Do springs lose their spring?......
09-18-2007, 03:56 PM
#1
Nordschleife Master
Thread Starter
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
Posts: 7,306
Likes: 0
Received 7 Likes
on
5 Posts
Do springs lose their spring?......
As my 03' cup finishes up it's 4th year of racing, I have a list of multiple maintaince items I'll be working on in the off season. I've just had my Sach's rebuilt, and I wondered about springs. I know some have replaced theirs (and I'm sure they're using the stock spring rates 
...), so I was just thinking about the normal wear & tear on springs. Are they considered a maintaince item?....
...), so I was just thinking about the normal wear & tear on springs. Are they considered a maintaince item?....
09-18-2007, 05:14 PM
#3
Dont get rid of the old ones. They will sag a bit but that is actually desirable, especially in a car aas softly sprung as the Cups are. They need stiffer springs but thats not legal so the next best thing is old springs with some sag that are closer to coil bind at rest. Andy, this is positive in light of what we discussed earlier today also...fyi...
09-19-2007, 10:12 PM
#4
Addict
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Join Date: Aug 2001
Location: SF Bay Area, CA
Posts: 716
Likes: 0
Received 0 Likes
on
0 Posts
Yes. The factory H&R equipped springs do lose their rate, they will develop unequal rates and promote difficulties in corner balancing. They also are more prevalent to "coil bind". Coil bind is where the spring coils bind up on each other in place of the entire spring compressing as one. We recommend upgrading all Cup Car springs.
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
09-19-2007, 10:25 PM
#5
Rennlist Member
Yes. The factory H&R equipped springs do lose their rate, they will develop unequal rates and promote difficulties in corner balancing. They also are more prevalent to "coil bind". Coil bind is where the spring coils bind up on each other in place of the entire spring compressing as one. We recommend upgrading all Cup Car springs.
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
09-20-2007, 10:30 AM
#7
I prefer the older stock cup springs for my reasons stated above...all I know is lap times, dont have any other reasons. If changing springs is ever allowed I will go much stiffer...
Trending Topics
09-20-2007, 12:39 PM
#8
Drifting
It is easy enough to measure the free height and test the spring rate and see if there is any variation. A well equipped race shop should have a spring rate tester like this http://www.stockcarproducts.net/springs11.htm
Before the local circle track closed up for good a couple of years ago they used to have a guy show up on race days that would test your spring rate for a small fee. Those guys are changing springs all the time so you could try a circle track shop if none of the Porsche shops have what you need.
Before the local circle track closed up for good a couple of years ago they used to have a guy show up on race days that would test your spring rate for a small fee. Those guys are changing springs all the time so you could try a circle track shop if none of the Porsche shops have what you need.
09-20-2007, 01:15 PM
#9
Pro
Join Date: Mar 2004
Location: SoCal
Posts: 744
Likes: 0
Received 0 Likes
on
0 Posts
Yes. The factory H&R equipped springs do lose their rate, they will develop unequal rates and promote difficulties in corner balancing. They also are more prevalent to "coil bind". Coil bind is where the spring coils bind up on each other in place of the entire spring compressing as one. We recommend upgrading all Cup Car springs.
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
In the spring world, Eibachs are high grade. We remove H&R's in favor of Eibachs on all our own Cup Cars and customer (by request) Cup Cars for the 996's and 997's.
Eibachs are also on the standard measurement system, making perch, collar, and hat availability easier.
Eibachs also have easy to read part numbers, first number is length, second is inner diameter, and third is pound rate.
Example:
0700.225.0800 = 7", 2.25" ID, 800 lb rate
This might explain why some of those NorCal guys seem to go around corners like go-Karts. Changing springs is NOT legal in PCA amd POC for GTC-3 class - do your clients know this or are they only racing SCCA/NASA or PRC (not sure about the PRC rules)?
09-20-2007, 05:08 PM
#10
Addict
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Join Date: Aug 2001
Location: SF Bay Area, CA
Posts: 716
Likes: 0
Received 0 Likes
on
0 Posts
We're excited about the proposed rule changes for PCA for 2008. Would be great to finally use JRZ or Moton in place of the Sachs also.
09-20-2007, 05:20 PM
#11
Nordschleife Master
Thread Starter
Join Date: Oct 2004
Location: Vacuuming Cal Speedway
Posts: 7,306
Likes: 0
Received 7 Likes
on
5 Posts
POC us adapting the PCA change to stay compliant in the GTC3 & 4 classes. I wonder how the different dampening systems will work with the Cup's too soft springs....
09-20-2007, 08:59 PM
#12
Addict
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Join Date: Aug 2001
Location: SF Bay Area, CA
Posts: 716
Likes: 0
Received 0 Likes
on
0 Posts
Yup, we're excited to see the rules opening up to accommodate all double's. I still can't believe all these years people were restricted to run the same Sachs and even Bilstein dampers.
Someone needs to get springs "open" in the rule book too, it adds way more fun to the adventure and secrecy of set-ups. It's not IMSA Cup or IROC, having a spec car doesn't mean every single detail must be identical to the next guy's.
Maybe if we get enough people together here we can do a survey?
09-21-2007, 04:49 AM
#13
Drifting
Join Date: Dec 2004
Location: Munich
Posts: 2,722
Likes: 0
Received 0 Likes
on
0 Posts
Austin
I would be very cautious about opening up springs and shocks in 'spec' series. In the Supercup there are teams spending north of $60,000 on set up equipment to get the 'perfect' alignment as quickly as possible. This requires a lot of on track support, and space and time. I wonder if people really want to go further than this when life is complicated by being able to stasrt swapping spring rates, shocks, valving as well as the 'simple' stuff.
I would hazard that the people who want to fiddle are either in the process of moving out of spec series or have already done so.
R+C
I would be very cautious about opening up springs and shocks in 'spec' series. In the Supercup there are teams spending north of $60,000 on set up equipment to get the 'perfect' alignment as quickly as possible. This requires a lot of on track support, and space and time. I wonder if people really want to go further than this when life is complicated by being able to stasrt swapping spring rates, shocks, valving as well as the 'simple' stuff.
I would hazard that the people who want to fiddle are either in the process of moving out of spec series or have already done so.
R+C
Last edited by Nordschleife; 09-21-2007 at 08:22 PM.
