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Discussion Starter · #1 ·
A couple of questions. I'm looking for someone in the Alaska area that has experience in doing SAS work. Planning on a 3-link for an 05 tacoma. I basically need help with link-geometry and the placement of the links and johnny joints on the frame or a crossmember. I was leaning towards a 9-inch or possibly a d-60. Should I get a diamond high-9 or go with a sunray 609? Should I get a D-60 instead? I noticed most people are running D-60/D-44 front and D-60/14-bolt rear. What's the advantage of D-60 over a 9-inch? I would think it would be easier to remove the 3rd member from the 9-inch and it seems strong enough for the front. I'm planning on detroit locker and 4.88 gears. Any thoughts or suggestions? How important is the geometry for a front 3-link?
 

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A couple of questions. I'm looking for someone in the Alaska area that has experience in doing SAS work. Planning on a 3-link for an 05 tacoma. I basically need help with link-geometry and the placement of the links and johnny joints on the frame or a crossmember. I was leaning towards a 9-inch or possibly a d-60. Should I get a diamond high-9 or go with a sunray 609? Should I get a D-60 instead? I noticed most people are running D-60/D-44 front and D-60/14-bolt rear. What's the advantage of D-60 over a 9-inch? I would think it would be easier to remove the 3rd member from the 9-inch and it seems strong enough for the front. I'm planning on detroit locker and 4.88 gears. Any thoughts or suggestions? How important is the geometry for a front 3-link?
How much money do you have to spend on an axle is the first question. Then I would say put your plans on hold for a while cause if your asking how important the geometry is for a front 3 link you need to learn a whole lot more before you start cutting. Proper geometry is EVERYTHING if you want it to drive, flex, steer right etc. Better get busy and study up some first.
 

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There are a bunch of things that you are going to need to know before you start cutting on that '05. Geometry for a three link is everthing. Then there's the whole issue of where and how you strengthen the frame. What size tires you plan to run, how your going to place your steering box, what type of steering box, do you need a sway bar, what size coilovers are you going to run, how you deal with the brakes, what will you do with the rear drive haft when it starts to jump all over the place. Study my friend. You've got alot to learn before you cut your truck.
 

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Discussion Starter · #5 · (Edited)
The sunray is way cheaper than the Diamond, I'll probably get it, they told me if I get a hi-9 center that they would turn it into a 609 with 35 SPL d-60 outers.

There are a bunch of things that you are going to need to know before you start cutting on that '05. Geometry for a three link is everthing.
The 3-link is for the front. I'm assuming squat and anti-squat are an issue when driving in 4WD, I guess I would want a small amount of lift in the front on excelleration vice front squat. I've read quite a bit on this and I understand the theory of it, but I lack the experience with hands on stuff.

Then there's the whole issue of where and how you strengthen the frame.
I plan to plate the entire frame as part of the project

What size tires you plan to run
Between 34-38". I'll probably plan the geometry around a 34" tire initially and make it adjustable since I'm not doing both the front and rear at the same time, but eventually build the rear chassis, if cost were no issue I'd have a 4-link rear.

how your going to place your steering box, what type of steering box, do you need a sway bar,
well, I'll probably go with an IFS box and do it similar to the way you have yours mounted on the frame. I don't plan on doing hydro at this time. Are there hi-steer/crossover steer options with a 9-inch? Part of this thread is to invite a debate over the advantages and disadvantages of 9-inch vs D60

what size coilovers are you going to run, how you deal with the brakes, what will you do with the rear drive haft when it starts to jump all over the place. Study my friend. You've got alot to learn before you cut your truck.
Both of the axles I mentioned come equip with disk brakes. I'll look forward to a selector switch for ABS if Demello comes out with it. Eventually I'll just have to stop putting it off and cut. I was considering doing leaf springs since this is my first SAS unless I can find someone that I trust knows what they're doing, but in any case I do want the geometry to be right.

I understand about not only the rear but front driveshaft. I'll just have to take it easy until I either get limit straps or replace the driveshafts.

To answer the others questions, it's going to cost some money
 

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I'm not real familar with the high 9's. I know part of the attraction is getting the pinion up and out of the way. You can accomplish the same thing with a high pinion Dana 60 like both of mine and have more strenght in my opinion and ease of finding parts should something brake. Thats one of the reasons I went with the Dana 60 over everything else. Plus, with the Currie units I got 1 ton knuckles and 35 spline chromo shafts with 5.38 gears. Not going to brake much unless I'm supid out there. You also want the anti-squat and dive for on road manners as well. Mine drives really nice on the street and thats with 40's because we took the time to search out those that knew something about three links. We spent many hours on the computer getting the front end set up.
 

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I have a diamond 9" 60. with ctm's. with deden bear knuckles.
its some of the beefest stuff i have ever seen. I know I dont have to worry about the houseing being the tubes are 3.5"x 1/2 wall.
the thinest pieace of steel is 1/4". so if i bend or break it i shouldn't be doing it any way.
 

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The 3-link is for the front. I'm assuming squat and anti-squat are an issue when driving in 4WD, I guess I would want a small amount of lift in the front on excelleration vice front squat. I've read quite a bit on this and I understand the theory of it, but I lack the experience with hands on stuff.
You assume WAY wrong. They are an issue with BRAKING which is the most important thing to consider when setting up a front suspension like this. Anti-dive is only one consideration to braking performance. The 4wd and acceleration considerations can come second once you've given proper thought and design to braking parameters. In the front anti-squat is termed anti-dive.



well, I'll probably go with an IFS box and do it similar to the way you have yours mounted on the frame. I don't plan on doing hydro at this time. Are there hi-steer/crossover steer options with a 9-inch?
Well, there are no such things as 9" knuckles so more than likely you'll run some kind of 60 knuckles. Do they have steering options for those? That's your answer.





As for the axle, it's whatever the heck YOU want and YOU like. Both have advantages and disadvantages. A full 60 can come out of a junkyard and a 9" front can't. Axle vs axle for what it is I prefer a 60. However, I have the opinion that the huge advantage to a front 9" is the aftermarket housings and the ability to easily fab with the steel housing and get away from the nodular iron center section of the 60. There are ways to work around the 60 center sections and I have done it, but it can possibly be a big pain.
 

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Discussion Starter · #9 ·
You assume WAY wrong. They are an issue with BRAKING which is the most important thing to consider when setting up a front suspension like this. Anti-dive is only one consideration to braking performance. The 4wd and acceleration considerations can come second once you've given proper thought and design to braking parameters. In the front anti-squat is termed anti-dive.




Well, there are no such things as 9" knuckles so more than likely you'll run some kind of 60 knuckles. Do they have steering options for those? That's your answer.





As for the axle, it's whatever the heck YOU want and YOU like. Both have advantages and disadvantages. A full 60 can come out of a junkyard and a 9" front can't. Axle vs axle for what it is I prefer a 60. However, I have the opinion that the huge advantage to a front 9" is the aftermarket housings and the ability to easily fab with the steel housing and get away from the nodular iron center section of the 60. There are ways to work around the 60 center sections and I have done it, but it can possibly be a big pain.

I've heard that the 9" is easier to work with due to the 3rd member. Sunray offers theirs with flat-top knuckles and Hi Steer. I think the 9-inch is what I will go with for the front, it seems like most people use D-60, but that's probably due to the availability. I'll have to do some research on Dive and Anti-dive. I know what it is but designing the links is another story. I found a software program called Suspension Analysis 2.0 which is supposed to provide that type of data. Has anyone used this to design their setup? On searching I mostly find info on rear 4-links, there's no alot of data on the front 3-link setup. Maybe most people set them up with a best guess by placing the center link as high as possible on the axle and placing the lower links sort of below center line on the axle and making them as long as possible.
 

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I've heard that the 9" is easier to work with due to the 3rd member. Sunray offers theirs with flat-top knuckles and Hi Steer. I think the 9-inch is what I will go with for the front, it seems like most people use D-60, but that's probably due to the availability. I'll have to do some research on Dive and Anti-dive. I know what it is but designing the links is another story. I found a software program called Suspension Analysis 2.0 which is supposed to provide that type of data. Has anyone used this to design their setup? On searching I mostly find info on rear 4-links, there's no alot of data on the front 3-link setup. Maybe most people set them up with a best guess by placing the center link as high as possible on the axle and placing the lower links sort of below center line on the axle and making them as long as possible.
You find too much info on three links for the front on a program like that. There has been a ton of info on this board as well as pirate about three links. some put the third link on the drivers side, some on the passenger side while others have tried it at the center. I have my numbers somewhere but it's designed for 40" tires. We built mine at full stuff which really helped and we did it all on the computer first then went out to the truck. Don't us your best guess. I don't think too many people here have. Mine tracks really well and even with 40" tires, 27.5" from bottom of the frame to the ground, and no sway bar, you cn whip it around corners pretty good and you can slam on the brakes and take your hands off the wheel and it wil still track straight. Now no, it DOES NOT drive better than it did when it was stock on the road. Those people that tell you that after they have dramatically changed their front suspension, that was designed for comfort and stability on the road, are out of their minds to think that any of these solid axle swaps are going to behave better than ifs on the road. There is a reason the factories are going to ifs over solid axles up front and it's not cost.

Any way. do some more research and then research again. Lots of info out there.

Go ahead guys. :flamethro Flame away. I can take it:cool:
 

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You assume WAY wrong. They are an issue with BRAKING which is the most important thing to consider when setting up a front suspension like this. Anti-dive is only one consideration to braking performance. The 4wd and acceleration considerations can come second once you've given proper thought and design to braking parameters. In the front anti-squat is termed anti-dive.
Anti-Dive is the same as Anti-Squat however I think you have to take into account the braking power to the front axle vs. rear. I was told to draw a line from your front tire contact patch through the instant center. Take the height of where that line crosses the rear axle and divide by the COG height. Then multiply by the % of front braking and that is your % anti-dive.

Anyone know if this is total BS?

Question I still have on this though...

For a daily driver or even a drive to the trail rig, seems like you would want more than 100% anti-Dive. This way you don't dive during harsh braking situations on the highway and you might actually get a little bit of sucking during a steep verticle climb to suck the COG into the rocks a bit.

Would like to hear what other's have done in their designs w.r.t. Anti-Squat on their daily drivers/drive-to rigs!
 

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You find too much info on three links for the front on a program like that. There has been a ton of info on this board as well as pirate about three links. some put the third link on the drivers side, some on the passenger side while others have tried it at the center. I have my numbers somewhere but it's designed for 40" tires. We built mine at full stuff which really helped and we did it all on the computer first then went out to the truck. Don't us your best guess. I don't think too many people here have. Mine tracks really well and even with 40" tires, 27.5" from bottom of the frame to the ground, and no sway bar, you cn whip it around corners pretty good and you can slam on the brakes and take your hands off the wheel and it wil still track straight. Now no, it DOES NOT drive better than it did when it was stock on the road. Those people that tell you that after they have dramatically changed their front suspension, that was designed for comfort and stability on the road, are out of their minds to think that any of these solid axle swaps are going to behave better than ifs on the road. There is a reason the factories are going to ifs over solid axles up front and it's not cost.

Any way. do some more research and then research again. Lots of info out there.

Go ahead guys. :flamethro Flame away. I can take it:cool:

I've been using the Triaged's calculators found here...

http://mysite.verizon.net/triaged/files/3LinkV1.0bBETA.zip
http://mysite.verizon.net/triaged/files/4BarLinkV3.0.zip

They seem to work but of course I have no way of verifying the equation and calculation accuracy for them. Also heard that Extreme 4x4 posted a calculator on their website last year.

And here is the Peterson's write-up...

http://www.4wheeloffroad.com/techarticles/suspension/131_0306_four_link_suspension_part_1/
 

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Anti-Dive is the same as Anti-Squat however I think you have to take into account the braking power to the front axle vs. rear. I was told to draw a line from your front tire contact patch through the instant center. Take the height of where that line crosses the rear axle and divide by the COG height. Then multiply by the % of front braking and that is your % anti-dive.
Anti-dive is found just the same as anti-squat. You can factor in braking %, but as a principle anti-dive is referred to as a geometric thing and braking % isn't factored in. Once you factor in braking percentages you are more on the way to estimating actual amounts of dive using the percentages. What you said above for determining anti %'s is correct. It works the same to figure anti-dive for the front and anti-squat for the rear. They're the exact same idea.

For a daily driver or even a drive to the trail rig, seems like you would want more than 100% anti-Dive. This way you don't dive during harsh braking situations on the highway and you might actually get a little bit of sucking during a steep verticle climb to suck the COG into the rocks a bit.
Here you're way off. You will find high anti-dive numbers are not good. You want the vehicle to squat some under braking and therefore let your springs take the load from the load transfer. Most guys start to get happy with front 3 links when anti-dive starts getting below 70%. My current project I've gotten it under 60%. Lots and lots of racecars will run as little as 0% if that tells you anything. Production cars tend to be pretty low too.

For a climb, that sucking gets to be pretty non existant when you consider how little weight the front tires and springs are carrying. It's not something to really concentrate on for helping to make climbs. It's more important to focus on braking performance for a good, safe, and effective front suspension.

Would like to hear what other's have done in their designs w.r.t. Anti-Squat on their daily drivers/drive-to rigs!
I'm doing my rear suspension now and probably looking to start with an anti-squat number in the 70-80% range. Really though, too much thought is given to rear anti-squat, imo, and I'm more concerned with other parameters and less so with AS but this is probably about where it'll end up if I were to guess. I think anti-squat is important in figuring if something is majorly wrong. For example if you whip out a setup and find you have 200% anti-squat you need to start over. For my front the AD is under 60% like I said, and while it's an important number to remember, the rest of the link setup is what will really make the difference. I'm going to get some odd characteristics, but not at the expense of braking and safety.
 

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Thanks for the data point and thoughts on braking %'s!

Anyone else willing to share their AD and AS%'s??
 

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The 9 inch ford has the edge over the D60 in terms of weight, cost and strength. The Hi9 with the load bolt and their oiling system solved all the problems previously associated with the 9". http://www.truehi9.com/
Definately consider going to this set up if you don't have a source for a donor D60. Sunray is a real beast and has tons of strength but the cost is way to high unless you need that type of strength - then the cost is very reasonable. Now you can go two ways with the hi9 - the junkyard route, which will give you extremely cheap parts for everything except the 3rd member, which is extremely strong and gives several inches of additional driveshaft clearance in the rear. With 31 spline stock axles you will have great strength at a very low cost - you can go chromo or 300M if you feel the need and have the bucks. The hybred route gets expensive and you can either go the D60 outer route or custom D60's - solid axle amoung others make a great C and kingpin knuckle and using Bobby Long's CV axles, you have plenty of strength, good steering radius and you can 3-link the front, 4-link the rear, add anti-sway bars and you're good to good anywhere on the highway or offroad. Carl St. Clair from outback offroad gear has kits, which he might be still tweaking a little for this type set up. He has a 3-link front and a 4 link back with an in-cab switch for the anti-sway bar. Here's his site: http://www.outbackoffroadgear.com/

Going the custom route will cost well over $10K - good luck.
 

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OK...This post got me curious about CO SAS setups out there and what their Anti-Dive setups were. So I went up to a friends house today to check out the All-Pro kit with their hybrid D60 setup. After measuring and plugging it allinto the calculator, the Anti-Dive came out to 169%! Assuming I got the height of the COG right (37-38") there is no freaking way that you could fab something up with a Anti-Dive of 60% with that All-Pro kit!!

So now I am REALLY curious to hear what people are using for upper and lower link lengths. On the calculator, in order to get an Anti-Squat of 90% the upper link frame mount was 4" higher than the bottom of the frame and the lower links had to be 3" lower than the bottom of the frame and 49" long! Doesn't seem practical.

Also curious about the lower link axle mounts. One was about 2" lower than the other...what sorts of issues does that cause if any?
 

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Discussion Starter · #17 ·
OK...This post got me curious about CO SAS setups out there and what their Anti-Dive setups were. So I went up to a friends house today to check out the All-Pro kit with their hybrid D60 setup. After measuring and plugging it allinto the calculator, the Anti-Dive came out to 169%! Assuming I got the height of the COG right (37-38") there is no freaking way that you could fab something up with a Anti-Dive of 60% with that All-Pro kit!!

So now I am REALLY curious to hear what people are using for upper and lower link lengths. On the calculator, in order to get an Anti-Squat of 90% the upper link frame mount was 4" higher than the bottom of the frame and the lower links had to be 3" lower than the bottom of the frame and 49" long! Doesn't seem practical.

Also curious about the lower link axle mounts. One was about 2" lower than the other...what sorts of issues does that cause if any?
This got me thinking and I got curious about how accurate you need to be to calculate the COG. If you're just using the top of the bellhousing, that may not be exact but it seems to be good enough. One guy on pirate said that he changed his COG height calculation by 3 inches and it only changed the Anti dive by 6%. If you are really going to get accurate and calculate the sprung weight + the new sprung weight it would involve subtracting the weight of the parts that you remove then add the new sprung weight minus links since the links haven't been designed yet. I think this is why people just use the top bolt on the bell housing. You could probably do it with the current suspension setup to get more accurate than using the bell housing bolt, but it's probably overkill with a goal of a range between 30-50%. I'm curious if awsumdc calculated the COG or if he went with the bell housing.

The only reason I would think that one axle mount would be lower than the other on the All-pro, and it depends on which side is lower, would be to counteract the force of rotation on acceleration, but it would change the dive and ant-dive for each side I would imagine unless the frame ends are placed differently. Did All-Pro install it this way or is this the way that everyone installs their All-Pro?

Does anyone disagree with 30-50% for a street + trail rig?
 

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Now no, it DOES NOT drive better than it did when it was stock on the road. Those people that tell you that after they have dramatically changed their front suspension, that was designed for comfort and stability on the road, are out of their minds to think that any of these solid axle swaps are going to behave better than ifs on the road. There is a reason the factories are going to ifs over solid axles up front and it's not cost.

Go ahead guys. :flamethro Flame away. I can take it:cool:
Mine drives about the same now as it did w/o the sway bar (IFS). Once I get some sort of sway bar and airbumps installed I bet it will be better than it was stock :p
 

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Mine drives about the same now as it did w/o the sway bar (IFS). Once I get some sort of sway bar and airbumps installed I bet it will be better than it was stock :p
By stock I'm sure you mean a well worn out IFS system. By nature a solid is not going to respond as well on the road as an IFS. When you drive a solid axle over a pot hole with the drivers side tire it also affects the passenger side at an equal but opposite reaction. With an IFS that same pot hole will only affect the drivers side while the passenger side continues about it's marry way. Now this is a simplified explaination of what happens but I think you get the point. Now, with a coilover solid axle there are some other things happening when your suspension travels up and down. As your suspension travels up the axle moves forward because of the arc it travels in. Not only that, if your panhard bar is attatched to the divers side as your suspension travels up the axle will move towards the passenger side as it is also moving forward. Thats what gives the coilover solid axle swaps that sometimes wierd handling at times while travel over certain bumps. Now this is all simplified versions of what happens and I'm sure that the "engineers" amoung us will chime in ith other bits of wisdom but this helped me understand the handling of both different suspension systems. Your coilover now are trying to control unsprung weight that is also trying to be contolled by another coilover on the other side. With an IFS that dosn't happen.

I love my solid axle and my coilovers. Wouldn't trade it for any leaf spring or IFS. But it doesn't handle as well as it did when it was stock and never will and mine is set up pretty good. Solid axle have a great place on our trucks while rockcrawling but it has no place on a race track under a sports car. Heck, the good ones have IFS and IRS. Theres a reason for that.;)
 

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By stock I'm sure you mean a well worn out IFS system. By nature a solid is not going to respond as well on the road as an IFS. When you drive a solid axle over a pot hole with the drivers side tire it also affects the passenger side at an equal but opposite reaction. With an IFS that same pot hole will only affect the drivers side while the passenger side continues about it's marry way. Now this is a simplified explaination of what happens but I think you get the point. Now, with a coilover solid axle there are some other things happening when your suspension travels up and down. As your suspension travels up the axle moves forward because of the arc it travels in. Not only that, if your panhard bar is attatched to the divers side as your suspension travels up the axle will move towards the passenger side as it is also moving forward. Thats what gives the coilover solid axle swaps that sometimes wierd handling at times while travel over certain bumps. Now this is all simplified versions of what happens and I'm sure that the "engineers" amoung us will chime in ith other bits of wisdom but this helped me understand the handling of both different suspension systems. Your coilover now are trying to control unsprung weight that is also trying to be contolled by another coilover on the other side. With an IFS that dosn't happen.

I love my solid axle and my coilovers. Wouldn't trade it for any leaf spring or IFS. But it doesn't handle as well as it did when it was stock and never will and mine is set up pretty good. Solid axle have a great place on our trucks while rockcrawling but it has no place on a race track under a sports car. Heck, the good ones have IFS and IRS. Theres a reason for that.;)
well...ok...on bumpy stuff it doesn't handle as well :p

anyone ever try a double pan hard bar? would that even work?
 
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