Projects Rear 4 link help

Okay so I have a couple of questions regarding rear 4 links. Any input is appreciated.

1. Is there any advantage of triangulated, other than not using a pan bar?

2. How do the lengths of the bars (and different lengths top and bottom opposed to top and bottom being the same length), angles (for triangulated), etc. have to do with handling and drivability?

3. Is there a "too short" length on bars?

4. Do they need to be running parallel with the ground?

5. Who makes a good kit at a decent price? I've looked at Speedway and Pete and Jakes, i'm sure there are others.

Thanks again and any input or help is greatly appreciated.

 

Pretty much all the answers are right here on the hamb... use the search function and you'll find tons of threads on 4 link stuff.

 

cheapest kit you can buy is the one you make yourself

 

triangle is the only true 4 bar, the other requires a 5th--panhard bar, to keep the axle from moving side to side

 

Hey ben. I like the triangulated style there easy to install and the handling has never gave me any problems.

1. Mostly it is the pan hard bar, the movement of the rear housing in full range motion without binding is another benefit. kinda like a stock car suspension.
2. Not sure on how to answer that question. Other than they need to make a close triangle to the mounting points. But not needed to extend all the way to the mounting points.
3. I'll get you my bar measurements. lower bars 27 inch, upper bars 18 inch. This is with out the threaded fittings installed.
4. As close as possible with the ground at ride height. but with each other is very important.
5. I bought a universal stainless kit from some site I found in iowa, while looking on e bay. Searching 32 ford it is the second one I bought and both have worked good $250.00

 

try this thread: http://www.jalopyjournal.com/forum/showthread.php?t=98967&highlight=suspension

read this book: http://www.amazon.com/Chassis-Engin...=sr_1_1?ie=UTF8&s=books&qid=1254783943&sr=8-1

good places to start

 

paul hortons welder series is a good kit

 

1. A triangulated setup is great if you have the space to make it work correctly. To make it work right, your upper bars need to be angled between 35-45 degrees. Any less than 35 and it will flex a bit, and any more than 45 is not necessary because if both bars are at 45 degrees you have created a 90 degree triangle with the link bars, and this is the most efficient it will get.

2. The lengths of the bars in relation to each other effect your roll steer. Their angle determines your instant center (IC). Here is a diagram that explains what IC is.


I often see this (IC) overlooked, and it is one of the most important parts when installing a link system. The text book way to set it up is to find your vehicles COG and make the IC intersect there, or above/below it depending on what type of anti-squat numbers you are looking for. For most street driven vehicles I usually tell people to put the IC right around the front bumper/grill.

The length of the bars is another important thing. A rule of thumb, is that the upper bars should be about 70-80% the length of the lower bars. This has to do with roll steer. This measurement is taken from the side, from pivot to pivot, like seen above in the IC diagram. It is possible than the actual length of your upper bar will be longer than your lower because it is triangulated, but when it moves the pivots only matter as if the bars where all parallel.

3. The length of the bar depends on the amount of travel you need. I usually try not to have a lower bar that is under 14 inches in length. On average however, my lower link bars are between 20-24". When installing a triangulated 4-link, I generally figure out what length my uppers need to be to acquire the right angle, and calculate the lower bars length based off of that.

4. At your ride height the lower bars should be parallel to the ground, or pointing slightly up towards the transmission. The upper bar should be point down at this point.

5. Can't really help here, I build every 4-link that I install.

This is essentially a nut shell wrapped around your questions. I could go on explaining this with enough length to publish a book. So if you have more specific questions, ask and I can try to help. I can also recommend a few books.

Chassis Engineering - Herb Adams (this book is good for learning some basics, but I disagree with a few of his theories, and the book is a little dated).

Tune To Win/Engineer to Win - Carroll Smith (read them twice, once for content once for comprehension. When you are done you will probably disagree a bit with the Adams book, but you should have a good understanding.)

 

thanks everyone i am going to need some pretty short bars and am considering building my own setup. guess we'll see what all i can find and what prices. christmas won't get here soon enough ha

 

Twisted thanks that helped a lot!

 

Twisted, I know this is an old thread, but wanted to thank you for specific advice with logic behind it. This is what makes the HAMB unique.