Welcome to the North American Subaru Impreza Owners Club Monday January 24, 2022
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC General > Proven Power Bragging

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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 09-16-2021, 10:03 PM   #51
K3rm1tth3fr0g
Scooby Specialist
 
Member#: 508105
Join Date: Nov 2019
Chapter/Region: NWIC
Location: Greater Seattle Area
Vehicle:
2002 WRX - Link ECU
being installed :)

Default

Quote:
Originally Posted by PotatoFlakeSTi View Post
The .83 AR got here last week, going on in a week or two.
I still think that you'll have enough back pressure to benefit from this if you are going all out.
* Registered users of the site do not see these ads.
K3rm1tth3fr0g is online now   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 09-17-2021, 01:30 AM   #52
silversurfer05
Scooby Newbie
 
Member#: 366241
Join Date: Aug 2013
Chapter/Region: South East
Location: broward county, Florida
Vehicle:
2009 09 wrx delivery
Dgm

Default

Quote:
Originally Posted by PotatoFlakeSTi View Post
The .83 AR got here last week, going on in a week or two.
If you are going above 30 pounds of boost, you will probably see you nice big benefits. Under 25 pounds of boost I donít think this would help as much, but it would still help. Iím thinking about doing it as well to try and get the last bit of horsepower I can out of my set up before going six speed. (Currently 400whp @15psi spring pressure)
silversurfer05 is offline   Reply With Quote
Old 09-17-2021, 07:42 AM   #53
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

In general the closer to the turbine exit, the bigger the reduction in backpressure and larger gains. Putting the valve near the muffler will have much less impact than say a hood exit at the top of the downpipe.

Quote:
Originally Posted by PotatoFlakeSTi View Post
I really want to do this, but also don't want to waste a bunch of money if I'm not generating enough backpressure for this to help. Hmmm!
Google search exhaust diameter calculator. There's a bunch of stuff out there, even for turbo stuff. It will give you a rough idea. Say for example, you're near the bottleneck point for 3", you'd get much bigger gains than if you were in the flow sweet spot. Also keep in mind the gains scale with power output.

Quote:
Originally Posted by K3rm1tth3fr0g View Post
Aren't you running a G30-900 on a .61 housing?

I imagine there is certainly enough back pressure for this to be beneficial.
With that, you likely have way high manifold pressure and less post turbine pressure because of it.

A G30-900 is going to have a BIG compressor and small turbine. That's backwards from what EJs like. EJs typically perform best with large turbines on a big A/R, and smaller compressors. For that turbo I would run the biggest A/R turbine you can find, especially if you're running E85 or race fuel. Small and medium turbines will chose the potential of the turbo. If these engines were like a 1.6 B16A from a Civic the argument would be different, but the EJ25 is actually large for a 4-banger and the better the exhaust breathes through the ENTIRE system, the better they perform. You'll also have better EGTs and improved low load transient response with a larger A/R
KillerBMotorsport is offline   Reply With Quote
Old 10-28-2021, 08:37 PM   #54
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Doing it! With a 60mm Tial, since that's what was available.

Won't be able to do a direct before/after since fueling is being sorted, but excited anyway!
PotatoFlakeSTi is offline   Reply With Quote
Old 10-30-2021, 08:06 AM   #55
user1029
Scooby Specialist
 
Member#: 57064
Join Date: Mar 2004
Vehicle:
2008 STi IAG built
HTA86 E85 Kel272s Cos IM

Default

Quote:
Originally Posted by PotatoFlakeSTi View Post
Doing it! With a 60mm Tial, since that's what was available.

Won't be able to do a direct before/after since fueling is being sorted, but excited anyway!
You can put two on your McLaren
user1029 is offline   Reply With Quote
Old 10-30-2021, 01:41 PM   #56
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Quote:
Originally Posted by user1029 View Post
You can put two on your McLaren
There's an idea! Although with as short as the exhaust is already it might not make a difference.
PotatoFlakeSTi is offline   Reply With Quote
Old 11-06-2021, 12:18 PM   #57
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: Mooresville, NC
Vehicle:
96 3MI Racing
search FIRST, then PM!!!

Default

Off topic, but what is your McLaren set up? I've been consulting with a McLaren shop lately. Definitely a fun platform.
Homemade WRX is offline   Reply With Quote
Old 11-06-2021, 04:50 PM   #58
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Quote:
Originally Posted by Homemade WRX View Post
Off topic, but what is your McLaren set up? I've been consulting with a McLaren shop lately. Definitely a fun platform.
2020 720S Spider w/ Carbon Package
Custom 200CEL Downpipes by Fern Ochoa
Custom Titanium Exhaust by BlueChip here in Denver
Pure Turbos Turbo Inlets
Green Filters
M-Engineering tune for 91/93/100oct + rolling antilag.

On topic: Shop couldn't (or didn't want to??) get the wastegate and talked me into a vacuum operated cutout instead, will slap up a picture from my phone in a moment.

It should open at 5psi. Which might be too early (loudness wise), but we'll see.

Edit:



Last edited by PotatoFlakeSTi; 11-06-2021 at 06:09 PM.
PotatoFlakeSTi is offline   Reply With Quote
Old 11-06-2021, 04:58 PM   #59
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Speaking of which, shop owner is confident a cutout is not needed and won't make a power difference, but I insisted.

Last edited by PotatoFlakeSTi; 11-06-2021 at 06:22 PM.
PotatoFlakeSTi is offline   Reply With Quote
Old 11-06-2021, 07:02 PM   #60
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Quote:
Originally Posted by KillerBMotorsport View Post
In general the closer to the turbine exit, the bigger the reduction in backpressure and larger gains. Putting the valve near the muffler will have much less impact than say a hood exit at the top of the downpipe.



Google search exhaust diameter calculator. There's a bunch of stuff out there, even for turbo stuff. It will give you a rough idea. Say for example, you're near the bottleneck point for 3", you'd get much bigger gains than if you were in the flow sweet spot. Also keep in mind the gains scale with power output.



With that, you likely have way high manifold pressure and less post turbine pressure because of it.

A G30-900 is going to have a BIG compressor and small turbine. That's backwards from what EJs like. EJs typically perform best with large turbines on a big A/R, and smaller compressors. For that turbo I would run the biggest A/R turbine you can find, especially if you're running E85 or race fuel. Small and medium turbines will chose the potential of the turbo. If these engines were like a 1.6 B16A from a Civic the argument would be different, but the EJ25 is actually large for a 4-banger and the better the exhaust breathes through the ENTIRE system, the better they perform. You'll also have better EGTs and improved low load transient response with a larger A/R
They came out with a G40-900, huge turbine. Give it a go!
PotatoFlakeSTi is offline   Reply With Quote
Old 11-06-2021, 11:20 PM   #61
user1029
Scooby Specialist
 
Member#: 57064
Join Date: Mar 2004
Vehicle:
2008 STi IAG built
HTA86 E85 Kel272s Cos IM

Default

Quote:
Originally Posted by PotatoFlakeSTi View Post
Speaking of which, shop owner is confident a cutout is not needed and won't make a power difference, but I insisted.
Show him the after dyno
user1029 is offline   Reply With Quote
Old 11-07-2021, 12:00 AM   #62
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Quote:
Originally Posted by user1029 View Post
Show him the after dyno
I have.
PotatoFlakeSTi is offline   Reply With Quote
Old 11-07-2021, 12:02 AM   #63
user1029
Scooby Specialist
 
Member#: 57064
Join Date: Mar 2004
Vehicle:
2008 STi IAG built
HTA86 E85 Kel272s Cos IM

Default

Your after dyno
user1029 is offline   Reply With Quote
Old 11-07-2021, 12:06 AM   #64
PotatoFlakeSTi
Scooby Newbie
 
Member#: 273267
Join Date: Feb 2011
Chapter/Region: RMIC
Vehicle:
2011 STi / 98 LSTi

Default

Quote:
Originally Posted by user1029 View Post
Your after dyno
With our high reading dyno I'd expect 725whp'ish after the Fuel pump upgrade and holding better, though that's just guesswork... So I guess we'll have to see if there's a 10% gain on that.

Our turbo's are pretty comparable though
Edit: turbine aside...
PotatoFlakeSTi is offline   Reply With Quote
Old 11-11-2021, 05:55 PM   #65
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: Mooresville, NC
Vehicle:
96 3MI Racing
search FIRST, then PM!!!

Default

Quote:
Originally Posted by PotatoFlakeSTi View Post
2020 720S Spider w/ Carbon Package
Custom 200CEL Downpipes by Fern Ochoa
Custom Titanium Exhaust by BlueChip here in Denver
Pure Turbos Turbo Inlets
Green Filters
M-Engineering tune for 91/93/100oct + rolling antilag.
Nice. I'm looking forward to seeing what the shop 12C and 720S cars do. Practically the same engine wise outside of exhaust manifolds, stroke, and heads.

Quote:
On topic: Shop couldn't (or didn't want to??) get the wastegate and talked me into a vacuum operated cutout instead, will slap up a picture from my phone in a moment.

It should open at 5psi. Which might be too early (loudness wise), but we'll see.

Edit:


I would have told you the same. EWG housings flow like crap as a valve. This is low pressure, so that butterfly valve will have much higher mass flow for the same pressure.
Homemade WRX 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

All times are GMT -4. The time now is 06:36 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2022 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.