Spring Rate Update
08-26-2008, 11:42 AM
#16
Rennlist Member
Thread Starter
None yet, although when I do the stiffer springs I was going to lower and corner balance it. This can be a pretty complicated dance of combinations. I am trying to hook up with a Cup race shop, to get some ideas and help, I don't there set up but I assume they can point you in right direction. At this point I am gathering my thoughts for the winter months. I don't want to take the car out of action, in the mid west we only have a few more track months, over the winter, going to do, springs, maybe GT2 bar, toe links, locking plates, Lower corner balance. would like to work with original dampers for right now. Can't go to motions at this point, plus I want to make small changes at a time not a total re due. I will pass on what I learn. I think we have reliable spring rate data, but to be sure, I am going to pull a spring and have a shop test the rate.
09-09-2008, 01:28 PM
#17
Pro
>> am trying to figure out your response in lbs. to convert
I get asked this all the time so I thought I'd pop in when I saw this question...
Hope this helps those reading who get confused by the various abreviations.
When people refer to "N" they usually are meaning Newtons per Millimeter (N/mm) not simply Newtons. And the conversion to lbs/in from N/mm is quite simple... just multiply N/mm by 5.7 (5.709) to arrive at your lb/in rate.
Caveat Emptor as H&R, Eibach & KW do not all print their rates on the spring in the same order. So a 140-180-60 H&R is not the same as a 140-180-60 KW !
In one case the 140 is length (mm) while in the other it is the rate (N/mm)
Keep in mind that KW is also doing some unique things with their valving that allow these higher rates with their suspensions. I've tried revalving Bisteins using KW spring rates that I knew worked and it doesn't work anywhere near as well.
I get asked this all the time so I thought I'd pop in when I saw this question...
Hope this helps those reading who get confused by the various abreviations.
When people refer to "N" they usually are meaning Newtons per Millimeter (N/mm) not simply Newtons. And the conversion to lbs/in from N/mm is quite simple... just multiply N/mm by 5.7 (5.709) to arrive at your lb/in rate.
Caveat Emptor as H&R, Eibach & KW do not all print their rates on the spring in the same order. So a 140-180-60 H&R is not the same as a 140-180-60 KW !
In one case the 140 is length (mm) while in the other it is the rate (N/mm)
Keep in mind that KW is also doing some unique things with their valving that allow these higher rates with their suspensions. I've tried revalving Bisteins using KW spring rates that I knew worked and it doesn't work anywhere near as well.
01-02-2009, 11:37 PM
#18
Needs to Get a Life
Rennlist Member
Rennlist Member
None yet, although when I do the stiffer springs I was going to lower and corner balance it. This can be a pretty complicated dance of combinations. I am trying to hook up with a Cup race shop, to get some ideas and help, I don't there set up but I assume they can point you in right direction. At this point I am gathering my thoughts for the winter months. I don't want to take the car out of action, in the mid west we only have a few more track months, over the winter, going to do, springs, maybe GT2 bar, toe links, locking plates, Lower corner balance. would like to work with original dampers for right now. Can't go to motions at this point, plus I want to make small changes at a time not a total re due. I will pass on what I learn. I think we have reliable spring rate data, but to be sure, I am going to pull a spring and have a shop test the rate.
Did you ever end up doing anything with springs or the sway bar? Just curious. I was researching tonight and saw this thread.
Lindsey
01-03-2009, 09:56 PM
#19
Rennlist Member
Thread Starter
Ya, I got big plans and a small budget. the year did not end the way I wanted it to. I never did confirm for sure the spring rates, so my plan is to pull the springs off an have a local shop test them first. the following is an email from 3 weeks ago from Peter Thomas from TRG regarding his recommendations.
Thanks for your email. I don't off hand know the factory stock spring rates. Typically though, they are much too soft for HPDE or other track day. On GT3s, typically we change the entire shock and spring combination to a double adjustable coilover, with a select spring rate, rather than changing springs alone. The factory dampers won't keep up with increased spring rates, so you may experience a bouncier ride as the dampers valving try to keep up.
We have our 997 JRZ/Eibach coilover combination that uses double-adjustable dampers and then they can be fined tuned for just about any spring rate up to 1500lbs. The kits come with all the pieces necessary for direct bolt on, including upper monoball mounts, toelinks, and adjustable front droplinks.
Spring rates it comes with are 500 front and 600 rear, though we can substitute out a different rate by request. The entire kit costs $5139 plus shipping.
If you have any other questions, please let me know.
Peter Thomas
After looking at this, I really want to test the current springs first before deciding what to replace them with but this kit looks interesting. Truth be told, I am going to wait till late spring now as I am going to have to save a few more bucks, unless this market makes a quick turn around.
Thanks for your email. I don't off hand know the factory stock spring rates. Typically though, they are much too soft for HPDE or other track day. On GT3s, typically we change the entire shock and spring combination to a double adjustable coilover, with a select spring rate, rather than changing springs alone. The factory dampers won't keep up with increased spring rates, so you may experience a bouncier ride as the dampers valving try to keep up.
We have our 997 JRZ/Eibach coilover combination that uses double-adjustable dampers and then they can be fined tuned for just about any spring rate up to 1500lbs. The kits come with all the pieces necessary for direct bolt on, including upper monoball mounts, toelinks, and adjustable front droplinks.
Spring rates it comes with are 500 front and 600 rear, though we can substitute out a different rate by request. The entire kit costs $5139 plus shipping.
If you have any other questions, please let me know.
Peter Thomas
After looking at this, I really want to test the current springs first before deciding what to replace them with but this kit looks interesting. Truth be told, I am going to wait till late spring now as I am going to have to save a few more bucks, unless this market makes a quick turn around.
