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How and where do I set 4 link???

Posted By: Mopar_racer_99

How and where do I set 4 link??? - 02/22/09 11:28 PM

OK guys, as you know I just finished new sw 4 link back half, now where do I set the bars and shocks, and no I have not scaled the car have to work a little more OT for afford the 700 for the scales. Here is the ic list from a program. car is 115.5 wheel base motor is 9 inches to the crank cl. Shocks are single adjustable qa1. John

Attached picture 5045000-4linksettings.JPG
Posted By: MR_P_BODY

Re: How and where do I set 4 link??? - 02/22/09 11:54 PM

SB or BB, would help if you knew the CG of the car
or at least the % of the rear and total weight.
But as a start point I'd go with the 42.3" IC length
and it was something like 3.8" up, shocks set about
3/4 of the way to full tight ... this is just a guess
without knowing the other facts
Posted By: Mopar_racer_99

Re: How and where do I set 4 link??? - 02/23/09 12:19 AM

578 ci big block 914 hp 850 tq old weight w/ladder bar was 2880 52% front 48 rear, weighing everything in and out looks like weight should be same.
Posted By: MR_P_BODY

Re: How and where do I set 4 link??? - 02/23/09 12:25 AM

Quote:

578 ci big block 914 hp 850 tq old weight w/ladder bar was 2880 52% front 48 rear, weighing everything in and out looks like weight should be same.




In that case I'd use a base line of 56 long and 3 up
Posted By: dthemi

Re: How and where do I set 4 link??? - 02/23/09 12:31 AM

That sounds very close, I was thinking 52 and 4
Posted By: Mopar_racer_99

Re: How and where do I set 4 link??? - 02/23/09 12:41 AM

I can get 55.5 and 3 but I can only get 52 and 8 not 52 and 4. John
Posted By: Quicktree

Re: How and where do I set 4 link??? - 02/23/09 12:53 AM

I would have some wheelie bars on it first time out. you don't want to put it on the bumper. I would go with the longer of the 2.
Posted By: MR_P_BODY

Re: How and where do I set 4 link??? - 02/23/09 01:09 AM

Quote:

I would have some wheelie bars on it first time out. you don't want to put it on the bumper. I would go with the longer of the 2.




I'd start with the longer set up... it
might be a little conservative but that me
Posted By: jkwedge540

Re: How and where do I set 4 link??? - 02/25/09 12:41 AM

Ok guys, same car,4 link,3500#,925 hp,765tq, 10.5 tire, lots of spray. Were do i start.
Posted By: Mopar_racer_99

Re: How and where do I set 4 link??? - 02/25/09 12:54 AM

When moving the bars do you move one bar at a time. adjust hiems so bolt slips in tighten jam nuts and then move to next bar, or move bar and force housing into postion so bolt goes in? I know this sounds stupid but remember I have never worked on a 4 link suspension and my bickle book doesnt say. JOhn
Posted By: MR_P_BODY

Re: How and where do I set 4 link??? - 02/25/09 01:22 AM

Quote:

When moving the bars do you move one bar at a time. adjust hiems so bolt slips in tighten jam nuts and then move to next bar, or move bar and force housing into postion so bolt goes in? I know this sounds stupid but remember I have never worked on a 4 link suspension and my bickle book doesnt say. JOhn




Once you get the rear end into position then each bar
has a purpose... the 2 lower bars set your length
the top left sets the pinion angle, then the top
right is for setting pre-load. When you want to
change IC lengths and heights the first thing is
to get the pre load bar back to 0(bolt slips in and
out)... you always have 3 bars in place unless you
want to have the rear roll on you, one at a time
you
move each bar to the new hole, lengthening or shortening
the heim as needed.... once all the bars are in the
new holes measure the rear for being square(I use
my front 4 link cross bar), next is to check the
pinion angle... once these are set then tighten
down the bolts and lock nuts.... leaving the pre load
for the last thing... then set it back to what it
was before(1/2 turn or what ever). When we talk
pre load we USUALLY talk flats, thats the flat of
the hex on the bar. IF the car launches but goes
slightly right... you need to add pre load this
means SHORTEN the top right bar... we might say
give it 1 more flat.... if the car goes left you
have too much pre load OR you might need to go
negative pre load.... this is when you lengthen
the top bar...... there ya go now you are just like
the rest of us 4 link guys... time to test
Posted By: Chassisman

Re: How and where do I set 4 link??? - 02/25/09 01:45 AM

...and remember...out of all those IC points on that sheet of paper...only about 4 of those will work.....now go find em !!!!
Posted By: MR_P_BODY

Re: How and where do I set 4 link??? - 02/25/09 01:55 AM

Ron, maybe you can give JKwedge some suggestion for
his set up. But wedge will you be hitting any spray
off the line and will you be using a progressive timer
for the spray. Also what do you figure the bias is
for the weight and do you know the CG of the car
Posted By: Chassisman

Re: How and where do I set 4 link??? - 02/25/09 02:18 AM

Quote:

Ron, maybe you can give JKwedge some suggestion for
his set up. But wedge will you be hitting any spray
off the line and will you be using a progressive timer
for the spray. Also what do you figure the bias is
for the weight and do you know the CG of the car



Mike....your doing just fine...I only pop in and out anymore.Besides I got pretty roughed up by a fellow member because I didnt answer his email in a timely manner.So I'm not feeling sooooo generous anymore.Especially since I was gone for over a week on my only vacation for the year when he sent me the Email.
Posted By: Al_Alguire

Re: How and where do I set 4 link??? - 02/25/09 06:09 AM

Well to start and I am no expert here but long and low is a good place to be. So I would go with the 55 or more out numbers. Mine is WAY out and down, but it is a different style car. In the end each car will need something different. Only way to know is to try different spots. With trial and error you will find the "sweet spot". Good luck with it.
Posted By: jkwedge540

Re: How and where do I set 4 link??? - 02/28/09 01:07 AM

Ok, I found my notes. First, car is 53.2% front 46.8% rear.Balance point is 62inc. Car is 3500# 540 big block. lot of spray. spraing off the line.I have tried a few ic points.need some info.
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