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 Post subject: 4 link program ???
 Post Posted: Sun Jan 25, 2009 10:50 am 
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Ok I have all the stuff put into the program and as far as the IC I used Bubster's thing on this as a cam measurement that is 13.75 inches off the ground.....

Anyway here is where it's at: 59.9 ICL
                                          6.1 ICH
                                          66.6% AS


From what Im reading here it's to long right???

I was playing with it and this looks like where I should change it to by what Bubster has said in his "Tech Article"  53.2 ICL, 7.2 ICH, 89.3% AS

If not tell me what you chassis gooroos think....Thanks

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 Post Posted: Sun Jan 25, 2009 9:34 pm 
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I have a  question. This 66.6%, is located where compared with the Squat/anti squat line? Is always confusing to many, when a percentage of anti squat is used. For me it starts with an squat/ anti squat line. Simply put, if your instant center is above that line, it promotes separation, and below that line promotes compression. While there are values of how much it does so, as the farther from this line in either direction promote more of squat or anti squat.

I believe in the KISS method. Keep it simple. If we know where we are going it makes it easier to get there. What we want is  no separation or compression, To get there you have to be pretty close to the A/S line. I say pretty close. This is because you A/S value works with your sprin/shock rate to equalize the transfered weight. If you get it right, it means you will not distort your slick, nothing more. This does help one part of our total launch package. This package is Center of gravity, Power and traction. These three parts have  to balance to get that great  60 Ft time. The I/C only insures you apply traction, with out distorting contact patch.

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 Post Posted: Mon Jan 26, 2009 6:42 am 
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Dennis, The S/AS line is 100%,,,,, above that line is over 100% and below that line is less than 100%..From where it is now to where I wanted to move it is a big change...

Chuck's chassis is very smiler to mine but he has a standard trans. Maybe he can tell us where he is as far as the S/AS %...

I used your measurement as far as CG using the cam as a height for that.

Ken, George, also have this program and hopefully they can tell us where they are set........

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 Post Posted: Mon Jan 26, 2009 7:22 am 
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I'm a little busy right now but give me some time later to do some typing. Basically your over thinking this and I'll show you a much easier way. And you can throw the software away.  \:D/


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 Post Posted: Mon Jan 26, 2009 10:37 am 
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I had mine set up at 49.6" X 5.7" with 51.7% AS and it seemed to be getting on the wheelie bars a little too hard. I moved it to 56.5" x 5.7" with 45% AS and it seemed to calm the launch down and made it more consistent.  I have been told to try to get the lower bar down a couple of degrees in the front and not worry about the IC height. I think mine is only down about 1*.  My car has 53% of the static weight on the rear and I'm sure weight % is going to make a difference on where you set the suspension.

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 Post Posted: Tue Jan 27, 2009 3:06 am 
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Barry, that percentage is pretty much as I thought, but it's good we all are on same page.

I like to look at I/C settings as just a means to regulate tire contact pressures. We know with weight transfer we will be shifting 100% of the cars weight to the rear, The only things that transmit or cushion this shift is springs, shocks and the I/C. This is all about putting as much of the transfered weight on the contaxt patch, with out distorting the tire or inducing enough squat to loose traction. It has nothing to do with weight transfer other than keeping or loosing traction.

For years the standard was 100%, bo compression, no separation. Lately there is a tendency  to go to the squat side of the line. Looking for reasons, I came up  with a few possibilities, The first could be compensating for too high a center of gravity for power/ traction. The there could be a little less air pressure used in the tires. The one that makes the most sense to me would be if you used spring rate with the lower I/C to gain more stability down track.This would not be an issue with a anti roll bar.

I still believe a nutral setting is best for a car that has proper center of gravity for it's power/ traction. It is very forgiving of shocks and springs because they have to do very little and that alone makes them more efficient.  As all caes  have differebt centers of gravity and different location points for links and different power and traction, you can't use some one elses Set up. Set it and treat the symptoms if there are any. Separation abd compression are the only two things an instant center adresses well.

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 Post Posted: Tue Jan 27, 2009 1:05 pm 
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Well I just got off the phone with Hoosier and he said that the co7 slick should work O:) for me....He had said that it will need more air than the 6 psi that I was running ans also told me that up to 8 psi is not uncommon. But he also said if I race into the night and there is down time that that tire may spin O:) ....So it's kind of what Scott was saying before....So Im going to get a set of the do6s and he said that there a mix of the co7 and do5 compound and will hook better if I still have a spin problem.......


Scott If you have time to Type I would like to here what you have to say about the 4 link settings....

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 Post Posted: Tue Jan 27, 2009 3:54 pm 
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I'll do it tonight if my wife lets me.  O:)  :-$  =;


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 Post Posted: Tue Jan 27, 2009 4:20 pm 
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Barry that D06 compound is what I'm running also and I've been 1.15 60ft on'em a couple of times down at Piedmont Dragway.  

Mine are 33x16x15 and the roll out is 106 inches?  If you do the math, that 106 number comes out to a 33.740 inches in diameter.   O:)  The MTs I took off the car were 33x17x15s with 104 inch roll out.  Scott told me yesterday that he was running a 32" MT on his car now, which are around 100 inch roll out.

We wound up running 10lbs HOT in mine, ie, start out at 9.5 and they were always 10lbs when I got back to the trailer.  The MTs liked that pressure also but they were a real soft compound and sidewall.

Looks like I'll get two seasons out of these Hoosiers.

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 Post Posted: Tue Jan 27, 2009 6:50 pm 
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Ken0069 wrote:
Barry that D06 compound is what I'm running also and I've been 1.15 60ft on'em a couple of times down at Piedmont Dragway.  

Mine are 33x16x15 and the roll out is 106 inches?  If you do the math, that 106 number comes out to a 33.740 inches in diameter.   O:)  The MTs I took off the car were 33x17x15s with 104 inch roll out.  Scott told me yesterday that he was running a 32" MT on his car now, which are around 100 inch roll out.

We wound up running 10lbs HOT in mine, ie, start out at 9.5 and they were always 10lbs when I got back to the trailer.  The MTs liked that pressure also but they were a real soft compound and sidewall.

Looks like I'll get two seasons out of these Hoosiers.




So Ken your saying that you ran 9.50 lbs of air in the Hoosiers!!! I know that the MT always want a lot of air...

How does you 4 link settings come out on the 4 link program???

My car weights just 2300lbs with me in it and the program says it has 52% on the rear :-k

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 Post subject:
 Post Posted: Wed Jan 28, 2009 12:27 am 
 
CO7's suck in cooler air and on a heavy car they suck all the way around  or they did for me that's what i was saying a long time ago i traded mine to one of the locals that is running a dragster they seem to be OK on it .

I tried every thing with those damn tires even the hoser tire guy was at the track we went from 10lbs down to 5.1/4 and they still didn't work as good as a set of wore out M/T's on my car.

I will stay with the M/T's .


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 Post Posted: Wed Jan 28, 2009 2:10 am 
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Let's talk about the kong and short. There is bo such thing as too long. Where the to long comes from, is people not knowing where their I/C line is. You can have a 4 bar car, that is one with equal length bars parralel to each other. Their I/C is infinity, but if the hight is correct they will work as well as any.

There is a little difference in how fast they react but not really an issue. Where this too long or short comes from is people not taking into account that the I/C line rises as it goes forward. Not taking this ino your figuring, a shorter I/C is higher and a longer one is Lower, even at the same hight off the floor..

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 Post subject:
 Post Posted: Wed Jan 28, 2009 9:02 am 
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Dennis, I have 6 pages of possible settings but it really looks like only a half of one page of settings that I can only use....

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 Post subject:
 Post Posted: Wed Jan 28, 2009 10:17 am 
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Bubstr wrote:
Where this too long or short comes from is people not taking into account that the I/C line rises as it goes forward.


You lost me here Dennis??  

The way Scott sets his up is to set the bottom bar at X* angle down in front depending on how much power the engine makes.  That means that the last part of your statement is correct in that the further away from the axle centerline you go, the further down the IC will be, IF the bottom bar is pointing down in front that is.  This contradicts the statement you made in the quote above, does it not?  Or, were you referring to the AS line instead?

But what if the bottom bar is level to the ground?  Moving the IC forward or backward won't change it's height off the floor but will change the AS location, which would be a lower percentage of Anti Squat the further forward you go assuming that the actual anti squat line is 100%.

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 Post subject:
 Post Posted: Wed Jan 28, 2009 11:46 am 
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Barry, right now mine is set at 50.4 out, 4.1 up and 43% AS and this is within "Dave Morgan's" sweet spot.

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