Power Output - Liberty STI vs WRX STI

by **PRO20B** » Thu Mar 20, 2008 9:50 am

Hi all,

I am awaiting delivery of a MY08 Liberty GT Spec B Tuned by STI, and am wondering what differences there are with regards to engine set-up/tune or anything else that leads to the difference in power output compared to the MY08 WRX STI, ie 221kw vs 194kw.

I am keen to hear more.

Cheers
Daniel

by **Spec B Wgn** » Thu Mar 20, 2008 9:53 am

i think they are totally different engines...

definitely the STI runs more boost and now tuning on the Dual AVCS exhaust as well as inlet valves...bigger intercooler. theres a lot more im sure

by **PRO20B** » Thu Mar 20, 2008 10:59 am

Spec B Wgn wrote:i think they are totally different engines...

definitely the STI runs more boost and now tuning on the Dual AVCS exhaust as well as inlet valves...bigger intercooler. theres a lot more im sure

Thanks for the info.

Not quite what i was hoping to hear, but thems the brakes.

Cheers
Daniel

by **tangcla** » Thu Mar 20, 2008 11:05 am

Spec B Wgn wrote:i think they are totally different engines...

definitely the STI runs more boost and now tuning on the Dual AVCS exhaust as well as inlet valves...bigger intercooler. theres a lot more im sure

I'm not sure which I find more amusing... your avatar, or your sig :lol:

by **sooobi** » Thu Mar 20, 2008 11:08 am

Spec B Wgn wrote:i think they are totally different engines...

Yep.. the wrx has an sti built/spec'd engine (worth over $10k) where the lib has the same engine as the GT..

Buy my B4 and spend the rest of the coin on your missus..

by **Spec B Wgn** » Thu Mar 20, 2008 2:25 pm

my thoughts are as mentioned before.

the tuned by STI is a 2.5 litre WRX motor with a few ECU tweaks.... ie a bit more boost and timing

the STI motor is a balanced WRX motor bigger turbo, more boost, sodium filled valve stems, bigger intercooler, totally different motor. etc etc.

by **PRO20B** » Thu Mar 20, 2008 3:21 pm

I put the question to Subaru and pretty much got the same info as you guys have mentioned...

The MY08 Liberty GT SpecB tuned by STI features an enhanced engine management tune that results in a 10kw gain in power and an 11Nm gain in torque over the standard Liberty GT & Liberty GT SpecB. All other engine and ancillary components remain unchanged.

The Impreza Sti however utilises Dual AVCS, modified camshafts, the turbocharger and intercooler are capable of much greater air flow and the engine management is tuned accordingly.

Unfortunately the turbocharger & intercooler from the Impreza STI are not interchangeable with those on the MY08 Liberty GT SpecB tuned by STI

Cheers
Daniel

by **Arith** » Thu Mar 20, 2008 4:07 pm

The MY07+ Liberty STi with the 2.5 engine was designed around the philosophy of a smooth, linear powered ride. I'd hate to compare it this way, but SA set up the STi just like Toyota set up the difference between a normal Aurion and the Sportivo model: not necessarily more power or performance, but rather driving dynamics.

The 2.5 Liberty STi (the reason I specify the 2.5 is because the STi with the 2.0 engine was much more aggressive and revved higher and freer) only has very subtle 'add on' parts to it like the Brembo's, the strut, lower strut, springs, and lower control arms. The increase in power with the STi mufflers and the ECU is minimal at best. It's the dynamics that seperate the STi from the GT B.

Those thinking the STi label will mean better performance, like the Impreza STi, will be disappointed. No, the Impreza STi is rally bred and is geared towards performance. The Liberty STi is still marketed towards the executives, so it still had to retain a dignified appearance. And in order to keep the price down to stay competitive, SA chucked on the minimum (compared to the JDM STi the AusSpec STi is pretty weak). If they were to include the same engine performance upgrade as the Impreza STi, it would have blown out the cost.

Anyway, that's just my 2 cents.

by **chriskan** » Thu Mar 20, 2008 4:38 pm

Pretty much what Jim (Arith) said - different intentions for each car. And both have their +'s and -'s. My decision on the Lib was that for 95% of my driving I would prefer the comfort over the extra grunt offered by the STI 'prez.

Having said that, as you've probably seen already on this forum Daniel, there's a vast range of parts available for the Libs to get the power up, and improve on the car. I haven't driven the MY08 prez STI yet, but the MY07 was like driving a go-kart and I don't think I could handle it as a daily especially around tram lines and the rougher city roads we have in Melbourne. The car itself is also very basic.. but as others have mentioned, you are paying a premium for the engine and associate upgrades in the imprezza.

Enjoy the lib and don't worry about the peak power figures too much..

That can be changed later!

by **Mano™** » Tue Mar 25, 2008 5:22 pm

wrx's are for fags..

the bottom end on the wrx has always been weaker and will always b weaker then the libs

but hte new wrx sti's r okie.. lol other then that GHEY!

by **Akwoo** » Tue Mar 25, 2008 5:26 pm

oi shuddup mano

i'm thinking about getting best of both worlds.
the STi for weekend racer,
GT for cruising around.

by **Mano™** » Tue Mar 25, 2008 5:30 pm

haha well now u all hurd it... alan turnin gay

by **Mano™** » Tue Mar 25, 2008 5:32 pm

betta get the new1 tho.. still the gt will b betta pal

u must b makin to much money to get anotehr car.. i think u should buy my rims 4 me son shine!

by **GTSPECB STI** » Wed Mar 26, 2008 11:36 am

plus 1 for what Arith said. If you want a track car that you can drive around on the road then WRX STI is a good choice. If you want a road car that you can track then Lib STI is probably a good choice.

I traded my modded 06 WRX STI for the 07 Lib STI last year. No comparison in terms of ride quality and comfort but clearly less power. Lib is far more linear in terms of power whereas my old WRX STI was more like a rocket but very uncomfortable to drive long distances on bumpy roads.

In my mind the trade off was an easy one. Having test driven the 08 WRX STI I can truthfully say that the 08 WRX STI is closer in comfort to the Lib STI and a bit more linear in power delivery as well. Would I trade my Lib STI Sedan in on a Ugly Betty STI - hell no.

by **overl0ad** » Wed Mar 26, 2008 12:30 pm

GTSPECB STI wrote:In my mind the trade off was an easy one. Having test driven the 08 WRX STI I can truthfully say that the 08 WRX STI is closer in comfort to the Lib STI and a bit more linear in power delivery as well. Would I trade my Lib STI Sedan in on a Ugly Betty STI - hell no.

external looks aside. would you?

Power Output - Liberty STI vs WRX STI

Power Output - Liberty STI vs WRX STI

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