Spring Rates Continued???
03-23-2006, 07:11 AM
#1
TECH Fanatic
Thread Starter
iTrader: (14)
Join Date: Dec 2003
Location: Salisbury,MD
Posts: 1,729
Likes: 0
Received 0 Likes
on
0 Posts
Spring Rates Continued??? Guys, it seems there is alot of confusion regarding spring rates, well atleast on my part anyway. I constantly hear talks of potential energy in the spring. OK, now lets consider the higher rate vs. lower rate spring on the front of the same car with the same front weight, cg, yadda yadda yadda.
You have the first spring which is a 275 pound spring. According to most this spring does not have as much potential energy as the 300 pound spring, but is it that easy? The 275 pound spring will compress more in an at rest position then a 300 pound spring which means the front of the car will be pushed up for a longer time when launching with the 275 pound spring then a 300 pound spring which is not compressed as much right? The question then becomes though does the 300 pound spring have enough potential energy to actually aid in pushing the front end up more or less then the 275 pound spring. To answer this question wouldn't you have to consider the average force the spring exerts during launch? Maybe in terms of force/distance or something?
Also, this will have an effect on the landing of the front after the wheely as well in terms of unloading the rear tires. It seems to me that the 300 pound spring would unload the tires less as it does not want to compress as easily and let the front of the car fall down and unload the rear tires.
Any suggestions, answers, or comments are appreciated
You have the first spring which is a 275 pound spring. According to most this spring does not have as much potential energy as the 300 pound spring, but is it that easy? The 275 pound spring will compress more in an at rest position then a 300 pound spring which means the front of the car will be pushed up for a longer time when launching with the 275 pound spring then a 300 pound spring which is not compressed as much right? The question then becomes though does the 300 pound spring have enough potential energy to actually aid in pushing the front end up more or less then the 275 pound spring. To answer this question wouldn't you have to consider the average force the spring exerts during launch? Maybe in terms of force/distance or something?
Also, this will have an effect on the landing of the front after the wheely as well in terms of unloading the rear tires. It seems to me that the 300 pound spring would unload the tires less as it does not want to compress as easily and let the front of the car fall down and unload the rear tires.
Any suggestions, answers, or comments are appreciated
03-23-2006, 07:43 AM
#2
The theory is the higher the spring rate the more stored energy to throw the front end up. In theory the perfect setup is a spring that is the correct weight to just hold the front end up with the shocks at rideheight. The problem lies in that we arent in a perfect world and most peoples cars are not set up perfectly. plus we dont have any adjustments on the front for ride height.
In practice I use different weight springs to make these cars transfer. If I had 2 cars that weighed the same on the front I would use the same spring weight. Now is car A was prone to wheelstanding I would first go to a travel limiter and a 25lbs lighter spring. Now on car B the car seemed to not transfer as well as car A I would go to a heavier spring to throw the front end up.
In practice I use different weight springs to make these cars transfer. If I had 2 cars that weighed the same on the front I would use the same spring weight. Now is car A was prone to wheelstanding I would first go to a travel limiter and a 25lbs lighter spring. Now on car B the car seemed to not transfer as well as car A I would go to a heavier spring to throw the front end up.
03-23-2006, 07:53 AM
#3
TECH Fanatic
Thread Starter
iTrader: (14)
Join Date: Dec 2003
Location: Salisbury,MD
Posts: 1,729
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by MADMAN
The theory is the higher the spring rate the more stored energy to throw the front end up. In theory the perfect setup is a spring that is the correct weight to just hold the front end up with the shocks at rideheight. The problem lies in that we arent in a perfect world and most peoples cars are not set up perfectly. plus we dont have any adjustments on the front for ride height.
In practice I use different weight springs to make these cars transfer. If I had 2 cars that weighed the same on the front I would use the same spring weight. Now is car A was prone to wheelstanding I would first go to a travel limiter and a 25lbs lighter spring. Now on car B the car seemed to not transfer as well as car A I would go to a heavier spring to throw the front end up.
In practice I use different weight springs to make these cars transfer. If I had 2 cars that weighed the same on the front I would use the same spring weight. Now is car A was prone to wheelstanding I would first go to a travel limiter and a 25lbs lighter spring. Now on car B the car seemed to not transfer as well as car A I would go to a heavier spring to throw the front end up.
03-23-2006, 09:44 AM
#4
The problem is that if you raise the spring perch to raise the car then you are also changing the stroke of the shock from center. When I mount a aftermarket shock on these cars I set side height then measure the distance from shock mount to mount.(I do not use the factory rubber upper mount) Then I get a shock that will fit these measurements with the shock in the center of its travel.
03-23-2006, 10:02 AM
#5
TECH Fanatic
Thread Starter
iTrader: (14)
Join Date: Dec 2003
Location: Salisbury,MD
Posts: 1,729
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by MADMAN
The problem is that if you raise the spring perch to raise the car then you are also changing the stroke of the shock from center. When I mount a aftermarket shock on these cars I set side height then measure the distance from shock mount to mount.(I do not use the factory rubber upper mount) Then I get a shock that will fit these measurements with the shock in the center of its travel.
Thanks a bunch!
