Re: Make it handle
 

FYI, I've never heard of a 1" drop spindle. They start @ 2", then 2.5", & 3" increments. A 2" spindle & 1" spring would be an excellent choice if you're targeting a 3" drop up front.

Re: Make it handle
 

Thanks for the correction.

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Hey Rob, have you gotten any of the new rear sway bars for the 67-72 Chevy C10 coil sprung pick-ups like the one on JT yet? I sure would like one.

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I have to admit that this project has slipped off of my top pile. I'll make a call today to see where we're at. All prodution samples have been approved, just waiting on a few parts.

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Lots of questions lately about rear suspensions. 3 and 4 bar, traling arm, .... I'm going to try to sort these out a step at a time. First, realize that there is a LOT going on here. to really compare, think about all that is happening. The basic scenario goes like this. The rear suspension has to locale the axle. Front/rear, side/side, and up/down. Next, it will aply forces from the ground/tire contact patch, to the chassis. Forward, rearward, side/side, bump/jounce. How these forces are applied is important to us. Next, you have to consider pinion angle change, roll steer, IC movement, anti-squate, or rate-of-rise, and lastly, packaging onto the chassis. At this point, we havent even started to think about how to get a good ride. I'm still thinking about how to lay this out for discussion. Give it some thought, what is most important to you?

Re: Make it handle
 

LOW budget handling, simple stuff for average person, not a 5k handling kit lol

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Since my truck is a daily driver, personally I shoot for about 75% performance and 25% ride quality. The way I see it, if I wanted a daily driver that feels like a Corolla, I'd go buy a corolla. I am willing to sacrifice some comfort for sake of a very fun ride.

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Agreed. I'm cheap. Low buck is king, but only to a point. 50/50 ride/handling- cake AND eating it, too. Too much to ask?
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Re: Make it handle
 

I think we should really go back to the begining. Lets start out by looking at the basic types of rear suspension available for these trucks.

Leaf Springs These are pretty common, and one of the most used and sometimes under rated. Leafs are widely used because of the manufacturing costs, and vehicle packaging. Leafs do many jobs at one time. They are the locators, front/rear and side/side, and the spring. The 'Instant Center', where the force pushes on the truck, is right at the center oof the front spring mount - non adjustable. The roll center is appx at the same height, and non adjustable. There is some side/side motion due to spring flex. HP threshold is around 400, after that the spring wrap is a big problem. Sway bars, shocks, and bushins can help. Be honest with your build. Once you add traction bars, sway bars, shocks and bushings, you've passed up the cost of link style suspensions.
Leafs can ride great, and handle good. Mary Pozzi won MANY autocross championships with her leaf spring 72 camaro. Keep in mind that the Big three automakers are there to make a profit, and leafs are a low cost, effective way to get the job done.

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Dude, your such a wealth of knowledge, you need to build a website for guys like us to reference.
I'm building a trailing arm 68 with a 1950 international cab and bed. My sister and brother in law both auto cross and would love to get into the sport in an unusual truck.
Ive started (made it about 20 pages in) reading this whole thread, and thought how nice it would be to be able to open a page and look up specific topics. Roll center and Instant center are perfect examples of things I need further understanding and education on to understand d their cause and effect.
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Re: Make it handle
 

Sounds cool, and thanks, BTW, nice place to live.
, Another note on leafs. The WIDTH of a leaf can make a big difference. '54 and earlier chevys, and '47 and back fords use a 1 3/4" wide leaf. Through the 50's it was 2", then 2 1/4", and in the late 60's, 2 1/2". Some newer trucks have 3" or 3 1/2". The wider springs have less side flex, and usually a smoother ride, fewer leafs are required. Changing you leaf set up from 'truck' style, Axle under and shackle going up, to a 'car' style, Axle over, and shackle going up, can really improve the ride, but it drops the load capacity. Many, many people 'flip' the axle, which drops the truck, but almost nobody flips the shackle. Yes, that will lift the truck a bit, appx. 1 1/2", but the ride is way better.

Re: Make it handle
 

Let's say you wanted to do a drop but didn't want to go as low as a flip kit provides. I assume flipping the axle AND the shackle would be a good way to lower it, but not go quite as low as a flip kit by itself and would provide a better ride. Also, I assume this may help remove the need for a C notch, but that's just a guess since I've never done a flip kit before. Am I completely off on this one?

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[QUOTE=hairlesshobo;5114016]Let's say you wanted to do a drop but didn't want to go as low as a flip kit provides. I assume flipping the axle AND the shackle would be a good way to lower it, but not go quite as low as a flip kit by itself and would provide a better ride. Also, I assume this may help remove the need for a C notch, but that's just a guess since I've never done a flip kit before. Am I completely off on this one?[/QUOT

Right you are. A flip drops you 6-7" and requires a notch. There is no ride improvement. If you flip the shackle also, the net drop is 4 to 5". This can done without a notch, and gives you a better ride.

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Edit: sorry, this was too far off topic to bring up right now.
Moving on............:smoke:

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:lol: this is exactly what i've been planning to do mainly just to lift the rear end back up a little bit is there any way to flip the shackle that is better then another? we did this on my brother in laws 4x4 and i think we just took out the factory rivets flipped the mount over and used the same holes but i wasn't sure if it would be better to move the mount maybe?

also you said the ride is better so i assume that it changes the spring rate somewhat any insight you can share on that? as always thanks for all the great info :metal:

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Awesome thread, i've been keeping up with it for a while now. I picked up the Herb Adams book and have read it a couple times now. Rob, I see you recomended the suspension pro computer program, is there any other programs out there or is that the best one?

I've been doing a good bit of tortional frame bracing and am real close to welding up my No Limit 4 bar kit. I'm gettin real excited, this thread has really done it for me!!!!

http://i257.photobucket.com/albums/h...9/DSC09663.jpg
http://i257.photobucket.com/albums/h...9/DSC09785.jpg
http://i257.photobucket.com/albums/h...9/DSC09706.jpg

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With the shacle running 'UP', truck style, the heavier load, or bump, puts the spring and shackle 'at odds' with each other. The spring wants flatten out, and extend (this would cause the shackle to lean back), but the load if pushing the shackle to be straight up (gravity) This gives a steep Progression in effective spring rates. With the shackle 'down', car style, the leaf and shackle work together. When the spring wants to flatten out and extend, the load, or bump, is also causing the shackle to want to lay back. This gives a more consistant spring rate, and a smoother ride. I usually move the shackle hanger forward 5/8" when I flip the mount, this helps the shackle to be straight up/down at RH

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Looks good Matt R. Keep it up, and kkep us posted.

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The "Wrap-up" on leafs. Easy to understand, fairly inexpensive. They can have a good ride and handling. Mostly non-adjustable. Expected Hp/Tq limit, 400/400. The lower the front spring eye mount is, the lower the anti-squat is, this could have less traction.

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Rob, Do you know anyone running Tilton master cylinders on the street? I saw an installation article in a mag and loved the look plus no booster, but not sure about use on the street.
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Well, not tilton exactly. But I do know several guys running Wilwood and/or CNC set ups using two masters on a balance bar (no prop valve needed, just check valves), and some using the clutch masters also. They work good, but you have to get the bore size and pedal ratio correct. Wilwood has some good info on thier site. I will be running this type on my new C-10 project, (No Limit K-10) I'll try to get some picts up next week.

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Thanx. I will take a look at both of those. I have been following your K-10 build and love it.
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I've run both and for my money I would stick with wilwood for you pedal assembly, master cylinders and bias valve . Tilton has it together when it comes to clutches and related parts

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I looked at both today and really like the wilwood pedals. I wish they had the drilled style pedal in a single pedal design. Might get it which would allow me to switch to a manual later if I decide.
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#2. Trailing Arms Lets look at these next, since many C-10's have them, and they're fairly simple. A trailing arm is a 2-link suspension. The arms control the front to rear axle placement, and the pinion angle. The front eye mount of the arms defines the 'Instant Center' or IC, the point where the tires traction pushes on the truck. A locator (panhard rod) is needed for side to side control. Coil springs, Air bags, or Coil-over shocks can be used as the 'spring' to hold up the weught of the truck.
We now have three component sets doing the 'jobs' required. With leaf springs, one part has to do all of the jobs. - not specialized. Now, we have some parts doing specialized jobs. Because of this, these parts can do a better job. The panhard rod's main job is to locate the rear axle, and it can do this very well if designed correctly. It also defines the rear Roll Center, or RC. The roll center hieght is the average of the two mounting points, the axle mount, and the chassis mount. Raising or lowering the RC can change the handling of the truck. The springs only hold up the truck, and provide the ride quality, and can easily be tuned for a better ride and handling. These are the trailing arm basics. More in a bit.