScoobieWRX]

Getting your exhaust mod right is important. You only have two cats on the STi so it's your choice whether you go fully decat with a nice complete Stainless steel exhaust or you get rid of the scrubber after the main cat and leave the main cat in place for MOT emissions pass so just get a cat back system. In fact a cat back is all you need.

The STi uppipe is very good so leave as is. Also, stick with the standard 2.5/8" standard diameter exhaust pipe. That's good enough for 350bhp as is the standard exhaust header. 320bhp and similar torque numbers is very achievable with these mods and will be no problem for a good tuner to exploit.

High flowing flat panel air filter (K&N, Green Panel etc...) and a walbro fuel pump is all the other hardware you need to change.

Then you choose to get your remap done by an EcuTek dealer or Open Source tuner. Their is a cost difference but ultimately both mapping tools will give equally good results. It's really down to the skill and experience of the tuner not the software tools with Subaru.

Your end result is only as good as your mods and your tuner is. Period!!

ETA: Fitting colder spark plugs is great if the standard heat plugs aren't coping. If you do change go for NGK Platinum PFR7B. They are very good. Don't be tempted to use Iridium plugs, IMHO i think they are ste!!

Edited by ScoobieWRX on Monday 26th November 11:24

[omar2010]

Thats really helpful guys.

Is it the straight line speed that improves or the overall responsiveness?

I find that the car is fantastic in 1st / 2nd / 3rd but it can feel a bit breathless in 4th gear and above.

I take it that there are no major reliability issues as long as the standard car is okay and I don't try and go for obscene BHP figures?

Thanks again, guys

[ScoobieWRX]

Your engine should handle up to 500bhp on standard internals. In fact there are a handful of STi's that are already running 500 on standard internals but like anything else you've got to be living on borrowed time at those power levels. Mine included in the new year. Will be good to see just how much these engines will take with standard internals before they go pop. And pop is a good excuse for a Mega Rebuild!!

However, your engine will happily take 420-430 safely all day long, no problem at all, probably more like 450 without any issues so don't worry about your engine as long as the mods are right, the remap is good and you change the engine oil and filter every 5000 miles, so in between normal services you'll be rockin and rollin.

Same to be said for everything else in the drivetrain like the gearbox, front and rear diffs and centre diff. Absolutely bullet proof!!