Welcome to the North American Subaru Impreza Owners Club Thursday August 21, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 05-18-2009, 12:53 PM   #26
TechMJ
Scooby Specialist
 
Member#: 145804
Join Date: Apr 2007
Chapter/Region: South East
Location: AL
Vehicle:
2002 Bugeye Beast,
Murdered Out,2.5,6spd,20G

Default

What about just a cross over pipe instead of getting a header at all.
* Registered users of the site do not see these ads.
TechMJ is offline   Reply With Quote
Old 05-18-2009, 04:28 PM   #27
pooster.online
Scooby Newbie
 
Member#: 120461
Join Date: Jul 2006
Chapter/Region: BAIC
Location: Bay Area/ L.A
Vehicle:
2004 WRX STi JBP

Default

^gains will probably be negligible.
pooster.online is offline   Reply With Quote
Old 05-18-2009, 04:50 PM   #28
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

My MadDad equal length headers made way more power than the stock headers.

It spooled faster and made more power EVERYWHERE especially in the tq and midrange. And the headers were the ONLY change. Both setups were Topspeed tuned.

CoolRex is offline   Reply With Quote
Old 05-18-2009, 08:02 PM   #29
TechMJ
Scooby Specialist
 
Member#: 145804
Join Date: Apr 2007
Chapter/Region: South East
Location: AL
Vehicle:
2002 Bugeye Beast,
Murdered Out,2.5,6spd,20G

Default

Thanks CoolRex I was hoping somebody would respond with some good info.

Last edited by TechMJ; 05-18-2009 at 11:16 PM.
TechMJ is offline   Reply With Quote
Old 05-19-2009, 05:22 AM   #30
Joshwrx04
Scooby Specialist
 
Member#: 135429
Join Date: Dec 2006
Chapter/Region: NWIC
Location: Lake Stevens WA
Vehicle:
'05 CGM STi cornfed
'82 s-10 (427'nd soon)

Default

nice numbers!
Joshwrx04 is offline   Reply With Quote
Old 05-25-2009, 04:16 AM   #31
don_radeon
Scooby Specialist
 
Member#: 202583
Join Date: Feb 2009
Chapter/Region: NESIC
Location: Mass
Vehicle:
2004 Legacy GT
Black w/Domo on back

Default

Quote:
Originally Posted by CoolRex View Post
My MadDad equal length headers made way more power than the stock headers.

It spooled faster and made more power EVERYWHERE especially in the tq and midrange. And the headers were the ONLY change. Both setups were Topspeed tuned.

7hp is WAY more power? Am I reading the chart wrong?
don_radeon is offline   Reply With Quote
Old 05-25-2009, 09:56 AM   #32
eatus ravenous
Scooby Specialist
 
Member#: 26068
Join Date: Oct 2002
Chapter/Region: NESIC
Location: north central mass
Default

The cool boxer rumble everyone is refering to is the product of a poorly designed exhaust system for a turbo car . or a na car for that matter . spacing the exhaust pulses equally not only creates a more efficent exhaust flow but the pulses are evenly spaced so when they come in contact with the turbine wheel its a smooth efficent rate of flow and thus a better way to have the exhaust run on any car . remember evenly spaced pulses also scavenge the combustion cylinder better and thus give a better response and more HP & TQ everywhere . not to mention the engine just runs smoother
eatus ravenous is offline   Reply With Quote
Old 05-25-2009, 10:21 AM   #33
marcus.raw
Scooby Specialist
 
Member#: 97675
Join Date: Oct 2005
Chapter/Region: SCIC
Location: 909
Vehicle:
93 Stroked LS3 FD
Launch Edition 2015 STI

Default

Quote:
Originally Posted by don_radeon View Post
7hp is WAY more power? Am I reading the chart wrong?
thats only comparing the difference at peak, theres a difference throughout the entire power band, in some areas more than others. more often than not mods pre turbo usually sacrifice bottom end for top end, or vice versa, in different ratios, but this is an improvement over all. therefore, further proving that equal is way more efficient in every area to unequal
marcus.raw is offline   Reply With Quote
Old 05-25-2009, 10:30 AM   #34
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

Quote:
Originally Posted by don_radeon View Post
7hp is WAY more power? Am I reading the chart wrong?
You are making the same mistake everyone makes....looking at peak numbers only. Look in the midrange....30-40 more tq and 20-30 more horsepower in the meat of the powerband FTW!
CoolRex is offline   Reply With Quote
Old 05-27-2009, 12:35 AM   #35
JASWRX
Scooby Specialist
 
Member#: 40742
Join Date: Jul 2003
Location: LA, Ca
Vehicle:
2002 WRX
WRB

Default

how do you spool faster. It looks like it hits harder but way later. the stock seems to spool way quicker according to your chart.

anybody know the difference between MaddogEL, Tomei, and Perrin?

I am about to die deciding which header to get. Might even keep stock and just port them and coat. I want to have quicker spool if possible than stock on vfseries turbo.

Last edited by JASWRX; 05-27-2009 at 01:28 AM.
JASWRX is offline   Reply With Quote
Old 05-27-2009, 08:19 AM   #36
zeropsi
*** Banned ***
 
Member#: 175453
Join Date: Mar 2008
Chapter/Region: MWSOC
Location: wilCO, IL
Vehicle:
AE86 GT-S coupe
i <3 alqonquin homosauce

Default

Quote:
Originally Posted by JASWRX View Post
how do you spool faster. It looks like it hits harder but way later. the stock seems to spool way quicker according to your chart.

anybody know the difference between MaddogEL, Tomei, and Perrin?

I am about to die deciding which header to get. Might even keep stock and just port them and coat. I want to have quicker spool if possible than stock on vfseries turbo.
Difference between them in terms of?

The Tomei has the widest inner diameter uppipe of the three...I can tell you that much. More of a true EL design than @ least Perrin (not sure about the other one), comes with header wrap, and hasn't cracked in 13Kish miles and one nasty winter. Just saying.
zeropsi is offline   Reply With Quote
Old 05-27-2009, 01:03 PM   #37
crampfan
Scooby Specialist
 
Member#: 74321
Join Date: Nov 2004
Chapter/Region: MWSOC
Location: clarksville AR
Vehicle:
2004 wrx wag
black UTEC stg 4

Default

maybe I'm just old, but back in the good old days, the good headers where EL and the cheap ones where not. my thinking is choosing mods that make the most HP. to me the "boxer rumble" sounds like a misfire.
crampfan is offline   Reply With Quote
Old 05-27-2009, 01:07 PM   #38
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

Quote:
Originally Posted by crampfan View Post
maybe I'm just old, but back in the good old days, the good headers where EL and the cheap ones where not. my thinking is choosing mods that make the most HP. to me the "boxer rumble" sounds like a misfire.
Every older guy around here that has messed with cars used to always tell me my car was misfiring back when I was still on the stock headers .
CoolRex is offline   Reply With Quote
Old 05-27-2009, 01:28 PM   #39
oscarmayer
Scooby Specialist
 
Member#: 33863
Join Date: Mar 2003
Chapter/Region: TXIC
Location: DFW
Vehicle:
2001 rs2.5
silver/champaign

Default

Quote:
Originally Posted by novacivic View Post
unequal length= a little more low end plus boxer rumbel

equal length= more power overall but no boxer rumble will sound more like every other 4 cyl minus the raspyness
incorrect...
boxter rumble comes from the firing order. i have an equil length and have the rumble.
oscarmayer is offline   Reply With Quote
Old 05-27-2009, 01:28 PM   #40
kellygnsd
Scooby Guru
 
Member#: 32669
Join Date: Feb 2003
Chapter/Region: SCIC
Location: Rancho C
Vehicle:
2007 2.34LR, EFR7670
LINK G4 hybrid STi

Default

Quote:
Originally Posted by don_radeon View Post
7hp is WAY more power? Am I reading the chart wrong?
Yes your are reading it wrong
kellygnsd is offline   Reply With Quote
Old 05-27-2009, 01:30 PM   #41
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

Quote:
Originally Posted by oscarmayer View Post
incorrect...
boxter rumble comes from the firing order. i have an equil length and have the rumble.
Then you aren't truely equal length. Firing order is not the same as when the exhaust pulses hit the turbo.

In UEL headers the pulses are all staggered out hence the burble. In EL headers the pulses are all in line and in sequence. Think blowing a fan steady vs blow in hesitant pulses.
CoolRex is offline   Reply With Quote
Old 05-27-2009, 03:53 PM   #42
JASWRX
Scooby Specialist
 
Member#: 40742
Join Date: Jul 2003
Location: LA, Ca
Vehicle:
2002 WRX
WRB

Default

I still do not see how you say you spool faster?
JASWRX is offline   Reply With Quote
Old 05-27-2009, 03:55 PM   #43
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

Quote:
Originally Posted by JASWRX View Post
I still do not see how you say you spool faster?
On the street it does. It spools faster and makes more power sooner. Period.
CoolRex is offline   Reply With Quote
Old 05-28-2009, 05:01 PM   #44
JASWRX
Scooby Specialist
 
Member#: 40742
Join Date: Jul 2003
Location: LA, Ca
Vehicle:
2002 WRX
WRB

Default

does anybody have maddad's number. I have emailed them but have not heard back. I want to find out more about the EL header.
JASWRX is offline   Reply With Quote
Old 05-28-2009, 05:41 PM   #45
jonpark
Scooby Specialist
 
Member#: 141449
Join Date: Feb 2007
Chapter/Region: Tri-State
Location: Glen Mills, PA
Vehicle:
2007 EvoIII16g WRX
UGM EJ257+05/6speed

Default

I see a good gain around 5K-5.5K
jonpark is offline   Reply With Quote
Old 05-28-2009, 06:15 PM   #46
FuJi K
Scooby Guru
 
Member#: 3687
Join Date: Jan 2001
Chapter/Region: MWSOC
Location: St. Paul, MN
Vehicle:
MY99 GF4 JDM 6spd
NF Performance

Default

Drive an equal length header around town in your daily driving manner, and one without the EL...... the ndrive around town with the stock.... You'll notice the difference. Off boost response is much improved. Don't just look at WOT.

You should ask Big Al (Dynoflash) why he changed to equal lengths....at least that's what it sounds like during his 704whp pull..... I could be wrong. ....yes I am wrong... he uses twinscroll setup!!! Best of BOTH!!!

Last edited by FuJi K; 05-28-2009 at 06:21 PM.
FuJi K is online now   Reply With Quote
Old 05-29-2009, 02:57 AM   #47
JASWRX
Scooby Specialist
 
Member#: 40742
Join Date: Jul 2003
Location: LA, Ca
Vehicle:
2002 WRX
WRB

Default

so you are saying off boost and below full torque, the Equal Length is much more drivable and feels more torque down low?
JASWRX is offline   Reply With Quote
Old 05-29-2009, 07:51 AM   #48
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

Yes definately. But you also have to use a good setup. I liked the maddad's because the 1.6" piping. That's bigger than stock. The only downside is that you have to heat them up to get full power but header wrapping them solves that issue. Mine are ceramic coated but when I put the built 2.5L I will be header wrapping them.
CoolRex is offline   Reply With Quote
Old 05-29-2009, 08:30 AM   #49
wrxhard
Scooby Specialist
 
Member#: 108091
Join Date: Feb 2006
Location: Fargo, ND
Vehicle:
2002 WRX

Default

Quote:
Originally Posted by JASWRX View Post
I still do not see how you say you spool faster?
You honestly don't see how the light red line (after header torque) goes up on the chart before the light blue line (before header torque)? REALLY?!?!?! This indicates he's producing quite a bit more power earlier in the powerband. On a turbocharged car, that usually means it's spooling faster (torque has to come from somewhere).
Here's the graph one more time...

Quote:
Originally Posted by CoolRex View Post
If you don't see that, you either need to:

A: get your eyes checked
B: Hit yourself in the face with a hammer and give up
wrxhard is offline   Reply With Quote
Old 05-29-2009, 09:16 AM   #50
CoolRex
*** Banned ***
 
Member#: 85813
Join Date: Apr 2005
Chapter/Region: South East
Location: Myrtle Beach, SC
Vehicle:
2002 E46 M3
2006 RC51

Default

^^^^Yes.

It's not insane faster spool but it's faster spool nontheless. Instead of a smooth pull back now the car literally snaps and plants your head back.

Also note that simply slapping headers on won't help much....I actually lost power because the AFR went from 11.0:1 to 10.2:1 in the upper rpms. But tuning for the headers made all the difference.
CoolRex is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
GT-Spec equal length vs. unequal length headers SW00P_G Factory 2.5L Turbo Powertrain 31 02-17-2009 07:40 AM
equal vs unequal length headers on an 06 TR VRT Gump Factory 2.5L Turbo Powertrain 25 08-06-2007 04:28 PM
Please compare equal vs. unequal length headers... shemoves Normally Aspirated with bolt-on Forced Induction Powertrain 6 09-02-2006 02:44 PM
Equal length vs. Unequal length headers 4080wrx Factory 2.0L Turbo Powertrain 6 09-21-2004 10:03 PM
Equal Vs Unequal length headers Onederer Factory 2.0L Turbo Powertrain 2 05-10-2002 02:13 AM


All times are GMT -4. The time now is 03:12 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.