Welcome to the North American Subaru Impreza Owners Club Wednesday April 10, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC General > Motorsports

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 06-26-2009, 09:05 AM   #1
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default Pad knockback solved!

Im sure many of us have felt knockback before and have decided to just deal with it. Well I was tired of dealing with it, and doing wheel to wheel racing and having to brake hard from high speeds needing to trim 75-100mph with a car inches off both bumpers and having the pedal travel 3/4 to the floor is less than confidence inspring. Since AP, Alcon and other racing caliper companies use antiknock back springs from the factory in their calipers, I figured it was worth a shot. I found sets of 4 springs for 36.5mm+ pistons on HRP's site and they are only $6.90 per set. Calipers off and open, springs in and knockback is gone 100%. I ran my car on NJMP's lightning circuit yesterday and I didnt get even a hint of knockback once, when I typically felt it twice per lap. Go get em guys, thank me later

http://www.hrpworld.com/index.cfm?fo...action=product

Brandon
* Registered users of the site do not see these ads.
brandonl is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 06-26-2009, 02:23 PM   #2
Fred
Scooby Guru
 
Member#: 3560
Join Date: Jan 2001
Chapter/Region: South East
Location: Four Oaks, NC
Vehicle:
20 BRZ
04FXT22WRX95rallyimpreza

Default

I thought about getting a set of those for my STi when I had it. Ended up selling it first. How do they install? Does it cause the brakes to drag a little? If not, how does this work?

Good to hear from someone like you that they actually work.

Thanks.
Fred is offline   Reply With Quote
Old 06-26-2009, 02:26 PM   #3
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: Milton Keynes, UK
Vehicle:
96 3MI Racing
search FIRST, then PM!!!

Default

yes, they do cause brakes to drag...it gave the spring rate in the link. 6 lbs IIRC.
Homemade WRX is offline   Reply With Quote
Old 06-26-2009, 03:11 PM   #4
Element Tuning
Former Vendor
 
Member#: 54918
Join Date: Feb 2004
Chapter/Region: MAIC
Location: Gaithersburg, MD
Vehicle:
673 WHP Element
Tuning Pro Comp Engine

Default

Or you can left foot, tap, tap before you enter your braking zone. I just got used to it and I still have to tap with my 08 WRX. I sure don't miss having to do that on my 06 STi though
Element Tuning is offline   Reply With Quote
Old 06-26-2009, 03:13 PM   #5
grippgoat
Scooby Specialist
 
Member#: 62182
Join Date: May 2004
Chapter/Region: NWIC
Location: Kirkland, WA
Vehicle:
2005 STI
White

Default

Quote:
Originally Posted by Homemade WRX View Post
yes, they do cause brakes to drag...it gave the spring rate in the link. 6 lbs IIRC.
6lbs is a drop in the bucket compared to what's exerted under even light braking, though, isn't it?

-Mike
grippgoat is offline   Reply With Quote
Old 06-26-2009, 03:24 PM   #6
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default

I do not feel a brake drag at all. A 6lb spring is so light it is hard to really explain without having felt one yourself. The force is not enough to really apply the brakes just enough to "reset" the pads into position should they shift away from the rotor surface. I can not say for a fact that they do not drag at all, I did not take any steps to measure the drag, but it honestly can not be felt at all. The car rolls across the floor just as it did before, there is no different feeling of resistance when you turn the rotors by hand either.

The left foot tap does work for sure, but I do not like to have to phantom brake check the guys behind me at speed. You are right Phil, NOT having to do it sure feels good.
brandonl is offline   Reply With Quote
Old 06-26-2009, 03:36 PM   #7
Astartes
Scooby Specialist
 
Member#: 183813
Join Date: Jul 2008
Chapter/Region: South East
Location: The REAL SC
Vehicle:
2006 WRX TR OBP
WRX STi SGM

Default

If they're dragging the only thing it'll really influence is the brake wear and it'll be minimal at that. If this is a track only set up brake wear won't really matter as you're changing them out often.
Astartes is offline   Reply With Quote
Old 06-26-2009, 03:48 PM   #8
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default

Dragging makes it sound worse than it is, whatever amount of drag there may be is nothing you will feel, and on a track car you will never see the difference in the pads service life. 6lbs of force at the pad is equal to an eye lash falling on the brake pedal... not literally, but its as minimal as minimal gets in comparison the force exerted when you actually apply the brakes.
brandonl is offline   Reply With Quote
Old 06-26-2009, 04:08 PM   #9
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: Milton Keynes, UK
Vehicle:
96 3MI Racing
search FIRST, then PM!!!

Default

Quote:
Originally Posted by grippgoat View Post
6lbs is a drop in the bucket compared to what's exerted under even light braking, though, isn't it?

-Mike
yes, the pressure isn't much but my concern would be more of wear and heat. Though I'm sure those would probably be minimal when you look at the grand scheme things...still makes for a higher pad, rotor and caliper operating temp.

Quote:
Originally Posted by Darks View Post
If they're dragging the only thing it'll really influence is the brake wear and it'll be minimal at that. If this is a track only set up brake wear won't really matter as you're changing them out often.
true but wear items do add up...

We used springs in the formula car one year for the front and noticed some decent heat increase and pad wear.
Homemade WRX is offline   Reply With Quote
Old 06-26-2009, 08:01 PM   #10
555ideways
Scooby Specialist
 
Member#: 36652
Join Date: May 2003
Chapter/Region: NESIC
Default

For those who've actually experienced constant pad knock back weekend after weekend - it is a PITA and the tiny increase in pad wear/heat will be worth it.

-Paddy
555ideways is offline   Reply With Quote
Old 06-26-2009, 08:56 PM   #11
Fred
Scooby Guru
 
Member#: 3560
Join Date: Jan 2001
Chapter/Region: South East
Location: Four Oaks, NC
Vehicle:
20 BRZ
04FXT22WRX95rallyimpreza

Default

My temporary solution with my 04 STi was to adjust the brake pedal underneath the dash so that there was just a little bit of pressure/ dragging. Worked for all but the hardest cornering side to side at autoxes.
Fred is offline   Reply With Quote
Old 06-26-2009, 09:01 PM   #12
iLuveKetchup
Scooby Specialist
 
Member#: 66258
Join Date: Jul 2004
Chapter/Region: Tri-State
Location: NYC
Vehicle:
05 STi

Default

I get consistent pad knockback at the auto-x & its driving me crazy. However, I was at NJMP Lightning this past Sunday & I didnt get any knockback. Lightning is a very smooth rhythm based course. So I wonder if the knockback is gone because the course you tested them on doesnt produce much knockback? But I'll give these a try, for sure. Thanks!
iLuveKetchup is offline   Reply With Quote
Old 06-26-2009, 09:15 PM   #13
iLuveKetchup
Scooby Specialist
 
Member#: 66258
Join Date: Jul 2004
Chapter/Region: Tri-State
Location: NYC
Vehicle:
05 STi

Default

Also, how are these installed?
iLuveKetchup is offline   Reply With Quote
Old 06-27-2009, 04:59 PM   #14
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default

I agree it is very much rythm based, but I know through turns 3, 4, 5 I generate enough cornering force to feel knockback at the brake zone for the left hander under the bridge. They are installed directly behind/under the piston in the caliper.
brandonl is offline   Reply With Quote
Old 06-27-2009, 05:18 PM   #15
Mykl
Scooby Specialist
 
Member#: 14311
Join Date: Jan 2002
Vehicle:
2010 GTI
White

Default

I solved my pad knockback by installing '05+ parts on my '04. I almost sold my car over it.
Mykl is offline   Reply With Quote
Old 06-28-2009, 10:22 AM   #16
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default

In hindsight I would have done the same but I already have too much invested in suspension, brakes, and wheels to change the bolt pattern now.
brandonl is offline   Reply With Quote
Old 06-28-2009, 11:14 AM   #17
Turn in Concepts
Former Vendor
 
Member#: 93646
Join Date: Aug 2005
Chapter/Region: MWSOC
Vehicle:
Many Track Records
Let us help you go fast!

Default

We have used them before and always had good results.

For those asking, you have to remove the pistons from the calipers and install the springs behind them.

Tony
Turn in Concepts is offline   Reply With Quote
Old 06-28-2009, 11:41 AM   #18
REX8
*** Banned ***
 
Member#: 24038
Join Date: Sep 2002
Chapter/Region: South East
Location: Godspeed Cale...
Default

Quote:
Originally Posted by Element Tuning View Post
Or you can left foot, tap, tap before you enter your braking zone.
Which is a damn good idea to do anyway.
REX8 is offline   Reply With Quote
Old 06-28-2009, 02:30 PM   #19
Mykl
Scooby Specialist
 
Member#: 14311
Join Date: Jan 2002
Vehicle:
2010 GTI
White

Default

Quote:
Originally Posted by brandonl View Post
In hindsight I would have done the same but I already have too much invested in suspension, brakes, and wheels to change the bolt pattern now.
Yeah, that's why I did it before I purchased anything. My '04 spec bearings were starting to feel dead after four hours of track time. I knew that I didn't want to have to go in and change them that frequently, so I just bit the bullet and went through with it.
Mykl is offline   Reply With Quote
Old 06-28-2009, 09:53 PM   #20
iLuveKetchup
Scooby Specialist
 
Member#: 66258
Join Date: Jul 2004
Chapter/Region: Tri-State
Location: NYC
Vehicle:
05 STi

Default

Quote:
Originally Posted by brandonl View Post
In hindsight I would have done the same but I already have too much invested in suspension, brakes, and wheels to change the bolt pattern now.
I agree. Or if I would have researched more & found about the knockback, I would have just bought an 05.
iLuveKetchup is offline   Reply With Quote
Old 06-28-2009, 11:53 PM   #21
grippgoat
Scooby Specialist
 
Member#: 62182
Join Date: May 2004
Chapter/Region: NWIC
Location: Kirkland, WA
Vehicle:
2005 STI
White

Default

Quote:
Originally Posted by brandonl View Post
In hindsight I would have done the same but I already have too much invested in suspension, brakes, and wheels to change the bolt pattern now.
http://www.6gunracing.com/products.asp

2nd one down?

-Mike
grippgoat is offline   Reply With Quote
Old 06-29-2009, 08:07 AM   #22
brandonl
Scooby Specialist
 
Member#: 3341
Join Date: Dec 2000
Chapter/Region: Tri-State
Location: NJ
Vehicle:
04 STi
track rat black

Default

I tried to go that direction Mike, I dont know whats up with 6gun... I tried calling, emailing and going through a distributor (TIC) with no luck. No returned calls or emails, and TIC said they didnt have any in stock and hadnt had luck getting any kits or a lead time on them.
brandonl is offline   Reply With Quote
Old 06-29-2009, 03:04 PM   #23
grippgoat
Scooby Specialist
 
Member#: 62182
Join Date: May 2004
Chapter/Region: NWIC
Location: Kirkland, WA
Vehicle:
2005 STI
White

Default

Quote:
Originally Posted by brandonl View Post
I tried to go that direction Mike, I dont know whats up with 6gun... I tried calling, emailing and going through a distributor (TIC) with no luck. No returned calls or emails, and TIC said they didnt have any in stock and hadnt had luck getting any kits or a lead time on them.
Oh well.

-Mike
grippgoat is offline   Reply With Quote
Old 10-06-2012, 11:41 AM   #24
bossdog
Scooby Newbie
 
Member#: 297370
Join Date: Oct 2011
Location: SE Michigan
Vehicle:
2005 STi
Crystal Grey Metallic

Default

Quote:
Originally Posted by iLuveKetchup View Post
I agree. Or if I would have researched more & found about the knockback, I would have just bought an 05.
I have an 05 I track. What makes the 05 better regarding Knock back?
bossdog is offline   Reply With Quote
Old 10-06-2012, 12:54 PM   #25
Counterfit
Scooby Guru
 
Member#: 124254
Join Date: Aug 2006
Chapter/Region: NESIC
Location: Rhode Island
Vehicle:
2006 06 SGM Slowbaru
"The Scoobinator"

Default

Bigger better hubs.
Counterfit 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
Pad knockback on '04 RS Grant Motorsports 10 01-14-2007 01:21 AM
2005 STi pad knockback? fourdegrees Brakes, Steering & Suspension 21 06-28-2005 12:35 PM
'05 STi owners/vendors/racers: pad knockback w/ the new 5x114.3 hubs/wheel bearings? gills Brakes, Steering & Suspension 15 09-17-2004 10:48 PM
Auto-X with pad knockback? Capt Crunch Motorsports 27 04-09-2004 10:47 PM
sti pad knockback milessport Brakes, Steering & Suspension 1 09-24-2003 10:53 PM

All times are GMT -4. The time now is 05:31 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.