adjusting your 4 link
#1
Burning Brakes
Thread Starter
adjusting your 4 link
T all you 4 link solid axle guys......
I finally got this thing finished up and took the car for a spin around the block last weekend. So far everything seems to be pretty good just on the initial drive. I need to fix the fiberglass storage boxes but I do not want to attack that until I get the rear setup correctly to know how the rear will move.
My question for you guys....I used the AutoFab 4 link kit. I setup everything per their measurements. How much are you guys moving your bars around off of AutoFabs measurements? Are you finding them to be close to make the car work or not close at all? I have been reading a lot on setting up 4 links and feel I have an ok knowledge of it but it seems you cant really know how close your setup is until you make hits to see how the car works.
I would like to hear from you guys that have the setup and what settings did you find to work the best.
I finally got this thing finished up and took the car for a spin around the block last weekend. So far everything seems to be pretty good just on the initial drive. I need to fix the fiberglass storage boxes but I do not want to attack that until I get the rear setup correctly to know how the rear will move.
My question for you guys....I used the AutoFab 4 link kit. I setup everything per their measurements. How much are you guys moving your bars around off of AutoFabs measurements? Are you finding them to be close to make the car work or not close at all? I have been reading a lot on setting up 4 links and feel I have an ok knowledge of it but it seems you cant really know how close your setup is until you make hits to see how the car works.
I would like to hear from you guys that have the setup and what settings did you find to work the best.
#2
Burning Brakes
Thread Starter
almost 90 views and no response lmao! Probably can count on my hands the number of straight axle guys on this forum!
#3
Racer
Member Since: Mar 2013
Location: Boca Raton Florida
Posts: 423
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I have my 4 link installed but have not driven the car yet to give you any feedback. But from my limited knowledge on the subject is that you want the lower bars straight and level with the chassis and the upper bars should point to the balance point of the center of the car. Then start making adjustments from there. Car looks bad ***
#6
Team Owner
Instead of me explaining a hole for link system look up adjusting a 4-link rear end online and it'll actually really tell you exactly what you need to do
#7
Safety Car
First off you need to know where the Instant Center (IC) is now.
Instant Center (IC) is the point where the plot lines for the 4 link bars intersect.
IC is measured in 2 variables. UP (how high off the ground) and OUT (how far from the axel centerline).
Alot of people talk about the lower bars needing to be parallel to the ground... That is not true. Espc with a small tire car. What matters is the IC measurements because once you compare the IC intersect plot to the cars Center Of Gravity (CG) you can see how much Anti Squat (AS) the car has.
The lower bars on my 84 actually point up hill to the front and the IC on my 84 measures 12" UP and 53" OUT. It goes 1.19 60fts on 275 radials and low 8's in the 1/4 mile@ over 160MPH.
Just from those 2 numbers I, or anyone who has knowledge of suspensions, can make adjustments and know how the car will react.... IF I shorten the IC to say 46" OUT I know the car will react more violently on launch... I know if I lengthen the IC to say 63" OUT the car will leave softer. IF I raise the IC height it will tend to wheelie more or try to separate the rear suspension more (raise the rear of the body at launch) and the opposite if I lower the IC height.
Here are a few explanations of Instant Center (IC), Anti Squat (AS) which is also refered to as Percentage of Rise (PR) by some people.
You need to read thru these pages and get an understanding of what the suspension does and what the terms are used to describe the suspension set up before you go trying to do a base line set up and adjusting it.
http://www.baselinesuspensions.com/i...A_Drag_Car.htm
http://www.how-to-build-hotrods.com/tuning-4-link.html
Without a basic understanding of how the suspension works, the forces involved and the terms used to describe your suspension, no one in the world is going to be able to help you adjust it.
I hope this helps you out.
Will
Instant Center (IC) is the point where the plot lines for the 4 link bars intersect.
IC is measured in 2 variables. UP (how high off the ground) and OUT (how far from the axel centerline).
Alot of people talk about the lower bars needing to be parallel to the ground... That is not true. Espc with a small tire car. What matters is the IC measurements because once you compare the IC intersect plot to the cars Center Of Gravity (CG) you can see how much Anti Squat (AS) the car has.
The lower bars on my 84 actually point up hill to the front and the IC on my 84 measures 12" UP and 53" OUT. It goes 1.19 60fts on 275 radials and low 8's in the 1/4 mile@ over 160MPH.
Just from those 2 numbers I, or anyone who has knowledge of suspensions, can make adjustments and know how the car will react.... IF I shorten the IC to say 46" OUT I know the car will react more violently on launch... I know if I lengthen the IC to say 63" OUT the car will leave softer. IF I raise the IC height it will tend to wheelie more or try to separate the rear suspension more (raise the rear of the body at launch) and the opposite if I lower the IC height.
Here are a few explanations of Instant Center (IC), Anti Squat (AS) which is also refered to as Percentage of Rise (PR) by some people.
You need to read thru these pages and get an understanding of what the suspension does and what the terms are used to describe the suspension set up before you go trying to do a base line set up and adjusting it.
http://www.baselinesuspensions.com/i...A_Drag_Car.htm
http://www.how-to-build-hotrods.com/tuning-4-link.html
Without a basic understanding of how the suspension works, the forces involved and the terms used to describe your suspension, no one in the world is going to be able to help you adjust it.
I hope this helps you out.
Will
Last edited by rklessdriver; 09-23-2016 at 03:00 PM.
The following users liked this post:
ajrothm (09-25-2016)
#9
Burning Brakes
Thread Starter
Guys thank you for the responses! I am aware of the IC and and antisquat line. I have researched a lot on adjusting a 4-link. I do realize that I need to set my base and then see how the car reacts.
My question was for the guys running the Autofab kit, how well did the setup they give you work. I have yet to take measurements on my car to find the IC of the Autofab recommendations but to my understanding the kit was designed for the C3 so I would assume the settings they give would be relatively close.
I plan to leave the setting at the recommended points and do a few hits and see if the rear squats or lifts. From my understanding if it's setup correct it should do neither.
Thanks again guys for the input, lots of 4-link info out there I was looking for C3 specific setup. I'll report back to you guys my findings in hope to help others that did this swap.
Thanks for the input Rckless!
My question was for the guys running the Autofab kit, how well did the setup they give you work. I have yet to take measurements on my car to find the IC of the Autofab recommendations but to my understanding the kit was designed for the C3 so I would assume the settings they give would be relatively close.
I plan to leave the setting at the recommended points and do a few hits and see if the rear squats or lifts. From my understanding if it's setup correct it should do neither.
Thanks again guys for the input, lots of 4-link info out there I was looking for C3 specific setup. I'll report back to you guys my findings in hope to help others that did this swap.
Thanks for the input Rckless!
#10
Burning Brakes
http://www.baselinesuspensions.com/i...A_Drag_Car.htm
http://www.how-to-build-hotrods.com/tuning-4-link.html
I hope this helps you out.
Will
http://www.how-to-build-hotrods.com/tuning-4-link.html
I hope this helps you out.
Will
The following users liked this post:
Amelio (09-26-2016)
#11
Racer
adjust 4-link
I don't race mine, I just drive it.
I was mainly interested in centering the wheels in the wheelwell and keeping the driveshaft angle reasonable. It rides, handles and stops as well as it did with the IRS. But, I am very interested in this thread to see if there are any adjustments I can make to improve my car.
Thank-You for sharing information
Rick
I was mainly interested in centering the wheels in the wheelwell and keeping the driveshaft angle reasonable. It rides, handles and stops as well as it did with the IRS. But, I am very interested in this thread to see if there are any adjustments I can make to improve my car.
Thank-You for sharing information
Rick
#13
Drifting
the AF settings were close, had to set pinion angle but you know that already. I dont remember the exact settings and my car has been down a few months since I got the new motor. Worked well at the track with my old 406.
#14
Burning Brakes
Thread Starter
I will post up my reults so you guys have an idea of what is working. I will hopefully have some time next weekend. This com,ing weekend is the Street Car take over here in Atlanta. I though about bringing my 2012 GS but I think I am just gonna go watch. My buddy has a bad *** C6Z he just did some work to so it will be fun!
I plan on hitting my car pretty hard at the track so it needs to work halfway decemt. Once I get the rear dialed in I need to start looking at the trans. I do not think my old Munice $ speed is gonna hang in there that long.
Thanks again for the comments!
I plan on hitting my car pretty hard at the track so it needs to work halfway decemt. Once I get the rear dialed in I need to start looking at the trans. I do not think my old Munice $ speed is gonna hang in there that long.
Thanks again for the comments!