another strut sectioning question

[rags]

What is up with the search tool?? I don't have access to corner scales any longer and was looking for a post I remember seeing about sectioning amounts. I'm using MR2 struts in the front of a 71 with 200 pound ten inch springs. The car is slightly heavier than stock because of a ZXturbo motor, intercooler and oil cooler. Does anyone have a recommendation for amount to be taken out of the strut tube to lower the front of the rocker panel say an inch and a half? Thanks.

 

Joe

[JMortensen]

Section the tube so that it fits the strut. IIRC that measurement is 1 5/8". Then use your coilovers to adjust the height of the front end. Is that what you were asking?

[rags]

Yes that's what I was asking. But shouldn't you be taking weight into consideration? 200 into corner weight will give you the amout of spring compression then take that amount into consideration to place the insert in the middle of it's travel at rest. When this is done I want the ride height to be 1.5" less than stock. Did that make sense? I guess what I actuall need is a guesstimate on corner weight for the front of my car.

 

Joe

[JMortensen]

Why try to engineer it like that when you have a coilover? Even if you can get a pretty close guess on the weight of that you've added to the car, you still won't know the corner weights until you set it on scales anyhow, since every turn of the coilover is going to throw the weight off and cornerweights are going to vary from car to car. If you want one and a half inches lower at the rocker, just guess where the spring perch needs to be, set it on the ground and roll it back and forth a bit, and if you're wrong jack the front end up and turn the spring perch up a few turns until you hit the height you want on the nose.

[rags]

I will just take a guess with one set of strut tubes I have but my thinking is if I cut the strut tube to fit the MR2 insert, when I adjust the spring perch to achieve proper ride height theoretically I could be at full compression or full extention of the insert. I agree that it is unlikely. I was just trying to mathmatically "guess" to take most of the error out of the equation. I also agree that most cars will have different corner weights on each corner. What I was looking for is an average. I seem to remember 540ish for front corner weights on a Series 1 240. Am I in the ballpark?

 

By the way, this is how I did it on the 280 strut tubes that I put in the rear of the 240 and it worked out well. I did the rear a few months ago and for the life of me I can't find the paper that I wrote the corner weights on which included the front weights.

 

Joe

[blueovalz]

http://forums.hybridz.org/showthread.php?p=490250#post490250

 

Here is a string that should help some. In essence, the sectioning requirements revolve around the strut dimensions and the car's change in ride height. Springs do not come into the equation at all. A car that is set up to ride at a specific height (hopefully at the midway point of strut travel) will use the same strut dimensions, whether using a 100lb spring, or a 500lb spring.

Probably most important is this: In general, you will need to lower the top of the strut housing the same amount as the chassis is lowered (e.g. lower the car 2", then you'll need to lower the top of the strut housing 2" as well, with all other things being equal).

[rags]

Thanks Terry, that's the thread I was looking for! After thinking about it some more, I finally see how spring rate does NOT figure into how much to section the tube. I was making it more difficult than it has to be. I guess all I did was make sure the spring collar was in the right spot.

 

Joe