2 questions that need an answerin' to

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Mar 25, 2003 | 09:38 PM

Jimi Dixon

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2 questions that need an answerin' to

Hello.
I have a 2001 2.5 RS and once i save up the dinero i plan to turbo it

. I know enough to know that i need to do a vast amount of research, and i was hoping someone could help and answer these 2 simple questions:

-What is the maximum boost on the stock internals on the EJ25?

-After doing some searching i came across the phrase "closing the deck". Just wondering what that means.

Mar 30, 2003 | 10:27 PM

hayscoob

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Joined: Nov 2002

Posts: 336

From: North Idaho it's c-c-c-c-cold!

Car Info: 2002 WRB WRX / 06 f150 King Ranch

here is a pic of an open deck block. Notice cylinder seems to float in the middle of the block space...

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2 questions that need an answerin' to-opendeck.jpg

Mar 30, 2003 | 10:30 PM

hayscoob

Registered User

Joined: Nov 2002

Posts: 336

From: North Idaho it's c-c-c-c-cold!

Car Info: 2002 WRB WRX / 06 f150 King Ranch

Here is a pic of a semi closed deck. The cylinder is now supported at several points to help stabilize it durring super high boost pressure. This is told to help the cylinder not squirm durring operation at high boost.

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2 questions that need an answerin' to-semiclosed.jpg

Mar 30, 2003 | 10:37 PM

hayscoob

Registered User

Joined: Nov 2002

Posts: 336

From: North Idaho it's c-c-c-c-cold!

Car Info: 2002 WRB WRX / 06 f150 King Ranch

As far as boost pressure on a stock block... Well it's like asking how many licks does it take to get the middle of a Tootsi Roll Pop? In my estimation and after fussing with my own set up, I found that with NO electronics/fuel and timing computer, not much boost is needed to destroy your eninge. With proper eninge management, I have seen people here on this club run up to 12-15 psi. The question you have to ask yourself is how long can it last in time. Head gasket failure may be a huge issue with running high boost on stock engine. O-ringing the block is an affordable way to help this problem. Lower the comp ratio and you can run more boost. But you will have to run more boost to be at the same level as a high comp ratio and lower boost. So, it begins to be a question of reliability. Strong engine internals will last longer with high boost. High boost on stock internals will make more power but you wont be without worry. It's a hard questoin to aswere with any degree of accuracy. The 7 psi range seems to be popular with the stock internal crowd.

Mar 31, 2003 | 07:55 PM

Jimi Dixon

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Thanks Hayscoob!
I basically figured that it would be wise to "play it safe" and go no more than 7 or 8 psi with my eventual setup. I know that even at 7 or 8 psi things can possibly go wrong.
Im reminded of something i learned in architectural engineering, and that is you never design a stucture with the intent to have it to full load capacity, and a good rule of thumb is to design the structure to be able to withstand at least twice the load that it will ever be subjected to.
Maybe im comparing apples to oranges, but its probably a good (and safe) theory to get use to.
At the moment, i would just like to get my Subie turbocharged, run a decent boost, and have a car that can keep up with those Type-R Saturns that i see driving around!