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95 and 05 legacy
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102 Posts
Discussion Starter · #1 ·
7 psi max boost.i know its high compression.if i tune it right can it run properly?on street gas?
i have all these parts already except the mega squirt.what do you all think?
chasis is obd 1 1995.
 

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...Lower it
01 Aspen Ej205'd RS
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7,013 Posts
i cant tell if he wants to use 22 heads on a 25 or 25 heads on a 22

22 heads on a 25 and your engine will blow

25 heads on a 22 and you can run boost and be happy
I thought the sohc ej's work awesome with 2.2 heads? Maybe it was the other way around. Never really looked into n/a stuff

I like boost :lol:
 

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01 Aspen Ej205'd RS
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7,013 Posts
nah 22 on 25 is the high comp build

so if normal na ejs dont like boost high comp ejs will implode lol
Well yea that's what I thought cuz believe it or not tons of people want high compression :lol:

I know on that kind of build you fo sho need to run 93 oct.
 

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GF OBS-T, GM RS EJ20, SF EJ20
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i cant tell if he wants to use 22 heads on a 25 or 25 heads on a 22

22 heads on a 25 and your engine will blow

25 heads on a 22 and you can run boost and be happy
I like the 2.2 block with 2.5 DOHC's for different reasons...

DOHC 2.5's HAVE the same 46.x CC heads as ej22t which are supposedly the same cc as ej22e's.
SO
If the HGs used are stock ej22e thickness the CR will be the same as a stock ej22e.

But the 2.5l heads have bigger ports than ej22e/t heads which can't hurt...
&
The DOHC 2.5l heads will start up on a sohc ej22e or ej22t ECU with NO PROBLEMS - so its a fairly simple conversion.
&
I'd bet they'd make more power than ej22e either in N/A or boosted Trim.

Phase I 2.0l turbo heads from JDM Legacys & WRX's will lower CR some on ej22's & have even bigger ports stock vs stock than DOHC 2.5ls + they will still start right up even on the OP's stock 1995 sohc ECU...

I'm not really a ej25/boost fan as the ej25s knock very easily even in stock N/A compared to EJ22's.
 

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95 L, 96 OUTBACK
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2,925 Posts
High compression on any boost won't do well... No matter meth, C16, or anything...
What???


Thats the reason you use the fuel. Its a much higher octane. The problem is when most people raise compression they use domed pistions which are bad for knock resistance. If you would run meth, E85, C16, CNG, or propane high CR and boost isnt a problem. There are allot of people with different cars running this setup. It works you just have to know what raising CR does to the CC.
 

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opendeck251+stiInternals
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483 Posts
DOHC 2.5's HAVE the same 46.x CC heads as ej22t which are supposedly the same cc as ej22e's.
SO
90-98 EJ22 is 40cc chamber, 99-01 is 41cc. EJ22T pistons have 28cc's of dish to make the CR lower, it's not in the heads. Just FYI.

I have an EJ22 block with SOHC EJ25 heads and Delta 2000 cams, not fast but it pulls nice. Either the SOHC or DOHC heads will work. If I were to do it again, I would use the DOHC heads simply for the easy of wiring and the IACV doesn't need to be messed with.

C/N: EJ22 block, DOHC EJ25D heads=WIN


~Josh~
 

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2001 D2 A8L
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929 Posts
90-98 EJ22 is 40cc chamber, 99-01 is 41cc. EJ22T pistons have 28cc's of dish to make the CR lower, it's not in the heads. Just FYI.

I have an EJ22 block with SOHC EJ25 heads and Delta 2000 cams, not fast but it pulls nice. Either the SOHC or DOHC heads will work. If I were to do it again, I would use the DOHC heads simply for the easy of wiring and the IACV doesn't need to be messed with.

C/N: EJ22 block, DOHC EJ25D heads=WIN


~Josh~
The problem is he wants to put ej22 heads on a ej25 block. This will produce a high CR that is not good for boost.

Yeah maybe a little boost on 93 and some tuning. Maybe more with water/meth but it is really limited and the heads are going to hold him back.
 

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opendeck251+stiInternals
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483 Posts
The problem is he wants to put ej22 heads on a ej25 block. This will produce a high CR that is not good for boost.

Yeah maybe a little boost on 93 and some tuning. Maybe more with water/meth but it is really limited and the heads are going to hold him back.
I know, that's why I put the cliff notes in there so he would get the point.

Bottom line OP, boost + high compression franken-motor= FAIL!!!!

You can try if you want, it's your wallet, but I can't physically stop you so i'll just yell at you from the other side of the interwebs....



~Josh~
 

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RIP 08.24.2013
01 legacy L
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8,015 Posts
High compression on any boost won't do well... No matter meth, C16, or anything...
I beg to differ. well plead would be more accurate.
Motorsports magazine or one of them took an old LS1 that was rusty and nasty, blew it up with 28lbs of boost and ran like 117octane in it.

Didn't blow up with a full day worth of dyno'ing. :blol:
 

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Green 97 OBS
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On our knock happy ALUMINUM EJs, High compression and boost don't like each other, especially on hybrids with sketchy combustion chambering. You're lucky if you blow out ringlands, you can split the cylinder bores.
 
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