power to ground

[VTStang66]

'66 fastback, tremec 3550, currie-built 8" 4.10 rear, 225/55/16 tires.

I am in the process of rebuilding the car, I want to put out around 400 horsepower at the flywheel plus maybe some nitrous. I'm not building a drag car and I'm not running huge wheels or slicks because I'm limited by the 8". It will have an 8 point cage. I'm just trying to figure out what options I have for upgrading the rear suspension to get a little more power to the ground.

I really just don't know what I want to do with the rear suspension. I'm not comfortable hacking up the whole back half of the car, but I want to upgrade beyond stock. I found some pics of 4-links here:

http://forums.stangnet.com/showthread.php?t=690958&highlight=4+link+rear

but that looks like it's probably a little more work/cost/possibility for getting in over my head than I'm looking for. I just want the car to handle better than stock and put a little more power to the ground, without being all-out race ready. I want to build it myself if possible, not order a kit, but if the price is right I'm not opposed to kits. Suggestions?

 

[rbohm]

the least expensive way to go is good leaf springs, 5 leaf are best, with cal tracs will do real nice in your car.

 

[66forfun]

im going to try the slide a link bars. good hook and leave "some" suspension travel for the road. much tighter than the stock rear but not solid links

 

[dennis112]

As mentioned, Caltracs or Slide-a-links work well with leaf spring cars. Slide-a-links are more forgiving on the street, but will work well in a street/strip situation. The Caltracs are more dragstrip oriented and offer more adjustments than the Slide-a-links. Either will be a good street choice.

The 5 leafs have already been mentioned and some people like the 4 1/2 leafs.

With the stiffer rear suspension that the 5 leafs give, I suggest getting an good adjustable rear shock that allows you to tune the ride you want to drive. You can adjust them to be firm for the strip and then soften them up for everyday driving. My Rancho 9000's make it easy as they have a little knob that you turn to adjust the firmness.

 

[VTStang66]

I already have the 4 1/2 leafs that I put in a couple years ago, so I'll be keeping those. I have been doing some looking around on the internet at 3 and 4 link suspensions and in theory it doesn't look like it would be too hard to build one. Just brace the rear end laterally to the frame rails. But the pics I saw on here looked like people back-halved the car to do it. I haven't gotten under there and looked at it very well, maybe today or tomorrow I'll do that, but would it be hard to put a bar or two in there to make a simple 3 or 4 link? Is there any reason I wouldn't want to do that?

I'll look at those slide-a-links too.

 

[SoCalCruising]

I use GW leafs with their soft-valved CureRide shocks. No wheel hop, at all, and decent ride quality. The spring rate matches well with the TCP coil-overs. These springs were a huge improvement over the stock GT springs (also 5-leafs). Personally, after using this rear, I would not consider a more complicated setup for street and some track use.

 

[BullittStangV8]

Ill be going with 5 or 4.5 leag springs and caltracks in the rear. Adjustable shocks as well. Its pretty cheap and simple and works well for drag racing.

 

[VTStang66]

I guess part of what concerns me is tire scrub. I tore up the quarter panels and tires running the combo I have now (225/55/16s on '03 v6 wheels, 1.25" adapters). I'm going to roll all 4 fenders to get a little extra room but it will still be tight and I don't want any side-to-side movement when I go hard around a corner. The stock rear setup just doesn't seem very stable in that regard. It seems like the only thing holding it there is a big couple acting through the flexible springs on a short arm (the spring bolts). It just seems like an inherently weak design, but I guess it has won a lot of races over the past 100 years.

 

[65 fastback]

VTStang66,

First good to see you around here again.

I think you need either a panhard bar (Maier is making a nice one - http://www.maierracing.com/) or the Global West Del-A-Lum leafspring bushings - http://www.globalwest.net/mustang_1964 -73 catalog.htm#Rear Springs: Both should control the side to side movement of the body over the axle.

I have a panhard bar and love it. It keeps my car centered directly over the axle on the track and makes the rear end much more predictable then the stock set up or a rear sway bar.

Also, for traction, consider modified Traction Masters. You install the Traction Masters, then replace the fixed rod with spring rods - http://www.cobraautomotive.com/cobra_cat.pdf (page 9 in the PDF catalogue).

Tim