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EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 9:37 am
by daddykubs
Hi guys.
I have a theoretical idea ( at least for now)
General market EJ204 is 165hp with CR 11.1:1 AVCS
JDM market EJ204 is 187hp with CR 11.5:1 Dual AVCS and variable intake manifold (?)

Now I read about Forester, Liberty/Legacy and Outback being turboed with AVO kits.
unning strong at up to 6psi.
Base was EJ25 170hp with CR 10:1
At up to 6psi running on 93-95 octane fuel engines reach safely (apparently)
190whp 200ft of torque without forged pistons and rods !!!!

I know it is expensive to charge n/a but high enough power for 2 liter engine
combined with small charger that spools quick could be quite responsive
and firey combo than GT.
Idea is to have around 230hp on flywheel, small Fmic, maybe oil cooler in place
of tmic, wrx injectors, fuel pump and some small turbo.
It won't ever outrun mapped GT , but this wouldn't be a target.
I'm interested if oil and coolant amount changes after conversion.
Or
Stay n/a, port polish, get biger injectors and pump, agressive camshafts and remap and
hopefully get 200+ n/a power??

Did anyone try to charge n/a 2.0R?
Could be cool project...

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 9:58 am
by Robbks
one of teh guys on OzFoz has turbo's his 06 NA forester (EJ25)
BUT, your approach is a little wrong.

the car has a good amount of low down power already due to high compression.
what you want to fit is a larger turbo say VF24/28 or TD05, something with a big exhaust side and run the same low boost, BUT it supports a higher overall airflow
the high compression aids in spooling a larger turbo faster, and having a big exhaust housing makes the engine more efficient by lowering back-pressures and removing as much residual heat as possible.
it's that heat which increases in-cylinder temps/ pressure and will fail big-ends or ring-lands.

before embarking on any of it you need to work out if your ECU is able to be re-flashed, otherwise it's very expensive and not worth it.
personally, it's not worth it. sell the 2.0 and buy a 3.0 or a GT and be done with it.

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 10:54 am
by jslayz
correct!

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 11:33 am
by bigBADbenny
daddykubs wrote:Stay n/a, port polish, get biger injectors and pump, agressive camshafts and remap and
hopefully get 200+ n/a power??


I'd start with a tune or maybe a tune, you may not need to go further (for a little while) :wink:

Unleash the latent drivability for starters...

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 3:57 pm
by Kormoran
If its Hitachi, you're out of luck for the tune. I encountered this problem, very disappointing to say the least..

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 4:02 pm
by bigBADbenny
So in that case, you'd have to go aftermarket mgmt... or just swap in the right ecu?

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 4:31 pm
by Robbks
bigBADbenny wrote:So in that case, you'd just buy a GT

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 5:33 pm
by bigBADbenny
lovin' these "corrected" comments... :lol:

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 7:53 pm
by daddykubs
Thanks for replies.

My reasoning behind that idea is:
In UK 2,5 is most popular, then 3,0, 2,0(130hp), 2,0R, 2,0D and GT.
If I wanted GT I'd go to mainland Europe and get US or get 3,0R spec B facelifted gen 4.
I smoked WRX (poor shifter) already with my 165hp tin box.
I don't want SWAP or diferrent car really, I'd love to keep and tune what I have.

I'm aware that You have to use piggy-back , bov, boost controller etc.
I read about some crazed guy charging 11:1 miata with 12psi!!!!!

What I wasn't aware is that smaller turbo creates heat issues as main concern is
how responsive motor will be.
If I ever wanted 380hp or close then hawkeye motor it is if I wanted 400+hp then EZ
30 twin turbo.

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 8:03 pm
by bigBADbenny
Check out the raptor supercharger kit threads on this forum if response is the aim.
But +10% from a tune is pretty good. NA is good enough for BRZ, right? :D

Re: EJ204 vs turbochargers

PostPosted: Tue Sep 18, 2012 11:24 pm
by daddykubs
Yup, supercharger sounds interesting.
Just started to read about BRZ and its 197hp/7000, 205Nm/6600 at CR 12,5:1
Bore and stroke are different 86x86 where EJ20 is 92x75 and reaches max output lower.
Haven' t read about it yet but some crazy people charged BRZ to 400+hp!

Re: EJ204 vs turbochargers

PostPosted: Wed Sep 19, 2012 12:12 am
by bigBADbenny
Also everyone raving about wringing out every last kw right through the revs with the BRZ = a pure fun thats hard to beat.
NA is special in that regard...

Re: EJ204 vs turbochargers

PostPosted: Wed Sep 19, 2012 7:57 am
by daddykubs
As research and theory on EJ204 N/A T goes further...
Raptor only mentioned kit for Impreza 2.0R which I believe to have this motor.
Simple Raptor kit makes 220hp (164whp) @ 7psi.
Not impressed , but would indicate 7psi is safe for that engine.
Now Accelerated Performance boosted BRZ with Garrett T28.
They squeezed 278whp @ 10psi! That I like, but unsure about
internals of that engine.
Following Raptors idea and twisting it a bit:
If running 7psi with cold intake, big fmic, port polish, bigger injectors and everything
in heatwrap will make 165whp then it seems like unwanted struggle.
On UK forum we had a case where 2.5 N/A has been tuned from if I remember it right
140 to 160hp. Mods included intake, exhaust and remap.
+15% on SOHC non AVCS, no mods to tumble valves etc. seems ok...

Re: EJ204 vs turbochargers

PostPosted: Wed Sep 19, 2012 8:49 am
by bigBADbenny
Have you read HyRax profile re NA tuning?
Indeed he loves it so much he's tempted by Raptor!

Looks like NA tune with supporting mods could lead to: built engine w/ square bore/stroke or Raptor SC... or... BOTH :P

Re: EJ204 vs turbochargers

PostPosted: Thu Sep 20, 2012 3:35 am
by daddykubs
Just did. Thanks.
It's pretty cool: +10% with just remap/ chip is really good!
For now I'm in progress of building smog pump block off plates and grounding kit-
Not much of a mod, but something to start with.
Back to topic:
"Square engine" on SC or turbo would be a killer!
I guess if You rebuilt EJ204 to WRX sort of spec with few improvements You could get like 260hp
maybe 210whp?
I mean FMIC, Garrett T28 or TD05, Sti oil pump, Sti fuel pump and injectors, forged
rods and pistons (crank is the same), everything heat wrapped and stainless cat back.
If You asked me why, I'd say it would be quicker than WRX, but more economical and responsive,
possibly more reliable- forged parts and OTT cooling system (by the way is there a difference between
2.0, 2.5 and 3.0 n/a cooling systems? Could upgrade that too).
See I would never dare to compete against other Subies but gladly surprise A3 , 325 and Golf owners.
I am not keen on German cars.