Transverse spring weight rating
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 839
Likes: 0
From: Lewiston, Maine
Transverse spring weight rating
Okay, so we have one spring in the back that goes L <--> R. I just got a 360 lb./sq. in. composite mono spring that I'll put in my car in the next month or two (my whole car is a project.)
I know this will feel much better and more firm than my stock 9 leaf, but how do we tell how firm each side is?
I've had one friend say that since there is a fulcrum point in the middle, that both sides can get close to, if not the full, 360 lb./sq. in. rating. Yet another friend said that since the spring is long, some degradation in weight rating would occur side to side. Do we divide the 360 in half to get 180 lbs./sq. in. on each side? Is it another mathematical equation like dividing by 1.75 or 1.5 of the rating?
What does each side get rating wise? With my front 550s it's easy to tell; they each get their own spring.
I know this will feel much better and more firm than my stock 9 leaf, but how do we tell how firm each side is?
I've had one friend say that since there is a fulcrum point in the middle, that both sides can get close to, if not the full, 360 lb./sq. in. rating. Yet another friend said that since the spring is long, some degradation in weight rating would occur side to side. Do we divide the 360 in half to get 180 lbs./sq. in. on each side? Is it another mathematical equation like dividing by 1.75 or 1.5 of the rating?
What does each side get rating wise? With my front 550s it's easy to tell; they each get their own spring.
Burning Brakes
Joined: May 2000
Posts: 958
Likes: 0
From: Brisbane, Australia 1985 Coupe
Re: Transverse spring weight rating (1969Vette350)
There would be some calculation. From what I've been told, the fronts are different rating because of where the spring sits on the a-arm. I just can't remember the exact explanation.
:cheers:
:cheers:
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: Transverse spring weight rating (1969Vette350)
Ask Paul at VB this question.
I have read that composite springs have more "cross talk" than steel springs. I other words wheel movement on one side affects spring reaction on the other.
I have read that composite springs have more "cross talk" than steel springs. I other words wheel movement on one side affects spring reaction on the other.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Transverse spring weight rating (Chris O')
The fronts are different ratings because the spring does not sit directly under the wheel but between the wheel and the pivot point. There is a leverage effect. By knowing the distance between the center of the tire and the lower A arm pivot point and the distance the center of the spring is from the same pivot point the real pressure can be calculated.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 839
Likes: 0
From: Lewiston, Maine
Re: Transverse spring weight rating
There is one thing I'll have to conclude; the 550/360 combo will feel better than stock :D Alright, I'll ask Paul my question. Thanks guys.
Burning Brakes
Joined: May 2000
Posts: 958
Likes: 0
From: Brisbane, Australia 1985 Coupe
Re: Transverse spring weight rating (norvalwilhelm)
The fronts are different ratings because the spring does not sit directly under the wheel but between the wheel and the pivot point. There is a leverage effect. By knowing the distance between the center of the tire and the lower A arm pivot point and the distance the center of the spring is from the same pivot point the real pressure can be calculated.
