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Old 11-20-2018, 05:02 PM   #51
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Originally Posted by mrsaturn7085 View Post
You've got it backwards - these motors do great with high torque around 4000 RPM. Raising the redline or leaning them out to make high RPM power... not so much.
Backwards? You're suggesting that big bore/short stroke engines are designed for low/mid power? Better call up Porsche and tell them they are doing it wrong with the GT3! Wait, similar bore/stroke/displacement per cylinder (a little larger and a little shorter) and check that powerband! pretty much 250-300wtq from low rpm to 8500rpm with 420ish whp on a 3.8. that's how an ej257 turbo should look.

I don't understand why you think that high rpm power means leaning out fuel though... that's not a thing.

Quote:
Originally Posted by whiterabbitrexy View Post
Its true torque do kill internals but on a serious question how do u make 400hp with only 300tq lol never seen that happen....
its just simple math, 300wtq at 7000rpm is 400whp. I make 300wtq flat to almost 7k, it drops a tiny bit after 6400rpm so only 365whp because stock heads and cams.
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Old 11-20-2018, 06:38 PM   #52
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Originally Posted by blurred View Post
Backwards? You're suggesting that big bore/short stroke engines are designed for low/mid power? Better call up Porsche and tell them they are doing it wrong with the GT3! Wait, similar bore/stroke/displacement per cylinder (a little larger and a little shorter) and check that powerband! pretty much 250-300wtq from low rpm to 8500rpm with 420ish whp on a 3.8. that's how an ej257 turbo should look.

I don't understand why you think that high rpm power means leaning out fuel though... that's not a thing.



its just simple math, 300wtq at 7000rpm is 400whp. I make 300wtq flat to almost 7k, it drops a tiny bit after 6400rpm so only 365whp because stock heads and cams.
Lol Not sure why your quote me when we can clearly see if you take your car to 400whp it will definitely not be on 300wtq.... maybe 330wtq..... still stand by what I'm saying its very hard to have 400whp with a shocking low of 300wtq
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Old 11-20-2018, 06:39 PM   #53
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Quote:
Originally Posted by blurred View Post
Backwards? You're suggesting that big bore/short stroke engines are designed for low/mid power? Better call up Porsche and tell them they are doing it wrong with the GT3! Wait, similar bore/stroke/displacement per cylinder (a little larger and a little shorter) and check that powerband! pretty much 250-300wtq from low rpm to 8500rpm with 420ish whp on a 3.8. that's how an ej257 turbo should look.
Uh oh - you don't think just because you have a motor similar in geometry to a Porsche that you drive a GT3 do you? The RS ratio on the Porsche 3.8 is closer to that of the EJ207. Piston speeds are slower, hence the increased redline. It's also... you know... a high compression N/A motor and has cams and intakes designed for this kind of performance; but that shouldn't matter much, right?

The EJ25 motor is a bored out 2.0 design that was originally developed to have low-end torque given the redline on competition motors was 5300 RPM at choke. The EJ207 *will* breathe better in the higher RPM range given the head design and factory turbo selection. The IHI VF turbos also do NOT at all perform well at higher RPMs on a larger displacement motor.

Think that the EJ lends itself naturally to circuit racing favoring higher RPM? Let me know how Subaru's GT300 cars did from 2005-2008.

Quote:
Originally Posted by blurred View Post
I don't understand why you think that high rpm power means leaning out fuel though... that's not a thing.
Look at any hop-up OTS base map (i.e. Stage 1/2) provided by Cobb if you don't think this is 'a thing'. More boost, leaner fuel, maybe some minor AVCS tweaks.

Lean/mean best torque @ high RPM is unsafe due to the additional cooling provided by a richer mixture on these motors (all turbo motors, but ours especially due to geometry). For a dyno queen, go for it... but if you try to sustain a mixture too lean on these motors and drive them hard for extended periods of time, you'll be melting cylinders.

Most factory turbo cars are extra rich @ high load/RPM from the factory - lean them out a little and you get more power. This is hot-rodding advice as old as factory warrantied turbo motors have existed.

Quote:
Originally Posted by blurred View Post
its just simple math, 300wtq at 7000rpm is 400whp. I make 300wtq flat to almost 7k, it drops a tiny bit after 6400rpm so only 365whp because stock heads and cams.
You didn't define RPM, you just said:

Quote:
It might be pushing it at 400whp/400wtq, but at 400whp/300wtq probably not.
GpN EJ20 motors regularly produce about 400 wtq reliably with nothing more than high octane fuel, raised boost, an open exhaust, and a restrictor (the last part being the key). I understand restricted motor design isn't a common idea on a street car... but I'm just saying that with an open exhaust and the right parts adjusting the powerband, these motors (even the 2.0) produce 400 wtq stock and will do so very reliably (although it's a little rough on the turbo given the PR increase).

My point was - it's easier to add low-end torque to a EJ motor than it is to turn it into a high-strung dyno queen and have it last. The old 'RPM' acronym will never NOT be valid.
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Old 11-20-2018, 07:00 PM   #54
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Originally Posted by whiterabbitrexy View Post
Lol Not sure why your quote me when we can clearly see if you take your car to 400whp it will definitely not be on 300wtq.... maybe 330wtq..... still stand by what I'm saying its very hard to have 400whp with a shocking low of 300wtq

If you can make 330wtq at 7000 you'll be at 440whp so even better. I'm not talking about my car doing it with current setup, but if I had cams or a slightly bigger turbo it would be simple.
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Old 11-20-2018, 07:11 PM   #55
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Originally Posted by mrsaturn7085 View Post
Uh oh - you don't think just because you have a motor similar in geometry to a Porsche that you drive a GT3 do you? The RS ratio on the Porsche 3.8 is closer to that of the EJ207. Piston speeds are slower, hence the increased redline. It's also... you know... a high compression N/A motor and has cams and intakes designed for this kind of performance; but that shouldn't matter much, right?

The EJ25 motor is a bored out 2.0 design that was originally developed to have low-end torque given the redline on competition motors was 5300 RPM at choke. The EJ207 *will* breathe better in the higher RPM range given the head design and factory turbo selection. The IHI VF turbos also do NOT at all perform well at higher RPMs on a larger displacement motor.

Think that the EJ lends itself naturally to circuit racing favoring higher RPM? Let me know how Subaru's GT300 cars did from 2005-2008.



Look at any hop-up OTS base map (i.e. Stage 1/2) provided by Cobb if you don't think this is 'a thing'. More boost, leaner fuel, maybe some minor AVCS tweaks.

Lean/mean best torque @ high RPM is unsafe due to the additional cooling provided by a richer mixture on these motors (all turbo motors, but ours especially due to geometry). For a dyno queen, go for it... but if you try to sustain a mixture too lean on these motors and drive them hard for extended periods of time, you'll be melting cylinders.

Most factory turbo cars are extra rich @ high load/RPM from the factory - lean them out a little and you get more power. This is hot-rodding advice as old as factory warrantied turbo motors have existed.



You didn't define RPM, you just said:



GpN EJ20 motors regularly produce about 400 wtq reliably with nothing more than high octane fuel, raised boost, an open exhaust, and a restrictor (the last part being the key). I understand restricted motor design isn't a common idea on a street car... but I'm just saying that with an open exhaust and the right parts adjusting the powerband, these motors (even the 2.0) produce 400 wtq stock and will do so very reliably (although it's a little rough on the turbo given the PR increase).

My point was - it's easier to add low-end torque to a EJ motor than it is to turn it into a high-strung dyno queen and have it last. The old 'RPM' acronym will never NOT be valid.
That's a lot of stuff.

Clearly you missed the point, talking about stock turbos and how you know what Subaru meant for the ej257....

I don't think you've ever seen what these engines can actually do when you build them to rev, or exploit them in stock bottom end form to make high power at higher rpm.

We are talking about can the ra stuff make more power, and I simply said that keeping torque in check and (only) running to 7000rpm you can easily make a safe 400whp. I don't need to define rpm because its a mathematical equation, if you can't tell what kind of powerband you'll get with a 400/400 setup vs a 400/300 setup simply from the numbers then you wouldn't have understood anyways. This goes for any 257 because making that power (obviously any ej with 400whp at any rpm will have a different turbo) at higher rpm will require less torque if you manage it, which will reduce the need for building the bottom end etc...

They aren't dyno queens because they rev, they become faster, safer, and easier to drive in some ways.
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Old 11-21-2018, 12:13 AM   #56
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...I don't need to define rpm because its a mathematical equation, if you can't tell what kind of powerband you'll get with a 400/400 setup vs a 400/300 setup simply from the numbers then you wouldn't have understood anyways.
I think you missed the point - making 400 ft-lb of torque at 3000-4000 RPM is entirely different than making 400 ft-lb safely at 7000 RPM on these motors. That's why I said you had it backwards - 400 wtq in the low end is easy and reliable but has some serious trade-offs (zero power over 5000 RPM, being the biggest one). That said, most people don't build their motors like this unless they're building for competition.
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Old 11-21-2018, 01:34 AM   #57
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Originally Posted by whiterabbitrexy View Post
Its true torque do kill internals but on a serious question how do u make 400hp with only 300tq lol never seen that happen....

300 lbft at 7000rpm is 400hp. You could do that by limiting boost in the midrange to create a flattish torque curve. Which would be more reliable and result in lower peak cylinder pressures than just letting the same setup make 400lb-ft or whatever earlier on.
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Old 11-21-2018, 06:33 AM   #58
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300 lbft at 7000rpm is 400hp. You could do that by limiting boost in the midrange to create a flattish torque curve. Which would be more reliable and result in lower peak cylinder pressures than just letting the same setup make 400lb-ft or whatever earlier on.
Yeah true very well said... also backing off ignition timing will kill torque figures...also running pig ritch at WOT...also long Diff gears....sorry i guess its very possible to make your car put out very low torque.... i just know torque can be made to be very close high to hp figures..... I forgot some people are not like me to aim for high hp/torque figures on the dyno
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Old 11-21-2018, 12:44 PM   #59
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Originally Posted by jamal View Post
300 lbft at 7000rpm is 400hp. You could do that by limiting boost in the midrange to create a flattish torque curve. Which would be more reliable and result in lower peak cylinder pressures than just letting the same setup make 400lb-ft or whatever earlier on.
The ability of restricted motors making 400 ft-lb early and QUICKLY tapering down is a result of the restrictor acting as a sonic nozzle. It is not a sustained high cylinder pressure because the boost needs to taper fast (or you overspeed the turbo).
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Old 11-21-2018, 01:01 PM   #60
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What does a restrictor have anything to do with this?

You can make 400hp with a peak torque of 300lb ft, or the same 400hp with a peak torque of 400. Which is going to be nicer to the pistons?

Last edited by jamal; 11-21-2018 at 02:39 PM.
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Old 11-26-2018, 02:20 PM   #61
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So is anyone in a position to do material testing of the metals to see if Subaru has done anything other than make dimensional changes to the Pistons/con rods? I'm talking Instron type testing to check material hardness etc. I am also ignorant of the availability of single pistons/con rods to buy instead of getting the whole block, any possibility here? Increased strength internals is the main driver for my decision to give back my leased 2016 STi and potentially get the 2019, but since these are not forged I am wary of trusting that Subaru actually did much besides cast a different shape piston.
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Old 11-26-2018, 10:15 PM   #62
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Originally Posted by jamal View Post
What does a restrictor have anything to do with this?

You can make 400hp with a peak torque of 300lb ft, or the same 400hp with a peak torque of 400. Which is going to be nicer to the pistons?
It allows for a very early, very high torque peak on these motors; notice the difference between the torque band on the GpN motors vs. stock Evo 9 motor in the below chart (only pay attention to the Evo 9 differences if you want a real apples-to-apples comparison). The only difference is a 33 mm restrictor.


Last edited by mrsaturn7085; 11-26-2018 at 10:43 PM.
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Old 12-08-2018, 01:48 AM   #63
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Originally Posted by speedslayerr View Post
So is anyone in a position to do material testing of the metals to see if Subaru has done anything other than make dimensional changes to the Pistons/con rods? I'm talking Instron type testing to check material hardness etc. I am also ignorant of the availability of single pistons/con rods to buy instead of getting the whole block, any possibility here? Increased strength internals is the main driver for my decision to give back my leased 2016 STi and potentially get the 2019, but since these are not forged I am wary of trusting that Subaru actually did much besides cast a different shape piston.
Well, if you can provide 50mg sample of each piston type you want to test, I will run ICP-MS which will give comprehensive elemental composition of the respective materials used to make these pistons.

Feel free to PM to discuss further.
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Old 12-08-2018, 02:31 AM   #64
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thanks for taking the time to document this
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Old 12-10-2018, 12:47 AM   #65
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Originally Posted by speedslayerr View Post
So is anyone in a position to do material testing of the metals to see if Subaru has done anything other than make dimensional changes to the Pistons/con rods? I'm talking Instron type testing to check material hardness etc. I am also ignorant of the availability of single pistons/con rods to buy instead of getting the whole block, any possibility here? Increased strength internals is the main driver for my decision to give back my leased 2016 STi and potentially get the 2019, but since these are not forged I am wary of trusting that Subaru actually did much besides cast a different shape piston.


I traded in my 2016 for a 2019 no regrets. Actually ended up in a better payment situation. Also they fixed the steering consistent all angles.
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Old 12-14-2018, 10:34 PM   #66
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i've got about 500 miles on my RA shortblock w/ 18G turbo and 1000cc injectors. Dyno time next week. I'll report back on how much we can pull out of it on pump fuel.

It's much more smooth and quiet than my last block, but that could simply be the new exhaust gaskets-(150k 2010 STI)

I havn't pushed it beyond 4500 rpm, or introduced any boost yet
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Old 12-14-2018, 10:43 PM   #67
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Originally Posted by mountainmanSTI View Post
i've got about 500 miles on my RA shortblock w/ 18G turbo and 1000cc injectors. Dyno time next week. I'll report back on how much we can pull out of it on pump fuel.

It's much more smooth and quiet than my last block, but that could simply be the new exhaust gaskets-(150k 2010 STI)

I havn't pushed it beyond 4500 rpm, or introduced any boost yet
I dont believe there is any reason it will make more power than a previous STI shortblock, the improvement everyone is hoping for is that it lasts longer and handles more abuse.
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Old 12-14-2018, 10:55 PM   #68
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agree! i don't think the block will make more power by itself, but with a bigger turbo, injectors, ect, ect i'll place my experience out here to record the longevity on this block while running slightly elevated boost/power.

https://www.flickr.com/photos/[email protected]/?
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Old 12-15-2018, 02:11 AM   #69
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Unless your displacement or compression ratio has changed, you wont "make" more power.
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Old 12-18-2018, 07:29 AM   #70
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This is all great but do we actually even know if this engine can handle more power?
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Old 12-18-2018, 02:04 PM   #71
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nope. no power gains or additional headway are advertised with this block. I ended up with one because it was slightly cheaper than the standard STI block.

Only reason anybody would think these are any better than a stock block is a supposedly "reinforced" piston design. I'm sure the difference is negligible, if any

I just hit my 1000 mi break-in. My dyno tune is setup for later this week. Will post back once we've got something
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Old 12-20-2018, 11:28 PM   #72
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310 ft/lbs and 320 HP @20PSI

5900 ft. Smooth like silk all the way to redline. 18G compliments it perfectly.

Tuned pretty well up to 330 but my old intercooler w/ bent fins was causing some heat issues.

1200mi and climbing.
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Old 12-21-2018, 10:36 PM   #73
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Well, if it makes anyone feel better....
We also purchased a RA shortblock.
It's going into a '09 WRX running a 20G turbo.

We measured the ring gaps at around .008" top, .009" bottom. The gaps where increased to .018" top, .020" bottom. It should be running in a month should everything go well. I'll update later???
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Old 12-21-2018, 10:44 PM   #74
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Fuji, Was that with or without Torque Plates?
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Old 12-28-2018, 02:52 PM   #75
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Fuji, Was that with or without Torque Plates?
I didn't measure them, but my friend did. We didn't put on our torque plates.
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