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Old 03-25-2020, 11:32 AM   #1
redline144
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Default Tomei Unequal Length Headers for FA20DIT?

So I was under the impression that unequal length headers are impossible to use on the FA20DIT due to the twin scroll turbo, then Tomei puts this out. What's everyone's thoughts? I'm not looking to buy or anything, just starting discussion on it. Here's the link..

http://www.tomeiusa.com/?p=15773
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Old 03-25-2020, 11:59 AM   #2
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Going to get a lot of hate here, but to me it appears you'd get the boxer rumble back from those.

They do look like an UELH design, so I'm curious if they actually perform decent.
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Old 03-25-2020, 12:12 PM   #3
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UEL Headers are worse... More just for the rumble SwAgz I guess. Way better performance and efficiency out of EL headers.
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Old 03-25-2020, 12:15 PM   #4
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well you are kind of taking half the benefit away from the twin scroll, but otherwise it won't harm anything.
but agreed with waddlz there are going to be some outraged people on this topic
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Old 03-25-2020, 12:18 PM   #5
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Sounds amazing, less efficient. I wouldn't run it but that's just my opinion. Im sure some tuners would also not recommend it
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Old 03-25-2020, 12:20 PM   #6
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An equal length header should perform better regardless of turbo design. Certainly the car isn't going to implode on on itself by using a UEL header with a twinscroll turbo.
The question is, are some enthusiasts willing to sacrifice performance for sound, my bet is the answer is yes. This product will likely fit a demand.
Being new to the Subaru community, I was slightly disappointed that my 2018 wrx didn't have the signature rumble, but function over form I guess...
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Old 03-25-2020, 01:01 PM   #7
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This is absolutely hilarious
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Old 03-25-2020, 02:13 PM   #8
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Oh yeah I'm sure people are going to be hating big time. I guess if you just want the sound and don't care about efficiency they're the product for you. Oh well, I'm not trying to spend $800 for less efficiency but better sound.
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Old 03-25-2020, 03:17 PM   #9
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Quote:
Originally Posted by redline144 View Post
Oh yeah I'm sure people are going to be hating big time.
you ain't seen nothin
Try saying you don't need to slam redline 15 times on a new motor to prevent cylinder glazing and it's going to be like when the Iraqis pulled down that statue of Saddam in an angry mob
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Old 03-25-2020, 04:38 PM   #10
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Quote:
Originally Posted by redline144 View Post
Oh yeah I'm sure people are going to be hating big time. I guess if you just want the sound and don't care about efficiency they're the product for you. Oh well, I'm not trying to spend $800 for less efficiency but better sound.
I would be interested to see oem header versus the tomei UEL on the dyno. The larger runners and better collector should provide some performance over the stock cast piece?
Maybe it will be enough to offset the losses of the UEL design?
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Old 03-25-2020, 04:52 PM   #11
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Quote:
Originally Posted by dpetro1 View Post
I would be interested to see oem header versus the tomei UEL on the dyno. The larger runners and better collector should provide some performance over the stock cast piece?
Maybe it will be enough to offset the losses of the UEL design?
At that point, for the cost, upgrade to killer B or perrin headers.

Pretty sure i remember reading a thread by one of those 2 where they mentioned the stock headers were pretty good and difficult to improve on for the cost.

IMHO, if you replace the stock headers it should be for EWG killer B set up. Stockers are good for everything else.
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Old 03-25-2020, 05:04 PM   #12
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Quote:
Originally Posted by Waddlz View Post
Going to get a lot of hate here, but to me it appears you'd get the boxer rumble back from those.
No. The boxer rumble is the sound you get from boxer engines. There are similarities even across manufacturers that makes them sound unique. Adding an EL header does not make it sound less 'boxer' in fact it makes it sound more like all the other boxer engines out there. Love or hate it, THAT is the 'boxer' sound.

The 'burble' that is unique to USDM turbo EJs (Impreza, Forester, Legacy, Outback) is due to the UEL manifold that Subaru uses in their base model performance trims. The good stuff from Subaru mostly goes to UEDM and JDM, and since they are the top tier performance cars, they get the EL manifold from the factory for the performance enhancing benefits.
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Old 03-25-2020, 05:04 PM   #13
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Also on the videos about the perrin equal length it stated no tune was required for gains
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Old 03-25-2020, 05:28 PM   #14
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I also would like to see a dyno comparison between stock and the tomei uel
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Old 03-25-2020, 06:13 PM   #15
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Wow, this actually happened. Did April Fools' come early?

No video or sound clip to hear the UELH "rumble"?
No dyno charts showing gains (or rather losses) compared to the stock header?

Their own advertisements pretty much say all there is to say...

ELH = Efficiency & Power




OR

UELH = a symphony of colliding exhaust pulses & inefficiency




.. pick one.

Take away the advantages of an equal length header and a proper twin scroll turbo setup.. and you end up with slower spool, worse transient response, a narrower powerband, reduced fuel economy, and so on.. all while spending $700+ to do it And increasing the chances of unequal cylinder exhaust pressures & EGTs.. and detonation/knock.

Keep in mind that that the EJ257's UELH allowed for shorter primaries due to the turbo's location. This UELH is actually increasing the length (also diameter & volume) of the primaries reducing the exhaust velocity.

Sadly, I'm sure a lot of people will fall for this gimmick despite tuners advocating against them.

Many FA20DIT owners value Ron's opinion.. so maybe this will help:
"Equal length headers are better, especially on a twinscroll turbo. Slip joints will leak over time. Everyone used to dream about having twinscroll equal length setups on EJ's and very few people did it because it was so expensive. And now that we are given it stock, companies are doing this and making single scroll turbo kits."

A local Subaru tuner, Travis @ Snail Performance, responded with:
"Waste of money."

Edit: Also note this is a Tomei USA product.
http://www.tomei-p.co.jp/tomei-brand/
http://www.tomei-p.co.jp/news/info/1990/

Last edited by WRXnick16; 03-25-2020 at 09:37 PM.
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Old 03-25-2020, 06:51 PM   #16
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I haven't done headers on this car yet but watching the videos alone it looks like a pain in the butt. I like the rumble but not sure I would go thru that headache if it losses power.
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Old 03-26-2020, 10:12 AM   #17
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I just ordered a boat load of parts for my 16 wrx. (turbo back exhaust, AOS, Boost controller, AP, TGV/EGR deletes, Short shifter, shifter bushing,shift stop, hardware kit for the jpipe) ive been researching a header that i want and as much as i miss the rumble, how do you put efficiency up against sound? i dont get it lol
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Old 03-26-2020, 11:44 AM   #18
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There's a video somewhere out there on youtube of a fa20dit with UEL headers. Sounded great but, well lets just wait for the dyno charts.
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Old 03-26-2020, 11:47 AM   #19
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Patiently waiting for some internet clout god to install this without a tune and blow his motor then rant about how bad the product is on YouTube.

Tell me I'm wrong.
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Old 03-26-2020, 12:06 PM   #20
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Yes. You no longer have the advantages of an equal length header or twin scroll setup.. and you're also stuck with the "restrictions" of a twin scroll turbine housing without utilizing any of the benefits

So lose. lose. lose.

Not to mention you're also sacrificing reliability of the manifold itself compared to the OEM or Killer B header (welds, material, slip joints, etc.). I'd also much prefer the OEM manifold with the OEM heatshields or the Killer B header with SwainTech coating compared to wrapping a header on a daily driven street car...

And then there's the merge collector.. even in comparison to Tomei USA's equal length header:
  • Killer B uses cast 321 SS collectors to improve longevity, flow & performance.
  • Killer B is 321 stainless steel vs. Tomei's 304 stainless steel (321 is stronger, lower thermal conductivity (less energy lost due to heat transfer), will probably outlast the car, used for aircraft exhaust manifolds).
  • Killer B is a single piece design with minimal welds (less disruption of flow, less chance of failure/leaking, etc.)
  • Killer B also offers the option for SwainTech coating.

Tomei:



Killer B:





Although, Tomei's collector does at least look better than Perrin's:



Given the similar pricing.. it's a no brainer if you feel the need to upgrade the OEM header.

Last edited by WRXnick16; 03-26-2020 at 12:12 PM.
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Old 03-26-2020, 12:09 PM   #21
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yeah but


how wide is Killer-Bs?

That Tomei is WIDE
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Old 03-26-2020, 12:16 PM   #22
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Quote:
Originally Posted by adam99 View Post
There's a video somewhere out there on youtube of a fa20dit with UEL headers. Sounded great but, well lets just wait for the dyno charts.
Not Tomei.. but custom made UELH.





Definitely produces an unusual FA20DIT torque curve like suspected. Torque comes on later and falls off sooner.



More reminiscent of the EJ257 (blue) than the FA20DIT (red):



And stage 2 Killer B (red) vs OEM (blue):



At 3k rpm, it's easily down 70+ wtq compared to a standard stage 2. It makes that wtq figure ~1,000 rpm later @ 4k rpm.

Some of the loss is likely due to the CVT, but it appears to even be down 50+ wtq @ 3k rpm compared to a Cobb stage 1 CVT.

But you can get a subtle "rumble"?

Last edited by WRXnick16; 03-26-2020 at 02:06 PM. Reason: Added dyno charts
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Old 03-26-2020, 12:26 PM   #23
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Quote:
Originally Posted by Waddlz View Post
yeah but

how wide is Killer-Bs?

That Tomei is WIDE
Wide?
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Old 03-26-2020, 02:09 PM   #24
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Quote:
Originally Posted by KillerBMotorsport View Post
Wide?
...WIDE

im being totally sarcastic btw
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Old 03-26-2020, 02:15 PM   #25
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Killer B didnt even put a graphic to show their tubing is WIDE!, clearly it's impossiblce for them to match Tomei's precision.
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