Coil spring diameter - is bigger better??

RSengineering

New Member
Posts
2
Reaction
1
Looking for some feedback regarding peoples experience with coil spring failure on their cars. I am working o a design to reduce weight and want to run as small diameter of coil spring as possible. My concern that the failure rate of these lighter springs (small overall diameter) is going to be higher. I would love to here back from anyone with some real world experience on the matter.

-Steve
 

Shannon

Bear on a Unicycle
Posts
2,267
Reaction
496
Not trying to highjack your thread, but I'm currently trying to trim weight on a new project I acquired , has 3" cool overs with 3" bypasses in front and 3" coil overs 4" bypasses in the rear .
I would like to go to 3.5" bypasses in front and to a 2,5" coil over.. and 4" bypasses in rear with a 2.5" coil over.

What am I going to losing by doing that.
How much harder does that 2.5" coil over going to have to work? With the bigger bypasses in front compensate for spring size loss?


Sent from the RDC Mobile App. Get it for your IOS device today
 

cosmo

Super Moderator
Posts
1,900
Reaction
172
Not trying to highjack your thread, but I'm currently trying to trim weight on a new project I acquired , has 3" cool overs with 3" bypasses in front and 3" coil overs 4" bypasses in the rear .
I would like to go to 3.5" bypasses in front and to a 2,5" coil over.. and 4" bypasses in rear with a 2.5" coil over.

What am I going to losing by doing that.
How much harder does that 2.5" coil over going to have to work? With the bigger bypasses in front compensate for spring size loss?


Sent from the RDC Mobile App. Get it for your IOS device today
I'd say, start a new thread.
 

cosmo

Super Moderator
Posts
1,900
Reaction
172
I would start with the top spring manufacture's, Eibach and Hypercoil. Spring building is a science. If you break a Hypercoil spring, they will send it to an independent lab to find out why.
 

cosmo

Super Moderator
Posts
1,900
Reaction
172
Not trying to highjack your thread, but I'm currently trying to trim weight on a new project I acquired , has 3" cool overs with 3" bypasses in front and 3" coil overs 4" bypasses in the rear .
I would like to go to 3.5" bypasses in front and to a 2,5" coil over.. and 4" bypasses in rear with a 2.5" coil over.

What am I going to losing by doing that.
How much harder does that 2.5" coil over going to have to work? With the bigger bypasses in front compensate for spring size loss?


Sent from the RDC Mobile App. Get it for your IOS device today
Valved right, you should have no problem.
 

Shannon

Bear on a Unicycle
Posts
2,267
Reaction
496
Valved right, you should have no problem.
Thank you for your input, I have a 7 truck that runs 2.5 coil overs that perform well, and this new project will weigh about the same , just wanted to make sure I'm not totally screwing the pooch .


Sent from the RDC Mobile App. Get it for your IOS device today
 

The Hero Lab

New Member
Posts
1
Reaction
2
I've never had a spring fail in terms of just quitting on me. i have replaced "tired" springs that didn't rate out over time. But to answer (hopefully) your question. I attended the spring seminar by Hypercoil at PRI and learne some new things. First is that a wider coil diameter will bow or deflect less than a narrow wind, and the side loading from bowing directly effects the side load pressure of the shock shaft and piston, that added friction could lead to eventual binding and premature wear of internal parts. Also, a wider diameter winding means that the spring rake/pitch doesn't have to be as drastic to achieve the same rate and makes the linear progression much smoother throughout the travel, which in turn means the spring doesn't have work as hard to provide it load carrying abilities. To, combat these problems I guess hypercoil is now offering a "barrel" shaped spring that is wider in the middle but wraps tighter at the end to fit in a traditional coil over seat. The only question I did not get to have answered is if they are offering them in the length and rates we use in the dessert since the seminar was pavement specific. I have NO affiliation with them but you might want to give them a call the info given was pretty notch and seemed spot on. I know that weight is weight, and every ounce counts, but my two cents is buy a beefier spring, they get used too hard out there to have one fail in BFE. You could probably shave the weight to make up for it else where.
 

Chris Tobin

Well-Known Member
Posts
5,998
Reaction
1,177
Many engine builders have switched out to "Bee Hive" style valve springs versus multiple element straight springs and are getting better control with less failure...
 
Top