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· Registered
146 Posts
guys i mean between ej20 and ej25 engines which of these engines can hold more boost or more pressure !!!!

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based off my very cursory stint in public education, I'm going to go with the ej25 because bigger number

but ultimately, you'll be safe as long as you double clutch instead rather than granny shift

· Premium Member
11,374 Posts
whats better in terms of anti lag ej20 or ej25.. and who is more reliable
i mean between ej20 and ej25 engines which of these engines can hold more boost or more pressure !!!!

These are two completely different and unrelated questions. :confused:

There is no specific engine labeled as an ej20 or ej25 (all ej Subaru engine codes consist of three digits, not two). There are several varieties of both the ej20 and the ej25. An ej20 will be a 2L engine, and an ej25 will be a 2.5L engine, but the different versions of each engine have vastly different componets and construction. Some of them are designed to be normally aspirated, some are designed to be turbo charged, some are single overhead cam, some are dual overhead cam, open deck/closed deck/semi closed deck, etc.

If I'm to assume you mean fairly recent turbo charged USDM engines, either an ej205 or ej255(or 257), I'm still not sure what you mean by "better" for anti-lag. Given the same hardware and programming for the anti-lag system they should both be capable of building an equal amount of boost while the ALS is in effect. Mod for mod the 2.5L engine will produce more torque across the board than the 2L engine, but that doesn't really have anything to do with anti-lag. With ALS running I would say both engines should be just as unreliable as the other. With regular ALS use I would expect to get somewhere around 1000 miles of driving before the heads will need to be rebuilt. It really depends on how often you use the ALS and how aggressive you have it set up to run. The turbo will probably fail before the exhaust valves, but that's not part of the engine so I guess it isn't relevant to your question.

As far as which one can handle more boost and/or cylinder pressure they're pretty close to each other as well. Maximum boost pressure before engine failure has little to do with performance, so the answer doesn't matter much. A GTX3576r running 15psi will produce more than twice the horsepower as a TD04-13t would at 22psi. Stock engine vs stock engine, the ej255 and ej257 will be able to handle more power output than an ej205 before failing.. partially because the 2.5L will be putting down more power mod for mod so you won't have to push it quite as hard as you would a 2L engine to make the same amount of power.

If both cars are left completely stock and similarly driven and maintained I would say the ej205 will last a little longer than an ej255 or ej257 (the 2L has a shorter stroke, hence lower piston speeds), but it's really hit or miss. Both engines should last >200k miles if properly cared for.

I hope this answers your questions. :wiggles:

· In Æternum
23,700 Posts
Jesus Robin. Stop playing with the trolls.

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