[TheLimitedProject]

Okay guys, here it goes. I generally don't like threads like these, but it'd really help to get some opinions from guys who've done medium to big builds on their STI's.

Here's the obligatory power mod background:

Daily Driven 2007 STI:
Cobb AP
GT52 turbo
Perrin Water/Meth Injection kit
FMIC
Cobb catted TBE
APS 70mm CAI
Perrin Inlet
CF DS

I estimate pump gas power (91octane) will be in the mid to high 300's (~350-380WHP) at 19-20PSI. From what I've read, I estimate power on pump/meth will be in the low to mid 400's (~400-450WHP) probably tuned for around 23-24PSI.

Now the dilemma is whether or not I want to pull my motor, crack it open, and put in forged rods and pistons. I know I'm right on the edge of having too much power for the stock motor to take. Just reading fastcb's journal shows that you don't even need crazy amounts of horsepower to blow your pistons.

So, I need advice. I have confidence that all the parts will be installed perfectly and that the tune will be very, very good. So, those two things aside, is it really necessary to go that extra step and spend huge amounts on labour and parts to upgrade my block?

Marginal benefit... marginal cost. There's got to be a smart answer here, and I'm hoping the guys with more experience in this department will chime in.

Thanks for the help.

[WESTI]

is this your daily driver? if you can afford to just let the motor blow and have the car down for months while the motor is being built, then let it ride and wait for the motor to go. If you cant afford to have the car down for long periods of time, get it built now. Or if you like to gamble, you could just stick to the stock block

[TheLimitedProject]

^Daily driver (edited my first post). Months out would be a sad, sad thing.

[WESTI]

well you could just buy a beater car for a couple grand..... but if you go on the stock block, its a gamble. The motor may last a few thousand miles or 10s of thousands of miles depending on how you drive. If you can afford it, id say just build it up now. Whats the point of waiting until the engine blows randomly one day and then having to have a shop totally rebuild you a motor?

[KiR DieseL]

As i think many guys here will tell you....

Build the block

[mxpop]

with a safe/smart tune and smart driving, you should be fine, but you will be near the edge...

I say, let it blow and then do a motor or be getting one ready in the meantime.

[scott's06]

Why not take it easy on your car for now and buy a stage 1 block with internals, this way when your block does give u can transfer parts over to the new block and drop it in.

[Black_Sun]

Your fine man.... My last STi had the APS DR 65 running 26 lbs of boost at 470 WHP with no problems. This was my daily driver. Not the best daily driver due to when she made power, but none the less, drivable... Its all in the tuning.... Go with a HYDRA, or a good tune with ECUtek.....Hope all goes well man!

[Boxer]

It depends more on the tune and how you drive it. Even a built motor will develop problems if those two items are of poor quality. Some members here, and on other forums, have had the stock motor last well beyond what they expected, even with 500+whp.

[crystal_Imprezav]

Upgrade it, its not worth the pain and suffering later not to mention the potential for damaging parts. ARFabrication.com Racesleeves.com FTW

[RacerXS]

Take your time & build a block, this gives you time to do it right & does not hurt too bad financially all at once. Mine lasted 34K with similar mods & that is the path I took. The car is in right now having the block installed.
The main thing you have to worry about doing this is the motor grenading & taking out more expensive components like heads & turbo, so keep your fingure on the pulse....so to say.

[T3h_Clap]

go pick up a STi short block from subaru for $1500, and build that.

then pull your stock motor in it's healthy condition, that way you have a spare.

and spare parts

[spazegun2213]

Dude, you should talk to phil. Last time i heard, he ONLY has forged pistons and he rags the crap out of his car on track and has never had a problem. I've yet to hear or see him have ANY motor problems in the new car running even his 65 kit.

I'd say if on the street you use a lower boost more conservative map you'll be just fine.

[Tortfeasor STi]

Heh, I know the highly modded daily driver game. I blew the engine on my last car, not by bad tuning, not by beating on it, but simply because cylinder pressure was too high and it eventually defeated my piston rings' ability to seal the combustion chambers.

With your build you will be on the raggedy edge. With a proper tune and proper monitoring it SHOULD be fine. But that is no guarantee that it will be. I think the real answer to your question will be whether you can put off the build up until you have a short block set up to receive the swap. If you can wait, I would suggest ordering a built block and heads and having the whole shebang installed and tuned at once.

[stiscooby]

Just my opinion, use the stock motor. You have to remember that there are sti's out there that are running in the 500+ ranged with stock everything! thats impressive. Stock internals and still on stock clutch? cool. Also, you have an 07. Why are you worrying about blowing up? Are you driving 150 everywhere you go? Do you drive like an idiot 99% of the time? If so, maybe a new block is in your future. If you can keep it chill and get on it at the right times, then you are golden. If you need some help, talk to some tuners. I recommend Scott Siegel in Georiga if you have some deep questions. I think he is a great guy and he is tuning my new setup next week. Then, im driving up with him to robeling in Savannah. Anyway.