Welcome to the North American Subaru Impreza Owners Club Thursday July 10, 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 > Normally Aspirated with bolt-on Forced Induction 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 10-20-2001, 11:03 PM   #1
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2013 335i, 2011 G37 coupe
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Default Any done a sequential on a GC8?

I did a search and came up with a whole bunch of crap. Has anyone done a sequential setup on our cars? With such a high rpm capability that the boxer engines have, it seems like a perfect candidate for such a setup.

Eric
* Registered users of the site do not see these ads.
Eric SS is offline   Reply With Quote
Old 10-20-2001, 11:04 PM   #2
boysetsfire
Scooby Specialist
 
Member#: 6218
Join Date: Apr 2001
Chapter/Region: SCIC
Location: Agoura, California
Vehicle:
2001 2.5rs-t
silverthorn metallic

Default

whats a sequential setup?
boysetsfire is offline   Reply With Quote
Old 10-20-2001, 11:05 PM   #3
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2013 335i, 2011 G37 coupe
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Default

Two different sized turbos. The first (the smaller one) spools up at a lower rpm for low end boost, the second (the larger one) spools up at a much higher rpm for high rpm power.

Eric
Eric SS is offline   Reply With Quote
Old 10-20-2001, 11:13 PM   #4
Andrew
Scooby Specialist
 
Member#: 1170
Join Date: Mar 2000
Chapter/Region: BAIC
Location: San Jose, CA
Vehicle:
2005 STi
White

Default

its a waste of time. i believe after minnam broke up one of the guys toyed with a TT setup. im not sure if they used 2 different sizes...i forgot the website but they wanted 8k or some crap for a kit that produces the same amoutn of power as a single turbo setup.

just forget the idea its a waste of time on our cars

just build up your engine and get a T3 and you should be very happy.
Andrew is offline   Reply With Quote
Old 10-21-2001, 01:20 AM   #5
bsquare
Scooby Specialist
 
Member#: 1911
Join Date: Jul 2000
Location: Seattle, WA, USA
Vehicle:
2000 Impreza 2.5RS
Silverthorn Metallic

Default

Look at the dyno sheet for Project Impreza in the WRX shootout issue of SCC to see why sequentials are not popular. The wall of torque obviates the complexity of a twin turbo setup, especially a sequential twin turbo setup.


Ben
bsquare is offline   Reply With Quote
Old 10-21-2001, 03:02 AM   #6
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

No need for a sequential setup. and besides boxers spin but if you want to turn 10g's all day long get a Honda 4 cylinder
HndaTch627 is offline   Reply With Quote
Old 10-21-2001, 03:07 AM   #7
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2013 335i, 2011 G37 coupe
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Default

lol.. I guarantee you can spin more rpm's in a Subaru engine than a Honda Engine

Eric
Eric SS is offline   Reply With Quote
Old 10-21-2001, 03:13 AM   #8
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

i'd beg to differ that. But that's another arguement
HndaTch627 is offline   Reply With Quote
Old 10-21-2001, 03:16 AM   #9
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2013 335i, 2011 G37 coupe
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Default

The Subaru Motors (boxer motors) are inherently balanced and there have been people that spin them to 12k rpm's. Although I can;t produce any evidence, I don;t think that there are many Honda's that can do this. I'll start a good-hearted thread on something like this in the next couple day to see what people say

Eric
Eric SS is offline   Reply With Quote
Old 10-21-2001, 03:31 AM   #10
bsquare
Scooby Specialist
 
Member#: 1911
Join Date: Jul 2000
Location: Seattle, WA, USA
Vehicle:
2000 Impreza 2.5RS
Silverthorn Metallic

Default

I guarantee you you are wrong on this. There are production Honda engines that get close to 10krpm and can happily sit there for extended periods. The natural balance of the boxer engine certainly makes it stable, but the narrow main bearings do not stand up well under such stress. Even Porsche normally aspirated racing engines do not crack 10krpm, and that is with titanium rods and all the other goodies.

Additionally, the main limiting factor in high rpm engines is the valvetrain, not the bottom end. Even the STI motors with their sodium filled valves and other strengthened components redline at 8krpm.

Now, the trade-off is torque: Honda gets 240hp out of 2.0L in the S2000...and 120ft/lbs of torque, very little of it at the low end. I guarantee you a stock WRX has more torque through the entire powerband than the S2000, and as we know, the WRX peaks at a _lot_ more.

For 99% of the driving I do I want torque, I want gobs of it, and I want it the second I touch the accelerator. This is why I don't drive a Honda (among other reasons, like lack of AWD). If your goal is high speed (a goal for which our cars are really not properly shaped), then go to a different final drive ratio and let that stump pulling boxer do the rest and stop worrying about whether your engine revs like a motorcycle. Just look at the Hondas in your rear view and smile.


Ben
bsquare is offline   Reply With Quote
Old 10-21-2001, 03:32 AM   #11
kgb
Scooby Specialist
 
Member#: 1366
Join Date: Apr 2000
Chapter/Region: VIC
Location: Delta, BC, Canada
Vehicle:
2000 RS-T -> RSTi-8
Blue Ridge Pearl

Default I think there is no need...

There is enough torque down low for a EJ25, so unless you're aiming for obscene HP number (>400), the lag is not big enough to notice. The only reason for sequential is to reduce the lag while providing high HP, but sequential setup usually involves complex piping (witness the Supra twin-turbo). At this point, I have yet to hear (let alone see) a GC8 EJ25 with more than 450hp with strictly turbo (no Nitrous). What would be interesting is a twin turbo (non-sequential) H6, if someone can find enough room in the engine bay to fit 2 turbos. Usually, twin-turbo (sequential or not) is not needed for 4 cylinder engine, but could be beneficial for 6 or 8 cylinder engine.

As a side note, the problem with running the EJ engines at high revs is the valvetrain. For example, you will be looking at valve floats starting aroung 7000 rpm for stock Phase II SOHC EJ25. I don't know how advance a valvetrain can Subaru design, but at this point, I'm pretty sure Honda & BMW lead the pack (for general production factories). Balancing advantage doesn't quite factor in yet - just look at S2000, inline-4 and it revs to the sky.
kgb is offline   Reply With Quote
Old 10-21-2001, 03:35 AM   #12
bsquare
Scooby Specialist
 
Member#: 1911
Join Date: Jul 2000
Location: Seattle, WA, USA
Vehicle:
2000 Impreza 2.5RS
Silverthorn Metallic

Default

For advanced head designs, Audi is definitely at or near the top of the list. The 1.8T is really a pretty amazing piece of work.


Ben
bsquare is offline   Reply With Quote
Old 10-21-2001, 03:39 AM   #13
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2013 335i, 2011 G37 coupe
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Default

I agree with all of your posts. However, I am talking potential rpm's. I am well aware that out valvetrain is the limiting factor in our engines, however, I believe that our boxer design will alow for a higher rpm that an inline engine if built right

Eric
Eric SS is offline   Reply With Quote
Old 10-21-2001, 03:48 AM   #14
bsquare
Scooby Specialist
 
Member#: 1911
Join Date: Jul 2000
Location: Seattle, WA, USA
Vehicle:
2000 Impreza 2.5RS
Silverthorn Metallic

Default

Maybe a boxer design, but not this boxer design. The bearings are just too narrow and would quickly fail if subjected to that sort of load for any length of time. Subaru made the EJ series quite short, taking advantage of the way the opposite pistons can effectively "overlap". In an inline engine, this is not possible, but instead they are left with a lot more area for crank bearings.

I think rather than focus on whether the Subaru boxer engine can match a single, potentially uninteresting metric, such as the redline on a Honda (or other) inline 4, we should focus on what the Subaru boxer engine does well. In my opinion, what it does well is provide a lot of low end grunt with decent top end (however low in the rpm range that high end might be). This is perfect for a daily driver.


Ben
bsquare is offline   Reply With Quote
Old 10-21-2001, 12:44 PM   #15
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

i 100% agree w/ bsquare. Use the boxer for what it was intended. Lots of power down low and thruout the powerband. Never seen an Audi 1.8T head off the car but the Factory Integra Type R intake valves flow 295CFM and exhaus tis 260ish(IIRC) That things a work of art. The S2000's factory redline=9200 RPM and it's not even happy if you don't keep it above 6700. Personally i'd rather have a car that makes torque @ 3k rpm that way i don't always have to wind the piss out of it to make it go.

Jeremy
HndaTch627 is offline   Reply With Quote
Old 10-21-2001, 01:23 PM   #16
LVSUBARU
Scooby Specialist
 
Member#: 4520
Join Date: Feb 2001
Location: LAS VEGAS
Vehicle:
93 STi V.4 RA
www.flat4lv.com

Default

The EJ25 motor has a large stroke that prevents it from spinning really fast. But that's were the torque comes from!!!
LVSUBARU is offline   Reply With Quote
Old 10-21-2001, 06:04 PM   #17
bsquare
Scooby Specialist
 
Member#: 1911
Join Date: Jul 2000
Location: Seattle, WA, USA
Vehicle:
2000 Impreza 2.5RS
Silverthorn Metallic

Default

The other EJ motors have significant torque for their displacement. Horizontally opposed engines are known for this. Increasing the stroke is just icing on the cake.


Ben
bsquare 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
who has done a wide body on thier gc8? slowrs13 Interior & Exterior Modification 3 04-03-2010 07:30 PM
Concave Volk on my GC8? Any calculators? OneArmedScissor Tire & Wheel 4 11-28-2007 06:08 PM
Those that have done pre96 ej20 wiring to GC8 help Norcalrallyist Subaru Conversions 4 05-08-2006 01:29 AM
Any pics of ROH Adrenalin on a GC8? typhoon116 Tire & Wheel 0 09-21-2004 08:58 AM
Has anyone had any luck getting good camber on a GC8 without camber plates? Eric SS Brakes, Steering & Suspension 11 02-25-2003 08:51 PM


All times are GMT -4. The time now is 12:11 AM.


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.