JDM EJ20T(STi) v.s. USDM EJ20T(WRX)
 

Sup guys. I wanted to know more of the differences of the STi EJ20T v.s. the WRX USDM EJ20T...


Thanks,
MArky

The USDM EJ20T is open deck, compared to JDM Sti's Semi-closed deck. The JDM STI motor also has AVCS which stands for Active Valve Control System, it's a high tech vtec. It also has strenghtened pistons and tuftride treated crankshaft.

I think you could call it more than a high tech vtec. the AVCS (I believe) is Constantly adjusting the valves while VTEC just switches the cam lobe at high RMP for higher lift.

so is there a down side to the avcs?

Other than complexity and cost, no. It helps make more low end torque with no sacrifice in top end power. It's even more of a benefit on the smaller 2.0 liter engine compared with the 2.5. It's not a magic bullet, though - at lower RPM it just gives the 2.0 a camshaft profile simulated to be like one that is made for low end torque and emissions. Doesn't transform it into a stump-pulling Chevy 454. ;)

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so if it have low end power.. could i possibly charge it iwth a fp green or a vf22 that has a lot of lag and it will even things out?

There are people running those turbos on the street with no AVCS so it should help. Tuners are now gaining experience with AVCS on the USDM STi so you'd have to ask them if EcuTek tuning tools can set AVCS parameters for a 2.0 liter engine running the system. The WRX and STi ECU[color=gray]s[/color] are not the same.

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"…axles of evil…" - george w. bush[/color][/size]

couldn't i just get the jdm sti engine with the ecu together and that should do the job right?

Yes.

If you get a complete JDM motor and ECU it is an easy swap. You just add 9 wires and you are set.

You can also get just the AVCS heads, get an engine harness and ECU also. Add same 9 wires.

Let me know if you have any more questions, as I have just done this swap.

so which did you do. motor with ecu or just head with ecu. are the two blocks completely the same? how much was your buildup and if you did it urself, how long was the install. oh yea, what turbo are u charing it with?

awesome, i wanna leearn about this. alex have u posted details on that swap anywhere?

I got the MY02 Spec C complete motor with ECU.

Swap will take about 2 days to do. You can do it in a day if you really want to and have help.

I also have a fully built 2.2 motor which I am putting AVCS heads on and will run JDM ECU on.

And yes, I did the install myself.

I will post the details in the project forum soon when I get a free minute, hehe.

swt, hmmm how much was the spec C motor with ecu

Check Gruppe-S.com for pricing.

RA Spec. C
 

I just did this swap too. I just tuned mine yesterday on the our Dynapack and made 350 whp without any problems. It's much easier to get the power out of this motor than the USDM block and heads. My only real question is how much boost this thing can take(JDM Sti RA spec C heads and block). I know it has forged rods and pistons so it should be able to take more that 22 psi which is what I'm pushing rith now. I don't have the AVCS hooked up yet and I noticed I lost a little torque and the turbo spools a little slower with the new motor. I can't explain it other than to assume that the valve overlap is much worse with the AVCS motor if you don;t have the AVCS running. I'm using a Link stand alone ecu right now but I'm about to switch to the AEM EMS w/ built in wideband. Imprezer, do you know what kind of max power the rods will take? I'm trying to get all the hp I can get outta this beast. I have a built 2.5 bottm end going in whenever this gets old. :) Plus if you have any thoughts on the torque loss, I'd love to hear it. I'll send you some picts if you want to see 'em. It's pretty trick. I have the 6speed with full STi rear swap, flipped intake manifold and a custom garrett turbo conversion with SC61. I'd love to hear your input. You gotta love that 8k redline.

EJ20T v.s. I-speed 2.8L Short Block
 

O.k., since the JDM-spec EJ20T redlines @ 8000k and the 2.8L short block from I-speed also redlines at 8000k, which one would be the better choice? I know the JDM-spec EJ20T has AVCS but has a smaller displacement and the 2.8L I-speed shortblock has a bigger displacement(duh) but has no AVCS....

To make you guys understand where I'm coming from here, I'm trying to build a "streetable" track car. What I mean is that I wanna build a WRX motor that can handle power in the excess of 500whp or whatever horsepower level the 2.8L motor can handle at the max...

Any opinions would help me out...


MaRkY

hmm, well it depends on mroe than redline, but i really dont know.they're botht good choices, the 2.8 liter ispeed short block would probably be easier to install, you wouldnt need the JDM ECU and the wires. Could you maybe get the 2.8 with the AVCS heads and the JDM ECU? MOre complex, but what a setup!

For max power applications, you want a 2.35 liter stroker EJ22 engine. With forged internals, it's the strongest Subaru block available, with redline capabilites above 10k with the right internals.

[QUOTE=BAN SUVS]For max power applications, you want a 2.35 liter stroker EJ22 engine. With forged internals, it's the strongest Subaru block available, with redline capabilites above 10k with the right internals.[/QUOTE]
But you'll have to pay serious attention to cooling because a closed deck block isn't exactly efficient in those respects. Stout as hell? Yes. Cooling efficiency? Not as much.

Tim Kelsch
[url]www.stoptech.com[/url]

Also, a high reving powerplant is not as important for a turbo car. Your trying to make your power with boost, not by reving the piss out of the motor. Better to go with the highest displacement and keep the RPM within reason. This will keep your motor in good shape and minimize wear on the engine. I would take a look at what Easystreet has done with stroking and poking the 2.5 Sti block. "There's no replacement for displacement." my two cents...

If your coolant system has a nice large capacity, and your radiator is big and efficient, you won't have cooling problems. As for more displacement, when you bore out the motor, it gets inherently weaker. And with turbo OR NA cars, the more revs you can make power at the better. Remember that hp is a function of torque and RPM. The more revs you have, the more air you flow through your motor, whatever size it is.

DAMN i guess everyone is getting the spec C im behind

the JDM 2.0 has a higer red line 8k not 7k