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Old 06-07-2020, 02:26 PM   #451
KillerBMotorsport
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Originally Posted by NighthawkSTI View Post
well ya....a straight pipe flows the best. I am saying the larger picture here....a performance UELH on an FA 2.0 is not going to be the horsepower limiter when matched with other bolt on mods and meets the builders goals..whether it be 300, 400 or more horsepower....that UELH is actually overkill for the stock FA, its going to work better on a fully modded FA as would a better ELH. ELH scavenge better.
EH headers and optimized engergy transfer of exhaust gasses from port to turbine is always going to make BEST power. BEST power is simply total area under the curve. This is what makes drivability more enjoyable and wins races. Who cares if you make the same peak power if you make 30wtq less 1,000 RPMs before, and 30 whp less 1,000 RPMs after that peak. Obviously one car would be slower, while making the same peak power. So yeah, put a bigger turbo, or a bunch more mods, and you can certainly make the same peak power (or more if you spend even more), but peak-for-peak the UEL setup will make less overall power.

The further you go in the direction of inefficient design, the more difficult it will be to match those peak numbers, and the more disparity there will be in the rest of the power curve.

Quote:
Originally Posted by NighthawkSTI View Post
If you can translate the 180 degree bends on a FA(because that graphic while informative leaves out the design variables of everything before and after the 180 deg bend specific to the FA engine design) that for example is using a performance UELH and making 400 horsepower...how much power those bends are taking away...I'd love to see that illustrated....it would bring everything full circle here. I dont see that header limiting the FA to 340 horsepower as I argued against here when it was thrown out there or that it changes the way the twin scroll operates relatively speaking....the exhaust pulses are still entering a twin scroll housing...albiet with relatively less efficient scavenging over the ELH. Thank you for your input in advance.
The lower graphic shows 180 degrees. The pressure profile plot would obviously look worse (flow less) than the 90.

A crappy header design doesn't 'limit power' it limits performance. There's a difference. You can get a barn door to fly if you put a big enough rocket on it, but that doesn't mean it will fly well

Turbines are ALWAYS most efficient when exhaust pulses are delivered with consistent energy from each exhaust event. Just like the bend plots above going from 0-90 shows ideal flow-to-poor flow, as you deviate exhaust pulses from perfectly spaced, turbine performance deteriorates. Not even getting into how UEL has a negative effect on the engine's Volumetric Efficiency: Cylinder Scavenging, Intake Charge Fill, AFRs, EGTs, etc., etc...
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Old 06-07-2020, 04:22 PM   #452
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"But you're still not getting the big picture..." - NighthawkSTI probably
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Old 06-07-2020, 08:20 PM   #453
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Originally Posted by Norm Peterson View Post
Obviously you're not listening to the 'character' of the sound, only the deepness/muscularity (mainly a function of displacement).

"Aggressive" is such a worn-out term these days that it has really lost any meaning it might have had, never mind that it does not describe the character of a sound very well to begin with. It's the word that people these days reach for before even trying to describe anything that's a bit out of the ordinary.

Basically, if you can't hear the similarity between a flat-four VW and a flat-four unequal-length EJ or FA, you're either in denial or musically deaf.

I suppose I could have used the term 'syncopated' to describe the boxer rumble, but subjectively that's too complimentary of a term to use for a sound that's not particularly pleasing to the ear. And it might be a term that only a few people here would be familiar with, anyway. So rattle-y is it for now (it's certainly more descriptive than "aggressive").


Norm
the "character" of the UELH sound of a Subaru IS the stacked pulses from the different length pipes into the collector. You seem to want to redefine what the word "character" means in this context to align with your disdain for that sound. You are in the pool of people that dont like the sound in an illogical way. And really this air cooled V.W rant....the ping ping ping ping, of an air cooled V.W isnt even in the same league as free flowing UELH set up Subaru that roar! air cooled v.w's are anemic...more comparable to lawn mower or old carburated snowblowers.

Quote:
Originally Posted by beau13990 View Post
Check out an LS1 dyno graph vs. an FA20F dyno graph. Under 4,000rpm, it's pretty damned close. Of course, you've made it clear that you only consider the peak horsepower number, so screw that, right? I mean, who ever ran an engine at under 4,000rpm?

And that dude's exhaust tips were disgusting. A bunch of crap spewed out when he started up, and even the guy standing by the back of the car looked disgusting. That car is running too rich or something. Whole video is just made of jackassery.
I will check out graphs and get back to you...this is the first I have ever heard of the Subaru 2.0 FA being compared to modern muscle car V8's torque. a relative shift I the torque curve can be compensated for with the 6 speed manual...as opposed to say an automatic equipped car limited by the cvt with no wat to slip it....and bring the engine up into the torque curve on demand.

Quote:
Originally Posted by KillerBMotorsport View Post
EH headers and optimized engergy transfer of exhaust gasses from port to turbine is always going to make BEST power. BEST power is simply total area under the curve. This is what makes drivability more enjoyable and wins races. Who cares if you make the same peak power if you make 30wtq less 1,000 RPMs before, and 30 whp less 1,000 RPMs after that peak. Obviously one car would be slower, while making the same peak power. So yeah, put a bigger turbo, or a bunch more mods, and you can certainly make the same peak power (or more if you spend even more), but peak-for-peak the UEL setup will make less overall power.

The further you go in the direction of inefficient design, the more difficult it will be to match those peak numbers, and the more disparity there will be in the rest of the power curve.



The lower graphic shows 180 degrees. The pressure profile plot would obviously look worse (flow less) than the 90.

A crappy header design doesn't 'limit power' it limits performance. There's a difference. You can get a barn door to fly if you put a big enough rocket on it, but that doesn't mean it will fly well

Turbines are ALWAYS most efficient when exhaust pulses are delivered with consistent energy from each exhaust event. Just like the bend plots above going from 0-90 shows ideal flow-to-poor flow, as you deviate exhaust pulses from perfectly spaced, turbine performance deteriorates. Not even getting into how UEL has a negative effect on the engine's Volumetric Efficiency: Cylinder Scavenging, Intake Charge Fill, AFRs, EGTs, etc., etc...
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Originally Posted by Doughdreads View Post
"But you're still not getting the big picture..." - NighthawkSTI probably
good summary. ELH are relatively more efficient than UELH, been saying that throughout. These uelh "sound" haters are trying to say that an FA cant make more than 340 horsepower....which simply isnt true...that's the misinformation going around here. Some were saying it would be impossible to make power with it, that the engine will blow pistons and that turbo wouldnt work...all false....I have been countering with another perspective as to why these headers are fine, as with a performance uelh chosen by an enthusiast to build 300-350-400-4** horsepower and the meet those goals then its just a bonus if they like the sound...in those cases its the sound of success. Manual equipped cars arent as critical of torque curves shifted to higher rpms compared to an automatic...so again the effects of an uelh on an fa20 are relative. Your input here and time taken to respond and contribute are appreciated! informative.
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Old 06-07-2020, 08:49 PM   #454
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Nighthawk really getting that post count up in here lol
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Old 06-07-2020, 08:53 PM   #455
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Full of sound and fury, signifying nothing.
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Old 06-08-2020, 08:12 AM   #456
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Would you also be able to comment with any thoughts of the affects of using an unequal length header with a twin scroll turbo? Not talking specifically about the Tomei header here, just in general.

Is it as simple as everyone seems to think? You just get slower boost response and that's it?
^seriously?

scroll back and re-read the 47 posts where this is simply stated.
You really need KillerB to repeat for the 48th time what a twin scroll does and how headers are designed to optimize it?
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Old 06-08-2020, 09:55 AM   #457
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Originally Posted by NighthawkSTI View Post
the "character" of the UELH sound of a Subaru IS the stacked pulses from the different length pipes into the collector. You seem to want to redefine what the word "character" means in this context to align with your disdain for that sound.
I'm not redefining anything. What I am doing is using the term 'character' as an attribute of exhaust sounds in general. Some are pleasant, but this unequal-header H4 sound isn't one of them, not to my ears anyway. "Stacked pulses" - I actually like that as a more specific description, although that still doesn't make the sound itself any more appealing. It even hints at dissonance.

There's just something jarring and rackety about that sound that is at odds with any notion of smoothly-running machinery.


Quote:
You are in the pool of people that dont like the sound in an illogical way. And really this air cooled V.W rant....the ping ping ping ping, of an air cooled V.W isnt even in the same league as free flowing UELH set up Subaru that roar! air cooled v.w's are anemic...more comparable to lawn mower or old carburated snowblowers.
Not liking that sound is at least as logical as whatever reason you might have for liking that sound. A smooth-running engine should sound like it's running smoothly. At any power level.

You say you hear "ping ping ping ping" from a VW - well, so do I. Are you saying you can't pick up a deeper-toned version of that same sound (let's describe it as being something like pung pung pung pung) coming from your Subie?

It still beats me why you care so much about what the FA WRX sounds like when you already have the WRX sub-model that has the right sound for you. I know if I had an STi and liked its rumble I wouldn't have gotten involved in this discussion in the first place. Probably wouldn't have even opened up this section's list of topics. Then again, I suck at fishing, and going out in a boat on somebody else's pond and throwing a baited line over the stern would be a waste of too much time . . .


Norm

Last edited by Norm Peterson; 06-08-2020 at 10:06 AM.
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Old 06-08-2020, 11:23 AM   #458
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Originally Posted by Norm Peterson View Post
I'm not redefining anything. What I am doing is using the term 'character' as an attribute of exhaust sounds in general. Some are pleasant, but this unequal-header H4 sound isn't one of them, not to my ears anyway. "Stacked pulses" - I actually like that as a more specific description, although that still doesn't make the sound itself any more appealing. It even hints at dissonance.

There's just something jarring and rackety about that sound that is at odds with any notion of smoothly-running machinery.



Not liking that sound is at least as logical as whatever reason you might have for liking that sound. A smooth-running engine should sound like it's running smoothly. At any power level.

You say you hear "ping ping ping ping" from a VW - well, so do I. Are you saying you can't pick up a deeper-toned version of that same sound (let's describe it as being something like pung pung pung pung) coming from your Subie?

It still beats me why you care so much about what the FA WRX sounds like when you already have the WRX sub-model that has the right sound for you. I know if I had an STi and liked its rumble I wouldn't have gotten involved in this discussion in the first place. Probably wouldn't have even opened up this section's list of topics. Then again, I suck at fishing, and going out in a boat on somebody else's pond and throwing a baited line over the stern would be a waste of too much time . . .


Norm
because the vast majority of the UELH on an FA haters are spewing false information just because of the way they sound...."the engine is going to blow up", "won't make over 340 HP with an UELH", "the turbo wont work".....all false misinformation based on the sound LOL. That's why.

you re-invent ways to say how much you hate the UELH Subaru boxer sound in every post LOL. The LEGENDARY Subaru signature sound of the UELH on their boxer engines will always get more attention than the raspy high pitched ELH...that are only relatively more efficient. I'd say CONSERVATIVELY that the UELH sound is more bad ass over the exhaust leak sound of ELH by 5-1....and again I think that is a fair but conservative estimate.

You cant stand the boxer UELH sound, more than I have ever seen anyone hate anything LOL. You hate the UELH sound so much that you will compare it to an Air cooled V.W which is basically an lawnmower engine....and then go on in a hate fueled UELH rant to say that the STI is a "sub model" to the WRX LMAO. Hasn't been since 2015 separated them. The STI is the flagship performance car of the Subaru line up. Your a funny guy.
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Old 06-08-2020, 11:29 AM   #459
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Check out an LS1 dyno graph vs. an FA20F dyno graph. Under 4,000rpm, it's pretty damned close. Of course, you've made it clear that you only consider the peak horsepower number, so screw that, right? I mean, who ever ran an engine at under 4,000rpm?
Its no where near close.....in that RPM range you referenced there are stock LS1's that record 80-100 Ft lbs more torque than a stock FA2.0 turbo Subaru.
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Old 06-08-2020, 11:37 AM   #460
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Originally Posted by NighthawkSTI View Post
because the vast majority of the UELH on an FA haters are spewing false information just because of the way they sound...."the engine is going to blow up", "won't make over 340 HP with an UELH", "the turbo wont work".....all false misinformation based on the sound LOL. That's why.

you re-invent ways to say how much you hate the UELH Subaru boxer sound in every post LOL. The LEGENDARY Subaru signature sound of the UELH on their boxer engines will always get more attention than the raspy high pitched ELH...that are only relatively more efficient. I'd say CONSERVATIVELY that the UELH sound is more bad ass over the exhaust leak sound of ELH by 5-1....and again I think that is a fair but conservative estimate.

You cant stand the boxer UELH sound, more than I have ever seen anyone hate anything LOL. You hate the UELH sound so much that you will compare it to an Air cooled V.W which is basically an lawnmower engine....and then go on in a hate fueled UELH rant to say that the STI is a "sub model" to the WRX LMAO. Hasn't been since 2015 separated them. The STI is the flagship performance car of the Subaru line up. Your a funny guy.

Sound, 100% aside, it's been stated and or proven that the UELH is an inferior design to the ELH header.

No one thinks your motor will give up because you changed to a UELH, but it's going to have to work harder and ultimately give you less. If a tuned, well modified, WRX ultimately lost power and ended up with more lag - that's obviously not ideal.

You can make power on a UELH header, when it's designed to run it like the STi is - granted we know an ELH will make more power.

There's no real "hate", it's the mentality of modifying a vehicle to produce less power, more lag and ultimately leaves the "gains" to "sound" that are being questioned.

If you want to praise the UELH, go for it, just know the ELH will probably make more power on a Subaru platform.
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Old 06-08-2020, 12:05 PM   #461
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^seriously?

scroll back and re-read the 47 posts where this is simply stated.
You really need KillerB to repeat for the 48th time what a twin scroll does and how headers are designed to optimize it?
There has been some very general posts about how equal length headers are better, but we didn't have much that shows the affects of using an unequal length header with a twin scroll turbo (like comparative dyno graphs). I think there are many people that appreciate responses from reliable sources like Killer B. KillerB's response above is quite informative though.

Let's be clear, I have never once even considered getting these unequal length headers. It makes no sense to me, I appreciate the advantages of equal length headers and it would be silly to change that. BUT, I do like learning new things about engines, so I am interested to learn about the affects of using an unequal length header on a twin scroll turbo. I haven't been able to find much on this specific subject, so if you know a link with some good reading feel free to share it.



........Can anyone tell me why people come to a car forum to talk about cars and then get annoyed with people when we talk about cars too much? Isn't this the point of forums? I understand the anger over mis-information, but if you are tired of reading about headers, maybe stop clicking on this thread.

Last edited by Comikazi; 06-08-2020 at 12:14 PM.
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Old 06-08-2020, 12:15 PM   #462
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Originally Posted by Comikazi View Post
There has been some very general posts about how equal length headers are better, but we have nothing that shows the affects of using an unequal length header with a twin scroll turbo (like comparative dyno graphs). I think there are many people that would appreciate a response from a reliable source like Killer B on this.

Let's be clear, I have never once even considered getting these unequal length headers. It makes no sense to me, I appreciate the advantages of equal length headers and it would be silly to change that. BUT, I do like learning new things about engines, so I am interested to learn about the affects of using an unequal length header on a twin scroll turbo. I haven't been able to find much on this specific subject, so if you know a link with some good reading feel free to share it.



........Can anyone tell me why people come to a car forum to talk about cars and then get annoyed with people when we talk about cars too much? Isn't this the point forums? I understand the anger over mis-information, but if you are tired of discussing headers, maybe stop clicking on this thread.
the posts are general because the fundamentals are about as simple as it gets.
Twin scroll: 2 hot side impellars, headers oriented for pulses arriving exactly 25% of cycle time apart to alternating ports.
Results: Faster spool
Take away equal length. . .reduced spool due to less than perfectly even pulse spacing.
That's it, seriously, there's nothing more to it.

People talking about scavenging are making statements out of context. The length just changes the optimal scavenge RPM, not the scavenging in general, so yes, each cylinder has a different ideal rpm.
splitting hairs at this point.

Nobody is annoyed about talking about cars too much, but let's be honest, this thread is 500 posts and counting and Nighthawk and Norm have honestly argued the same points 30 times in a row now.
I'm almost sure they aren't going to agree at this point.
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Old 06-08-2020, 03:22 PM   #463
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People talking about scavenging are making statements out of context.
Then lets keep this in context. Scavenging is an effect brought on by uneven flow (like from an engine).

There are two primary locations scavenging happens.

In the primary; determining factors include length and diameter. If you have a small diameter 2" primary, your primary's scavenging capability will be terrible as the exhaust gasses have nowhere to go. If it's too long, there is no scavenging effect that is times correctly for the next exhaust event. Somewhere in the middle is where magic happens.

The other area that can produce a beneficial scavenging effect is the merge collector. This is where the passing of one or more exhaust pulses can improve scavenge from other primaries. In a symmetrical order and maximum separation produces ideal results. Secondary size, collector design, and other factors play a role here too.
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Old 06-08-2020, 03:33 PM   #464
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Thanks Killer B for providing some actual facts and proof.
Sigh. He hasn't provided 'actual facts and proof'. He didn't give false statements either.

At this point i think it's all mostly a matter of semantics (in terms of what is fact and what is theory), so I personally won't really bother.

Carry on...

Last edited by F1EA; 06-08-2020 at 04:47 PM.
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Old 06-08-2020, 04:09 PM   #465
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Originally Posted by KillerBMotorsport View Post
Just for a taste or reality, here's a pic that's commonly found in a text book in regards to tube angle and flow dynamics. The short of it is the longer the bend angle the more turbulence and worse flow capacity, PERIOD.



Some of you should be ashamed of the misinformation you're spreading in a public forum where people are seeking knowledge.
Yep. That applies to a specific type of curve/bend.
But the actual loss coeff also depends on the type of bend... short radius vs long radius... Also depends on the temperatures, the pipe diameter, etc.

A aftermarket pipe will change all 3. So gotta look at it as a whole system. Either full calibrated CFD models of the 2 systems or... a simple hp/toque comparison of the stock header and the aftermarkt UEL (same car, same dyno, same day) if one only cares about the end result.
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Old 06-08-2020, 04:09 PM   #466
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Originally Posted by KillerBMotorsport View Post

In the primary; determining factors include length and diameter. If you have a small diameter 2" primary, your primary's scavenging capability will be terrible as the exhaust gasses have nowhere to go. If it's too long, there is no scavenging effect that is times correctly for the next exhaust event. Somewhere in the middle is where magic happens.
Bold. . .Totally false.
Seriously? 2" primary is too small for 1/2 liter cylinder? Ever heard of a 572 big block? What do you think they have on them? Three inch primaries? You couldn't even physically fit that in place.
I don't even have 2" primaries on my 6.2 liter supercharged V8.

Underlined. . . .totally false

If it's "too long" then it will be timed for a lower rpm. So when you say "too long" you mean it won't be timed for "x" rpm. Ok fine, so what rpm do you want it timed for?
Because whatever you pick you will get, and every other rpm won't be timed right.
So like I said, if you have unequal lengths then each cylinder will be timed differently, making the net result generally ok, but it won't be dead nuts optimized for say. . . .low rpm peak torque.

So again, the 'scavenging' references are all out of context because they are stated kind of like you just did where you imply scavenging disappears with UEL when it does not, it just doesn't happen at the same time for each cylinder.
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Old 06-08-2020, 04:58 PM   #467
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Originally Posted by KillerBMotorsport View Post
Then lets keep this in context. Scavenging is an effect brought on by uneven flow (like from an engine).

There are two primary locations scavenging happens.

In the primary; determining factors include length and diameter. If you have a small diameter 2" primary, your primary's scavenging capability will be terrible as the exhaust gasses have nowhere to go. If it's too long, there is no scavenging effect that is times correctly for the next exhaust event. Somewhere in the middle is where magic happens.

The other area that can produce a beneficial scavenging effect is the merge collector. This is where the passing of one or more exhaust pulses can improve scavenge from other primaries. In a symmetrical order and maximum separation produces ideal results. Secondary size, collector design, and other factors play a role here too.
My comments on scavenging at least have been in context; specifically that the ELH available for Subaru turbo 4's are "relatively" more efficient because the pulses are arriving at the turbo at the same time(determined by the firing order) vs the UELH with one side getting to the turbo first and the longer side stacking up behind it, yet still determined by the firing order. ELH will scavenge the combustion chamber exhaust stroke without the stacking associated with UELH scavenging so the low pressure events will allow for more efficient pulling of the next combustion event out the chamber and through the pipe. On these Subaru engines though we are talking about relatively short distances from the exhaust ports to the collector/turbo.

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Originally Posted by F1EA View Post
Yep. That applies to a specific type of curve/bend.
But the actual loss coeff also depends on the type of bend... short radius vs long radius... Also depends on the temperatures, the pipe diameter, etc.

A aftermarket pipe will change all 3. So gotta look at it as a whole system. Either full calibrated CFD models of the 2 systems or... a simple hp/toque comparison of the stock header and the aftermarkt UEL (same car, same dyno, same day) if one only cares about the end result.
That's what I said when it was posted...it needs to be APPLIED to the header/s being discussed and specifically how the theory proves out on the FA turbo engines. A graph all by itself is way to general although informative. Everything before and after the bends in the FA Turbo 2.0 needs to be taken into the formula as you have pointed out.

Lets see actual engine stand dynos of an FA with both headers back to back with pressure readings at the points of flow in the pipes..being discussed here. That would answer a lot of debate....at least on the flow end. A 2 horsepower difference is negligible in actual application....torque shifts can be compensated for by modulating RPM and shift points with a 6 speed manual. if an automatic/CVT were the only transmission available for the FA2.0 the torque curve shifts would be more critical for drivability and response.

Clearly this is a discussion that needs much more data way too many variables to say that just because the "sound" of an UELH reveals stacked pulses that it will limit power potential on a FA 2.0 turbo. I really dont see why it would...the pulses are still entering a twin scroll turbo from relatively short distances from the exhaust ports in either scenario, and UELH have supported HUGE horsepower and torque outputs on Subaru boxer engines. Its an air pump..more air and fuel that goes in with mods will be happier with an aftermarket performance header that removes restrictions in the stock castings whether uel or el to the collector/turbo...UELH have proven to give enough margin if flow capability that they are overkill on a lot of builds, as well as aftermarket EL headers. If either supports the output that the builder sets as a goal that's all that matters.
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Old 06-08-2020, 06:16 PM   #468
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It would be funny if the new 2021 STI come stock with an ELH.
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Old 06-08-2020, 07:59 PM   #469
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Originally Posted by rtv900 View Post
Bold. . .Totally false.
Seriously? 2" primary is too small for 1/2 liter cylinder? Ever heard of a 572 big block? What do you think they have on them? Three inch primaries? You couldn't even physically fit that in place.
I don't even have 2" primaries on my 6.2 liter supercharged V8.

Underlined. . . .totally false
Easy there fella Maybe I wasn't detailed enough. Let me rephrase...

If you have a small diameter, 2" LONG primary...

I was giving example extremes to make the point... which I obviously did not do a good job of, lol

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Old 06-08-2020, 08:09 PM   #470
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Its truly interesting how some of you are trying to minimize the role of proven design principles because it's not speaking directly to THESE headers; like they are exempt from the rules of physics somehow.
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Old 06-08-2020, 08:18 PM   #471
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Originally Posted by KillerBMotorsport View Post
Easy there fella Maybe I wasn't detailed enough. Let me rephrase...

If you have a small diameter, 2" LONG primary...

I was giving example extremes to make the point... which I obviously did not do a good job of, lol
that's actually interesting. I mean are these UELH being discussed an "EXTREME" example of the flow principles in that graph you linked?? The graph is informative, but if its not applied to the specifications of the FA 2.0 its not telling us anything. Arent the 180 deg bends on the side of the header that's shorter? In any case the header length on Subaru engines is quite short in distance from the exhaust ports to the turbo/collector/up pipe. the dyno example we DO have of this header vs the stock ELH 2.0 header showed a 2 horsepower difference...that's hardly extreme. The UELH haters in here would have made one think the FA would be down 30 horsepower with this header on it....blow the pistons and render the turbo useless LOL. It just means the physics aren't extreme so the differences aren't extreme.

We need an actual measured test on THIS engine to put this to rest.
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Old 06-08-2020, 08:28 PM   #472
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Originally Posted by KillerBMotorsport View Post
Its truly interesting how some of you are trying to minimize the role of proven design principles because it's not speaking directly to THESE headers; like they are exempt from the rules of physics somehow.
a 2 horsepower difference is minimal, you would think the way the UELH haters in here were talking that the laws of physics would cause a black hole to open up under the hood of a FA2.0 WRX with an UELH on it LOL.

The extreme example of the physics involved simply doesnt translate to this application from what I have seen so far....the physics reveal a relatively less efficient scavenging but that's about it.

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Old 06-08-2020, 08:38 PM   #473
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Originally Posted by NighthawkSTI View Post
a 2 horsepower difference is minimal, you would think the way the UELH haters in here were talking that the laws of physics would cause a black hole to open up under the hood of a FA2.0 WRX with an UELH on it LOL.

The extreme example of the physics involved simply doesnt translate to this application from what I have seen so far....the physics reveal a relatively less efficient scavenging but that's about it.
how many rpm's later is the turbo hitting full boost though..?
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Old 06-08-2020, 08:47 PM   #474
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the dyno example we DO have of this header vs the stock ELH 2.0 header showed a 2 horsepower difference...
I must have missed it. Is there and independent tests with an apples-to-apples comparisons? Plots and logs please

Please don't say there just one plot and log. Not that a source can't be reputable, but validating results means they are proven to be repeatable.
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Old 06-08-2020, 09:45 PM   #475
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I must have missed it. Is there and independent tests with an apples-to-apples comparisons? Plots and logs please

Please don't say there just one plot and log. Not that a source can't be reputable, but validating results means they are proven to be repeatable.
ya there is a FA2.0 WRX video back in this thread that had the tomei header installed post dyno base run and after it was dynoed again with the header there was a 2 horsepower difference. But I agree its basically meaningless...no graphs were posted no torque or horsepower curves etc. Nothing about the before and after state of tune. a plus or minus 2 horsepower difference is a wash either way...even if were across the entire RPM band.
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