Notices

Spring rates

Thread Tools
 
Search this Thread
 
Old 11 December 2002, 08:39 AM
  #1  
P20SPD
Drag it!
Thread Starter
iTrader: (1)
 
P20SPD's Avatar
 
Join Date: Jun 2002
Location: Flame grilled Wagon anyone?
Posts: 9,866
Likes: 0
Received 0 Likes on 0 Posts
Wink

Currently got 250 front and 200 rear on my AVO coilover kit. Now used to the setup and think that it still rolls a bot too much, so i was wondering what spring rates you would suggest.

I was thinking of moving the 250's to the rear and getting some 300's for the front.
Old 11 December 2002, 12:52 PM
  #2  
Kippax
Scooby Regular
 
Kippax's Avatar
 
Join Date: Aug 2001
Posts: 1,012
Likes: 0
Received 0 Likes on 0 Posts
Post

450 front/ 275 rear
Old 11 December 2002, 04:09 PM
  #3  
Stuart Knight
Scooby Regular
iTrader: (2)
 
Stuart Knight's Avatar
 
Join Date: Jan 1998
Location: Nr. High Wycombe, Bucks
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
Post

At the moment I have 275 fron and 225 rear on my AVO's, but cannot get the damping setup right at all. So I am going to change my fronts for the rear 225's and put some 200's on the back. Want to buy my 275's if I sell them?
Old 11 December 2002, 04:46 PM
  #4  
P20SPD
Drag it!
Thread Starter
iTrader: (1)
 
P20SPD's Avatar
 
Join Date: Jun 2002
Location: Flame grilled Wagon anyone?
Posts: 9,866
Likes: 0
Received 0 Likes on 0 Posts
Post

Dont know stuart, i think the 250's are way too soft for the front, so i dont think the 275's would make much diff. thanks anyway, remind me if you do.

Will wait and see a few more suggestions 1st.
Old 11 December 2002, 09:55 PM
  #5  
DuncanG
Scooby Regular
 
DuncanG's Avatar
 
Join Date: Sep 2002
Location: Glasgow
Posts: 429
Likes: 0
Received 0 Likes on 0 Posts
Post

The suspension frequency varies with the square root of the spring rate which means if you want for example the suspension to 'feel' 20% stiffer you really need 44% stiffer springs!

So changing from 250 to 300 will only feel like a 10% change. Sounds like you want more. Of course the dampers should also be stiffer to match the springs.
Old 11 December 2002, 10:31 PM
  #6  
JIM THEO
Scooby Regular
 
JIM THEO's Avatar
 
Join Date: Oct 2001
Posts: 1,833
Likes: 0
Received 0 Likes on 0 Posts
Post

From what I have seen, all Prodrive, STI, DMS, Whiteline etc springs have a rate front to rear 1,20:1 to 1,30:1 if that make sense.
JIM
Old 13 December 2002, 10:33 PM
  #7  
Pavlo
Scooby Regular
 
Pavlo's Avatar
 
Join Date: May 2002
Location: home
Posts: 6,316
Likes: 0
Received 2 Likes on 2 Posts
Post

The best way is to try.

Given that you have a wagon, with a little more mas at the rear than a saloon (about 50kg) you would expect higher rates to be used. Indeed the std wagon rears are stiffer than the saloon.

The frequency change may be proportional to the square of the rate change, but that's all a bit academic really. There is no one rate that is ideal, as so much depends on the mass distribution etc etc etc.

Best advice is to suck it and see. 2.25" coil springs are about £20-25 each for perfectly good british made parts. Get them from demon tweeks or merlin motorsport (first 2 that come to mind).

If you got for much harder springs on the front, you may wish to get them sightly shorter, as the car will settle less, you may have plenty of adjustment left though.

Cuscos are 450fr 320rr
Leda (old) 325fr 250rr(?)
Leda (new) 375fr 275rr(?)

If I was starting I think i would go 300ish front, 250 rear, only going to cost £50 plus a little time. I know someone that runs 350fr and 275rr on a saloon, described as "a little harsh".

Depends how hard you push. Don't forget increasing the rate at either end will reduce pitching, so a 20-25% change at both ends should make quite a difference.

Uprated ARBs too?

Paul
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Frizzle-Dee
Essex Subaru Owners Club
13
01 December 2015 09:37 AM
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
Ganz1983
Subaru
5
02 October 2015 09:22 AM
InTurbo
ScoobyNet General
21
30 September 2015 08:59 PM



Quick Reply: Spring rates



All times are GMT +1. The time now is 09:32 PM.