Got a bad rod in my '99 EJ253 so I need to do something soon! Planning on new forged pistons and rods if crank is still good. Probably use STI set-up or get a stroker kit.
If I lowered my compression would my engine run good(not lose low-end TQ) with stock ECU until I can afford to turbo kit.
Will use SOHC on STI block as last resort but I dont know the benefits of open, semi-closed or closed decks. What are they?

Any insight on any of this?

 

NA cars usually have a higher compression ratio 9.7:1 (EJ253). The EJ205 is about 8.0:1 (correct me if I am wrong) running about 13.x not sure the exact munbers. For every 7 lbs of pressure increases the compresion ratio about 1.0:1.

as for Hondas (example) the B16A2 (USDM 99 Si) has a compression ratio of 9.5:1 and the B20 (CRV) has a ratio of 8.5:1. with running 7lbs of boost on both (giving everything else is the same) the B16A2 ran a 13.2 in the 1/4 mile and the B20 ran a 14.6 1/4 mile.

So if you were to run the STi motor (full swap) you should be fine as long as you do the full swap. If you plan on using just the bottom end of the STi and not the rest...not sure what would happen. I would have to say use the 22B block and increase the compression ratio.

Two links that might help.

Subaru EJ Series Engine Compression Ratio Calculations
http://wac.addr.com/auto/obs/turbo/ejcalcs.html

Just for reference:
https://www.i-club.com/forums/archiv...p/t-41488.html

 

To simply an answer for you.
No your engine will not run the same.
The difference will be horsepower and torque loss.
But if you are planning on doing a turbo. Do it and live with it until you get a kit.

 

time for a swap man don't waste the energy on a tired engine

 

yea. instead of rebuilding i would swap it. how much money would you spend on parts and labor? compare the two