Anybody has experience with this hybrid build? Is it worth the time? How much does it cost and any problems?? TIA :RockOn - not mine:

 

which heads?? get jdm wrx 2.0L heads, they're better flowing than usdm 2.0L/2.5L heads. the intake ports on the jdm 2.0L are substantially larger than that of the usdm 2.5L. Aussies, UK, and Japan does it. That's why they buy our shortblock and mate them to their better flowing heads.

joe

 

my friend just did that swap...it seems to be running fine...its farken animo =)

 

well you could add AVCS to the USDM 2.0 heads since its got the port. Actually the JDM 2.0L depending on the ones you get are either big port or small port. The determining factor is the numbers on the side of the heads. If you go with V8 heads those should be big ports all the way. You'll need EM that can control the AVCS and you'll need to add an additional 7 wires to your existing WRX harness (i think it's the same pin out as your 4EAT front harness) that connect from the ECU to the black and brown connectors on the drivers side engine bay area

The ones that I've got my V7 are big ports (I did some research on them)

V7 big ports are RHS20V & LHS20V they are casted on the head itself I believe

 

Jon, please correct me if Im wrong but if Chucky uses a 257 block with a 205 head, he would get a ton of low end /mid range power and no high right if he was using the stock cams??? I've talked to my brother about this subject and told me that he those hybrids would wear out the OEM clutch on a stock tranny because of the extra torque it spits out and a bunch of other stuff but was to occupied to listen. I think Head Gaskets would be an issue to if I remember correctly but I have a not so good memory. So in conclusion,

fairly alright memory + Walter = :newbie; :

 

I know there are several guys running around like this. Right now, only Bodie comes to mind, and stockblue maybe?

 

Tomei had a great breakdown article in either Turbo or Dsport on the EJ25.

 

Like everyone said above me, the heads are the key to maximize the swap. With stock WRX heads, you'll increase the low end torque, but it will quickly peter out thanks to the restrictive heads. It is WAY more fun to tool around in though, you start to push the gas and it goes. The only install issue you'll run into is that there is a breather port on the top of the block that you won't use, and will need to plug. You'll have to use the headgaskets for the EJ257.

 

Thx for the input!

Yea, Ryan, I read on Nasioc that you'll need to plug those breather holes...

So I should use JDM 2.0 Head with the EJ257 SB then? I don't have to go with AVCS right? That part was lil confusing Jon... you might have to clarify again for me. Thanks!

Where is a good place to get them (JDM heads)? I have an 4EAT, would tranny be an issue? Caz I remember the 4EAT is good up to 300hp. Any changes on the ECU?

 

You're right, you don't have to use AVCS, but you would have to get non-AVCS heads. The extra wires Jon was talking about controls the AVCS solenoid and I think there's a couple of extra sensors as well. I'm not too sure which non-AVCS heads have big ports, but I know they're around. Probably something like Ver. 6 STi-RA or similar.

 

Thanks Ryan. I might drop by the shop and talk more this week. Just gathering some parts & cost info for now.

 

I got a feeling that I'll have to change to a manual trannie to make this work...

Maybe I should just do a STi swap... hahaha...

 

Well, Jon did 12's when his car was still auto...

 

auto/manual doesn't matter for engine work. the difference would be the engine harness, front bulkhead and ECU combination you'll be using.

you can do any mechanical change on an engine and it'll do what it's designed to do but without EM to run it and nkow what's going on you won't be able to use it to it's potential let alone be able to run it right.

unfortunately for you running and 04 WRX you're ECU's were only designed for a single map for auto or manual. The 02/03 ECU's had dual maps on them and auto/manual was determined by an extra wire connecting into one of the connectors on the ECU to say it's an auto.

shift points aren't determined by the ECU either for an auto tranny but is determined by the TCU (transmission control unit). I believe there are a copule companies that made upgraded or user programmable TCU's for your purpose.

So EM to control the engine and a PTCU would be great. you'll need to also do upgrades to your tranny though like a upgraded TC/VB and possibly get stronger belts if they make them or change them out more often.

Jon

 

So essentially I will need a new/upgraded ECU and TCU along with the other parts.

- Short Block
- JDM 2.0/Aftermarket Heads
- New headgasket
- New/upgrade ECU
- New/upgrade TCU
- New timing belt