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Old 11-23-2007, 01:46 PM   #1
Defiant Autospeed
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Default Public Service Announcement. "I want 400whp!" Are you sure?

I see these posts on a weekly basis. We all do. It always makes me feel really aprehensive (sp?) when I read it. So I just wanted to put this out there for those that are asking this question.


Are you relatively new to the Subaru thing? Have you ever owned a TRUELY high performance import before? Have you ever owned any HIGH powered car before? Do you have fairly deep pockets?

If you say no to any or all of the above, then I beg you, please read on.


Many many times people have come into the Newbie forum and made the statement "My goal is 400whp" and they almost always JUST got the car.

It needs to be said, and anyone wanting 400whp needs to understand that 400whp is a LOT of power, and it takes a LOT to get there, and even more to do it reliably.

What will get you there?
Well, that depends on the dyno and tuner, along with how agressively you tune it. Dynos read differently and what makes 400whp on one dyny will make 450 on another, an 340 on yet others. Do you want 400whp on your local high reading dyno? Or do you want a TRUE 400whp that will make 400whp on almost any dyno out there?

In general you can hit 400whp on pump gas with something like (this is speaking of a 2.5L motor)

FP green turbocharger (this is larger than a 20G, its a 20G with a 49lb wheel)
Intake (GOOD intake, there are a few)
Front mount intercooler
Injectors
Pump
turboback exhaust. Catless prefered for this turbo and power goal. 3" would definately be recommended but 2.5 wouldnt hold it back much if at all.
Headers or P&P manifold and better crossover pipe.
Larger/better up pipe Definately recommended.

Custom tune obviously, and to hit 400whp you will likely need 24+PSI.
If you run alcohol injection you will get there easier and safer at a little lower boost. This setup will not reach 400whp on all dynos, but it will get you there on most.



Or, and this would MUCH more easily hit 400whp, and on many more dynos. I consider this a "true" 400whp setup.

GT30R rotated mount turbo kit
Front mount intercooler
Header to go with whatever up pipe that setup uses, even better if they make a header specifically for their rotated kit.
Injectors
fuel pump
Intake (this will be part of the rotated kit most likely)
Custom tune obviously. If you are looking for meat and burger deals, check out Albertsons Ad this week.

Alcohol injection, again would allow lower boost/safer tune to hit 400whp, but this setup shouldnt have any problems hitting 400whp on pump gas by itself. Well over 400whp on race gas, I have seen 500whp on this setup with race gas on a semi high reading dyno.


So great, now you have 400whp.
Lets look at what the hidden costs are.

Clutch- Stock wont last long for 95% of people with this much power.
Flywheel- most do a light flywheel when they do a clutch. You may or may not.
Motor mounts are HIGHLY recommended at this point. Thats a lot of TQing around that the motor will be doing. The stock mounts were designed to hold a 300chp/300ctq motor still and keep noise at a reasonable level. If you are putting 400 to the WHEELS you are easily at 475 crank hp. Over 50% past what the stock mounts were made to handle.

Then lets look at the reliability limit of the stock motor.
400whp has been, since 2004 when the 2.5 came out shown itself to be the reliability limit of the stock pistons/rings. The rule of thumb is, upgrade the turbo, plan on a new shortblock. On something like a 20G or larger, at 20+PSI boost, its no longer a matter of IF, but when. There are of course some rare cases where someone makes 400whp for 50k+ miles, but believe me when I say this, that is RARE. Many with a good tune blow up well below 400whp. Best case scenario, pull the motor out and do pistons before you even install your 400whp setup. The crank/rods should be fine at this power level. Even so, doing a set of pistons can be a close to or just over $2000 investment, depending on what pistons and installer you use. Plan on at least $1500 to get some good forged pistons into your motor. Remember you will be paying for a full gasket kit, and with the motor apart a new timing belt and water pump is never a bad idea. Figure in oil and a filter as well. Small cost parts, but it adds up very quickly.

Then lets look at the safety aspect. 400whp is a LOT of power. In the hands of an unexperienced driver, it is quite litterally a deadly amount of power, especially so in an AWD car that can put the power down. 400whp in a RWD car is one thing, stomp on the gas at 40mph and you get massive wheelspin. Do it in an AWD car and you get hard acceleration. Are you experienced enough? The answer is in almost every case, no. Why? Lets use an example.

You are doing 65mph on the highway in a stock STI, or even light mods. You want to pass someone. Most will pass at roughly 85mph to get around that person. So you give it X amount of throttle, you dont look at the speedo because you have done it a million times, and you accelerate to 85mph.
Now lets swap that out for a 400whp car.
You are doing 65mph, you apply the same amount of throttle to do it, you are VERY quickly doing 90mph, you feel how hard it pulls so you back off a bit, but its all relative and even though it doesnt feel like its pulling as hard, its still pulling harder than it was when stock/lightly modded. You are doing well over 100mph by the time you get around that car.
Now someone comes over into your lane forcing you to turn and go around them while braking HARD. This is a delicate move.

Or, you decide you want to do a hard long pull. The kind that we all love, that puts a big dumb grin on our faces from feeling the seat pushing into our backs. You would have previously made it up to maybe 100-110mph.
So you are in the same place, same stretch of road. You do it again. Now you are doing 140 where you would have been doing 100. Go ahead, hit a bump at 140mph, and see how it feels. What was a "whump" at 100mph can quite litterally throw a 140mph vehicle into the air.

Your STI is a high performance vehicle that can handle high speeds and save your butt from a lot of dumb moves, but its not magic. AWD and the yaw sensors and such can only do so much, they arent miracle workers.

And if not for your own safety, think about what happens if you are doing the kinds of speeds you will EASILY hit with this kind of power and you hit another vehicle.


You may say "yeah but I wont do that kind of thing" That is all well and good, but the reality is that the more power you have, the more often you will drive at higher speeds than you did at the lower power level. I dont care who you are, its an almost 100% chance.





So lets review.

Do you REALLY know what this power goal will end up costing you?
Are you prepared to spend that kind of money?
Are you a good enough driver to handle that kind of power?

Have you even driven a 350whp STI?




My advice to those with a stock/lightly modded (like AP stage 2) STI/WRX, would be to take it in smaller steps. Most of the people I have met that wanted 400whp, were scared out of their mind when I took them out in a 330whp subby. Heck my 309whp 2.0Lwrx scared a lot of them.
Do this if you have a "stage 2" car (make sure you have these parts)

Custom tune. A GOOD custom tune. Do research before you pick a tuner. just because they own a shop doesnt make them good.
Full exh.
FMIC
20G@20PSI
injectors and pump.

Because that will be as much or more than 90% of people here will ever want or need. If you want more, drive that around for 6 months to get a handle on what the power is like.

if you are bone stock,
Do this.

Full exh
GOOD custom tune


Of course much of this is opinion, however this is opinion coming from 18+ years of driving, 15+ of those in high powered cars, 10 years of import scene and tuning experience and 5 years of Subaru specific tuning/driving and really importantly in this case, Meeting and speaking to people on Nasioc. So I like to think that it holds SOME truth to it at least

Opinion or not, I assure you the message behind it holds true and you should really take it all to heart if 400whp is your true goal.

Last edited by Defiant Autospeed; 10-18-2009 at 12:43 PM.
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Old 11-23-2007, 02:34 PM   #2
silentt
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How do I get 400whp on my 2.5i? Will STi turbo get me there?





Good post.
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Old 07-01-2016, 07:31 PM   #3
Deweyd86
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Default 400 hp...

Quote:
Originally Posted by silentt View Post
How do I get 400whp on my 2.5i? Will STi turbo get me there?





Good post.
I can tell you that an STI turbo will not get you to 400 hp, you need injectors forged Pistons, exhaust, preferably a FMIC, intake, and a good tune, probably a even bigger turbo like an blouche 1.5x
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Old 09-22-2016, 02:53 AM   #4
JBones81
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Wow, been reading thru this thread - The reliability stuff is probably spot-on, but I have to question the advice concerning using the power.

I've had many high HP cars, but most were RWD (Mustangs, Corvettes, Camaro, Supra TT). The only 2 AWD fast cars for me have been an 06 EVO IX and 12 WRX - both had minor mods only, so, surely no more than 300whp for either one. Both were obviously very easy to keep in a straight line.

Logic would seem to indicate that if I was able to avoid the pitfalls that come with having tons of power on tap in my RWD cars, I should be ok with 350-400whp in an STi...however, I have never driven an AWD car at that power level, so I can't say.

My question is whether I really should expect to be happy with my realistic goal of 320-350whp in my STi, given that I've owned several 11 sec RWD cars - is 350ish whp, but to all 4 wheels, really that amazing?
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Old 11-23-2007, 02:34 PM   #5
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Cliff notes please?
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Old 11-23-2007, 02:35 PM   #6
silentt
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Quote:
Originally Posted by stkbox View Post
Cliff notes please?
CN: Your VF39 COBB'd bugeye isn't 400whp.
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Old 11-23-2007, 02:43 PM   #7
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That is a great message for the ppl like me that have never driven a high hp car before.
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Old 11-23-2007, 03:00 PM   #8
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Quote:
Originally Posted by Ceez3607 View Post
That is a great message for the ppl like me that have never driven a high hp car before.
A 500HP car with MT racing slicks on a RWD car will almost leave a mess in your pants when you go WOT as the tires mushroom and the ass end raises up and the car slows down at 40MPH because the tires are spinning when you drop the hammer. Now imagine putting the down to 4 wheels, you'll break them them loose but (maybe not at 40) but I hope your harnessed in. Power to the ground is unreal.
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Old 11-23-2007, 03:32 PM   #9
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Quote:
Originally Posted by 4ST-AIR View Post
A 500HP car with MT racing slicks on a RWD car will almost leave a mess in your pants when you go WOT as the tires mushroom and the ass end raises up and the car slows down at 40MPH because the tires are spinning when you drop the hammer. Now imagine putting the down to 4 wheels, you'll break them them loose but (maybe not at 40) but I hope your harnessed in. Power to the ground is unreal.
I would love to take a ride in one tho.
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Old 07-01-2016, 07:37 PM   #10
Deweyd86
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Default Mess in your pants

Quote:
Originally Posted by 4ST-AIR View Post
A 500HP car with MT racing slicks on a RWD car will almost leave a mess in your pants when you go WOT as the tires mushroom and the ass end raises up and the car slows down at 40MPH because the tires are spinning when you drop the hammer. Now imagine putting the down to 4 wheels, you'll break them them loose but (maybe not at 40) but I hope your harnessed in. Power to the ground is unreal.
Now that would be funny... But not really accurate, it takes over 2000 hp to stand straight up on race slicks
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Old 12-29-2019, 03:54 PM   #11
BackinBlue
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Default

Quote:
Originally Posted by 4ST-AIR View Post
A 500HP car with MT racing slicks on a RWD car will almost leave a mess in your pants when you go WOT as the tires mushroom and the ass end raises up and the car slows down at 40MPH because the tires are spinning when you drop the hammer. Now imagine putting the down to 4 wheels, you'll break them them loose but (maybe not at 40) but I hope your harnessed in. Power to the ground is unreal.
Sounds like what I am looking for.
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Old 11-23-2007, 02:52 PM   #12
Chino Bling
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very nice write up.
i get so sick and tired of hearing people say "my goal is 400+ whp." what does anyone really need that much power on the street? my goal is to have a fun car to drive. and i'd say my car is a lot of fun to drive, and i dont make anywhere near 400whp.
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Old 01-05-2014, 07:02 PM   #13
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Quote:
Originally Posted by Chino Bling View Post
very nice write up.
i get so sick and tired of hearing people say "my goal is 400+ whp." what does anyone really need that much power on the street? my goal is to have a fun car to drive. and i'd say my car is a lot of fun to drive, and i don't make anywhere near 400whp.
+1 i agree 100% man, i'm going to stick with the bread and butter of any scooby mods and that's the exhaust. I got an access port coming in the mail as well. But i defiantly don't plan on 400 plus WHP.
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Old 10-20-2019, 03:50 PM   #14
zyinc
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Default

Quote:
Originally Posted by Chino Bling View Post
very nice write up.
i get so sick and tired of hearing people say "my goal is 400+ whp." what does anyone really need that much power on the street? my goal is to have a fun car to drive. and i'd say my car is a lot of fun to drive, and i dont make anywhere near 400whp.
Everyone has different goals , Imagine how boring the world would be if they had the same goals or same desires as you . Yes I want 400+ whp , I don’t need to give you a reason why it’s what I want it’s my goal .
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Old 10-22-2019, 07:30 AM   #15
bdubblu
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Quote:
Originally Posted by zyinc View Post
Everyone has different goals , Imagine how boring the world would be if they had the same goals or same desires as you . Yes I want 400+ whp , I don’t need to give you a reason why it’s what I want it’s my goal .


Not only that, but my SL55 is the reason I need 650 ft.lbs. on the street.
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Old 03-08-2022, 02:26 PM   #16
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Quote:
Originally Posted by Chino Bling View Post
very nice write up.
i get so sick and tired of hearing people say "my goal is 400+ whp." what does anyone really need that much power on the street? my goal is to have a fun car to drive. and i'd say my car is a lot of fun to drive, and i dont make anywhere near 400whp.
Agreed. I've driven a lot of beater cars and some nice cars. I've had the pleasure of having a 2011 WRX for 10 years. I've taken some professional driving instruction (not racing) and that professional instruction increased the fun more than any HP could. I've been hard pressed to find a car that is more fun for the money.
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Old 03-08-2022, 02:48 PM   #17
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Quote:
Originally Posted by patriot325 View Post
Agreed. I've driven a lot of beater cars and some nice cars. I've had the pleasure of having a 2011 WRX for 10 years. I've taken some professional driving instruction (not racing) and that professional instruction increased the fun more than any HP could. I've been hard pressed to find a car that is more fun for the money.
An old saying goes "It's more fun to drive a "slow" car fast than a fast car slow"

my brz was the most fun car to drive I've owned but it was absolutely the slowest
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Old 11-23-2007, 02:53 PM   #18
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+1 Defiant Awesome needs to be a Sticky!!!

I can tell you right now as I am Having P&L build my 400-420WHP car what it is taking and I still will have a few things such as headers, up and Spearco 1000CFM TMIC before I really see the cars potential. The AXIS Stage 3 shortblock and all supporting mods plus the ones I have done already I am already well over the $10,000 mark on a car I have only had since April and 2 months othat time its been down going on 3 month now. But I am going there taking the route that will last. Your right I know guys that drop the URGT35R package on and are making 430WHP for like $5000 but for how long? I have been through 2 OEM STI engines just on COBB Stage 2 and a tune.

Again nice writeup looks like you have been wanting to say this for awhile.

Dan
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Old 11-23-2007, 02:57 PM   #19
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Quote:
Originally Posted by 4ST-AIR View Post
I have been through 2 OEM STI engines just on COBB Stage 2 and a tune.
Get a new tuner ASAP. COBB OTS maps are safer than your tuner's...
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Old 11-23-2007, 03:03 PM   #20
4ST-AIR
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Quote:
Originally Posted by silentt View Post
Get a new tuner ASAP. COBB OTS maps are safer than your tuner's...
Are you high? Do you even know what you just said?

I am pretty sure the first tuner and rightfully so is going to tear your ass a new one when they get in here. My tuner just happens to be one of the best tuners in the Mid West.

P&L Motorsports FTW!
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Old 11-23-2007, 03:17 PM   #21
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Quote:
Originally Posted by 4ST-AIR View Post
Are you high? Do you even know what you just said?

I am pretty sure the first tuner and rightfully so is going to tear your ass a new one when they get in here. My tuner just happens to be one of the best tuners in the Mid West.

P&L Motorsports FTW!

LOL.. Too funny.
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Old 02-08-2010, 01:23 PM   #22
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This is good stuff
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Old 02-08-2010, 01:26 PM   #23
TheWReXDr
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OMGHi2U

Quote:
Originally Posted by 4ST-AIR View Post
Are you high? Do you even know what you just said?

I am pretty sure the first tuner and rightfully so is going to tear your ass a new one when they get in here. My tuner just happens to be one of the best tuners in the Mid West.

P&L Motorsports FTW!

I agree, the tuner had nothing to do with it.... probably more the driver's fault
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Old 02-12-2010, 10:43 AM   #24
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Thank you for this well needed post, hopefully it won't fall on deaf ears. I'm one of those that my '09 WRX is my first car that has anny kind of power (had a '08 Focus before my WRX :P ) I had the opportunity to drive a friend's STI that is putting down almost 400 whp on his street map, without even getting on the throttle much it would still throw you back in the seat without hesitation. That is something that I wouldn't mind working up to, but definitely see the benefit of a performance driving course and leaving the really fun driving for the track
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Old 11-08-2009, 04:37 PM   #25
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Quote:
Originally Posted by silentt View Post
Get a new tuner ASAP. COBB OTS maps are safer than your tuner's...
im still at this
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