Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Archives > NASIOC Archives > Technical Forum Archive

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. 
 
 
Thread Tools Display Modes
Old 09-20-2000, 08:55 AM   #1
skidplatez
Scooby Specialist
 
Member#: 1575
Join Date: Jun 2000
Chapter/Region: South East
Location: Atlanta GA, USA
Vehicle:
2011 WRX Premium
Blackest Black

Lightbulb Dispelling myths of the P1

Let me start by saying that this post is not meant to flame anyone who has bought the P1 suspension or anyone who likes it. I just wanted to share some things that I have found while researching the P1 suspension. First of all the P1 is an STI suspension. Despite what Prodrive marketing is trying to convince the world they designed the suspension by picking from STI's parts bin. Also the P1 suspension understeers more than an STI ver5 by design

quote: "So large is Subaru Technica International's ( STi ) range of springs and dampers that Prodrive tried no less than 22 variations. In standard spec the WRX is too harsh for UK roads, so the P1 retains the WRX's rear springs but uses softer front springs and uprated dampers all round to achieve a more compliant ride. "

This quote is from a P1 review on a british website. This change would make the P1 corner worse than the WRX but handle bad roads better. This was done on purpose. The Prodrive folks wanted to make a more streetable car for British roads. So, if you want a maximum performance suspension go through one of the subaru parts people like subaruparts.com and get the WRX STI suspension NOT the P1. What makes the P1 special is the Brit specific design and Prodrive heritage not the suspension.

quote:"VERDICT: Developed in the UK for the UK market" more about understeer-"The other slight blot in the copybook is the P1's less than dogged resistance to understeer. We're used to Imprezas amazing us with awesome front-end grip, but the P1's front 205/45 ZR17 Pirelli P-Zeros start to slither earlier than expected. Perhaps the biggest disappointment is not being able to deal with the understeer by adding to or cutting the throttle"


[This message has been edited by skidplatez (edited October 03, 2000).]
* Registered users of the site do not see these ads.
skidplatez is offline  
Sponsored Links
* Registered users of the site do not see these ads.
Old 09-20-2000, 09:46 AM   #2
Tony
Scooby Specialist
 
Member#: 287
Join Date: Sep 1999
Chapter/Region: MAIC
Location: Munich Germany
Vehicle:
2019 Outback
Blue

Post

Simply changing the front springs to softer ones would reduce understeer not add to it. Maybe it was something in the damper/swaybar selection that causes the poor handling.

Tony
Tony is offline  
Old 09-20-2000, 10:41 AM   #3
XT6Wagon
Scooby Specialist
 
Member#: 524
Join Date: Nov 1999
Location: WA
Vehicle:
04 STi
White

Post

That is not always the case, the softer springs could be allowing the P1 to washout the outside front tire, with exessive wieght transfer, or camber changes due to suspention compression.

XT6Wagon is offline  
Old 09-20-2000, 10:45 AM   #4
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2014 Q60S, 2016 Chevy SS
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Post

So if I go through Subaruparts.com, what are the part numbers for the WRX springs and shocks. I have the P1 part numbers but I want the suspension for aut0-x so I don't care how bumpy the ride is. Please help!

Eric
Eric SS is offline  
Old 09-20-2000, 10:48 AM   #5
Midwayman
Scooby Specialist
 
Member#: 1997
Join Date: Jul 2000
Chapter/Region: MWSOC
Location: Des Plaines, IL
Vehicle:
2006 Acura TL 6spd
STMGM6 alumni

Post

If you goto the STi section, they now list the WRX springs under the suspension section along with the struts.
Midwayman is offline  
Old 09-20-2000, 11:00 AM   #6
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Talking

The P1 as bought from the UK dealers does understear at the limit. All Imprezas do. It is designed in to make the car safe for the average driver.

Here in the UK lots of the really keen drivers of imprezas take there car to a company called powerstation.

What these guys do is move the position of the steering rack to eliminate bump steer from the front end, they also alter the geometries to make the chasis as neutral as posible.

These mods are not limited to the P1, i have friends with 22B's, P1's, STi's and of course UK turbos who all rave about how the car is transformed by these changes.

At the end of the day, subaru has to tune the cars suspension to be safe for the lowest common denominator, an inexperienced or relatively unskilled driver.

If you want a great handling subaru you have to change the stock suspension and steering settings, changing spring rates and dampers isnt always the answer.

Take a look at their web site, you will see non other than the Prodrive Impreza WRC car at their premises prior to the RAC rally having its setting checked.
http://www.powerstation.org.uk/Projects_Page.html
johnfelstead is offline  
Old 09-20-2000, 11:13 AM   #7
rsquire
Scooby Specialist
 
Member#: 265
Join Date: Sep 1999
Location: Kirkland, WA
Vehicle:
1998 22B Blue
1986 Ford RS200 White

Talking

hi John,,

i fully concur on the Powerstation setup.. It is absolutely awesome..

Although some people, "no names no pack drill" were trying to convince me that the Leda C suspension was a must have on the 22B their minds were changed after driving my car with stock suspension but with the Powerstation bump steer removal setup..

With this setup you almost "think" the car through a corner. Amazing on both the road and track. Understeer is eliminated but the suspension is still compliant and comfortable for everyday use ( I wish )

Richard

rsquire is offline  
Old 09-20-2000, 11:40 AM   #8
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Talking

hey richard,

As a lucky SOB i have had the pleasure of driving richards 22B both on track and road both before and after the powerstation mods.

Before the car was stunning, very easy to drive quickly but after, WOW, so easy to drive on the limit, 4 wheel drifts under full control are childs play and non of the dreaded understear.

Such a shame the 22B is over hear and not in WA with its dad where it belongs.

Its even more of a shame that i get to run around in the beasty on occasion, just to keep things from seizing up you see. LOL
johnfelstead is offline  
Old 09-20-2000, 02:21 PM   #9
wrxwannabe
Scooby Specialist
 
Member#: 1178
Join Date: Mar 2000
Chapter/Region: South East
Location: West Columbia, SC
Vehicle:
2011 BMW 535i
Alpine White

Post

Richard,
Or actually anyone in the UK that can get us poor Souls in the US the information on the "Powerstation" modification. If they were to train Rallispec or someone over hear to do that I'm sure there are plenty of us Lowly 2.5 Owners that would love to kill the dreaded Understear...

Thanks in advance
Eric
wrxwannabe is offline  
Old 09-20-2000, 02:31 PM   #10
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Wink

why dont you guys fire off an email to the guys at powerstation and ask the question.

The Impreza is basically the same car the world over, i dont see why the RS should be any diferent than the Jap and European models.

It's such a drag having friends like richard at times, takes a huge amount of effort to motivate me to sit in the 22B. LOL
johnfelstead is offline  
Old 09-20-2000, 04:38 PM   #11
Sauginius
Scooby Newbie
 
Member#: 277
Join Date: Sep 1999
Chapter/Region: SCIC
Vehicle:
98 Not a Subaru
BRACK

Post

I just sent an e-mail to the guys at Powerstation. I'll keep you guys posted.
Sauginius is offline  
Old 09-21-2000, 12:25 AM   #12
burr101
Scooby Specialist
 
Member#: 907
Join Date: Feb 2000
Location: Harrisville, RI
Vehicle:
2002 WRX Sedan
Silver

Thumbs up

johnfelstead,
what a good friend you are... making such a big sacrafice for your buddy richard. LOL.

richard,
just curious.. how often do you get to see your 22B?? do you have a job that you travel to the UK often or do you take lots of vacations? sorry for all the questions but to have such a beautiful car and not be able to see/drive it must be torture. thanks

shaun

burr101 is offline  
Old 09-21-2000, 12:30 AM   #13
Sauginius
Scooby Newbie
 
Member#: 277
Join Date: Sep 1999
Chapter/Region: SCIC
Vehicle:
98 Not a Subaru
BRACK

Post

Can our US spec cars benifit from a simiar bump steer elimination mod? If so, does anyone know where this can be done in the US? I've been keeping up with the UK peeps and yes, they all seem to rave about the results.
Sauginius is offline  
Old 09-21-2000, 04:07 AM   #14
wrxwannabe
Scooby Specialist
 
Member#: 1178
Join Date: Mar 2000
Chapter/Region: South East
Location: West Columbia, SC
Vehicle:
2011 BMW 535i
Alpine White

Thumbs up

Sauginius,
Thanks for sending off a E-mail.. Please let me know what you get back from them.. Anything that we can do the help solve some of the Understear situation would be awesome...

Thanks again
Eric
wrxwannabe is offline  
Old 09-21-2000, 04:57 AM   #15
Lovejoy
Scooby Newbie
 
Member#: 613
Join Date: Dec 1999
Location: Washington, DC
Vehicle:
'95 Nissan Maxima S

Post

Skid...one little error. Most of the suspension components may be STi, but the dampers and springs are not. They are Eibach/Bilstein, custom made to Prodrive specs. As far as understeer, as stated above, it is there by design. Most of us are not like Michael Schumacher, and cannot handle a totally neutral-light oversteering car.

Lovejoy

[This message has been edited by Lovejoy (edited September 21, 2000).]
Lovejoy is offline  
Old 09-21-2000, 05:33 AM   #16
Bob O
Scooby Specialist
 
Member#: 1502
Join Date: May 2000
Chapter/Region: MAIC
Location: Felton, PA, USA
Vehicle:
2000 2.5RS & SV1kS
BRP

Thumbs up

I may be no Schuey, but it sure is fun to try to drive like him. One question about the make up of the P1 sus, I had heard that the springs were Prodrive specified rates from Ebiach and the dampers were Version 5/6 (which are made by KYB from what I have read) from the STi WRX. The WR sport is the one that I thought came with the Bilstiens (hence the larger price increase). That sound right? Given that most of the roads in the NE (PA/MD backroads) are prob equilevent to UK roads AND the fact that I have been known to take a dirt road or two, I would think the less stiff P1 suspension would be better for me. Does anyone know if the WRX spec suspension would work as well as the P1 in that enviornment? Does the P1 have inherently MORE understeer than the full spec STi WRX? Can't we just run a bigger rear bar (or higher setting) to dial the understeer out? Also does either the WRX or P1 setup provide any lowering over the stock suspension?

Bob

[This message has been edited by Bob O (edited September 21, 2000).]
Bob O is offline  
Old 09-21-2000, 06:15 AM   #17
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Post

next get together i will crawl under my mates P1 and take a look, bilstiens are usually pretty well marked up with damping specs.

I will ask him also, he is a bit of a car nut so he may know off the top of his head.
johnfelstead is offline  
Old 09-21-2000, 08:23 PM   #18
5252
Guest
 
Member#:
Post

"What these guys do is move the position of the steering rack to eliminate bump steer from the front end, they also alter the geometries to make the chasis as neutral as posible."

I read a post somewhere on the sidc board that basically said "It doesn't matter where in the U.K. you are. You simply MUST get your Impreza into Power House for this susp. mod."

 
Old 09-21-2000, 08:27 PM   #19
Eric SS
Sooby Guru
 
Member#: 1914
Join Date: Jul 2000
Chapter/Region: SWIC
Location: 2014 Q60S, 2016 Chevy SS
Vehicle:
2000 2.5RS w/ EJ22T
swap and N20. gone. : (

Post

Anywhere in the US to get this done? Any instructions on the net??

Eric
Eric SS is offline  
Old 09-22-2000, 12:47 AM   #20
Sauginius
Scooby Newbie
 
Member#: 277
Join Date: Sep 1999
Chapter/Region: SCIC
Vehicle:
98 Not a Subaru
BRACK

Post

Well, still no word from Powerstation yet........
Sauginius is offline  
Old 09-22-2000, 04:31 AM   #21
wrxwannabe
Scooby Specialist
 
Member#: 1178
Join Date: Mar 2000
Chapter/Region: South East
Location: West Columbia, SC
Vehicle:
2011 BMW 535i
Alpine White

Post

As we sit and wait...

Oh to get rid of understeer

What a happy day that will be..

I feel like Dr. Fankenstein "It's ALIVE,,,IT'S ALIVE!!!!!" and it doesn't understeer

Oh well,

E.
wrxwannabe is offline  
Old 09-26-2000, 02:33 AM   #22
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Question

You guys still waiting?

I will have a chat with my mate who spends half his life doing work for these guys, see if he can get the info from them.

He is on holiday right now so may be a week.

cheers
john
johnfelstead is offline  
Old 09-26-2000, 06:05 AM   #23
5252
Guest
 
Member#:
Post

Yes still waiting. Now I notice the bumpsteering. I am wondering if the relocater shim for the rack is the a standard piece. I would like to have one.
 
Old 09-27-2000, 01:09 PM   #24
johnfelstead
Scooby Specialist
 
Member#: 856
Join Date: Feb 2000
Chapter/Region: International
Location: Cambridgeshire, England, UK
Vehicle:
2123 JDM STi
Black

Post

OK guys, some bad news i am afraid.

As powerstation brought this mod to market they are reluctant to let the info out.

Thats fair enough, they spent the time to check this out.

However. I can tell you how to sort this myself, it's not rocket science.

What you guys need to do is go to a race workshop or similar, someone who sets up race cars, and get them to measure the front bump steer. This is a straight forward thing to do, every race car should have this dialed out.

What they then need to do is shim the steering rack on its mounting points to move it until the bump steer is eliminated. A competent race shop will be able to do this, its common race car practice.

I am going to try and get hold of the suspension geometry settings from a printout taken from a car set up on there laser alignment kit.

The bump steer mod is worth getting done on its own, as long as you can handle a car with less inherant understeer.
johnfelstead is offline  
Old 09-27-2000, 01:25 PM   #25
boxerman
Scooby Newbie
 
Member#: 644
Join Date: Dec 1999
Location: Hoboken, NJ, USA
Post

Bump steer kits a very popular for lowered Porsches. If I remeber correctly bump steer is related to the tie rods not being parallel to the ground (at compresed ride height).

When a car is lowered, the rack is lowered hence the tie rods must rise to meet knuckle/hub. The kits lift the rack with shims until the tie rods are parallel with the ground (horizontal)again.

I am not sure if the same applies to the Powerhouse mod.

Tim
boxerman is offline  
 

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
10th anniversary of the P1 Chris & Rosy B Member's Car Gallery 13 05-11-2010 03:36 AM
The Myth of the Recovery Mike Wevrick Political Playground - Chaotic Neutral Edition 53 04-05-2010 06:41 PM
Myths of the Heathcare Bill matt30 Political Playground - Chaotic Neutral Edition 22 09-09-2009 02:02 PM
Unraveling the myth of the Straight Talk Express HB_Dad Political Playground - Chaotic Neutral Edition 4 09-14-2008 12:12 AM
Just ordered a set of the P1 rims (woo, hoo!) gtguy Brakes, Steering & Suspension 3 12-06-2000 07:29 PM

All times are GMT -4. The time now is 06:48 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.