Im torn, but leaning towards the blocks. I figure the add a leafs will stiffenthe suspension up, where the blocks will retain factory ride quality. What would you guys do?

 

Definately do the add-a-leafs. I put them on mine and they dont stiffen it up too bad, plus blocks put unwanted stress on everything.

[IMG]local://upfiles/40353/311C3F1B7A2245258DFBCCB3E6E387D6.jpg[/IMG]

 

I went with the add a leafs. It did not stiffen up the ride that much over stock at all.

 

lay down flat and put a block under your back, lemmy know how that feels, now your suspensions doing the same thing when you shove that block under the leaf. as ad a leaf just supports the whole leaf and still gives ya that lift

 

^^^^ never thought of it that way... nice

 

Plus there's an add a leaf DIY

 

This is kind of a hard concept to follow, but see what you can get out of it.

Think about when you put a breaker bar on something. It makes it waaay easier to bend, flex, and sometimes break off the target. Imagine putting 4' blocks on your rear axle. The axle would bend the springs so hard in the way that they weren't meant to be stressed or bent.

See, the axle is the component that connects the contact force of the tires to the springs to the frame/truck. When you hit the gas, your axle is the component that will go forward. As the axle moves forward, the u-bolts grab on the spring and transmit the force. Adding lift blocks would be doing the same thing as the breaker bar. If you could imagine the 4' lift blocks, the truck would practically stand still under acceleration as the axle would move forward and the blocks tweaked the springs until the near point of failure.

If you've had any basic statics class, the moment created by adding even this small distance between the force and spring is terrible when paired with the 245 horses from our trucks (okay, about 200 rwhp). It's a terrible idea and destroys the springs.

If you think about the breaker bar, imgaine we had 1000 ft*lbs of torqe. This could be accomplished two ways for my example. Either 1 pound * 1000 feet from the point of rotation or 1000 pounds * 1 foot from the point of rotation. Same effect. To double this force, you would either need to add 1000 feet or 1 pounds in the first case or add either 1000 pounds or 1 foot to the second case. Note that each example has an easier way to double the moment or rotational force.

Our axle is closer to the second example: high force with a small distance.

This is what you will be doing to your leaf springs. If you have a 1" leaf block (factory) with 200rwhp, lets say that you would have a force rating of 200 (1"*200rwhp). You could double this two ways: add 200 horsepower (400hp*1"= 400 force rating) or add 1" to your leaf blocks (200rwhp * 2" = 400 force rating). Quite a dramatic change from only 1", but a very very greatly increased force on your leaf springs that they weren't intended for. With high horsepower applications, usually suspension will need to be modified like the old muscle cars with traction bars or a 4 link setup.

The whole idea behind 4-link or traction bars to handle such forward accelerations and transmit this force to the frame for maximum acceleration. In a four link setup or coil setup, the coils only provide support for the weight of the vehicle while the 4 links transmit the forward force. The coils have no effect on forward trasmital of force to the vehicle. With leaf springs or hotchkiss suspension, the leafs both support the weight of the vehicle AND transmit the forward force to the frame. Not ideal for performance, but relatively simple, easy, and practical on daily drivers.

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My vote: AAL.
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By keeping the axle as close to the spring as possible, this will reduce the twisting stress under acceleration. It's true that leaf springs are designed to handle forward force and some type of moment, but the rotaional moment caused by an increase distanced between the axle and springs via lift blocks is not what the leaf springs were designed to do. Good luck.

 

Very, Very well put sir. I definitly understand what you are saying and I fully agree with the logic behind it. I am surely going with the AALs. Thank you.....