Sportswagon EJ20 N/A tuning

[Bradenrm]

G'day gents;

I've got a little red subaru sportswagon :P and I want to extract some more performance out of it, without going down turbo lane. The reason being that I'm on my "P" Plates. Yeah, sucks to be me.

I'm taking my chances anyway with mods that don't attract attention. So What I've started with is resonator removal, which then turned into plugging the fenderwell from the engine bay hot air (thus basically making a cold air intake) and finally a K&N air filter.











I've also switched to 98 RON fuel and done an ECU reset to re-calibrate for the new fuel and airflow characteristics.

I'm going to strap some borla headers and an exhaust system on next, but I was after some reccomendations especially concerning what muffler, new cat or not, and what size piping?

Then I'll do another ecu reset/tune if I can find a local tuner. Also on the agenda is a possible rear end disc-conversion, springs/struts (Can I just put WRX wagon springs on? I'll probably lower it 25-30mm if it will improve the handling), as well as a larger diameter wheel with a lower profile tire.
Then I'll just be looking at smaller gains such as strut braces, swaybars, upgraded bushes.

But is there anything else I can do? I know that N/A tuning isn't really worth it, but there have been some pretty nice gains already, with minimal expense and work. And I could always use an excuse for more carbon bits :P

I'm going to have a go at some track racing, and I'm participating in targa tasmania in a year or so as a co-driver, and the year following as a driver. I'll probably still be on my P's, so I won't get away with any outrageous turbo fun. For the record, my little red wagon will 0-60km/h in 3-3.5 recorded via gps and stopwatch, but the zero-100 is consistently 9-9.3. Obviously evident where a turbo would be beneficial :P


Thanks;

Braden

[El_Freddo]

G'day Braden.

All I can suggest to you is to go with the WRX suspension, forget too much about the boria extractors - rather go for a cat back setup that will bolt up to a turbo application reasonably easily.

Stick with this - basically grin and bear it, then once off your P's get a WRX half cut for the same year as your WRX - go from there

I've not had any experience in this so take this idea lightly - hopefully others will have more details as to what might be best.

Cheers

Bennie

[spike]

ENGINE WORK =)

so how much racing do yoyu want to do? go full wrx suspension, i think they have some tuning ability, if not get some suspesion that does

build a franken engine if youve got the money and the skills/balls from what ive seen they are pretty dam mental even in NA form

[H-top]

Because it is N/A and does not force air through
the intake system, you could look at making a new
intake from airbox to TB using silicone joiners and
aluminium tubing with fitting for lines.

Also oil type filters haw been known to take the
life from many Subaru air flow meters.

Keen to see more pogress!

[Bradenrm]

Because it is N/A and does not force air through
the intake system, you could look at making a new
intake from airbox to TB using silicone joiners and
aluminium tubing with fitting for lines.

Also oil type filters haw been known to take the
life from many Subaru air flow meters.

Keen to see more pogress!

I've looked into that. It's only money, I can't take it with me. I was thinking about the intake system just today, from the airbox to the throttle body. No backfire box though. It's running on 98, and if it backfires, it will definitely kill the MAF without the backfire box...whats the likelyhood of this occurring? I'm actually pretty stoked with the results thus far.


I am interested in this "fraken engine". What are we talking here, an ej22 intake manifold? Lets get serious :P Without going into cams and such, I don't have the facilities to pull an engine out.

[spike]

the franken engine is basically a subaru engine based on the idea of dr frankenstien =)

from what ive heard they are pretty much bolt together bits no need to machine or anyhting else.
Best engine ive seen in person (only subaru frankenstein ive seen in person) but also the best ive heard of EJ25 block, EJ20 T heads, EJ22 pistons (could be wrong on that one) the cams were standard or with a regrind cant quite remember but it really was an awesome engine

[spike]

I've looked into that. It's only money, I can't take it with me.

Without going into cams and such, I don't have the facilities to pull an engine out.

maybe its time to invest??

[H-top]

Bradenrm,

it's not the Backfire that kills it, it's the oil getting
sucked from the filter onto the meter.

Backfires are uncommon on a healthy engine.

You want as smooth and gentle curves as possible

cheers

[TOONGA]

the franken engine is basically a subaru engine based on the idea of dr frankenstien =)

from what ive heard they are pretty much bolt together bits no need to machine or anyhting else.
Best engine ive seen in person (only subaru frankenstein ive seen in person) but also the best ive heard of EJ25 block, EJ20 T heads, EJ22 pistons (could be wrong on that one) the cams were standard or with a regrind cant quite remember but it really was an awesome engine

it would've been EJ25 pistons as they are 99.5mm as opposed to EJ22 which are 98.9mm

TOONGA

[spike]

yeah it wasnt somthing we got into, are there any other pistons that are 99.5??

basically they have awesome flowing heads, used to feed air into a competion turbo engine (ej20t from an sti) then shaved to raise compression

the engines have so much power but no lag (no turbo) massive torque and power cause of the compression, doodle test = win

[TOONGA]

there are plenty of oversize pistons available, but the sizes I quoted are stock. I know if you go looking you will find 100mm + pistons for the EJ25 and the EJ22 as well, but then you get into sleeving territory.

TOONGA

[spike]

ahh ok yeah
i was reading a chart i have about combinations

twin cam heads from the EJ20T? TT? somthing like that
with the 2.5 block and standard pistons gives somthing like 10:1 CR
not too shappy
also theres another combination that give 13:1 but id guess thats a bit high

[H-top]

You don't need special combinations to
get the CR you desire.
Either shave it or get a bigger head gasket.

13:1 is perfectly acceptable with good fueling
and timing control

Sometimes mechanics is made too complicated.

Most stuff fits with EJ's

cheers

[spike]

your right H-hop however the CR is not the only reason to use the franken motor, shaving and head gaskets can only go so far, there is a limit after all

and the idea is to get better flowing heads more than the the CR quad cams are better i hope you would agree, and turbo heads are inherintly much freer flowing

[Bradenrm]

Alright...before the motor:
1. Airbox to TB Intake. Any tips on finding parts for that?
2. 2.5" Cat-back exhaust. Will discuss with exhaust place about the best setup possible which isn't going to be illegal (over the noise threshold)


The Fraken motor:
The EJ20 Currently has 153,000km on it. So sweet f all considering it's a subie motor.
The RH rocker cover has a slight leak. Basically a couple drops of oil on shutdown. And it recently tore a CV boot (a couple of mm, so going to seal it for the time being, then put a new cv entirely on it. Caught it within 20km of the tear).

I'm thinking I'd like to either have the stock heads shaved, or ej18 heads installed? Although that then runs he risk of not being aware of the ej18 heads, and If I had them shaved we'd be looking at too much compression, wouldn't we? It might have to run 95 RON at some point, as that is all that is available in tassie.

Ej18 heads/Ej20 heads shaved, Ej20t heads shaved
With standard ej20 block

Now, what Ecu? I cant get a response from any tuners as to whether they can play with my stock ecu, which limits the ej20 in my sportswagon to a roaring 85 kw. So soon enough, I'll run into that limit, won't I? Or will it not limit it, per se, but just wont make the most of it?

I'd have to pay a mechanic to install heads for me, I can do it myself, but my less mechanically inclined parents aren't so keen on me ripping an engine out in their front yard.

[H-top]

Spike;

Of course DOHC has more advantages and is a great leap.
most EJ20T heads flow well from the box.
There are however Differences.

Early Liberty/Legacy - Hydraulic Lash Adjusters - Noisy + no valve adjustment

WRX pre AVCS - Shim over or under bucket - silent

STI heads flow better again but heads are only as good as the CAMS in them.
look for a good set of STi RA to match the heads for decent lift and duration
without the engine having a shit idle that sounds like the engine is saying

"Potato, Potato, Potato, Potato" over and over again. much more discreet.

but with DOHC heads you will need the timing covers to match it.

to my knowledge the GTB TT heads are some of the best flowing heads out of the box
and am looking for first hand opinions from the rest of the forum.

Bradenrm;

The intake mod does not look stock, but done right. is not illegal anyway.

Ideally, in my world, this would be my combo in a semi conservative sense

EJ25 shortblock

GTB TT DOHC heads - ported - no polish (google pro's and con's)

V3/4 STI Cams

RA Inlet Manifold - COZ ITS RED! - if u paint it

440cc Injectors

Link G4 ECU - i like them, they work well, pretty advanced, well priced and lots of wank factor functions

Cold air intake

Equal length ceramic coated extractors and 2.5 zorst


Thats my list using mostly OEM parts from other quite available sources.


Cheers,
S

[Bradenrm]

I think for the money involved in all that, I should look at a rex once I'm off my p's. It's cost prohibitive without having the space to do it yourself. As it is the parents are pretty iffy that I went and did a service on it, with oil change, e.t.c. considering I'd literally never laid a finger on an engine before. So I'm not sure how they'd react if I went and started doing all of that. Paying for it + labour I'd be looking at near enough to 6 grand anyway, and I think I'd be pretty disappointed in the performance to $$$ ratio in that event.

So at this stage, the list would be a 2.5" exhaust from the cat back (will headers really not make a difference?) which is bloody cheap, $500-700 tops. Suspension, wheels+tires (probably get the lot done at the same place inside of $1500). Refine intake (super cheap again, maybe only $100 in parts).

Then If I'm really keen, strut braces are an easy way to sink a few hundred more. But that money would get me a disc rear end.


Paying for an engine swap is big $$$ also, in the neighborhood of a WRX of my preferred year and type.


Thanks heaps for all your help guys! I've learned heaps and I truly appreciate it. Thanks

[El_Freddo]

the franken engine is basically a subaru engine based on the idea of dr frankenstien =)

from what ive heard they are pretty much bolt together bits no need to machine or anyhting else.
Best engine ive seen in person (only subaru frankenstein ive seen in person) but also the best ive heard of EJ25 block, EJ20 T heads, EJ22 pistons (could be wrong on that one) the cams were standard or with a regrind cant quite remember but it really was an awesome engine

it would've been EJ25 pistons as they are 99.5mm as opposed to EJ22 which are 98.9mm

Are we sure we're not mixing up the idea of an EJ22 block and piston heads with an EJ25 crank and rods? This creates a stroked EJ22 that's something near 2.3 litres in capacity I believe. I'm sure someone knows more about this.

...and turbo heads are inherintly much freer flowing

Usually because they're the quad cam design.

The EJ20 Currently has 153,000km on it. So sweet f all considering it's a subie motor.
The RH rocker cover has a slight leak. Basically a couple drops of oil on shutdown.

Yep baby engine this one! And the rocker cover oil leak is a factory option - wether you like it or not it will leak at some stage!

I'm thinking I'd like to either have the stock heads shaved, or ej18 heads installed? Although that then runs he risk of not being aware of the ej18 heads, and If I had them shaved we'd be looking at too much compression, wouldn't we? It might have to run 95 RON at some point, as that is all that is available in tassie.

While the trick of running a head from a smaller capacity engine for bigger compression used to work on the likes of the old holden red engines, I think you'll find that you will only restrict the flow of the engine through smaller port sizes with the EJ18 heads. This is something I've only heard and have not had Ej18/20/22/25 heads to compare.

I'd have to pay a mechanic to install heads for me, I can do it myself, but my less mechanically inclined parents aren't so keen on me ripping an engine out in their front yard.

Best way to learn!

Your final assessment of the given information in the post above is well thought out from a bang for buck + effort factor. If you don't want to run a second vehicle you could get either a half cut or a written off WRX of the same year to shift all the parts over to yours. It could be a little cheaper but would mean down time on your current ride.
Also being that you've got an impreza and they came from the factory with a turbo option (the WRX) there's no requirements for engineering from Vicroads, the only thing you have to do is update your rego details and engine number

Cheers

Bennie

[spike]

i didnt think of that one bennie, but dont see the point of going up .1 of a litre when you can use the ej25 block

Apparently the heads fit straight on, its done in america a lot, ej 18 will get more compression but less flow so id go somthing quad cam for the flow like the ej 20 head
But were getting ahead of our selves!


Best place i know of the mount a cold air/ram intake is just before the windscreen

[El_Freddo]

i didnt think of that one bennie, but dont see the point of going up .1 of a litre when you can use the ej25 block

Sometimes its about cost effectiveness - if you can get your hands on an EJ25 crank and rods your stock EJ22 ECU should be able to handle the capacity changes without any real need for dyno retuning or an aftermarket ECU to be used, plus it looks stock from the factory on your rego details

Cheers

Bennie