Wrx Sti 2005 Standard Boost Level

[JIMMY R]

Hey guys a mate of mine just bought a 2005 WRX Sti, just wondering whats is the standard boost level it comes out with. i know the max boost it can take is 14.5psi, but what is the factory boost psi?

thanks

[R34GTFOUR]

you'll find the wrx's actually spike from factory to around 15-16psi then drop off to around 12psi and hold that to limiter. If you stick any stock rex on the dyno and monitor boost levels you'll see what im talking about. They do this to make it feel really strong coming onto boost and as most old blokes dont really rev the things past 5grand they think its super quick. With a rom tune you can get them to hold the 15psi boost level across the rev range, makes a fairly big difference.

Edited November 25, 2007 by R34GTFOUR

[TTT]

i know the max boost it can take is 14.5psi,

Who told you that?

You do realise the STI's have forged pistons and prepped rods as stock.

22psi is not an uncommon thing for these motors (with supporting fuel and tune mods obviously)

I believe that the classic shape (pre 2000) STI ran 17psi from factory.

[wrxhoon]

Subarus run high boost on all their cars . My05 STI runs about 16 psi stock, v5+ v6 ( my99+ my00) run even higher boost 17+ psi because they were pure Jap spec cars . Even normal Rexes run 14 psi on most models , its only the latest MY06 on (2.5 lt engines ) that run slightly lower boost about 15 psi on STI and 13.5 for normal WRX.

[pixel8r]

I thought it was around 16-17psi. Compare that to a GTR and then try pumping 16psi through a GTR (with supporting turbo upgrade of course) and see which has better power output.

interestingly the Mazda3/6 MPS also runs 16psi stock, which is where all the torque comes from.

But again, even in my stagea if I were to run 16-17psi of boost I could probably come close to a STi and beat a Mazda3 MPS easily...

[joeyjoejoejuniorshabadoo]

The amount of boost is relevant to the size of the turbo don't forget. I.e. A hks 2530 running 10 psi is VERY different to say a trust t88 34d on 10 pounds.

[DRD-00F]

per square inch

there are a shit load more square inches in a T88 then a 2530 basically... so 10psi out of a T88 would be a shit load more...

I'm often surprised how many people forget to take that into consideration...

[pixel8r]

Whats the diff in size between the stock STi turbo and stock skyline turbo for example? I would've thought these were similar.

EDIT: I think people misunderstood when I mentioned turbo upgrade on a GTR. I just meant something comparable to the stock turbo but with steel wheels in order to handle that much boost - i wasn't meaning BIGGER as such...sorry for the confusion.

All I was saying is that the subie 4cyl needs a lot more pushing to get the same amount of power as say an RB25 NEO or RB26. Not that they're a bad engine, I think they're quite good and sound awesome. Just that in my opinion Nissan get more power (and sometimes torque) from their engines - compare the VQ35HR power output with practically any other 3.5L n/a engine in the world (offtopic i know...).

I realise that different size turbos flow different amounts of air at the same boost level, but I thought the WRX turbo was about the same size as a skyline one...? yes or no?

Edited November 29, 2007 by pixel8r

[joeyjoejoejuniorshabadoo]

Bmw pull heaps of power out of natto 6's

[DRD-00F]

WRX turbo

33 turbo

WRX one is a bit bigger, but it also has steel internals...

[pixel8r]

[WRX one is a bit bigger, but it also has steel internals...

So this would mean that the WRX turbo would flow more air at the same boost? or can this comparison not be made just based on size?

I'll admit I got a little carried away in my last post about the nissan engines thing...lol

I'll also admit I'm not a big fan of WRX's. I dont know why that is, because I love the sound of them, but just think they're maybe a bit underengineered, and not as quick as the hype would suggest?

Of course the same could be said about skylines too (except for the underengineered bit). I wasn't into skylines until I got a bit older and sold the silvia turbs.

Only thing was I wanted a 4 door + a boot - hence the stagea...its kind of a skyline, passenger vehicle, and wagon all in one - if that makes sense

Edited November 30, 2007 by pixel8r

[TTT]

DR-DOOF.

that is not an 05 STI turbo.

that is a standard 94-96 Sti turbo or standard 94 wrx turbo.

TD05H was no used in standard WRX after 96 I think.

they went down to lady size td04's.

STI's went to VF series.

Largest STOCK STI turbo was the VF22 which is bigger than any stock Nissan turbo.

And saying a 2L subaru engine makes less power or torque than a 2.5 ro 2.6 is just stating the obvious.

Compare it to the Nissan 2L..

SR20, RB20..

more of an equal match.

the guy saying "if I ran 16psi in my Stag, I'd beat this and that.."

go run 16 psi in your stag.

when it gets to 10 psi, get an ecu to fix the R&R issue.

when it gets to 14psi and pops replace with another..

repeat until you manage to find a stock RB25 turbo that stays together at 16psi.

then lets see if your 1700kg whaling boat can actually beat anything.

[joeyjoejoejuniorshabadoo]

The difference between 10 and 15psi on the stock turbs is f**k all anyway... Its well maxed out by 12ish

[pixel8r]

And saying a 2L subaru engine makes less power or torque than a 2.5 ro 2.6 is just stating the obvious.

Compare it to the Nissan 2L..

SR20, RB20..

more of an equal match.

the guy saying "if I ran 16psi in my Stag, I'd beat this and that.."

go run 16 psi in your stag.

when it gets to 10 psi, get an ecu to fix the R&R issue.

when it gets to 14psi and pops replace with another..

repeat until you manage to find a stock RB25 turbo that stays together at 16psi.

then lets see if your 1700kg whaling boat can actually beat anything.

Ok, I'll bite. It was just an example...

anyway, I'm currently running only about 9-10psi, with a turbo (not stock) that will easily take over 20psi if I wanted it to. WRX's are obviously built from the factory to handle the psi. If nissan wanted to run 16psi through their engines they too would use a turbo and the correct fuel/engine management to support this. Fact is, they dont, because they dont need to. They get the same power running a measly 5-6psi even though the engine is capable of so much more.

I have the ecu to fix the R&R issue. I have the turbo that can support 16psi.

Maybe read through what I posted originally - you misquoted everything i said.

All I'd need is a bigger fuel pump (maybe injectors too) and my car could happily run 16psi maybe more...and with over 200kw at all 4 wheels, it'd be a damn quick wagon. 1700kgs is a bit over-exagerated too - its actually 1650, if you want to be technical about it.

The thing is, I did have more plans for the stagea, but being the fastest or best was never my intention. I just wanted it to go fast and still be comfortable enough and fuel-efficient enough for everday driving and also long trips. And now, even though its power/boost level does not reflect what the turbo is capable of, its fast enough for me at the moment, its way more fuel efficient than stock (how does 11.5L/100km city driving suit you?), and still very comfortable as a daily driver...

So I've kind of put the plans on hold for now. And it is a wagon after all. Say what you like about wagons, but sure if I could practically get by with a 2door coupe I would be more than happy to drive a skyline. But actually I sold my 2 door silvia turbo to buy the stagea because I need more doors and more space, and its paid off many times. Thats just the way life goes. Forgive me for wanting my "whaling boat" to still perform as well as my old 2door coupe (which it does btw).

Anyway, my point was simply that STi's do make good power, but when all things are considered, the power is nothing to write home about. Just par for the course.

btw aren't WRX's 2.5L these days?