Right rear spring height

[modman1010]

What is the difference in let's say a 16 inch 225lb spring and a 13 inch 225lb spring? Does it really matter the height of the spring on the right rear?

[Flyin Iowan]

ones taller then the other. say the rr corner weighs 225lbs both springs would be compressed 1". the idea of a taller spring is so you can go softer and still have room so it wont coil bind. i know some do that on the lr but havnt heard of any doing this on the rr.

just my opinion

[washeduptoo]

It also depends upon where you run the spring, I don't think a 16in spring will fit on top of axle tube. Just something to think about.

[racinjj]

Chris is spot on, the free hieght of the spring does not affect its rate or performance. I would use the shortest springs you can get away with and not coil bind, the extra hieght just adds extra weight.

[Dirtrunner35]

16 to a 13 inch spring will let the car roll over more since the spring is shorter

[JR. MECHANIC]

Dirtrunner, does it matter if it's on a coil over or just on a weight Jack bolt?

[DaveBauerSS6]

The top of a spring is the spring table. Keeping the center of gravity the same and the spring rate the same, lowering the roll table will allow the car to roll easier. Center of gravity pivots to the roll table. Makes a big difference.

[Flyin Iowan]

the top of the spring is the table? why wouldnt it be where the coil over bolts to the frame?

plus every car i have seen in my area run the coil over upside down on the rr so no matter what spring its the same at the top

[MasterSbilt_Racer]

the top of the spring is the table? why wouldnt it be where the coil over bolts to the frame?

plus every car i have seen in my area run the coil over upside down on the rr so no matter what spring its the same at the top

On a coilover, the attachment point of the coilover is what matters. You are correct. If the spring is sitting on the axle, in pockets, then yes height matters.

[racinjj]

I was reffereing to coil over/sliders, on top of the housing is a different story.

[powerslide]

Dirtrunner, does it matter if it's on a coil over or just on a weight Jack bolt?

seems to be some confusion.

If the spring is on a coil over the two mounting points matter. Spring height makes no difference. one may bow more than the other and weigh a little more but thats it

If the springs is on a weight jack bolt the height of the top spring cup is extremely important and need to confirm w/ chassis builder which spring height you use. If you get it to tall of a spring the weight may not be able to get on top of the spring. Get it too low and it may get on top of it too much.

[DaveBauerSS6]

I assumed the question was for screw jacks. Jacks are at the top of the spring, coil overs are at the top mount bolt.

Yes you can lower the roll table by lowering the upper coil over mount. This may require lowering the bottom mount. Be careful on your birdcage indexing.

[Dirtrunner35]

Dirtrunner, does it matter if it's on a coil over or just on a weight Jack bolt?

It doesn't matter, the bottom of the spring will always be the same, static weight will be the same, only difference is the shorter spring will let the car roll over more, like someone said bird indexing will be more, rear steer. Total weight transfer will not change but front to back weight transfer will change some.

[missile07]

Ok quick question for better understanding. Say you have a shock with spring mounted in front of the axle on the RR. Does it matter which way the shock is located? Some have the bulb area of the shock at the top with locates the spring lower and some have the shock upside down and moves the spring higher.

[MasterSbilt_Racer]

Ok quick question for better understanding. Say you have a shock with spring mounted in front of the axle on the RR. Does it matter which way the shock is located? Some have the bulb area of the shock at the top with locates the spring lower and some have the shock upside down and moves the spring higher.

There is some difference in unsprung weight. For the purposes of the spring, it does not matter. The location of your spring's attachment point is all that matters. The height of the spring is only important if changing it changes it's connection point to the chassis.

On a coilover, you can run a 14", 12", 10" spring and as long as you keep running the adjuster nut down to compensate it doesn't matter. It matters with a spring mounted on the axle with a jack bolt because you must run the jack bolt down to compensate. This lowers the springs interaction point with the chassis. It is the same as cutting off a coilover mount and spacing it down.