Calculate this.....low compression 2.5 makes 155 hp ( 8.5:1)
variable valve timing is worth 15 hp, and the STI intercooler should be capable of making the industry standard of at least 10hp per psi (130 hp) THERE IS YOUR 300 HP.

So the STI will most likely run 13 psi......think back to the 2.5 rs in sport compact, in the end they ran like 14 lbs of boost to make around 300 hp from a 2.5 turbo. The STI internals are much stronger than the sport compact car so 18 psi would maybe ( depending on which turbo we get ) equal 350 hp, add a uppipe and turbo back ,.and it should push close to 400.

My 944 turbo is a 2.5 liter 4 and with 19 lbs of boost and biggg turbo, it makes 395 at the wheels.

Keep in mind the shape of the combustion chambers have been reworked for forced induction so the STI IS very UNDERTUNED !!
The potential is incredible, good luck on the electronics though, you know Subaru Technica International is'nt gonna let anyone other than Prodrive-USA have a crack at the ECU.

944 turbo guy


what you guys think,..mav,.rhdude,..etc..

...I totally agree, I don't believe they would give us a car that isn't undertuned, + the internals on this STI alone are plenty strong enough to handle a piss load more boost, even with someone like me tunning it :eek:
I would be willing to bet you could get 400hp eaaasy with mediocre "home grown" bolt ons!

As far as electronic's go's, Subaru Int Tech. isn't dumb there ECU is probably going to be able to take use farther then we believe.


~B

Is it me ,.or does it seem likeMAYBE 5 PEOPLE IN MID ATLANTIC AREA CARE ABOUT THE STI?

944TG

Why do you assume that the STi will only run 13psi? The current one runs 17 IIRC.

As far as undertuned, I'm sure it is a bit. Subaru has to sell a car that is 50 state legal, and able to run in all 50 states. Last I knew, the best gas you could get at the pump in CA was 91 octane. You wanna put that in a car that's tuned to it's maximum on 93? I wouldn't.

I agree that 400hp is possible with bolt on's, but that should be a gimme...show me one turbo car that doesn't respond well to intake and exhaust mods.

Jim

IMPREZARIDER--

I didnt assume it will run 13 psi, its a calculation. did you read the first thread line? The current j-spec and uk-spec run 17.5 lbs of boost because they are 2.0 liters. That means they start out with
115 hp of motor power and the 17.5 lbs of boost makes up the
170 or so hp of "on boost " power. Based on an average of 8-11 hp per psi (lb per sq inch) . but because they are small displacement engines there isnt much torque. The STI on the other hand is a very large displacement 4 cylinder, and boxer engine at that, so it makes equal torque as horsepower.

944 turbo guy.

i am interested about the sti like everyone else, but at the same time im pissed off. i just bought my damn car because it was the top of the market. jan 02 when i got mine. i dont have money to keep jumping up. so no matter how much i am in love with it, i cant be all over it, or i'll get myself into even more debt and pick one up. besides the non sti can get 400hp also, if you want to tune it that way. deffinately not as reliably as the sti would, but hell, you could.

I had a feeling that was the case,'cause it just seems like no-one from mid atlantic give a flying sh-- ...
I just got my o3' in Sept, but my soon to be father in law is gonna buy it,...

944tg

Isn't the Japanese STi only a 2.0L boxer with top and front mounted intercoolers? If so, then the US STi is a freak version, lack of front intercooler they had to make up the power some where so they just boosted the engine size. As far as I know, the reason the WRX lacks a front intercooler is because of crash test issues, hence the reason the WRX only put out 227hp. Or am I just completely wrong?

But that's the reason I don't really care quite that much. Though I'm more curious what I could get out of my 03 RS if I added a turbo kit.

its 2.5L and since I havent seen a single STI pic with foglights, i'm assumeing that it does have a FMIC.

p.s. i would give my left nut for a fully tuned STI, totally mod-ed out to whatever i want.

I think only 5 ppl are interested cuz only 5 ppl can afford to buy it, lol. Now my only goal is to make sure my '03 can beat one ;)

Sounds great, but thats pretty high boost for pump gas, no? I have a RX7 and the rotory is a total different beast, but I don't run any more than 16psi on pump.

Originally posted by Jabzilla
As far as I know, the reason the WRX lacks a front intercooler is because of crash test issues, hence the reason the WRX only put out 227hp. Or am I just completely wrong?


Completely wrong. The WRX has never come from the factory with a FMIC. Also, it would be stupid to do a front and top mount intercooler. Can anyone say lag?

Jim

Originally posted by Impreza Rider
Completely wrong. The WRX has never come from the factory with a FMIC. Also, it would be stupid to do a front and top mount intercooler. Can anyone say lag?

Jim

Jim,
Your correct in that the WRX never came with a FMIC, but your incorrect about the FMIC and lag issue. Corky Bell, a well known engineer for his knowledge of turbo charged cars, wrote a book specifically about this topic and after reseaching found that one would have to have almost 25' of intercooler piping in order for the intercooler of loose efficiancy (hense "lag"). So the FMIC will not cause your car to have more lag, only a bigger turbo would. There was also research done on intercoolers being too big and it was found that this would also loose efficiancy, but this is more common knowledge.
Ernie
'93 Mazda RX7
516rwhp @ 20psi SR Motorsports KKK stage 2 turbo
10.73@128mph....

Originally posted by 944 turbo guy
variable valve timing is worth 15 hp,
This is your only point that I would really argue with.
Subaru AVCS is an extremely basic implementation of VVT, and I seriously doubt it is worth anywhere close to 15hp.
In addition, according to some people, the AVCS is tuned for better throttle response and turbo spool

I agree that it is under-tuned, a 300/300 split means that there is plenty of room to grow in the top end. Not to mention those 3 damn cats again

Originally posted by Elgorey
This is your only point that I would really argue with.
Subaru AVCS is an extremely basic implementation of VVT, and I seriously doubt it is worth anywhere close to 15hp.
In addition, according to some people, the AVCS is tuned for better throttle response and turbo spool

I agree that it is under-tuned, a 300/300 split means that there is plenty of room to grow in the top end. Not to mention those 3 damn cats again

I wasnt clear,..I think the variable valve timing is worth 15 hp when coupled to a low compression 2.5 engine with no boost.
Remember a 2.5 rs falls on its face at around 5000 rpm and thats with 10.5.1 compression, now take away the 2.3.1 worth of compression and add vvt and a turbo big enough to complement a 2.5 liter.

How about this,..I'm not an engineer by a long shot, I can see where you're coming from and I do think the 15 hp is a bit much, maybe 10, maybe 5. This much I do know .When I was all hot into VW's ,.if you advanced the timing on a A-2 golf with cis fuel injection, Techtonics and the rest of the world,..dynoed it to be worth 5 hp above 5000 rpm. They then found by raising compression 2 points, to 12.1, you picked up another9 hp ,.at the wheels !! This is on a 110 hp 8v motor.

The vvt allows the timing to be sweet on the bottom and on the top.The engineers keep the overlap good on the cam and make the mid range strong and let the vvt do the rest of the work.
I wish I did know the real answer, but I do see your point.


thanks for responding, I started this post like weeks ago.

944 turbo guy( used to be G-60 jetta guy with 210 @ the wheels)

yeah I dont come around here very much :p

very true, I guess it all depends on the implementation of the VVT. Agressive timing will yeild some good power no doubt.

oh , and I am definately excited as hell about the new STi. The only thing that worries me is putting such an expensive car on track! In retrospect I shouldnt have even done it with the WRX. Back when I started with the WRX I didnt think much about the possibility of a wreck, now that Im wiser ;) and I have seen too many of my friends ball up cars (not if...but when) I dont think its a very good idea to track an expensive car that isnt paid off. Which is why I just started building a showroom stock car. :)
But it would be a crime to not take an STi on track to pass some vettes! :p

so how is that World challenge ride coming? :)

Originally posted by ErnieT

but your incorrect about the FMIC and lag issue.

Not a FMIC by itself. My point was a turbo having to pressurize and push air through 2 intercoolers (top and front).

FWIW, I plan on doing a FMIC swap into my RS at some point after my new engine goes in.

Jim

No one wants to give up money for racing. When they do they want a Media package on the level of Nascar. So when you start talking to a person who has 5 successful ventures that generate like 20 million in revenues per year, and your asking for $ 12k per race ( 10 races a year) and looking for a 2 year commitment,..they start out excited and after thay talk to there accountant and board members, they dont shoot you down, they come back and say ,." yes we'll do it,....but,...only if you find someone to match us, because we'd like to do it for 4 years..."

Your sitting there thinking,..yeah fu--in' right,..you know that wont happen, if it did you'd change that later.

So my objective has changed and I will pay for 2-3 rides myself,..with along with buying an STI,..means I can barely run the Porsche in SCCA this year.

All oodles of noodles for me for the whole year. No 19 inch wheels for the STI (lol)

I have hired a company to search for sponsorship and they dont get paid unless they find money,...we'll see what happens....
thanks for asking though.

944 moneyless

Originally posted by Impreza Rider
Not a FMIC by itself. My point was a turbo having to pressurize and push air through 2 intercoolers (top and front).

Jim

I know you arn't that ignorant to think the car would have two intercoolers? Good lord, I don't mean to be rude, but you make yourself sound 16yrs old with your post.
I can't believe I have to tell you this, but when you go with a front mount intercooler, you take off the stock mount!!!

Thats kinda obvious Ernie, but damned if it isnt funny.
;)

Originally posted by ErnieT
I know you arn't that ignorant to think the car would have two intercoolers? Good lord, I don't mean to be rude, but you make yourself sound 16yrs old with your post.
I can't believe I have to tell you this, but when you go with a front mount intercooler, you take off the stock mount!!!
Ernie-

If you re-read the posts, you'd realize that I'm not the one that thought the car had 2 intercoolers. And, if you're going to criticize me, at least throw in some facts to shut me up ;) Anyway...what's wrong with having 2 intercoolers? Audi uses 2 on the TT, as does volvo on the S60R and S70R (IIRC).

When did I ever say that I was going to leave a TMIC on my car when I went with a front mount. Again, if you re read I said that I'd be putting a FMIC on my car at some point. If you just thought about it for a second, and saw that I was making an arguement against having both intercoolers, you'd realize that I'd replace the top for the front.

I think that you need to read this thread again and figure out who you're talking to, because I think you're getting 2 people mixed together :)

Jim

Originally posted by Impreza Rider
Ernie-

If you re-read the posts, you'd realize that I'm not the one that thought the car had 2 intercoolers. And, if you're going to criticize me, at least throw in some facts to shut me up ;) Anyway...what's wrong with having 2 intercoolers? Audi uses 2 on the TT, as does volvo on the S60R and S70R (IIRC).

Jim

Jim,
Once again you show your ignorance and lack of knowledge of turbocharged cars. And the S60/S70R use a single turbo/ single intercooler. Sorry to burst your bubble. The Audi uses the 1.8T which also has only one intercooler. My wife has one and I know this for a fact. You can't and wouldn't run two intercoolers on a single turbo application.

Ahem...

The 180hp one does, however (direct from the Audi website):


225 hp
Turbocharged DOHC in-line 4-cylinder with direct ignition, two in-line charged air intercoolers, electronic turbo boost regulation, 5 valves per cylinder
Displacement: 1.8 liters (107 cu. in.)
Bore: 3.18 in.
Stroke: 3.40 in.
Compression ratio: 9.0:1
Horsepower (SAE net): 225 @ 5900 rpm
Torque: 207 lb/ft @ 2200-5500 rpm


See for yourself: http://www.audiusa.com/features_specifications/0,,contentType-26_modelId-200315_status-P_countrycode-1_,00.html

Now who's being ignorant?

The two inline intercoolers they speak of are togeather making up about the same size intercooler as the stock wrx one. Mute point.

Originally posted by ErnieT
You can't and wouldn't run two intercoolers on a single turbo application.
Mute point.

Apparently it's not. You said your self that 2 intercoolers couldn't be run on a single turbo.

Oh, and by the way. about the Volvo S60 and S70R's:

And thanks to the continuously variable valve timing (CVVT), efficient KKK turbocharger and the intake charge cooling twin intercoolers

Ok this is just sad....... Jim is one of the more knowledgeable people in the Mid-A.

ErineT get a clue, the more you call Jim ignorant the more of an ass you look like. You're acting like a 16 y/o who jumps to conclusions that some one doesn't know something, from seeing one comment. Keep on going through, this is gonna be fun to see Jim school you with out breaking a sweat.


Buster
Patiently waiting for the "your mom" comments http://www.awdcars.com/forums/images/smiles/sigh.gif

Originally posted by EvasionOfTruth
Ok this is just sad....... Jim is one of the more knowledgeable people in the Mid-A.

ErineT get a clue, the more you call Jim ignorant the more of an ass you look like. You're acting like a 16 y/o who jumps to conclusions that some one doesn't know something, from seeing one comment. Keep on going through, this is gonna be fun to see Jim school you with out breaking a sweat.


Buster
Patiently waiting for the "your mom" comments http://www.awdcars.com/forums/images/smiles/sigh.gif

No "your mom" comments. Im an adult who owns a 10 sec. 516rwhp RX7. That being said, I wasn't talking about family cars with little pea shooter turbo's. I was talking about real street driven race cars.

are you saying 16 year olds don't know anything about turbo set-ups Ernie? If you are, then you are very ignorant and deserve to be slapped...

Lemme Splain Somethin To Ya

First you must know that when we are talking about Timing were talking about Variable Valve Timing we aren't talking about simply Ignition Timing. Much like Honda's V-TEC Subaru's with VVT rely on an oil pressure actuator to shift the cam's position and engage another set of lobes effectively changing how far the valve opens and for how long. Most V-TEC/VVT application use this on only the intake cam or cams.

The tuning of the VVT system are drastically different when looking at NA cars compared to Turbo applications.

NA cars use precise amounts of Valve Overlap (This is where the exhaust valves stay open while the intake valves are begining to open. Therefore the time that the Intake and Exhaust valves are open overlaps) to make intake manifold vaccum to pull enough air and fuel into the combustion chamber to make power.

Forced induction applications need to have nearly zero overlap in their valve timing to maximize the charge air coming in from the turbo. In other words you don't want any of that prescious compressed air from the turbo to leak out of the combustion chamber because the exhaust valves are open at the same time the intake valves are allowing air in.

We all know that turbos aren't on boost at all times. Infact at low RPM levels most stock turbo cars are like badly tuned NA pigs. To aid this situation VVT can be used in conjuction with other engine management to spur low RPM power until boost kicks in. During low RPMs the cam should be set up with the right amount of overlap to make power with intake manifold vaccum. Then when the turbo is spooled the cam is shifted to engage lobes that translate into little to no overlap.

All in all the intent of Variable Valve Timing on a Turbo car isn't necessarily to make more Max Power but more to increase low end power that isn't present in turbo cars.

Brad