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 Post Posted: Tue Nov 11, 2008 8:26 am 
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Beretta wrote:
Scott Smith wrote:
Mine stays down too. Without video I would say his IC is too high and too short.



Scott or somebody explain a little better in something I could understand..
Im getting "what's wrong" but no info on what to try in words that I can understand.... #-o


The IC (instant center)  is where the 4 link bars would intersect if you drew a line that would follow the direction the bars are pointing. When you dropped the front of the top bars down you shortened that distance. The angle of the lower bar determines the height of the instant center. Typically the lower bar should be down about 2 degrees in the front and a good starting point for the IC length is around 55". I think mine is set at 56" and 5.5" high.  The thing that makes it difficult to measure is the car has to have the weight on the tires on a level surface and you measure the points from where  the 4 link bars are attached to the floor and the length of the bars.  then you can map out the point that the bars will intersect. I used to do this with a chalk line on the shop floor.

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 Post Posted: Tue Nov 11, 2008 9:11 am 
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Chuck,Thanks for explaining that.. I don't have any video but do have this pi's from the last time I was out.... Ok so if I measure height off the floor to center of each 4-link bold front and rear and draw it on the floor or on a piece of cardboard I could find what we are looking for.....I don't know if you can tell anything from this pic but the car don't even pic the front tires off the ground...


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 Post Posted: Tue Nov 11, 2008 10:11 am 
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Barry usually the measuring is a lot easier if you have access to a drive on type of lift  like what is used for alignments. If you have a buddy that can get your car on one of those let me know and I'll give you some info so we can map all the possible ICs with a 4 link program I use.

I think you might have to change the IC and loosen the shocks up some. I noticed on the graph you posted it only compresses suspension less than 4 tenths of an inch. It may be that you're compression is set too stiff.

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 Post Posted: Tue Nov 11, 2008 5:44 pm 
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Chuck, Does your 4-link brackets look like mine???

This is not where the upper bars are now...


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 Post Posted: Tue Nov 11, 2008 7:07 pm 
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4 link calculator!  You have a PM!

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 Post Posted: Tue Nov 11, 2008 7:14 pm 
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Ken0069 wrote:
4 link calculator!  You have a PM!


Works great..Ken sent it to me...

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 Post Posted: Tue Nov 11, 2008 9:56 pm 
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Beretta wrote:
Chuck, Does your 4-link brackets look like mine???

This is not where the upper bars are now...



Yeah, I think so.

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 Post Posted: Wed Nov 12, 2008 3:46 am 
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Ken0069 wrote:
4 link calculator!  You have a PM!


i was just thinking the same thing & trying to work out how to send it

glad you got it sorted

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rod

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 Post Posted: Wed Nov 12, 2008 7:05 am 
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I have been playing with 4 links for about 20 years now. Been plotting other cars in the Bickle 4 link wizard for about 12. Honestly I don't even use it any more.

I simply measure the spread at the rear and the spread at the front. Those 2 measurements will give me the overall IC length.
That in conjunction with the angle of the bottom bar is all I need.

Your car needs to intersect in the mid 50's with a 3 to 4° down angle on the bottom bar. The more power the lower the angle. The less power the more angle.
Looks like your brackets are 5/8" on 3/4" centers. Each hole is worth about 2°


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 Post Posted: Wed Nov 12, 2008 7:30 am 
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OK Im going to try to get some measurements tonight and post them. I have an angle finder and will see what that is also :-k

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 Post Posted: Wed Nov 12, 2008 12:23 pm 
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Scott Smith wrote:
The more power the lower the angle. The less power the more angle.


Hummm, I guess I have a problem understanding this statement?  Want to clarify it?  O:)

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 Post Posted: Wed Nov 12, 2008 12:35 pm 
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800 HP car would have a ballpark number of 4° down on the lower bar.

1200 HP car 6-7° down.

400 HP car 1-2° down.

Make sense?


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 Post Posted: Wed Nov 12, 2008 7:02 pm 
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I got the #s...It was not easy but here they are..
The lower bar is 4* down in front so that looks Ok right???

The front lower bar is 6 1/2" from the ground and the upper is 14 3/8
The rear lower bar is 7 3/8 from the ground and the upper is 20 7/8

So what does that tell you??????????

Im going to plot O:) it out my self and see what it comes out to

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 Post Posted: Wed Nov 12, 2008 7:08 pm 
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I forgot to tell ya I need the Center to center length of the bottom bar too.


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 Post Posted: Wed Nov 12, 2008 7:39 pm 
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Beretta wrote:
I got the #s...It was not easy but here they are..
The lower bar is 4* down in front so that looks Ok right???

The front lower bar is 6 1/2" from the ground and the upper is 14 3/8
The rear lower bar is 7 3/8 from the ground and the upper is 20 7/8

So what does that tell you??????????

Im going to plot O:) it out my self and see what it comes out to


Assuming your bars are close to the length of mine (20.75") I get an IC of 51.8" out and 5.3" high. Sounds like a good place to start. I had mine at 49.6" X 5.7" but moved it out to 56.5" earlier this year to take some of the wheelie out of it.

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