[Scrumgees]

Does anyone know of any good books or resources for installation of a 4 link rear suspension? Something with some theory and diagrams would be a real bonus

I am building up a 70 chevy pickup and there is no kits I can find available for a direct fit and I am not interested in the non ajustable kit offered by ride tech and a few other companies. I am not opposed to welding up some bracketry for installing a universal kit. I would like to read up as much as I can on the proper geomerty before I go welding something in at the wrong angle or height or whatever.

[OneMoreTime]

http://www.racetec.cc/shope/ There you go..

Sam

[OLNOLAN]

Just wondering why you want to replace the truck arm/ coil spring setup you have. Its the basic design of what Nascar setups use now. Why change it? As stock, they ride real good too! olnolan

[Scrumgees]

The reason im thinking about changing the suspension up is honestly I have become quite curious lately. This build is not set in stone either, I have a second frame stripped and ready to work with and would like to take the time to learn something new while i fix it up for this truck.

Im also having trouble getting traction at the strip with a 450hp (at the engine) 383 stroker, mind you I am not running slicks yet, just a set of mickey thompson Sportsman SR radials that are 29" tall and an advertized 13" track width.

[ericnova72]

You will never get hooked, on any suspension, with the Sportsman Sr Radials, they are a hard street tire. They are not at all compounded like the Drag Radial or ET Street tires.

I have to say too that it would be a mistake to trash the stock suspension of the truck, it just needs good springs and GOOD adjustable shocks.

A good suspension book is "Doorslammers : The Chassis Book" by Dave Morgan.

[Scrumgees]

cool, I will be picking up the doorslammers book as well as the DVD from the racetec web site. I will certainly try slicks on my current frame and axle before I start fixing up my new frame.

Has anyone had any experience racing these frames before with good results? It sounds like you guys have more experience racing than me If I can get it to hookup without messing with the suspension then I suppose I will most likely leave the stock suspension alone, probably new trailing arms from early classics with air bags and double ajustable shocks or coilovers etc.

But im still interested in all the information I get my hands on, It never hurts to know more in this hobby. After all this wont be my last project for sure!

[OneMoreTime]

H'mmm on pickups i think one either needs a locker or a spool some stiff shocks to nail the rear end down and perhaps some stiffer springs..Of course some real sticky tires as mentioned before..

Good luck
Sam

[BillyShope]

Originally Posted by OLNOLAN

Just wondering why you want to replace the truck arm/ coil spring setup you have. Its the basic design of what Nascar setups use now. Why change it? As stock, they ride real good too! olnolan

There's nothing basically wrong with the truck arm. If Scrumgees is building something for the street with only an occasional trip to a dragstrip, I'd ask the same question.

If, however, he is interested in some serious dragracing, he's going to want an antisquat value near 100%. But, an antisquat value that high is not used in production cars because of the possibility of wheel hop during braking. So, he's going to need a suspension change and the truck arm is not easily adaptable to dragracing. Not saying its impossible; just not easy.

Keep in mind, also, that NASCAR constructors have no choice with regard to rear suspension. The truck arm is in the rule book.
http://www.racetec.cc/shope

[OLNOLAN]

Originally Posted by BillyShope

There's nothing basically wrong with the truck arm. If Scrumgees is building something for the street with only an occasional trip to a dragstrip, I'd ask the same question.

If, however, he is interested in some serious dragracing, he's going to want an antisquat value near 100%. But, an antisquat value that high is not used in production cars because of the possibility of wheel hop during braking. So, he's going to need a suspension change and the truck arm is not easily adaptable to dragracing. Not saying its impossible; just not easy.

Keep in mind, also, that NASCAR constructors have no choice with regard to rear suspension. The truck arm is in the rule book.
http://www.racetec.cc/shope

Hey Mr. Billy, I feel honored that my post even caught your attention.

I have read some of your stuff on Speed Talk and think that we are lucky to have an individual with your suspension knowledge on these internet forums.

You apparently have ESP or something. The reason I say this is, I recently was thinking to myself, it sure would be nice if I could get someone like Billy Shopes to help me pick my spring package.

Poof, there you are responding to my post. Spooky indeed!

Scrumgees, This man knows his stuff in case you don't know about him. Ask alot of questions while you have his attention.

So, apologies for the highjack, but if I post my spring question, will you give me your opinion Mr. Billy?

olnolan

[Scrumgees]

well this has gotten intersting

So the good advice is in favour of leaving the suspension alone. Fine enough as this truck will indeed be 95% street, but I still wanna hit the strip for some fun from time to time.

I admit I havent had time to read the article by billy shope yet, im a full time student also in the middle of a full time house resto, so my time is thin. I will be reading this article more than once come june 30 so im just probing to see if im on the right track.

So... The truck weighs 3600 lbs without me, 3750 ish, ha ha, with me in it. (and will be getting lighter with the fiberglass front end if I still go that route). 1400 lbs on the back axle, and 2200 on the front end, again without me in it.

Should I go air springs, coil overs, and if coil overs, How do I find the right spring? Did a lot of research and I figured out how to calculate wheel rates based on a srping rate and the given suspension geometry etc, but never found a resource to actually give me an idea of wheel rate to shoot for. got frustrated with that and figured I would just air bag it.

Wouldn't mind to get this truck to hook up with the right tires and suspension.

[BillyShope]

Originally Posted by Scrumgees

So... The truck weighs 3600 lbs without me, 3750 ish, ha ha, with me in it. (and will be getting lighter with the fiberglass front end if I still go that route). 1400 lbs on the back axle, and 2200 on the front end, again without me in it.

A wheel rate of 150 pounds per inch wouldn't be unreasonable. I'd recommend adjustable coilovers. If you use adjustable coilovers at the front, the stock rear suspension will perform quite well at the strip if you use a higher rate spring at the right front than at the left front. Don't recall the page number, but there's a page at my site which will help you in spring selection.
http://www.racetec.cc/shope

[Scrumgees]

cool thanks. I will get reading soon as I can

[BillyShope]

Originally Posted by OLNOLAN

...will you give me your opinion Mr. Billy?

olnolan

Still waiting for the question.
http://www.racetec.cc/shope

[Scrumgees]

I have one more question for you mr shope.

I believe what you are telling me is that 150 lbs/inch of spring rate measured at the wheel, not the spring, is a good starting point for the front wheels right? Taking into account the higher spring rate at the right front to equalize the loading of the back wheels, these numbers may vary slightly.

How do you come up with 150 lbs/inch? Is this from a ride comfort standpoint and is purely based on ones opinon on how a veichle should feel goung over bumps or is there more to it? There must be an optimum range that is safe, or for comfort, or for hauling heavy loads etc without being too soft or stiff?

If I were to put coil overs on the rear suspension aswell, where would I start at for a desireable wheel rate. The geometry is different back there so the spring rates may differ greatly if I were to achieve an identical wheel rate of 150 lbs/inch as the front suspension correct? ( if that were desireable of course)

[ericnova72]

The 150 lb rate spring is for the rear. Front spring rates will be in the 300-500 lb area on most front suspensions.