Hello everybody. Is it a good idea to turbo charge a naturally aspirated Ej 25 the block is jdm and the heads are soch any comments will be gladly appreciated

Depending on your goals, it may make more sense to build a frankenmotor, which would be EJ22 heads on the EJ25 block. It's not like you'd be able to run massive boost and get up to WRX like power numbers on a stock EJ25 block anyway so the 20 to 30 hp gain that going franken would get you would be pretty much all you could do with a turbo anyway, if longevity/reliability is of any concern.

 

you can run very light boost....reddevil and kevin thomas and others have done it and you can read their info, reddevils is out there and very extensive..though now he's into more in depth projects after blowing up some motors, he didn't start there.  the NA motors are high compression ratio so have to keep the boost really low, so the gains aren't tremendous for all the work...the temptation is to, after all that hard work and money, crank the boost and get some real power - then you blow the motor and you look into a turbo block...the best starting point for a turbo.

 

kevin was able to keep his under control with a turbo in his EJ22 impreza...

 

if it has stock headgaskets i'd definitely leave it alone...you have an engine that is prone to headgasket failure to begin with i'd keep the additional heat and power away from it.

It would be a ton of work to turbo a N/A motor for not a lot of gain.  If you're looking for a project, sure!  But for a few grand you can get a JDM turbo motor with harness, ECU, etc.