And the debate still goes on (4G63 vs. EJ / Forged vs. Cast)

[AtomicLabMonkey]

Originally Posted by BAN SUVS

Maybe I'll write a quick Import Engine Decoder Ring for you later.

Sweet! Does it come with a Captain Midnight sticker?

[MikeSTI]

[/rant on]

you guys always nit-pick the little things but never quite see the bigger picture........................

an engine is an engine. the engines being talking about are 4G63 2.0 liter inline 4 with forged internals and EJ20 2.0 liter horizontal 4 with cast internals.

You guys keep getting stuck with emissions but forget about the after market NOT EVERYONE CARES ABOUT CA EMISSIONS, get it

if the car came with forged internals we would see more WRX's with bigger after market gains, so what if its detuned from the factory if I have a good platform to start with I can see the overall gains with mods

I really dont care that I have the EJ257 with 300 hp if I can only get another 100 hp out of it before it blows(without changing the cast internals), while the 4G63 can support way more power with less mods, do to the fact they put it out on the market with better internals and detuned it for emissions. now you get cars like the FQ400, not CA emissions legal, but what did they change on the car? I bet it wasnt the pistons

[/rant off]

[Kevin M]

All I did was explain to Sergio WHY we didn't get the EJ207. You took that as some sort of statement that I thought the EJ205 was superior or equal to it. It's not. But the fundamental design of the EJ207 prevents it from being sold here or run on 91 octane gas. The aftermarket has absolutely nothing to do with what does and doesn't get sold from dealer showrooms. If you want forged pistons- go get them. But your EJ257 has no need for them. None. So why would Subaru spend the extra money for them when they gain nothing? Furthermore, it's not CA emissions that keep cars from getting imported. Any federalized engine can easily be adapted to CA emissions. The issue is with quirky EPA requirements that take precedence over power and even drivability. TGVs exist because of the EPA, hence JDM Subarus don't have them.

[AtomicLabMonkey]

Originally Posted by MikeSTI

You guys keep getting stuck with emissions but forget about the after market NOT EVERYONE CARES ABOUT CA EMISSIONS, get it

Manufacturers care, because they sell a lot of cars here.

[MikeK]

Originally Posted by MikeSTI

now you get cars like the FQ400, not CA emissions legal, but what did they change on the car? I bet it wasnt the pistons

I'll take that bet!!

linky

Lancer Evolution VIII MR FQ400 parts list:

Custom built Garrett GT Dual Ball bearing Turbocharger
Owen Developments custom manufactured cast Stainless Steel Exhaust Manifold and Exhaust Elbow
Omega Forged Pistons
HKS Forged Con Rods
HKS 680cc Injectors
Zytec ITP116 High Pressure Fuel Pump
HKS 1.6 mm Steel Head Gasket
Motec M800 OEM ECU
HKS Iridium Spark Plugs
Jan Speed High Flow Sports Cat
Alcon competition derived 240 mm high clamp mode, heavy duty clutch complete with Cera-metallic 6 paddle sprung centred drive plate
HKS High Strength Head and Big End Bolts
Alcon Mono6 Brake Kit incorporating Monobloc 6 pot road caliper with 343 mm curved vein Disc on a Aluminium mounting bell assembly with Ferodo DS2500 brake pads
Ralliart Aero Mirrors
Carbon Fibre Front Lip Spoiler
Carbon Fibre "Sharks Tooth" Rear Vortex Generator
PIAA High Performance Light and Wiper Upgrade
Gloss Black Team Dynamics Lightweight Alloy Wheels
Driver Training Course

[MikeSTI]

wow you guys just have it all dont you


MikeK - I cant believe even you came to the table with somthing..........


............I guess I should just give up and bow down because you guys cant be wronge



The Lancer Evolution is powered by a proven and potent version of the 2.0-liter, 4G63, DOHC, four-cylinder engine design that has been steadily refined for improved durability, flexibility and peak power over the past decade. The engine's reciprocating assembly has been suitably reinforced with forged metal components to better withstand the increased cylinder pressures of forced induction. cant seem to figure out why it only makes sence to me but ohh well

[MikeSTI]

Originally Posted by AtomicLabMonkey

Manufacturers care, because they sell a lot of cars here.

I take thats as Ford doesnt work with Saleen, Roush, Cobra, SVT?

oh yah all there products are smog legal

[sperry]

Originally Posted by MikeSTI

wow you guys just have it all dont you


MikeK - I cant believe even you came to the table with somthing..........


............I guess I should just give up and bow down because you guys cant be wronge



The Lancer Evolution is powered by a proven and potent version of the 2.0-liter, 4G63, DOHC, four-cylinder engine design that has been steadily refined for improved durability, flexibility and peak power over the past decade. The engine's reciprocating assembly has been suitably reinforced with forged metal components to better withstand the increased cylinder pressures of forced induction. cant seem to figure out why it only makes sence to me but ohh well

First the sarcasm is unnecessary. No one else is insulting others, just posting their technical opinions.

Second, I'm not even sure what you're arguing. Are you trying to say the only difference between the EVO motor and the WRX's 2.0L motor are forged pistons? That the reason the US WRX doesn't make the same power as the EVO with just bolt ons is because the US WRX doesn't have forged pistons?

As far as I can tell, everyone's agreeing that forged pistons in a 2.0L EJ motor would be better than not. Everyone's also saying that the EVO does very well to make lots of power out of an old design, and using forged pistons is part of that equation.

However, the US EJ205 (the 2.0L WRX motor) simply can't make the kinda of power an EVO can make even with the addition of forged pistons, since the design of the block itself leads to detonation. If that weren't the case, then there wouldn't be an EJ205 and an EJ207 (JDM 2.0L STi motor). If the EJ205 could make the power that the EJ207 makes just by adding forged pistons, then they're wouldn't be an EJ207.

the real reason for the two motors is that the better EJ207 can't come stateside because it won't pass US emmissions and fuel mileage requirements, forged pistons or not. That is the entire reason for the development of the EJ257 (2.5L US STi motor)... which doesn't need forged pistons to make the same power as the EJ207 because of the displacement.

Basically, the EVO motor makes more power than the WRX with bolt ons because it's got a better block, and not just forged pistons. If you want that kind of performance out of a 2.0L subaru motor, then you'll need more than just forged internals, you'll need the better EJ207 block, which Subaru simply can't sell in the US. Instead we get the EJ257 which is basically the same motor as the EJ205 as far as it's ability to pass emmissions and mileage requirements, but has the extra displacement that allows it to make power like the EJ207.

[MikeSTI]

Originally Posted by MikeSTI

I still like my STi

It would have been nice if they added the forged internals :?

you guys only jump people and dont see how it starts?

[sperry]

Originally Posted by MikeSTI

I take thats as Ford doesnt work with Saleen, Roush, Cobra, SVT?

oh yah all there products are smog legal

I believe that all Ford, Saleen, Roush, Cobra/SVT vehicles sold for use on US streets meet or exceed CARB regulations. Otherwise they're sold as off-road/racing application only, like Ford's huge crate NASCAR style motors.

It's similar to importing a Spec-C motor for a rally car. You can get 'em but they're expensive and aren't offered as OEM equimpent on a US market road-car.

[AtomicLabMonkey]

Originally Posted by MikeSTI

I take thats as Ford doesnt work with Saleen, Roush, Cobra, SVT?

oh yah all there products are smog legal

Saleen, Roush & SVT cars are all 50-state legal.

In general, OEM's do all kinds of things for mileage, emissions & cost concerns - and just because Brand-A puts one part in their car, doesn't mean Brand-B can or will put the same kind of part in their car, even if they are direct competitors. It might only cost $100 more per car to put forged pistons in vs. cast, but when you multiply that out over the entire run of cars for a year it adds up to a shiteload of money - which means the company is expending a large amount of money to please a relatively few car guys who need the extra strength. Those kind of expenditures are the first to go when the corporate beancounters start looking for places to cut costs.

As an unrelated example, my car came from the factory with a whopping 215bhp serving of weaksauce, even though Camaros of the previous years came with 275bhp. The Mustang still sold well despite the difference, so Ford obviously saw no reason to change what was "working".

[MikeSTI]

Originally Posted by AtomicLabMonkey

Saleen, Roush & SVT cars are all 50-state legal.

In general, OEM's do all kinds of things for mileage, emissions & cost concerns - and just because Brand-A puts one part in their car, doesn't mean Brand-B can or will put the same kind of part in their car, even if they are direct competitors. It might only cost $100 more per car to put forged pistons in vs. cast, but when you multiply that out over the entire run of cars for a year it adds up to a shiteload of money - which means the company is expending a large amount of money to please a relatively few car guys who need the extra strength. Those kind of expenditures are the first to go when the corporate beancounters start looking for places to cut costs.

As an unrelated example, my car came from the factory with a whopping 215bhp serving of weaksauce, even though Camaros of the previous years came with 275bhp. The Mustang still sold well despite the difference, so Ford obviously saw no reason to change what was "working".

I agree but with a car like the STi which is sold to a limited market they could have gone a step further with the design to help hold better power on the after market aplications. Thats all

[sperry]

Originally Posted by MikeSTI

I agree but with a car like the STi which is sold to a limited market they could have gone a step further with the design to help hold better power on the after market aplications. Thats all

I think what Kevin was trying to touch on was that by the time the lack of forged pistons in the EJ257 are limiting your power generation, the design of the block itself is going to be limiting you as well.

Basically the cast pistons in the EJ257 are good for tons of power, and once they max out you're going to need to switch to the EJ22 motor (2.2L fully closed deck, forged internals) anyway. In fact, the 1st run of US STi had forged pistons, but Subaru decided they were unnecessary and saved some money by going to cast ones.

Remember, forged pistons allow a motor to handle higher cylinder pressures, but they will still break if the car knocks. Unlike the EVO motor, the EJ motor will start to knock at high boost pressures, even if you're giving it enough fuel, as it's a limitation of the block itself. Even if the pistons were forged from the factory, they wouldn't reduce knock unless they were lower compression pistons, whch would allow for more power (assuming a bigger turbo) but would reduce the low-end grunt that make the STi motor so fantastic.

Frankly, the FQ400 may make 400hp, but I'll bet a 350hp STi is more fun to drive in the real world, due to the low-end torque.

[AtomicLabMonkey]

Originally Posted by MikeSTI

I agree but with a car like the STi which is sold to a limited market they could have gone a step further with the design to help hold better power on the after market aplications. Thats all

You'd be surprised at the amount of corporate restrictions that are in place even on limited market special projects like that. I've talked with some guys involved with SVT at Ford, and their design process is getting heavily controlled by the mainstream corporate entity these days.

[MikeSTI]

Originally Posted by sperry

I think what Kevin was trying to touch on was that by the time the lack of forged pistons in the EJ257 are limiting your power generation, the design of the block itself is going to be limiting you as well.

Basically the cast pistons in the EJ257 are good for tons of power, and once they max out you're going to need to switch to the EJ22 motor (2.2L fully closed deck, forged internals) anyway. In fact, the 1st run of US STi had forged pistons, but Subaru decided they were unnecessary and saved some money by going to cast ones.

Remember, forged pistons allow a motor to handle higher cylinder pressures, but they will still break if the car knocks. Unlike the EVO motor, the EJ motor will start to knock at high boost pressures, even if you're giving it enough fuel, as it's a limitation of the block itself. Even if the pistons were forged from the factory, they wouldn't reduce knock unless they were lower compression pistons, whch would allow for more power (assuming a bigger turbo) but would reduce the low-end grunt that make the STi motor so fantastic.

I guess I'll just agree to disagree simply because I think you limit the thinking process by running back to a smaller motor to get the horse power just after putting the smaller motor down. I would think if I was going to get a new short block I would want a 2.5 or bigger 2.8 as a replacement rather then a 2.2, to me it sounds like closed deck is more important then the size it self?

[MikeK]

Originally Posted by MikeSTI

MikeK - I cant believe even you came to the table with somthing..........

Actually Mike I do agree with you, I think the 4G63 engine is way better than the EJ205/07/57. And I agree that if they had come with forged internals, then detuned for emissions, you could push the car further with aftermarket parts. But no car manufacturer is going to spend extra money that they don't have to.

A lot of guys on nasioc are having luck pushing the EJ257 to 400+whp just adding forged pistons. Most of the 400 whp STis that have the stock pistons seem to be breaking after a while. Also, 91 craptane is a serious limitation, I am not convinced that a safe 400whp is possible at all on a small engine on 91.

I was talking with Nate last friday, and I asked him how far you can push one of those built blocks (you know, with the forged crankshaft/rods/pistons etc) ... I asked how much you could safely boost and his exact words were "you can boost until the cows come home". I am not sure what that is in psi, but I am guessing it is pretty high. He also said that a built engine in an STi could easily make 450 - 500 hp at the wheels :shock:

I guess like most problems in life, it can be solved by throwing vast sums of money at it

[Nick Koan]

Originally Posted by MikeSTI

... I would think if I was going to get a new short block I would want a 2.5 or bigger 2.8 as a replacement rather then a 2.2, to me it sounds like closed deck is more important then the size it self?

If you want ridiculous amounts of boost, yeah. Closed deck is more important then displacement.

I personally wouldn't do a 2.8 unless Subaru made it and made it was designed as a closed deck motor. If Subaru doesn't make it, I would assume that whatever 2.8 you want is a bored/stroked out EJ257 and it will actually be weaker then the EJ257 due to thinner cylinder walls. You can add more sleves and whatnot to strengthen the motor, but it still won't be as stong as a true closed deck motor.

[Kevin M]

Originally Posted by MikeSTI

I guess I'll just agree to disagree simply because I think you limit the thinking process by running back to a smaller motor to get the horse power just after putting the smaller motor down. I would think if I was going to get a new short block I would want a 2.5 or bigger 2.8 as a replacement rather then a 2.2, to me it sounds like closed deck is more important then the size it self?

Mike, you have to keep in mind that internal combustion engines are incredibly complex machines, with dozens and dozens of variables to account for. Each variable, when changed, causes domino effect changes to many others. Part of my inability to properly explain my points to you is that I'd have to bring you up speed on everything I've learned researching Subaru motors the last few years, and I can't. I'll try to limit this post to just a few key (hopefully, the most relevant) points to illustrate what I mean.

First, Forged pistons aren't "stronger" in terms of being able to handle more power/boost directly. Forged pistons are harder to destroy through detonation and pre-ignition damage. The reason they've fallen out of favor with me personally lies partly with the fact that the hyper-eutectic cast pistons in the STi are much stronger than standard cast pistons- in fact, they're very very nearly as strong as forged pistons. They're light and fairly detonation resistant, and they're less expensive. Here is a good link that explains the differences between the 3 kinds of pistons. The STi crank, rods, and bearings are plenty strong for building a usable track or race motor. Forged pistons vs. regular cast don't actually allow you to make more peak power- they just give you a little more margin for error with detonation. This link explains what detonation and pre-ignition actually are, and is one of the best primers for understanding tuning I've found.

Back to your last post. Displacement is important, but it's not the end-all be-all of turbo motors. In fact, within certain broad limits, motor size effects your peak horsepower in only one way- consider the following. A turbo, for example your stock VF39, has a certain range of air flow vs. boost pressure ratio that it is thermally efficient in. when people talk about compressor maps, this is what they mean. Example, using the stock WRX TD04 (sorry, nobody has published any IHI compressor maps yet, or I'd use the VF39):


See the small font numbers in the center of the graph, ranging from 60-75%? Those numbers indicate the thermal efficiency of a TD04 in those ranges. Thermal efficiency is basically a measure of how good the compressor is at not heating the air moving through it beyond what the pressure increase itself should create. Looking at a pressure ratio (basically, boost pressure, but not exactly) of 1.8 and a flow of 200 CFM, you see that it's in the peak efficiency range. If you look at 1.8 PR, at 350 CFM, you see the efficiency is barely 60%, meaning the air coming from the compressor is much hotter. you know what hotter charge air leads to.


Now, back to motor size. I said that motor size doesn't matter, right? This is because I can make up for air flow with higher RPMs. Obviously, there's a practical limit to just how high I can rev a motor. Current F1 motors see close to 18 or 19k rpms. That's way more than we need for this discussion. Lets say for sake of argument, the ratio of displacement needs to be matched by ratio of rev limit for the smaller motor. I.E., 2.0 is 20% smaller than 2.5, so it needs 20% more revs to flow the same amount of air. no problem. The EJ257 revs to 7k stock, and has been safely taken to 8k by quite a few people, with no mods. 20% more than 8k is 9.6k- call it 10. So, to match the flow of an EJ25 at 8k, an EJ20 spins to 10k. This relationship is why turbo size, and ONLY turbo size, determines how much torque you can make, with no octane limitations.

Man I'm wandering. See what I mean about having too much to explain at once to prove one point? I'm trying to keep it concise, honest.

Okay, so I've established that displacement is not crucial to making more peak power. What added displacement does is move your peak torque lower in the rev band, where it's more usable with reasonable gear ratios. I'd take 400 pounds of torque at 4k RPMs over 400 pounds at 7k. That's the advantage of displacement- not more power, just power lower in the rev band.

So, why did I say that you'd have to go to an EJ22 for over 400 whp? Well, I think you said something about closed deck- and that's it. To make over 500 hp at the flywheel, you need extremely high cylinder pressures- 25+ psi of boost on top of what the compression makes. I haven't stumbled on the equation for determining dynamic CR with FI yet- maybe Austin can pick me up on that later. anyways, it's EXTREMELY high- 3-5 times higher than your car has right now. Now, given high enough octane fuel, and good enough tuning to prevent knock, your pistons will still hold up to this, What can't hold up is the cylinder wall itself. it will start to flex, stretch, and warp at some point. This has several catastrophic effects. One, it causes head gaskets to blow. Two, it causes pistons to bind, bend, or excessively wear either their skirts or the cylinder walls. All 3 of these will result in near-instant engine failure at high torque outputs. The closed deck EJ22 is better able to resist the warping and bending forces that result from high boost pressures. That's why it's better for really high hp applications than the EJ25; it's not the forged pistons. A closed deck EJ25 would be better still, because it would be just as strong, but would move the power band back down while making the same amount of torque.

I guess that's enough for this post. If you want, I'll summarize the exact differences between the EJ207, the EJ205, and EJ257 and tell you what makes each one suitable for it's application. Then, I'll go into what makes the boxer motor so different from an inline 4, particularly the 4G63.

Edit: red X?

[MikeSTI]

Originally Posted by MikeK

I guess like most problems in life, it can be solved by throwing vast sums of money at it

its the down time that kills me

[Kevin M]

Originally Posted by MikeK

Actually Mike I do agree with you, I think the 4G63 engine is way better than the EJ205/07/57. And I agree that if they had come with forged internals, then detuned for emissions, you could push the car further with aftermarket parts. But no car manufacturer is going to spend extra money that they don't have to.

A lot of guys on nasioc are having luck pushing the EJ257 to 400+whp just adding forged pistons. Most of the 400 whp STis that have the stock pistons seem to be breaking after a while. Also, 91 craptane is a serious limitation, I am not convinced that a safe 400whp is possible at all on a small engine on 91.

I was talking with Nate last friday, and I asked him how far you can push one of those built blocks (you know, with the forged crankshaft/rods/pistons etc) ... I asked how much you could safely boost and his exact words were "you can boost until the cows come home". I am not sure what that is in psi, but I am guessing it is pretty high. He also said that a built engine in an STi could easily make 450 - 500 hp at the wheels :shock:

I guess like most problems in life, it can be solved by throwing vast sums of money at it

the Evo motor does have some advantages over the EJ series, especially once you start reaching for major power levels. In a stret car, in the 300 whp area, the EJ25 actually has advantages, namely low end torque.

Another thing I glossed over in that long post is octane- remember that all production engines have to work at the lowest common denominor; that means you have to be able to avoid knock on the worst gas in the worst conditions with the highest engine loads, without breaking. Ever. That really puts a damper on peak power you can make.

Also, both of yo have used the term "detuning"; that's really not something that exists. If I took a stock STi and tried to make 250 crank horsepower with it, it would run like ass, and be less reliable than it is stock. Not to mention, it would probably not run as clean. You simply can't take a high-octane JDM motor, and retune it on our 91 and expect it to run strong OR clean. You're asking it to do things it's not built to do.

Okay, I am running long again. I'm goin to start working on a series of posts for the tech archive. Hopefully it will be comprehensive enough that I can simply refer to it in the future.

P.S.- all Phase II EJ25 cranks are forged- even in the RS.

[BOO]

I am glad this thread was started... I am finding out a lot more useful information than I anticipated...
Way to go guys .. And MikeSTi, Thanks for the cool review ..Even if the comment was taken in a sarcastic state or not

[Kevin M]

Originally Posted by nKoan

If you want ridiculous amounts of boost, yeah. Closed deck is more important then displacement.

I personally wouldn't do a 2.8 unless Subaru made it and made it was designed as a closed deck motor. If Subaru doesn't make it, I would assume that whatever 2.8 you want is a bored/stroked out EJ257 and it will actually be weaker then the EJ257 due to thinner cylinder walls. You can add more sleves and whatnot to strengthen the motor, but it still won't be as stong as a true closed deck motor.

Oh, I forgot that part of Mike's post. 2.5 is as large as you want to take an EJ25 for high hp applications for several reasons.

There are two ways of increasing displacement- boring and stroking. There's not much more room for boring in either an EJ22 or EJ25- it's not really recommended to bore out more than what's required for an engine rebuild and remachining of the cylinder walls.

Stroking is safe, but doing it requires you to lower your redline at a faster rate than the displacement increases. A 2.8 liter EJ engine would have a redline of 5500 rpm, max. You lose your torque advantage by being forced to choose taller gears for your car. Frequently, you actually get a smaller powerband as a result of too much extra stroke.

[Dean]

Ughhhh... Are we talking about street cars, or race cars?

Maybe I'm wrong, but I don't think you are going to make anything with 2.0, 2.2, or 2.5l make 400WHP on 91 octane pump gas, so what are we talking about?

More displacement increases your ability to make more power with lower octane fuel, all other things being equal.

I'm with Mike K. on this one. I'll take a 2.5l over a 2.0, or 2.2 for use with pump gas every day, no matter what the internals. Of course, I'd prefer forged.

P.S. Do we know up to what VIN had forged internals on the US STI? Might be worth thinking about when looking for a used one.

[Kevin M]

Originally Posted by BOO

I am glad this thread was started... I am finding out a lot more useful information than I anticipated...
Way to go guys .. And MikeSTi, Thanks for the cool review ..Even if the comment was taken in a sarcastic state or not

For what it's worth, when you guys see me launch into a huge lecture about some technical subject, it's never to prove someone wrong. I do this because it's the catalyst for my own learning. I didn't learn all of the things I posted today until someone else asked the right question somewhere along the line, and I either went and dug up the answers somewhere or someone else did and posted it.

[Kevin M]

Originally Posted by Dean

Ughhhh... Are we talking about street cars, or race cars?

Maybe I'm wrong, but I don't think you are going to make anything with 2.0, 2.2, or 2.5l make 400WHP on 91 octane pump gas, so what are we talking about?

More displacement increases your ability to make more power with lower octane fuel, all other things being equal.

I'm with Mike K. on this one. I'll take a 2.5l over a 2.0, or 2.2 for use with pump gas every day, no matter what the internals. Of course, I'd prefer forged.

P.S. Do we know up to what VIN had forged internals on the US STI? Might be worth thinking about when looking for a used one.

IMHO, anything over 300whp is a "race car." In terms of engine anyway, even if it's driven daily on pump gas.

More displacement does indeed allow lower octane for a given power goal. hence the development of the EJ257 instead of adaptation of the EJ207 for the Us market. No other reason, period.

First I've heard of the EJ257 having forged pistons. Is this just an internet rumor?