I understand this is not reliable with stock engine as pistons go bad. What can I do to maintain this? It is tuned for a daily driver and I do not plan on pushing it to its limits very often. Rebuilding the engine is way out of my budget, however I may be interested in replacing it with forged pistons. What could potentially go wrong other than pistons wearing out? How much would that cost?
Im a bit confused, do you already have a WRX tuned for 400 WHP? or are you thinking that you want to set a target for your tuning? Maintenance on a 400 WHP EJ is similar to maintenance on any other high powered engine. You should increase your oil change intervals, service your brakes and inspect your suspension parts more often, and monitor the health of your engine with real time computer monitoring and used oil analysis. You will need to keep an eye on your transmission and change trans fluids more often and I would reccommend swapping for a stronger 6MT transmission or re-gearing your 5MT with hardened gears. You might as well add a set of blast plates to your transmission case as well to keep the gears meshing properly. While were on the topic of transmission your OE clutch will likley not be able to hold down 400 WHP, there are a few companies out there tht make staged clutches, a stage 1 or 2 exceedy clutch should hold down that power without being entirely undrivable in bumper to bumper traffic.
Its really a bigger issue than just the pistons not being built to handle that kind of power, yes the piston ringlands are a bit brittle but so are the rodas, bearings, oiling system, springs, valves and timing system when you get up into those numbers. Add to that, the Ej205 block was never designed to handle that kind of WHP output. If Im not mistaken you should be somewhere in the low 200s to the wheels with the stock engine.
If you are looking to make that kind of power you are better off picking up a performance closed deck 207 block. To get to 400 your looking at essentially replacing the whole engine and every engine component with performance parts. Then you will need to add a considerable amount of extra boost, lets say 23-24 lbs and fuel to feed the new engine so a new fueling system, new fuel rails and injectors would be in order.
Honestly if you dont have the budget for a complete rebuild or the money to buy a new car when your build fails you dont have the budget for 400 WHP on your 2007 WRX.
Why, might I ask are you shooting for 400 WHP? Are you entering a competition where 400 WHP is the limit or are you just looking to say you have 400 WHP? The supporting components for a 400 WHP build make them rather poor as dialy drivers, Stiffer clutch, poor fuel economy and uncomfortable ride all add up to a great track car but not so much a drive around town car.
You are totally right, 07 is 255, the rest of the statement stands. Even with a slightly higher stock output and a few other revisions its still effectivly attempting to double the power output and thats expensive.
Sorry for not being clear, I'm looking into buying a 400hp wrx. Just a bit concerned about the reliability with the stock motor especially as a daily driver. I'm thinking just stick with a low tune and work my way into a rebuild while carefully maintaining motor and trans.
You are totally right, 07 is 255, the rest of the statement stands. Even with a slightly higher stock output and a few other revisions its still effectivly attempting to double the power output and thats expensive.
Honestly, If you dont have the money to buy a complete engine dont drive around a car with a tuned engine. Your best bet is to find a stock example or mostly stock example with all its maintenance paperwork. Thats not going to be a bargain basement WRX and quite frankly you dont want a "Cheap" WRX that someone claims to be putting down "400 HP Bro". The examples of well built 400 WHP Subarus will cost you as much or more than a new WRX because they have years of tuning and care put into them and they are often sold as track cars.
Contrary to the common knowledge WRXs/STis are not cheap fast cars. There is no such thing as a cheap fast reliable car, there is an old adage Cheap Fast Reliable, pick 2.
there is nothing wrong with buying a 400hp subie... people play the lottery every day lol
all jokes aside, its pretty much rolling the dice. its possible you could have a well built subie that was put together by pros, but that is also a good chance it was put together in a backyard by by a monkey with no wrench or tuning experience.
its literally rolling the dice. you got about a 50/50 shot of tossing all your money down the toilet.
take a real good look at it by an independent subaru specialist (not a dealership), and possibly ask if you can get tuning logs, or ask to do some yourself. you really need to do homework if your buying a pre-modded subaru.
there is nothing wrong with buying a 400hp subie... people play the lottery every day lol
all jokes aside, its pretty much rolling the dice. its possible you could have a well built subie that was put together by pros, but that is also a good chance it was put together in a backyard by by a monkey with no wrench or tuning experience.
its literally rolling the dice. you got about a 50/50 shot of tossing all your money down the toilet.
take a real good look at it by an independent subaru specialist (not a dealership), and possibly ask if you can get tuning logs, or ask to do some yourself. you really need to do homework if your buying a pre-modded subaru.
unless the seller has has reciepts, and work orders for all the stuff done, there is really no way of telling who did the work. and as for the engine, it needs to be driven and data logs need to be re-corded in order to see the tune and see if is healthy.
honestly if i was buying a modded subaru, that would be one thing i would demand is datalogs.
your best bet is buying a rust-free stock wrx (or even just a clean shell), and build up your own. that why you know whats been done and whos done the work.
1) A person has a correctly built 400whp WRX and wants to sell it: There is no way in hell they'd sell it to somebody who's never owned one before because in the process of building it correctly, they've spent tens of thousands of dollars and talked to hundreds of Subaru nerds along the way who know what it is and what it's worth.
2) It's not a correctly built 400whp WRX but the owner says it is and wants to unload it on a poor unsuspecting sap. It's not a "roll of the dice", it's passing around a lit M-80 and seeing who holds onto it long enough to blow off their fingers.
Oh and if you did buy #1, not only would it cost more than a new one it would also break in <10k miles and require a new engine with like... 85% probability.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Subaru WRX Forum
329.6K posts
38.3K members
Since 2002
We're a forum community dedicated to the Subaru WRX. Come join the discussion on performance modifications, accessories, turbo upgrades, maintenance and more!