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Your answer to "I want 400whp" (or more?!)

231K views 156 replies 69 participants last post by  SubieEJ 
#1 · (Edited)
I see these posts on a weekly basis. We all do. Have you read these words before? If you know how to search and have done your research you have. You probably saw it in this thread:

Public Service Announcement. "I want 400whp!" Are you sure? - NASIOC

Much of the information below was taken from that thread, but it is still worth the read. I did plagiarize much of it, but the point here isn't for me to take credit for what is being said, it is to get the knowledge out there so you know what you are getting into.

But I figured it is time for IWSTI to have it's own, How do I get 400whp reliably, thread. While I did take some information from the thread above as it holds many truths, but I have also added much information from my own posts in the past. However, this thread will not concentrate on the, "are you sure you want 400whp" aspect. If you decided you want 400whp and you are willing to do what it takes and drop the money for it, then continue reading. I will warn you now, If you are not willing to budget AT LEAST $15,000 to do this the right way, stop reading now.

Is there more than one way to do this, sure there is. Will people disagree with me, I'm sure some will. But I feel I have responded to so many threads and I thought it was time to create a post that we can simply provide the link to someone when they ask this question. This is not the end all, be all threads about 400whp, but much of the information I will post will give you the general run of the mill and will either help you on your path or dissuade you from doing this build.

Step 1. 400whp is all relative to the dyno

The main problem with "I want 400whp," is.. on who's dyno do you want 400whp?

Stop concentrating on just one number of 400whp. What I am trying to say is you might make 500whp on one tuners dyno and then 300whp with the same set up on another. That is a bit of an exaggeration, but you get the idea. Final numbers mean nothing.

We have 2 local shops that work on Subarus and both happen to have low "heart breaker" Mustang Dynos that read very similar. Because most of the local cars are tuned on one of these 2 numbers, I tend to base a lot of what my thoughts of a true 400whp car is around these dynos.

Why do I base my thoughts on these dynos? Well, being that they read very low. If you make 400whp on one of these dynos, you will make 400whp+ on just about any other dyno.

Proof that they read low (yes, I am sure that there are other low reading dynos out there, but this is what I have to show you).

Our first example. This is a 2008 STI Stock tune vs a Stage 2 tune. Notice the stock tune is under 200whp. This is not the norm for many STI dyno charts out there. Many read, 220whp 240whp etc. Also the stage 2 setup is probably lower in HP that what you are usually used to seeing. So many people believe that they can get 300whp on a simple stage 2 setup. That may be true for a higher reading dyno, but not on such a dyno as seen below.


My 2nd example of, it depends on your dyno to know what kind of power you want. If you do a lot of reading on this forum, you will find out that a stage 2 car running meth injection and a protune usually nets around 330whp+ and near 400wtq.

Here is a chart of my car on a stage 2 tune, running 100% meth injection vs that same stock car. You can see the the gains and the curve is there, but nowhere near 400wtq. Why? It depends on the dyno. This setup would make 330whp/400wtq on a higher reading dynojet or similar dyno.


Big turbo build example.

Quoted from the owner
my 06 sti (same as the chart posted below)
3280lbs + me (220lbs) = 3500lbs
381 whp Innovative dyno. = 11.33 at 124mph

my drag car
2648lbs + me = 2868lbs
548whp Innovative dyno = 9.94 at 141mph with ã best mph of 142.

clear?
I personally have never seen any subaru go nines under 650whp from any other dyno..........which means.........?


One last example on a similar low reading dyno from another local shop. I call this a true 400whp car. This car is running a Dom 4 turbo or a GT35 stock location with all the supporting mods and a built engine. It is also pushing 29psi to reach this power. Many question whether even the built block on this motor would last at that PSI, but this is what the owner wanted.


So, once you know what dyno you are going to be tuned on, you can set your power goal. For my choice, I work with EFI logics in CT. I never had a 400whp goal set, but as luck would have it, that is near where I landed.

FWIW, I was also tuned on the same dyno from the first 3 dyno examples on a slightly different setup and netted 354whp.

Now that we have talked about the final numbers of a dyno meaning little to nothing; What is important here is your before and after charts. The difference between the lines. If you have the opportunity, get yourself a baseline before you go big turbo so you can see the difference.

here is an example from EFI logics of a Stage 2 setup vs a 30r setup on the exact same motor/car. You can clearly see the owner made gains going with a 30r over the stock turbo setup. The amount of HP you gain over your baseline is what is important, not the final number.






Step 2. You need to build the block.

So, many people argue this point. Well, so and so is running 450whp on his stock motor for XXXXX miles with no problems. Well, that is fantastic for them.

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.

Remember folks, this thread is about building a 400whp car to make it reliable.
Will a stock motor hold 400whp, yes. Is it a fact that it will blow up, I would say no. But I will say, you are living on the edge on the stock motor at that level. Some motors will last and others will fail. However, if you want to play it safe, stay below that number. If you chose to go above, be ready to build your motor, Period.

Will building the block make it bullet proof? Absolutely not. The idea is, you want to push a motor beyond the power range it was intended for. You can either push the stock block to the bleeding edge or you can build the block with stronger components to help deal with this higher power levels.

You can have the best of the best build you a motor and it can still fail as this this is the gamble you have when dealing with a modified car. The best you can do is build the block for the power level you have in mind and hope that it will last.

How much you chose to build the block is a discussion you should have with your tuner. Some higher horsepower options will require a more stout build block. Others may only need to install forged pistons. Most engine builders will give you an idea of what their block is capable in a safe range.

There are several reputable tuners/builders that come to mind that do build reliable blocks. A few worth mentioning that I have dealt with personally;

EFI Logics in Bethel CT
Innovative Tuning in Buffalo NY
Rallispec Hainsport NJ

I mention these because I have personal dealings with them and would vouch for their build skills. There are countless others out there you could also have for a built block, but I encourage you to do your own research.

Other shops worth mentioning from others in this thread that I have not dealt with;

CNC Engine Dynamics (Winchester, VA)
Cosworth
Crawford
Element Tuning (Gaithersburg, MD)
LIC motorsports (Novato, CA)
Maxwell Power (Marysville, WA)
P&L (Franklin Park, IL)
Topspeed (Alpharetta, GA)

At a minimum, I would encourage you to add forged pistons to a block if you are going for the described 400whp.





Step 3. Now, how do I get the described 400whp and what will it cost me?

I point you back to the, on what dyno do you want 400whp portion of this thread.

Many people always seem to chime in with a 20g or FPgreen build. There is nothing wrong with these builds, but unless you are going to build a car on e85 or meth injection, these turbos will not get you there unless you are on a really high reading dyno.

My point here, you take any "400whp 20g or FPgreen car" on pump gas and put it up against a 400whp 30r+ on any of these lower reading dynos. The 20g car is going to have it's a** handed to him.

As discussed before, if you want a 400whp car that will will read 400whp+ on most dynos including the heart breakers, you are going to have to at least start with a 30r. Even that alone will not get you there as demonstrated above. My car is built with 30r, built heads and cams and I am still falling just below 400whp on EFIs dyno.

There is a lot of good reading to be had here:
http://www.iwsti.com/forums/2-5-lit...rbo-thread-click-know-everything-30r-35r.html

Otherwise, there is no set guideline of what will get you to your power goals. The best advise is to speak with your tuner and to read what others have done in the power bragging forums. If there was a way to get to 400whp, someone else has already done it. These engines have now been around for >8 years. There have been many turbos proven to get to these power levels.

Im 99% sure you are not going to find or come up with some idea that someone else has not already tried.

Stick with what works.

That said, Below is a post created by TheLimitedProject and is one of the best "big turbo" guides on the forums. I take no credit below, but this is going to give you and idea of costs.
Newly updated, 03/03/10:
- I've again updated the spreadsheets to account for new or changed pricing, and to account for new kits that are now offered.

- Unfortunately, I think Full-Race was painted in an expensive light when they first came on the Subaru scene because of their presumed "high" pricing. However, the cattle on the forums didn't delve deeper into their pricing and realize that it included so much more than the regular, mediocre run of the mill kits on the market.

- Now, Full-Race has dropped their pricing. :tup: On top of that, as people will see below, for what you get (twinscroll, FR's manifold and UP, twin Tial 38mm MV-S WG's), for the bit extra that FR costs over the cheap kits (P&L, Perrin, Crawford) and the more well known kits (APS, UR, AMS) it's foolish IMO not to save a bit more and get the quality.

- I separated the 40R kits from the 35R kits. You can draw your own conclusions, but the UR singlescroll 40R "kit" is the biggest joke I've seen. I'm not sure if they made a mistake, but I'll give them the benefit of the doubt and say that they've mistakenly screwed up either the price, or what's offered at the price. Their twinscroll offering is expensive as well, and not near the quality (IMO) that Full-Race is.

- One last note: I didn't bother updating the small turbo kit pricing. It wasn't worth the time or effort. The conclusion of that spreadsheet still stands - starting from scratch, the price difference between a stock location turbo and a rotated setup is negligible. The various turbos are all priced in the same region (Blouch's new stuff, FP's stuff, ATP stuff...) so adjust accordingly.

Disclaimers:
1) What is below is MSRP website pricing. Everything is assuming you purchase it brand new from a vendor without getting a deal.

2) My bottom line for each turbo kit is an estimation. That isn't the final number. Discounts and sales will lower the cost, but the cost of tuning, miscellaneous costs, and unlisted hardware/tuning/hourly fees etc are not exact so that could and will raise the price.
- Sales, specials, shipping, tax etc is not factored in.
- Labour costs are an estimate, but some people would do it themselves, and others would rather have a shop do it. Add that cost in if it applies to you.

3) Each person will choose different parts manufacturers for things like intakes, intercoolers, BOV's, so I've taken a rough estimate of each part cost favoring towards the higher end products (ebay buyers will save a lot more than the prices I listed).

4) For the big turbo builds, top end motor work 'should' be done as well, but it's not a necessity. If applicable, add in the cost of cams, new valves, springs, retainers, head work, all block hardware etc, and labour to the cost (roughly $5,000-8,000 w/ install)










Things of note:
1) Stock mount turbos come in, on average, only around $715 cheaper than rotated mount kits, BUT add in the cost of an EWG setup, and the price difference in negligible. Therefore, the price difference between rotated mount turbos and stock mount turbos after adding everything is moot. It's a matter of preference and how much you want to gain from the setup.
- The reason most people believe staying stock mount is cheaper is because most people usually buy a TBE, intake and EM first. So, they look at having to buy a rotated DP and intake again and that adds to the cost.

2) I added in an estimated labor cost of 15 hours @ $90. That's an estimate so it could be a lot more or a lot less depending on how complicated the build is and if there are any problems.
I am not affiliated with any company. I made these spreadsheets on my own time while I was planning my build a couple of years ago, and have periodically updated them.

Hope this helps you guys spend your money wisely :)
Of course there are other ways to do it. My build for example which makes 392/345 on EFI's dyno. Note that this is not a 400whp on the heartbreaker dynos. I chose to go this route to have a decent reliable build, without too much lag. However, I am using it as an example in comparison to the above.

Note that this build did have a hiccup or 2 when it came to final tuning, but this is a pretty good idea of what it cost me to get my car to the current level. Also, much of the pricing does not apply any longer. I either had a good relationship with different shops, found really good deals on parts or the part pricing has gradually increased over time. Also note that some parts are very rare or impossible to come by now like all of the APS parts. There are replacements made by different companies that you could use.


Of course if you want someone to build this car for you, you will also be paying labor. I paid labor on some portions that I could not do myself like machine work, building the heads, building the block and tuning. Otherwise, the portions of the build were completed by a shop and I did all the assembly work, pulling the engine and everything else I could do in my garage to save money.

My final word of advise in this step that has been repeated over and over, but still holds true;

Cheap, Fast, Reliable. Pick 2.






Step 4. Get a good tuner

This is probably the most important of all the steps. You can purchase the best parts in the world, but they will be worth nothing unless you have a tune to make them run well together.

Again, your tuner can help you chose the best parts for your build and parts that they prefer to tune. I have had 2 different tuners tell me to get 2 completely different intakes to achieve the same goal. It is a matter of what they feel works best together.

As with everything else, Do your research. Many tuners that have a good reputation are mention on here, Nasioc or your local forums. Most good tuners don't always advertise as they do not have to. Their tunes speak for themselves and their reputation is based on word of mouth.

Speak to others that have a build similar to what you want and their experiences with different tuners.




Edit Step 5. What if I want more than 400whp?

All of the above still applies. A few changes would get you there depending on your power level of choice. A larger turbo would be needed and the supporting mods such as matched injectors. But otherwise, everything else still applies.

Of course the higher in HP you go, the more of a gamble it can becomes with parts failing and things going wrong as more power = more stress. Building the block to handle these power ranges will come more into play. Building and appropriate block again can be discussed with your tuner to handle the stresses of a high horsepower build






Optional #6. Is the STI the best platform for building a high horsepower car?

My answer to this is no. There are much better platforms out there to build a high horsepower car. Many of us build our car because we love it. I know that putting the same money into another car would far surpass the STI's power capability.

If you wanted to stick with AWD turbo 4cyl, there is always the Evo. IMO, this is a much better platform for making horsepower easily. The Evo's engine responds much better to modifications and will always make more power vs the STI mod for mod.

Also consider any v8 options. As with the STI you are dealing with a 2.5l 4cyl. Adding a turbo to an already more stout v8 would get you better gains with minimal boost. Just as a referense, my father in law runs a 2006 Charger R/T that is supercharged. On as little as 6psi on his stock motor, his motor still makes similar power to my completely built STI engine. However, being faster than I is another story :devil:

Of course much of this is opinion, however this is opinion based on my 6 years of experience with my STI. I have had several ups and some very hard disappointments down my modding road. The STI was my first performance car and my first heavily modded car. If I could do it all over again, I would, but would use much of the knowledge I have posted to build the car right the first time as not to waste money and time.

Most, if not everything I know, I attribute to members on this forum, Nasioc, my local forum and dealing with reputable tuners. I take little credit for what is posted above. I merely put it all into one post to have an definitve answer to give to someone when they ask how to get 400whp.

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

My special thanks to:
Defiant Autospeed - on Nasioc
EFI Logics
Innovative Tuning
TheLimitedProject
 
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#46 ·
I can understand 350whp on a low reading dyno, but remember, the number is just a guideline, not an absolute. You can reach 400bhp or crank HP very quickly with these cars.

FWIW, my motor was at 346whp on that low reading mustang dyno when it blew a ringland. It was either a meth leak that caused me to run lean or the stock motor just couldnt take any more.

Regardless, I knew the motor would go eventually, so it wasnt a huge shock. I have yet to get back on that same dyno, but play to this spring/summer to compare. I estimate I am in the 350-360whp on that dyno now.
 
#58 ·
Best way is to get forged pistons, bigger turbo, FMIC, or bigger TMIC at least 850cc injectors, 255 or greater fuel pump, Cobb ap, full 3" exauhst and meth. I have a boy that got over 450whp with this setup with no meth but ran e85 on id1000 injectors and twin walbros. I also have another boy that ran a stock block with the above setup and on 91 ran 398whp and with c16 hit 498whp.
 
#59 ·
So I have a 2002 WRX. As of right now I have a built PPG transmission and 300whp on my Ej205. I am getting ready to get CNC Engine Dynamics build my Ej257 block to handle 450chp. In terms of mods I already have is: 255 walbro FP, 1000cc DW Injectors, FMIC, UTEC EM, Ported Exhaust Manifold, Rotated Precision 5031 Turbo, Tial 44mm EWG, Perrin EBCS, Catless exhaust. I think thats it. I will be porting my WRX heads, 272 cams and stock valves and springs with ARP headstuds. As far as my block goes, I will be putting new oil and water pumps on, Forged Wiseco 99.5mm stock bore pistons, Eagle Forged Rods, ACL bearings and full block treatment with Gates timing belt and accessories. I should be fine for 450. Maybe not with the turbo I have not but with a 30R, I should be fine
 
#61 ·
great write up by reading this i just answered my own damn question... i have a full 30r kit but i was gonna toss it and get a 20g twin scroll...not anymore. Thank you! btw this is my first subie. 2011 stock block stock turbo made 350whp and 404ftlbs on e85. i guess im running on the edge.. but it is a dynojet.
 
#62 ·
Hey, some of you have come across a few of my posts last week and know that i just purchased an 06 stage 2 set up (to my knowledge - turbo back / intake / AP ) on my AP on a s2 93oct i produce 315-350 hp (hoping to have it dyno next monday) and on stu i've only tested once @ 381hp

are these accurate measurements w/ a stage 2 set up, or do i need to look further into the car to find other mods (i haven't had it on a lift yet to inspect the under body)
 
#64 ·
Using the AP for accurate numbers is horrible. There are too many variables that mess with the results.
 
#69 ·
Stage 2 mods + Injectors, Fuel Pump, EWG, EBCS should be pretty close.
 
#79 ·
Before I installed my EL hears and up pipe, I hit 370 hp on my buddies mustang dyno. I was a lil upset, lol. Then after header install I was right at 400 with airboys spreadsheet. I'm expecting if I go back and do another few run on the dyno I will still be dissapointed not hitting my mark. I am extremely happy with my tune and the car is crazy fast but that mental block of not hitting 400 on that particular dyno will probably drive me crazy. My numbers off the virtual are in the mid 550s LOL!
 
#80 ·
Try not to let it bug you. Throwdown at the strip and get a nice 60', 1/4, and trap speed. You'll have the bragging rights you need. ;)
 
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#82 ·
Nothing had been mentioned about E85. Since lots of people don't have access to it, I still think of 93oct as being the top fuel choice unless specified in post.
 
#83 ·
Again, the only way to 400whp is with injectors 850cc or greater at least a 255lph fuel pump, higher flowing intercooler, boost controller or 3 port boost solinoid, BIGGER turbo (fp-green up to 35r your choice between stock location or rotated) intake, turbo back exauhst, a Cobb ap or open source. This will put you between 380-420whp. Add some 50/50 meth and you'll be close to 500whp.
Don't forget to upgrade your clutch.
 
#84 ·
...he wanted 300whp.

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#89 ·
Thank you. I am definitely looking for better sound, so I hope that CBE helps a bit. I was looking at the suspension, as well. Any insight as to whether it's worth upgrading their suspension with SPT parts?

Also, how careful do I have to be upgrading an engine with 39k on it, if I decide to go outside of the warranty? I am just curious as to how much I can really do without jeopardizing having to dump large amounts of money into this car right away. I haven't owned a sports car since I was 18, so I am a born again virgin when it comes to performance parts...:)
 
#90 ·
The catback is not going to gain you anything that's very noticeable other than sound. You would need to change downpipes and a tune. Also the SPT intake isn't going to net you anything beneficial unless you tune for it.
 
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