Maximizing power from an EJ20k (reliably)

[TommyAtomic]

I dont exactly have a vested interest because I dont have an ej20k but I have been debating about importing a v3 STI so this has piqued my interest.

It seems a bit late to ask but in the the ej20k's with bearing failure issues does anyone know what the oil pressure was at the time of failure?

I'm not suggesting that the factory tune was not a significant factor. But what are the odds that insufficient or incorrect engine lubrication may have contributed?

Complete impreza's with EJ20K's are just now making it into Canada. Prior to that EJ20K's were mainly in north america as a result of imported front clips.

Very rarely (possibly never) do motor-swaped vehicles go to the dealer for service. Is it possible that the required engine lubricant for the EJ20K was used in Japan but that the new North american owners are dumping 4.5 qts of any old dino oil and putting down the hammer?

Everyone likely wants to know what specific octane fuel (likely insuffecient) was being used at the time of failure but I would be highly curious to know the engine oil temp and oil pressure when the bearing(s) failed.

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[wrxstijdm]

Building on TommyAtomic point... Anybody knows what the recommended oil was for EJ20K's? Maybe somebody with an Owner's manual from a Version 3/4 STi?

[TommyAtomic]

Originally Posted by wrxstijdm

Building on TommyAtomic point... Anybody knows what the recommended oil was for EJ20K's? Maybe somebody with an Owner's manual from a Version 3/4 STi?

Recommended oil from the manual. Good idea.

BUT I remember reading somewhere(might have been BobIsTheOilGuy) that regardless of the recommended OEM fluid from the original manual; The oil pressure should be right around 10psi (+/-10%) per 1000rpm @ operating temperature. Meaning as an example if the manual says 5W30 synthetic and you run 5w30 synthetic but you arent getting enough oil pressure then the manual is wrong.

I might need to post a question in the built motor forum to verify or at least lookup where I read that to make sure I remember it right.

[Marnix]

Crank, rods and oilpump are the same as the pre-EJ20K turbo engines so if the issue was with those parts the EJ20Gs would also suffer massive bearing failure. It must be said that the EJ20G does have a lower rev limit so that helps but they also had better rod bearings.

I would say the three contributing factors to bearing failure in EJ20K engines are factory tune, rev limit (rod bolts stretch) and bearing quality.

[TommyAtomic]

So EJ20G bearings and EJ20K bearings are significantly different?

[SpamMansXe]

I always under the impression that it was a combination of the aggressive tune and high rev? The bearing didn't seem to be any different than other years but the combo off everything else, especially the tune attributed most to the failures.

I am not overseas so I don't really know how they did where they were made for but it seems like the majority of bearing failures in the States are from people ragging on the cars with a stock tune and crappy gas. At this point, they are 15 year old engines and no one knows their history and than you put it in the hands of a kid who the engine rivals age with...and boom.

[Poppie]

5w30 is prefered according to handbook but 10w30,10w40,10w50 are widely used in the UK,I use 10w60 Castrol RS Edge.

Even on better fuel that we have in the UK they still go pop.
Personally apart form the actual mechanical parts being quite old that poor attention to servicing and actually taking care of the car contribute to them failing.

I've owned Imprezas (93wrx and 98 Type R) for the last 10 years and never had an engine issue yet many people have ,am I just lucky or is it because I properly maintain the the car, who knows.

[i_c_the_light]

15w40 is a common oil used in NZ on our imports. But other weights have been used in the local Subaru community in recent years.

[turboaddiction]

Originally Posted by Marnix

Crank, rods and oilpump are the same as the pre-EJ20K turbo engines so if the issue was with those parts the EJ20Gs would also suffer massive bearing failure. It must be said that the EJ20G does have a lower rev limit so that helps but they also had better rod bearings.

I would say the three contributing factors to bearing failure in EJ20K engines are factory tune, rev limit (rod bolts stretch) and bearing quality.

on my car aside from my headgasket starting to slowly let go its never had a problem but i run a custom tune and the car doesnt turn above 7k i think this may have been the reason my car hasnt crapped out

[rob]

This is a very timely conversation for me as I now have a Ver4 STi Type-R V-Limited half cut on it's way.

I am having a hard time deciding if I want to open it up and replace the bearings, rods and rod bolts (as per Marnix's recommendations) or take a chance on running as is. I am worried that once I open it up, I will want to replace all the gaskets and seals (which may be perfectly fine as is). The time and money to do it right may not be necessary at 89k miles.

I am thinking about sending in an oil sample with the hope that if the motor is in bearing trouble, the wear metals will be higher.

-Rob

[eg33GC]

Rob are you going to run the G ecu/wiring (hopefully intake!!) on the K?

I'm still thinking about rebuilding the g block w/ v4 ra heads, or a 207/v4 heads

[rob]

My goal is to keep as much of my current G wiring intact. If I am lucky the engine bay connectors will be the same. I will have to wait and see what the differences are.

I don't know what you mean by "intake"? Do you mean transferring the intake manifold harness?

-Rob

[eg33GC]

the master race intake manifold

[rob]

I am so confused.

[SpamMansXe]

Originally Posted by rob

This is a very timely conversation for me as I now have a Ver4 STi Type-R V-Limited half cut on it's way.

I am having a hard time deciding if I want to open it up and replace the bearings, rods and rod bolts (as per Marnix's recommendations) or take a chance on running as is. I am worried that once I open it up, I will want to replace all the gaskets and seals (which may be perfectly fine as is). The time and money to do it right may not be necessary at 89k miles.

I am thinking about sending in an oil sample with the hope that if the motor is in bearing trouble, the wear metals will be higher.

-Rob

When I bought my ej20k, it had roughly 25k on it so it was super low on the mileage. I have used it for over 3 years with no issues and I have recently sent my oil to Blackstone for analysis. Part of me wants it to be fine but the other is begging for trouble and a rebuild!

[Meeners]

bumpage... I have a version 4 ej20 and 2s ecu and am purchasing the ESL board and plan to have it tuned. I am purchasing the boarded ecu today.

Until then I will be driving the car under 5.5k and going 93 octane and running the PFR7B.

[04wrxjon]

Does anyone have any recommendations on what you would use for new internals? Would they be the same as the 20g?

[Marnix]

Yes the same when using uprated parts.

[04wrxjon]

Great sorry for the thread jack. Any recommendations on specific parts?

[jugomutt]

Just an update- I've had the car for 6 months now. It's always made a ticking sound which im pretty sure is the belt tensioner. Anyways Ive driven about 20,000 km and it hasn't given me a single problem.... Atleast the engine anyway

[CRX7]

Knock on wood, previous owner drove the ej20g from PA to Cali. I drove it from Cali to Texas. However this is on a tuned Power Fc running very very rich, my milage is horrible.

[eg33GC]

ditch that junk and do a proper g ecu rom tune

[Smoke]

Do people make more power from the stock EJ20K ECU or the PowerFC?

[blessthekellen]

Here is a power FC dyno, tuned conservatively for 91 octane, stock baseline was 212whp.