What engine do I want for my 818R? grrrrrr.

[C.Plavan]

I keep going back and forth- EJ20 or Ej25.....
JDM EJ20 STI motors can be had for cheap, The US EJ25's STI's are considerably more. I'm just looking at 325-350 HP for my 818R. I'm clueless with Subaru engine stuff, If I could stuff my extra 2.5L Porsche Flat six in there I would :P

I'm totally open to suggestions. Strictly going to be racing it.

[Xusia]

Both can make that HP fairly easily. The engine in my donor is an EJ205 and was making 300 AWHP bolt ons (list is on my thread "Found a donor; ordered my kit"). Also, AJW did a nice write up on the differences here: http://818donors.com/general/2002-20...2006-2007-wrx/

Bottom line is depends on more what you want from an engine. I like the idea of a cable throttle and the more rev happy nature of the 2.0L. Some like the throttle-by-wire and superior torque of the 2.5L (My personal opinion is that more torque will just translate to more tire spin, and will not actually help with forward momentum much).

It's up to you man...

[C.Plavan]

The torque/wheel spin of the EJ25 is exactly what makes me go back and forth! Haha. What final drive do you have?

[Goldwing]

I'm a little weak on the subie engines as well, and don't race, but as I understand it the 2.0 engine revs much higher. Near 8,000 vs. 6500 redline on the 2.5. Others, please correct me on that, I've seen those numbers float around. Going with the 2.0 liter engine, what you sacrifice in low end grunt, you'd gain with a little more range in each gear. Even if my numbers are off, it's just food for thought, and totally depends on the type of racing you plan to do with the 818.

[C.Plavan]

Strictly road Course wheel to wheel racing/NASA Enduro. No Autox for me.

[Mechie3]

Don't forget that the legacy GT (LGT) and 06+ WRX had 2.5L motors and aren't usually as expensive as STI motors even though they're almost identical. Only the 06/07 WRX motors can be purchased as part of a full donor, but since it sounds like you're sourcing the motor apart from the chassis bits, open up your options.

The "STI" badge on any Subaru part automatically drives up the price due to fanboy-ism.

[C.Plavan]

Don't forget that the legacy GT (LGT) and 06+ WRX had 2.5L motors and aren't usually as expensive as STI motors even though they're almost identical. Only the 06/07 WRX motors can be purchased as part of a full donor, but since it sounds like you're sourcing the motor apart from the chassis bits, open up your options.

The "STI" badge on any Subaru part automatically drives up the price due to fanboy-ism.

Thanks for that info- Yes, I'm piecing it together and not buying a donor.

[longislandwrx]

Go 2.0...

If you ever max out the stock motor, a built 2.0 short can be had for about $3500 good for 600BHP

Port the heads and add some cams for another $1200 and you'll have a monster that still can rev past 8000.

[Xusia]

My donor is a 2003, so it has the 3.9 final drive.

I also wanna say go for the 2.0, but hey... You're an adult, and it's your project... Do what YOU want!

[Xusia]

Another idea just came to mind that might actually be perfect for you. Have considered the hybrid 2.34 liter engine? I believe Maxwell Power Services makes these (http://www.getadomtune.com/). For a track duty car, this seems perfect!

[Mechie3]

Thanks for that info- Yes, I'm piecing it together and not buying a donor.

Almost forgot, not all LGT's were turbo. It wasn't until 2005 I think the LGT was a turbo'd 2.5.

[PhyrraM]

Almost forgot, not all LGT's were turbo. It wasn't until 2005 I think the LGT was a turbo'd 2.5.

Correct. 2005-2009.

2010+ hard the turbo remounted in front of the crank pulley and will likely not fit an 818.

[autostang]

From what I have seen it looks like the 2.0 tends to have a harsher spike in power where the 2.5 is more linear. Is there any concern that the power profile could make the light weight rear wheel drive car harder to control?

[Canadian818]

Would a tranny from a 06/07 bolt to a 2.0L?

[PhyrraM]

Would a tranny from a 06/07 bolt to a 2.0L?

Yes. Use the flywheel/clutch assembly that matches the transmission.

[Xusia]

From what I have seen it looks like the 2.0 tends to have a harsher spike in power where the 2.5 is more linear. Is there any concern that the power profile could make the light weight rear wheel drive car harder to control?

I'm certainly no EJ expert, but I really don't think so (and this coming from a guy who really doesn't like turbos and their power curves in general). If the power curve is harsh enough to be of concern, it would probably only be so under full throttle. So unless you are absolutely flooring it around a corner, I doubt you have much to worry about. The 2.5 has more torque, which, IMO, is more likely to cause the wheels to spin/lose traction under circumstances where the 2.0 wouldn't (i.e. part throttle).

Mechie3 and some others have experience racing these engines and can likely give you a much better real world idea of what to expect.

[Evan78]

I keep going back and forth- EJ20 or Ej25.....
JDM EJ20 STI motors can be had for cheap, The US EJ25's STI's are considerably more. I'm just looking at 325-350 HP for my 818R. I'm clueless with Subaru engine stuff, If I could stuff my extra 2.5L Porsche Flat six in there I would :P

I'm totally open to suggestions. Strictly going to be racing it.

What prices are you finding for these? I've never been in the market for an EJ207, but I thought they were more expensive than any used US engine.

A search of the Proven Power Bragging forum on Nasioc should yield a lot of results if you want to see the power curve of various setups.

[metalmaker12]

I have an ej207 for me and a couple ej205's for sale

[Mechie3]

The 2.5's can (with a small turbo) be flat in the HP curve, but peaky in the TQ curve. My torque with the stock wrx turbo was as peaky as could be, but HP was flat from 3200 to 5500 ish rpms. Great for slow corner exits, but if you weren't careful you'd spin both inside wheels (stock open diff).

[philly15]

id sell my ej255 from my 06 wrx if i can find a nice condition ej22t

[metalmaker12]

id sell my ej255 from my 06 wrx if i can find a nice condition ej22t

I will check on this, my friend has a couple ej22t in great shape, problem is I dont think he would even trade them .

[Ironhydroxide]

my plan is an EJ22T with an 83mm crank (making it close as makes no difference 2.5Liter) Easily a 10:1 Compression Ratio with normally Stocked parts (weisco piston, Eagle rods, Etc.)

EDIT: noticed i didn't put anything about heads on here.

my plan is the EJ207 head(intake variable cam), valves deshrouded, and a good knifeedge polish job, Upgraded springs/retainers, and a Long duration medium lift cam. for torque.

[papajon1000]

I've become very attached to my ej255 in my legacy gt. People are correct that it can not rev as a high as a 2.0 and it gets kinda spendy to rev it past ≈8k. But I have revved mine out to 7200 (50-100 mph pulls) on occasion with stock valve train and there are plenty of other people that have done the same.

In all honestly I like playing with the variable valve timing. The EJ255 or 257 are the only USDM turbo engines that received AVCS.

Also the Outback XT and the Forester XT had the ej255. As someone mentioned earlier these engines are less expensive to find than the STI EJ257.

But again this is my opinion and "different strokes for different folks"

Jon

[Mechie3]

I also increased my rev limiter to ~7200 as well. Turbo died way before that, but it was often faster to bang the limiter than to shift to third and back on an AX course.

[metalmaker12]

As mentioned before Version 8 EJ207 twinscroll, which is my favorite subaru engine along with the ej22t

securedownload-23.jpeg

photo-8.JPG

[philly15]

As mentioned before Version 8 EJ207 twinscroll, which is my favorite subaru engine along with the ej22t

securedownload-23.jpeg

photo-8.JPG

my two favorites as well if i had anyway to afford an ej207 i would maybe down the road...ive seen full ej22t long blocks go on nasioc for less than $800 so ive been very tempted to pick one up but im on a more strict of a budget for now at least until i have my initial setup going and they work out the auto x classing for the 818

[metalmaker12]

I have been saving, selling cars, parts and doing side work for like 12 years which has put me in a good position to build the 818. If your not given everything it just takes more time, but it is better this way. I have a friend who has two ej22t, but he does not part easy.

[IMPREZvWRX]

my two favorites as well if i had anyway to afford an ej207 i would maybe down the road...ive seen full ej22t long blocks go on nasioc for less than $800 so ive been very tempted to pick one up but im on a more strict of a budget for now at least until i have my initial setup going and they work out the auto x classing for the 818

I'd guess DM with a 2.0 and EM with a 2.5.

[Buzz Skyline]

I'm certainly no EJ expert, but I really don't think so (and this coming from a guy who really doesn't like turbos and their power curves in general). If the power curve is harsh enough to be of concern, it would probably only be so under full throttle. So unless you are absolutely flooring it around a corner, I doubt you have much to worry about. The 2.5 has more torque, which, IMO, is more likely to cause the wheels to spin/lose traction under circumstances where the 2.0 wouldn't (i.e. part throttle).

Mechie3 and some others have experience racing these engines and can likely give you a much better real world idea of what to expect.

We have a 2002 WRX with the 2.0 and a 2006 STI with the 2.5. The turbo lag is huge in the 2.0 and the torque takes off around 3500. The 2.5 is much more linear and useable, in everyday driving as well as autocross and rallycross. We're planning to use the WRX as a donor for our 818, mostly because you'd have to be nuts to tear apart a pretty '06 STI. I think the 2.0 will be a better match for the 818 anyway. Low torque at tip in and boost kicking in late could keep the wheel spin down and make the ride exciting.

[Dan Babb]

Does the type of tracks you'll be racing on come into consideration here?

For example, if you're running a track like Sebring (that has a couple long straights), wouldn't you want the advantage of more horsepower for higher top speeds? If you're on a track with a lot of shorter straights, then maybe you would want more torque ( or you could lose good time coming out of the turns ).

I don't really know if that does come into play in your decision...more thinking out loud and wondering.

[cmcintyre]

Plus, of course, if you can hold off until NASA has classed the 818, then you can see what your competition will be and which engine (and/or mods to it) will give you the best chances of winning. I guess thats why I chose a Spec E30 to race wheel to wheel. No engine or tire (big $$) decisions....

[RM1SepEx]

I'd guess DM with a 2.0 and EM with a 2.5.

AM for a while (est 2 years) then EM for both. A 2.0 turbo runs in EM

[C.Plavan]

Plus, of course, if you can hold off until NASA has classed the 818, then you can see what your competition will be and which engine (and/or mods to it) will give you the best chances of winning. I guess thats why I chose a Spec E30 to race wheel to wheel. No engine or tire (big $$) decisions....

I have been thinking about that also. I just want to get stuff rolling- but you are right, I only want to do it once.

[Xusia]

For example, if you're running a track like Sebring (that has a couple long straights), wouldn't you want the advantage of more horsepower for higher top speeds?

As I understand it, the 2.0 and the 2.5 can make similar HP. The main power difference between them is torque. The are also, of course, technical differences (i.e. throttle by wire) as well.

[JAubin]

Digging around for a dyno plot to compare the 3 engines. This doesn't look 100% correct to me, but it's a start at least. EFI Logics has a dyno plot database, I was hoping to find baselines for the EJ205, EJ207 and EJ257 but realistically nobody is going to run anything less than a stage 2 most likely, and for your purposes EJ205 definitely need a new turbo and supporting mods to get to the HP range you're looking at.
dyno.jpg

[Mechie3]

As I understand it, the 2.0 and the 2.5 can make similar HP. The main power difference between them is torque. The are also, of course, technical differences (i.e. throttle by wire) as well.

Peak HP, yes, area under the curve, no. A stage 2 ej20 and a stage 2 ej25 are both limited by the turbo, but an ej25 has a flatter hp curve while the ej20 will hit peak later and for a smaller rpm range.

If you really want a leg up in racing, and it's allowed, the new FA20 makes more hp than an ej series motor with the same turbo. There's some video about crawford and turbo brz's where they tell the praises of the new FA20 motor.

[philly15]

I have been saving, selling cars, parts and doing side work for like 12 years which has put me in a good position to build the 818. If your not given everything it just takes more time, but it is better this way. I have a friend who has two ej22t, but he does not part easy.

it most definitely does take more time im probably one of the very few if any other people who are college students building one of these lol i owned 4 wrxs and just wanted something different and i figure for what i could buy an STi for and set up for the track setup i want i could very easily have built an 818 which is most definitely going to be unique and in my opinion a lot more fun there was an ej22t long block with around 120k miles for sale on nasioc a couple months ago that someone was selling for 600 plus shipping probably should have bought it kinda regret that now

[C.Plavan]

Peak HP, yes, area under the curve, no. A stage 2 ej20 and a stage 2 ej25 are both limited by the turbo, but an ej25 has a flatter hp curve while the ej20 will hit peak later and for a smaller rpm range.

If you really want a leg up in racing, and it's allowed, the new FA20 makes more hp than an ej series motor with the same turbo. There's some video about crawford and turbo brz's where they tell the praises of the new FA20 motor.

That would be cool if they released the FA20 crate motors, and we knew it would fit right.

[rjh2pd]

it most definitely does take more time im probably one of the very few if any other people who are college students building one of these lol i owned 4 wrxs and just wanted something different and i figure for what i could buy an STi for and set up for the track setup i want i could very easily have built an 818 which is most definitely going to be unique and in my opinion a lot more fun there was an ej22t long block with around 120k miles for sale on nasioc a couple months ago that someone was selling for 600 plus shipping probably should have bought it kinda regret that now

Yeah, i think that you will be one of the luck few, if only, to build one while in college. I'm a college student on summer break in the middle of doing my headgasket. Ill be waiting till i get out to build mine (hopefully ill be done next may). The only bad thing about the boxer engine is that they are hard to work on the actual engine while in the car. I'm wondering if there will be more room to take the heads off in the 818. the AC compressor and alternator should be easy to get to thought.

back on topic I'm going to go with the the ej20 since it will be a road car and cheaper that the ej22 (most likely). But it is all up to you, I want mine to be able to rev which is why im not going with the 2.0 vs the 2.5.

P.S. the FA20 would be great, the turbo legacy in japan is putting out sti numbers with the turbo'd version. That does use a front mounted turbo though so you'd have to get custom headers to up-pipe.
Pros: more power, efficiency, and new
Cons: $$$$, and custom work

[philly15]

i do like the 2.0 not gonna lie i had 3 wrxs that were 02 or 03's and had some very fun setups on each one and that was in a 3200 lb car i just happened to get a great deal on an 06 so i went with it ive always wanted to do a 22t or one of the destroker 2.5 motors that ive seen Maxwell Power Services build just looks sick as lots of them rev to 8800 and higher on those destroker motors but there is no way i could afford that on the first go around here haha maybe down the road...