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Old 05-25-2003, 05:31 PM   #1
Overboosted STi
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Default USDM STi Engine Power potentials?

Hi everyone i was wondering if anyone knows of this motors power potental?

I was looking at the Easy Street WRX and they are running 9 sec 1/4 mile times. In the spec sheet I noticed that they bumped up displacement from 2.0L to 2.5L, so i was wondering if the USDM motor will have potential to run mid 11's relaiably.
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Old 05-25-2003, 06:31 PM   #2
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Default Re: USDM STi Engine Power potentials?

Quote:
Originally posted by Overboosted STi
Hi everyone i was wondering if anyone knows of this motors power potental?

I was looking at the Easy Street WRX and they are running 9 sec 1/4 mile times. In the spec sheet I noticed that they bumped up displacement from 2.0L to 2.5L, so i was wondering if the USDM motor will have potential to run mid 11's relaiably.
Yes..
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Old 05-25-2003, 07:48 PM   #3
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Default Re: Re: USDM STi Engine Power potentials?

Quote:
Originally posted by Scoobz


Yes..
it's nice to see that you know for sure that it can do that

nobody can really know the answear until some tuners get a hold of the block and examine it. even though i have a feeling that the engine will be strong, i don't think you can really compare it to the easy street engine which was build by tony rigolli and was designed to take the abuse. if you want more info i would suggest looking at cobbtuning.com and check out cobb's built engines. there are more things to the engine than just displacemant. things like pistons rods and material plays great role in how a engine will turn out to be. just by looking at some other motors like the RB26DETT and the 4g63 and you will see that even though displacent can help, there are many strong engines with smaller displacement that have a great potential.
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Old 05-26-2003, 09:49 AM   #4
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if a stock wrx engine block can go mid 11's in the quarter, then a sti block can go mid elevens.

i would put money down that the sti with a turbo back and a short ram intake could break into the elevens.

mark
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Old 05-26-2003, 09:55 AM   #5
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No offense but there is no way an STi will break into the elevens just with a turbo back and intake. Those mods would have to make up over 1 sec in the quarter and that just wont happen. We don't even know if the vf 39 will be good for elevens.

Btw, where in knoxville do you live. My Sti should be at grayson sometime this week.

jared
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Old 05-26-2003, 11:50 AM   #6
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Well, my buddy just bought a 03' Evo 8 and loves it. I am having a tough time deciding between the Evo 8 or the STi.

I know that both cars are awesome and I definately want to mod it so that it'll be able to run 11.5 1/4 mile times reliably. Even if it ran 12.5'd daily driven on the low -boost setting I'll be happy.

I guess when i'm ready to but the evo 8 or STi, it'll be a tossup...
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Old 05-26-2003, 12:42 PM   #7
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i spoke to a subaru rep at work (subaru) and he told me that the 14.5 psi the motor is running is the maximum boost that the motor can safely handle. supposedly the engine has been tweaked so much that the engineers were melting pistons at around 16 psi (peak pressure, excluding spikes). of course this is hearsay so i can't prove it's validty (sp?). not to mention the fact that a subaru spokesperson was quoted saying that the new 6-speed could not reliably handle 350hp. but i guess we won't know untill the first nut melts his pistons in his brand new STi - save your money!
oh yeah, who the hell cares about 1/4 mile times? this is no drag car, i guess that's why i see so many trannys missing all their teeth on 1st and 2nd.
B
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Old 05-26-2003, 01:15 PM   #8
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Well the Evo is certainly no drag car by your logic as the clutches are known to burn out quickly, and the car is notoriously difficult to launch according to Evo owners.

As for the STI, if it can't be modified reliably and inexpensively to make more power, then it would have to have some fundemental weakness or flaw that no one has really been able to point to logically or do anything more than speculate on.
After all, there are WRX's running 11's, and not just Cobbs either.
The weakness with the stock WRX is not making more power from the engine, even though it is open deck with cast internals. The weak link is in the strength of the tranny. The six speed tranny "should" help to resolve that as it is used in many high horsepower (400 hp and up) wrx's.

As for the Subaru rep's comments. I had a rep try and tell me that the engines already made "waay over" 300 hp and they were just keeping the nice round number for insurance reasons and to sandbag Mitsubishi. Those guys will say anything, depending on whether their agenda is either to sell a car or justify voiding a warranty.

Last edited by strangerq; 05-26-2003 at 01:23 PM.
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Old 05-26-2003, 01:26 PM   #9
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Well, just for the purpose of saving money and having what all my friends have, i'll porbably just stick with the evolution.

The engine is already proven and has potential...

handles better
brakes better
and has more supportive seats.

than the STi
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Old 05-26-2003, 01:31 PM   #10
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Quote:
Originally posted by Overboosted STi
Well, just for the purpose of saving money and having what all my friends have, i'll porbably just stick with the evolution.

The engine is already proven and has potential...

handles better
brakes better
and has more supportive seats.

than the STi
so that was the entire purpose of your post??
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Old 05-26-2003, 01:52 PM   #11
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guess we all know why mr. overboosted bought his integra...
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Old 05-26-2003, 02:10 PM   #12
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Quote:
Originally posted by strangerq As for the Subaru rep's comments. I had a rep try and tell me that the engines already made "waay over" 300 hp and they were just keeping the nice round number for insurance reasons and to sandbag Mitsubishi. Those guys will say anything, depending on whether their agenda is either to sell a car or justify voiding a warranty.
I went to the local Subaru dealer (Larry Miller in Boise) on Friday, and asked about the STi. The guy immediately started talking about a chip that made 350hp, coming out real soon. "Huh?" was my response. He walked me inside where the cool guy was sitting (with sunglasses and reclining about 45 degrees in his chair). This person said it was all over the forums (I didn't bother asking which ones) -- a well known tuner would come out with a chip to increase hp to 350 in just a couple months. Who? Doesn't remember. Prodrive, Vishnu, Cobb? No... not familiar with those, but he kept insisting that it was all over the net and everyone knew it would be out soon. Hence I should be thinking of the STi as 350hp.

One more reason I'm getting my STi somewhere else (that and the $5k over MSRP for both the STi and the Evo these guys are asking). 350hp I might believe with intake, exhaust, and ECU work, probably on 93+ octane gas as well. But not just a bolt-on chip 2 months after release. For some calibration, Vishnu's stage 0 for the Evo adds 40hp and requires both exhaust and chip. Vishnu's remapped ECU for the WRX, given 2 years of experience, gets 30-35 hp, while adding pulley and up-pipe (stage 0) gets to 50hp.
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Old 05-26-2003, 02:16 PM   #13
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Default What i think

Either Evo or STi once you boost up another 2 psi you will definetlly need at least a piggy back fuel managment , talk about reliable ..... once you step into motorsport thats no way call reliable , only if you have lotta money in the bank and thats call reliable ...
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Old 05-26-2003, 04:43 PM   #14
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Quote:
Originally posted by WRX Potential
guess we all know why mr. overboosted bought his integra...
No as a matter of fact I already sold my Integra. I am on the waiting list for a white/gold sti, and dont mind getting either one.... but if the STi's motor is limitied in what it can do in response to upgrades, I'll just go with the Evo instead.
My other buddy sold his GSR and just recently picked up a white Evo...hopefulyl mine will come soon...
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Old 05-26-2003, 05:07 PM   #15
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Quote:
Originally posted by Overboosted STi


I am on the waiting list for a white/gold sti, and dont mind getting either one.... but if the STi's motor is limitied in what it can do in response to upgrades.
Suit yourself of course. But all cars are limited. Including the Evo. I notice Vishnu Stage 0 for the Evo is out already, which is good. But it produces around 300 hp and pf torque for 1k. An STI is already there, on lower boost with less turbo lag.....and even a base WRX can get close to those nums for a little over 1k. I'd consider an Evo over an STI for handling, but not for straight line speed. You should consider that you're already down on power with a substantial and perhaps insuperable displacment disadvantage, while making near 19 psi of boost. Mod dollar for mod dollar I would question whether you'd ever be able to catch up. That's just an opinion, but supposidly that's what you are asking for.

Last edited by strangerq; 05-26-2003 at 05:16 PM.
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Old 05-26-2003, 07:15 PM   #16
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The block and the DBW on the USDM STi is unknown. Every single other component is known. Thus it's very tuneable, very modifiable. Plus it has two advantages over the Evo.

One is the turbo unit. Because Subaru didn't use the twinscroll and the supporting hardware due to displacement making it unnecessary, the turbo and it's hookup points are standard. Turbo replacements are numerous. The Evo uses a backwards-spinning twinscroll. Great turbo, but not easy to replace. Upgrades are limited, and expensive.

The other is displacement. In theory, and probably in practice, it simply has more overhead than the Evo. Yes, they are currently close in power, and yes the Evo can go higher, but they stroke Evo motors for a reason.

The disadvantage is the DBW, and how will that react to modifications. A piggyback or ECU reflash/replacement may be necessary. No conclusive answer yet (and tbh, you usually need something for management anyways).

And it's very, very unlikely that the engine implodes and gets sucked into a black hole when the power goes over 300. That's just wishful thinking on some people's part.

Cheers,

Paul Hansen
www.apexjapan.com
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Old 05-26-2003, 07:16 PM   #17
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Man.. this BS just grows by leaps and bounds about this car.. Melts pistons if you increase the boost 2 lbs or so?? The new tranny falls apart if the motor puts out 350HP? (50 over stock.. give me a break).

The car should be easily bumped 50 to 80HP. The only issue as far as I am concerned is the verdamted odd-ball ECU they are putting on this thing which will delay the more or less easy tweaks ala ECUTECK and Utec..
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Old 05-26-2003, 11:57 PM   #18
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Only time will tell.

Are the pistons forged or cast? I know the ver8 2.0 sti has some cast AL pistons that uses a new casting technolgy that is "supposed" to be stronger. It is probably just cheaper. Anyway I know the syclone and typhoon guys have a lot of trouble with hypereutectic pistons not taking kindy to det. That is why many employ water injection. Pretty much eliminates det.

The 6spd should hold up great. The DCCD center diff is the weak link in all that.

Aren't the 2.5STi injectors supposed to be a bit smaller (I had heard) No matter what you still need enough fuel for 11s What is the availability of upgraded bottom feed injectors?

-Jim
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Old 05-27-2003, 12:17 AM   #19
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Quote:
Originally posted by mr2guru
Only time will tell.

Are the pistons forged or cast? I know the ver8 2.0 sti has some cast AL pistons that uses a new casting technolgy that is "supposed" to be stronger. It is probably just cheaper. Anyway I know the syclone and typhoon guys have a lot of trouble with hypereutectic pistons not taking kindy to det. That is why many employ water injection. Pretty much eliminates det.

The 6spd should hold up great. The DCCD center diff is the weak link in all that.

Aren't the 2.5STi injectors supposed to be a bit smaller (I had heard) No matter what you still need enough fuel for 11s What is the availability of upgraded bottom feed injectors?

-Jim
good points,

as far as i know the STI pistons are forged and not cast. also, i have a few serious questions:

1) what are the options out there for bigger injectors?
2) will a stand alone ecu such as LINK will be able to work with the DBW? i have a link sitting at home and i am wondering if i should keep it.

TIA
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Old 05-27-2003, 12:47 AM   #20
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Sti uses side feed injectors. Not sure what is available yet.
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Old 05-27-2003, 12:49 AM   #21
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hi dan,

i wanted to call you today and talk to you about some things but it wasw memorial day. i need some help from poeple who actually know what they are talking about and since you got your STI i think that you can really help me out.
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Old 05-27-2003, 12:51 AM   #22
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also,

i noticed that BLITZ has some side feed injectors (880cc) that looks like it will bolt on to the sti
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Old 05-27-2003, 02:40 AM   #23
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Quote:
Originally posted by shirokuma

The other is displacement. In theory, and probably in practice, it simply has more overhead than the Evo. Yes, they are currently close in power, and yes the Evo can go higher, but they stroke Evo motors for a reason.
Cheers,

Paul Hansen
www.apexjapan.com
Do they use 4G64 cranks in Japan like they do here in the US? 4G64 plus a bit of overboring gets them a 2.4L, although a 2.4L with a horrindous rod ratio

Speaking of which, does anyone even know the rod length for the STi?

I'm willing to bet a STi could go 11s with intake/exhaust (no cat) and a boost controller. Maybe the injectors are a little small, just throw in way more octane than you need and crank up the boost.

2JZ-GTE pistons are hypereutectic, and they don't seem to mind det too much. But a lot of it has to do with engine management, and the Supra's ECU has good closed loop knock-control. Would anyone happen to know if Subaru's knock control scheme uses an amplitude-based system from the knock sensor (like many Nissan cars), or it does do a FFT on the signal (aka the non-sucky way, Supras have this) and listen for the right frequencies?
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Old 05-27-2003, 03:30 AM   #24
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Well, i'm thinking that once tuners crack the ECU it will end up being almost like VWs or Audis with the 1.8T or 2.7Bi-turbo with DBW that can be "chipped" rather easily for monster gains. Order the tuners ECU, put that in and send them yours to get the core charge back and voila! you have +50ft/lbs and HP for very cheap. We'll see though.....
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Old 05-27-2003, 06:47 AM   #25
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I must be having another brain fart here. What is "DBW"?
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