High Compression N/A EJ205 or turbo?

[matt167]

I've got my V5/V6 EJ205 coming complete ( turbo, everything on it ) with a 4.44 Turbo trans. I'm not sure if I want the hassle of needing to get the turbo operational to maintain HP.

With Opposed Forces, I crossed back and verified the rods for the EJ201/EJ202 were the same as used in the EJ205. And thus the right length for the EJ201/202 flat top pistons. Then I went over to Partsouq.com and verified I can get them from them. A or B size they have available.. They are only $46 each listed as a set. Are they sold seperatly from Subaru usually? $184 is more in line with what I would expect, but Partsouq seems CHEAP on everything ( They do USA spec stuff too )... Since an engine might need both A and B, I thought they were sold each. Because if I get a set of All A's and I need a B, then I would actually order 2 sets

 

Should I just go hi comp? my math tells me it won't be quite the 11:1 screamer the EJ204 is but not too bad. Or is it better just to run it Turbo.. An RRFPR, fuel pump, MAP voltage clamp and a wideband will get me running 7-8 PSI safely. But perhaps it's less a hassle then getting EJ201 pistons/ hardware and fitting them in.

[Bushwick]

Just run a turbo. The biggest issue that causes lag is the exhaust, notably the cats. If possible, run a single 3" race cat. They are round, short, and have larger holes through the ceramic- all of which will increase flow and decrease backpressure at the turbine. If possible, run 2 smaller high flow cats (one per side/header) BEFORE the turbo and it should be similar to running a straight pipe as the turbo will have unrestricted flow after it. Heat loss from the gases shouldn't be an issue in this scenario (especially when there are rear-mounted turbo kits). That'll give a ton of earlier, usable torque and HP until red-line, otherwise a 3" dump pipe AFTER the turbo feeding the 3" cat is the other option and running say a 2.5" exhaust after the cat (or full 3").

 

In order to get that as a high compression engine that actually runs strong, you'd probably need better valve springs, better cam, solid lifters, and the ability to run up to 7-9k RPM, though it'll be a dog as a daily driver unless you can get steeper gearing and keep it strung out in the powerband. Hydraulic lifters won't be very good at that higher RPM.

 

If we are talking a "get you to work and back" car, grab some exhaust manifolds from an NA car and plug all the turbo stuff up (oil feed, oil return, coolant) and switch to an NA intake pipe and filter. It probably won't make the power the factory NA cars have, but it should be close. ECM should be able to run it as full NA as it'll think it's off boost, though it may still run rich. Hard to say and it may not work with Subaru. I did this briefly over a summer with my Saab 9-3 while the turbo was getting rebuilt and it ran like a low-po NA.

[Numbchux]

What's this going into (I usually don't respond if I have to ask this)?

 

 

 

A piston set from Subaru (one part number) is piston, wrist pin, and 2 pin clips. It is only enough for one cylinder, and does not include rings.

 

If it were me, the decision would be made by the engine management system. If it's meant for turbo (although the stock EJ205 ECU is very tuneable), I don't think the hassle of tuning + cost of replacing pistons would be worth it. If your management is meant for N/A, then you won't be able to really take advantage of the turbo anyway....

 

 

We've put a few EJ201s in place of EJ251s here, and the power loss is not really noticeable.

[wtdash]

HI,

 

 

I've read enough of your posts to know YOU KNOW your way around a Subaru, but How RU going to wire that EJ205 in?

 

I'm not good w/the V-series of JDM stuff, so not sure on the year, but it may be older and not compatible w/whatever you have now. And the harness/ECU wiring may not plug-n-play...well. 

 

A couple of NASIOC v5/v6 Posts HERE and HERE, I found interesting.

 

Those early 205's 'might' be the Hi-Comp (for a turbo) @ 9.1:1, which would help.

 

I'm not an internal-engine piston/rod/etc. swapper so can't help.

 

BTW, that 4.44 trans will be a 'screamer' on the highway. I've read 4K RPM @ 65mph in 5th, or something like that.

 

Td

 

p..s Thanks for the Partsouq.com info. I just ordered an old 90° elbow as a backup for my turbo'd '96 EJ22e. 

[matt167]

It's going in my 2001 Forester S. The engine is on it's last legs and it's just time to either rebuild or replace, and I'd rather rebuild because the rest of the car is still decent.. Most of the V5/V6 EJ205's came out of Foresters and GF8's.. So it's only kinda logical to put it back in one.. If I ever get enough $$ again, I'll get a JDM SF5 STI front end, and then be the envy of the neighberhood..

 

The 'cool' thing with the older pre 2001 EJ205's ( production began May 1998 FWIW ) is that the cam/ crank signals used are the same as what is used on 1999-2002 USDM EJ25's ( 6/7)... So essentially, the engine can be made to 'run' without the turbo fairly easy. I verified that by checking the crank gear p/n which also lists for a 2001 Forester 2.5L SOHC N/A through opposed forces... In the event I get some kind of 'hybrid' which has the newer WRX style triggers. I verified the correct driver intake gear is still available from Partsouq for less than $100. It was only a $100 bet really. The Importers WILL NOT help you in any way beyond tell you the block and heads will swap with 2002-2005 USDM WRX... I think people get cought up in the "WRX Swap " and overlook other options. I've found a couple instances of people doing this but not to any great amount of info.

Basically it will take adapting the USDM throttle body and MAP sensor into the intake, extending a couple wires on my USDM engine harness since DOHC harnesses are longer in some cases. Many of the sensors share part numbers, even the knock sensors are the same. so my ECU should be ok with the EJ205 or close enough it'll adapt.

 

As far as tuning. I'm probably going to go for a Greddy Emanage Ultimate with a Boomslang harness for a fully PNP setup. Will need tuning, but even a WRX swap would need tuned since JDM EJ205's are 9:1 as built... Figure, $350 for a WRX harness w/ ECU and then $700 to Iwire or $400 for an Emanage and $289 for Boomslang harness. They are within $100 of eachother given variables but only one is truely PNP and does not require dash removal

 

 

The last version of the EJ20G is also listed sometimes as an EJ205 although most importers list it as a '97/'98 EJ20G.. Opposed Forces lists their engine codes as EJ205. It's somewhat confusing but easy to follow going by the where used dates as to what's what... I should also note that since Opposed Forces only lists EDM cars, there are some small part differences to their EJ205's but it's namely smaller turbo's and such. The

[matt167]

It's going in my 2001 Forester S. The engine is on it's last legs and it's just time to either rebuild or replace, and I'd rather rebuild because the rest of the car is still decent.. Most of the V5/V6 EJ205's came out of Foresters and GF8's.. So it's only kinda logical to put it back in one.. If I ever get enough $$ again, I'll get a JDM SF5 STI front end, and then be the envy of the neighberhood..

 

The 'cool' thing with the older pre 2001 EJ205's ( production began May 1998 FWIW ) is that the cam/ crank signals used are the same as what is used on 1999-2002 USDM EJ25's ( 6/7)... So essentially, the engine can be made to 'run' without the turbo fairly easy. I verified that by checking the crank gear p/n which also lists for a 2001 Forester 2.5L SOHC N/A through opposed forces... In the event I get some kind of 'hybrid' which has the newer WRX style triggers. I verified the correct driver intake gear is still available from Partsouq for less than $100. It was only a $100 bet really. The Importers WILL NOT help you in any way beyond tell you the block and heads will swap with 2002-2005 USDM WRX... I think people get cought up in the "WRX Swap " and overlook other options. I've found a couple instances of people doing this but not to any great amount of info.

Basically it will take adapting the USDM throttle body and MAP sensor into the intake, extending a couple wires on my USDM engine harness since DOHC harnesses are longer in some cases. Many of the sensors share part numbers, even the knock sensors are the same. so my ECU should be ok with the EJ205 or close enough it'll adapt.

 

As far as tuning. I'm probably going to go for a Greddy Emanage Ultimate with a Boomslang harness for a fully PNP setup. Will need tuning, but even a WRX swap would need tuned since JDM EJ205's are 9:1 as built... Figure, $350 for a WRX harness w/ ECU and then $700 to Iwire or $400 for an Emanage and $289 for Boomslang harness. They are within $100 of eachother given variables but only one is truely PNP and does not require dash removal

 

 

The last version of the EJ20G is also listed sometimes as an EJ205 although most importers list it as a '97/'98 EJ20G.. Opposed Forces lists their engine codes as EJ205. It's somewhat confusing but easy to follow going by the where used dates as to what's what... I should also note that since Opposed Forces only lists EDM cars, there are some small part differences to their EJ205's but it's namely smaller turbo's and such. The rest is pretty much the same.. Japan-parts can verify that kind of thing but the site is a mess

Edited August 23, 2016 by matt167

[matt167]

Took delivery of the engine today. Aside from a crap Pallet that importer put it on, and the shipping company breaking the pallet in half in my driveway by the road ( 75' or so to the garage ) before saying sorry and driving off.. I slid it off on one of my old hotrod frame jigs, and then drug it most of the way up the hill with the Forester ( front tow hooks, in reverse ). Then finished it off with the lawn tractor into the garage....

 

 

I think the condition of the 'extra' parts sealed the deal for the fact.. It's STAYING BOOSTED..  Clean uncut down pipe that I hope I can use. Intercooler is nice and straight. couplings look great. Pretty much everything looks mint.. I gotta tear everything off to check condition fully, but pretty pleased at this point.. The trans is dated 2001 and the plug wires are too, so it might need the other triggers. I'll get the one on order to be sure