Welcome to the North American Subaru Impreza Owners Club Sunday December 28, 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 > Built Motor Discussion

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 09-14-2011, 02:02 PM   #376
eg33GC
Scooby Specialist
 
Member#: 206851
Join Date: Mar 2009
Chapter/Region: MWSOC
Vehicle:
99 V4
EJ20K RS

Default

fuji you need to play with that h6 head you have had for years!
* Registered users of the site do not see these ads.
eg33GC is offline   Reply With Quote
Old 09-21-2011, 01:44 AM   #377
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

^^^^
I'll dig that head out and get some before and after pics. Let me catch up on some engines first.
FuJi K is offline   Reply With Quote
Old 09-21-2011, 10:17 AM   #378
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

be careful on the EZ30R heads as I've been made aware that they have thin spots throughout the port. So use some sonic help
Homemade WRX is offline   Reply With Quote
Old 09-21-2011, 10:21 AM   #379
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

^^^^
I haven't gotten to those yet, but the ones we're talking about are the EG33 heads. Thanks for the heads up!
FuJi K is offline   Reply With Quote
Old 09-21-2011, 11:02 AM   #380
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

oh, EG33 heads have lots of meat
Homemade WRX is offline   Reply With Quote
Old 12-12-2011, 02:00 AM   #381
AREA1320
Former Vendor
 
Member#: 112508
Join Date: Apr 2006
Location: Easton, PA
Default

Quote:
Originally Posted by Homemade WRX
rdrz14: don't gasket match the exhaust side!! leave a stepped lip. It helps to limit reversion....something most noobs don't know to check on a flowbench or even think about with gas flow of an engine.
But if the exhaust manifold is ported the same this theory is void no?
AREA1320 is offline   Reply With Quote
Old 12-12-2011, 04:49 AM   #382
Maxwell Power
Former Vendor
 
Member#: 190729
Join Date: Oct 2008
Chapter/Region: NWIC
Location: Marysville, WA
Default

It's not a theory and the oem header shouldn't be ported.
it's ignorant for people to think that Subaru couldn't make a well flowing exhaust. the steps are there for a reason. if you look it always goes from small to big. this is because you can't rely on any scavenging effect from the other cylinder in the factory header. You have to tune the exhaust like 4 single cylinder engines. When you use an aftermarket header, there is a merge collector that brings all the exhaust pulses to a single point, maintains flow in one direction and provides scavenging. In that exhaust you can port match the head if you desire, but it is still better not to for lower end torque.
Maxwell Power is offline   Reply With Quote
Old 12-12-2011, 09:48 AM   #383
MartinSTi05
Scooby Specialist
 
Member#: 145145
Join Date: Apr 2007
Chapter/Region: MWSOC
Location: Rockford, Il
Vehicle:
2006 wrx STi

Default

Agreed, the steps are there and directional. I think there are areas that could use a little clean up though; not because Subaru is incapable of designing an exhaust though. Cost dictates you can only spend so much on finishing for x amount of gain. From an OEM perspective the header is good enough, especially for those power levels.
I firmly believe Subaru configures their single scroll headers in the manner they do because it minimizes the volume between the head ports an turbo an that configuration naturally costs less.
MartinSTi05 is offline   Reply With Quote
Old 12-12-2011, 10:05 AM   #384
AREA1320
Former Vendor
 
Member#: 112508
Join Date: Apr 2006
Location: Easton, PA
Default

Quote:
Originally Posted by Maxwell Power
It's not a theory and the oem header shouldn't be ported.
it's ignorant for people to think that Subaru couldn't make a well flowing exhaust. the steps are there for a reason. if you look it always goes from small to big. this is because you can't rely on any scavenging effect from the other cylinder in the factory header. You have to tune the exhaust like 4 single cylinder engines. When you use an aftermarket header, there is a merge collector that brings all the exhaust pulses to a single point, maintains flow in one direction and provides scavenging. In that exhaust you can port match the head if you desire, but it is still better not to for lower end torque.
Yes sir!!! Relax buddy


Maybe i should have been more clear and specified oem manifold vs aftermarket. I understand the reasoning for the oem. Just couldnt find one for the aftermarket
AREA1320 is offline   Reply With Quote
Old 12-12-2011, 11:40 AM   #385
3MI Racing
Former Vendor
 
Member#: 200987
Join Date: Jan 2009
Chapter/Region: MAIC
Location: VA
Default

Quote:
Originally Posted by AREA1320 View Post
Maybe i should have been more clear and specified oem manifold vs aftermarket. I understand the reasoning for the oem. Just couldnt find one for the aftermarket
Most aftermarket companies seem to just build off of what fits and not so much as to what is better, an excellent example is Manley and their destroked EJ257 piston. It is completely backwards from what you should have for a piston in the applicatoin but is done for a bottom dollar attempt to get into the market.

Things like manifolds really are way more design intensive than catbacks and intakes, which are easy to make improvements upon for little design time. Making a good intake or exhaust manifold requires lots more R&D and requires more to make without trade-offs.

This is where we find ourselves in the niche market of a car where we can design these things without emissions limitations (see block geometry, cam lobes/timing, combustion chambers, AVCS, etc). Those who have studied what the factory did, not as they did it so it must be right but with they thought 'why was it done this way' and take with a system approach...keeping in mind nagging penny pinchers on the business side

/rant
3MI Racing is offline   Reply With Quote
Old 12-12-2011, 11:50 AM   #386
AREA1320
Former Vendor
 
Member#: 112508
Join Date: Apr 2006
Location: Easton, PA
Default

rant noted

Im all about learning, christ my wife yells at me all the time for constantly searching thing on the phone haha. Now that makes me more curious to see what can be improved with our twinscroll manifolds
AREA1320 is offline   Reply With Quote
Old 12-12-2011, 12:51 PM   #387
Maxwell Power
Former Vendor
 
Member#: 190729
Join Date: Oct 2008
Chapter/Region: NWIC
Location: Marysville, WA
Default

Quote:
Originally Posted by AREA1320

Yes sir!!! Relax buddy

Maybe i should have been more clear and specified oem manifold vs aftermarket. I understand the reasoning for the oem. Just couldnt find one for the aftermarket
I'm calm
A lot of people mistake exhaust for plumbing. we aren't pouring water through pipes. An exhaust is very dynamic with pressure waves that need to be timed/tuned to give a certain result.
The steps provide that function and the average enthusiast has no idea what is going on. Subaru owners seem to have a better grasp on engineering than Evo owners, no doubt.
Maxwell Power is offline   Reply With Quote
Old 01-26-2012, 04:44 PM   #388
maxpowr
Scooby Guru
 
Member#: 159243
Join Date: Sep 2007
Chapter/Region: Tri-State
Location: medford nj 08055
Vehicle:
sg3 Turbo Tek Tuned
Hakt Ecu e85 30r 6spd

Default

subscrib'd...
maxpowr is offline   Reply With Quote
Old 01-26-2012, 05:28 PM   #389
n2xlr8n
Scooby Specialist
 
Member#: 18960
Join Date: May 2002
Chapter/Region: South East
Location: Bama
Vehicle:
02 WRX MBP
It lives! ; )

Default

FuJi K,

Have you ever considered using Pipemax? To the point, it's simply the best tool I've ever used. Do a search for Larry Meaux maxracesoftware.

S.
n2xlr8n is offline   Reply With Quote
Old 01-26-2012, 07:54 PM   #390
ASF Machine
NASIOC Vendor
 
Member#: 236349
Join Date: Jan 2010
Location: Western Colorado
Vehicle:
1993 Impreza
OD Green

Default

Quote:
Originally Posted by n2xlr8n View Post
FuJi K,

Have you ever considered using Pipemax? To the point, it's simply the best tool I've ever used. Do a search for Larry Meaux maxracesoftware.

S.
That is a super handy program but the calcs but a bit difficult to apply to a forced induction setup unless your turbo setup is pretty closely optimized to run very close to 1:1 intake/exhaust, drive/boost.

Couple Pipemax with Performance Trends EAS and you've got quite the combo.
ASF Machine is offline   Reply With Quote
Old 01-28-2012, 05:55 AM   #391
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

Quote:
Originally Posted by n2xlr8n
FuJi K,

Have you ever considered using Pipemax? To the point, it's simply the best tool I've ever used. Do a search for Larry Meaux maxracesoftware.

S.
i have looked at that a long time ago. very fun thing to play with!
FuJi K is offline   Reply With Quote
Old 01-30-2012, 11:57 AM   #392
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

is smoother....but it'll be covered in carbon once the car is running.


FuJi K is offline   Reply With Quote
Old 01-30-2012, 02:50 PM   #393
smileyou
Scooby Specialist
 
Member#: 152045
Join Date: Jun 2007
Chapter/Region: SCIC
Location: Corona/Fontana
Vehicle:
2003 PIA wrx
wrb..future ppg/fggreen

Default

Fuji, can you pm me on how much you charge for porting?
smileyou is offline   Reply With Quote
Old 01-31-2012, 01:41 PM   #394
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

nasty lip on the short turn of the exhaust



FuJi K is offline   Reply With Quote
Old 02-02-2012, 01:13 AM   #395
project_skyline
Scooby Specialist
 
Member#: 153880
Join Date: Jul 2007
Chapter/Region: RMIC
Location: Western Slope, Colorado
Vehicle:
03 Evo VIII
2011 STI

Default

Do you have any flow numbers of your ported heads compared to stock on the same bench?

What exactly is the bottle caps and wrench sockets supposed to signify?
project_skyline is offline   Reply With Quote
Old 02-02-2012, 04:18 AM   #396
Marnix
Scooby Specialist
 
Member#: 51480
Join Date: Dec 2003
Chapter/Region: International
Location: The Netherlands
Vehicle:
1984 AM5, 1994 BC4,
2010 BR5

Default

Fuji, do you know how much meat there is on the clover style EJ20G/EJ20K heads to make them more bath tub shaped?
Marnix is offline   Reply With Quote
Old 02-02-2012, 10:38 AM   #397
B.R.E.D
Scooby Specialist
 
Member#: 289606
Join Date: Jul 2011
Location: Atlanta
Vehicle:
06 WRX
white

Default

Quote:
Originally Posted by Marnix View Post
Fuji, do you know how much meat there is on the clover style EJ20G/EJ20K heads to make them more bath tub shaped?
Why would you want to do that?
B.R.E.D is offline   Reply With Quote
Old 02-02-2012, 11:20 AM   #398
ASF Machine
NASIOC Vendor
 
Member#: 236349
Join Date: Jan 2010
Location: Western Colorado
Vehicle:
1993 Impreza
OD Green

Default

Quote:
Originally Posted by B.R.E.D View Post
Why would you want to do that?
My only guess would be to better match a donut dish.

That said, the clover style chambers deshroud very beautifully.

Matched to an EJ25 Bore


Still EJ20 bore
ASF Machine is offline   Reply With Quote
Old 02-02-2012, 03:39 PM   #399
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

Quote:
Originally Posted by Marnix
Fuji, do you know how much meat there is on the clover style EJ20G/EJ20K heads to make them more bath tub shaped?
look through the water jacket holes. I'm sure there is a good amount of meat... the '96 25D heads are a larger chamber similar to the B25 heads; HLA valvetrain.
FuJi K is offline   Reply With Quote
Old 02-02-2012, 07:14 PM   #400
Maxwell Power
Former Vendor
 
Member#: 190729
Join Date: Oct 2008
Chapter/Region: NWIC
Location: Marysville, WA
Default

I had a set of S20 heads that are on a big bore. I wanted to experiment with the clover style to see if there was any power to be had. So I cut the chambers out to resemble the clover. Obviously I was unable to add material in between the valves like the clover. But I was able to just deshroud around the valves to make the final chamber look very "cloverleafy". I have more room to work than most people because I'm running a 102.3mm bore.

no gains... at all. Total waste of time. Now I'm going back in to open them up like the STi chambers (only a little bigger around) because I know there are gains (I've done it many times already).
Maxwell Power 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
Garrett GT Series Turbo port sizes WAYGONE1 Built Motor Discussion 1 08-25-2009 09:11 PM
head porting and arp head studs..... ejsportcom Built Motor Discussion 6 03-24-2006 01:05 PM
IL: Gruppe-s header, TXS TBE, APS UP, Axis Stg 4, Ported heads, Ported TB, Manifold BLUETURBOWRX Private 'For Sale' Classifieds 20 03-06-2005 07:19 PM
IL:Gruppe-s Header,TXS TB,APS UP,Axis Stg 4, Ported heads,Ported TB,Manifolds & more. BLUETURBOWRX Mid West Subaru Owners Club Forum -- MWSOC 14 02-23-2005 10:47 PM


All times are GMT -4. The time now is 12:13 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.