Debating on leaf spring vs. 4-link

Quadra shocks work well. One big problem with the Fox suspension is the same as a stock classic Mustang problem - the suspension mounting points are rubber. When the rubber deflects and rebounds under load, you get wheel hop.

I had an '83 Mustang (pre quad shocks) and BAAAAD wheel hop. I didn't have that problem in my '89 with quad shocks. Now I have a better fix with Maximum Motorsports rear lower control arms. They have bushings that allow better articulation than rubber, but much less deflection.

htwheelz67 said:

snakepilot, how did you figure out the ride height needed with the flex a forms? I'm running 275 40 17's w/ 17x9.5s on the rear, I still have my sagged orig leafs an want to raise it about an inch above what I have now. I was thinking of installing a set of new TMC HD st height leafs I have had in my garage for 15 yrs and then measure from there.

Oh yea, how did you do the staggerd shock setup? I'd like to do that on my 67 vert, I have a 9" versailles rear I need to put in soon as my 8" will not handle my 500 hp 408 for long.

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Hack said:

Quadra shocks work well. One big problem with the Fox suspension is the same as a stock classic Mustang problem - the suspension mounting points are rubber. When the rubber deflects and rebounds under load, you get wheel hop.

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The guys at Flex-aForm have done enough of these for Mustangs that you just have to tell them what you have and what you want. I told him I have a '67 with a big block for street use and I wanted a one inch drop. He nailed the stance I wanted. In comparison, I changed front coil springs four times to get the stance I wanted.

We had a Boss302 in the shop when we converted my car to staggered shocks. In my opinion it looks more OEM than the factory. The cuts and welding were fairly crude on the factory car. Pictures I have seen on the web of other factory staggered shock cars confirm this. In addition to the shock mount there is a piece of sheetmetal that goes all the way across the bottom connecting the frame rails and an L-shaped piece in the trunk. A while ago I remember seeing a guy who advertised on the internet all of the conversion pieces needed.

Hack is right, having your suspension mounted with rubber is a major contributor to wheel hop. CalTracs work not just because of the transfer link (the traction bar) but becuase they use solid aluminum spring eye bushings. I have Global West Del-Alum bushings in my Flex-a-Forms. The bushings, front & rear, also help control roll defection so you don't need a sway bar and lateral deflection so you don't need a panhard or watts set-up.

I also have Shelby snubbers. These snubbers mount on the floor above the front part of the leaf springs. Shelby only used them in 1967. Under heavy acceleration when the spring wraps up the top of the spring contacts the snubber which increase the spring rate to prevent wheel hop and allow the car to launch harder. During normal driving, the springs work normally so you don't have a stiff ride. They also don't bind like underride bars do which negatively effects handling.Plus it's the first place Shelby snobs look when they want to prove a fake. The originals are cast iron but mine are aluminum. I was going to paint them cast iron but I'm not trying to fool anyone and they compliment the aluminum ends of the Flex-a-Forms nicely.

I had Shelby underrides in my car when it had a 390 and it wheel hopped bad. I didn't want to take any chances with the 482 so I went staggered, glass monoleafs, solid bushings, and Shelby snubbers. Overkill? Maybe but it looks good, doesn't hop, and launches very well.



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Snakepilot -

What spring rate are you using on the rear springs? How much power are you putting to the ground and what type of tires?

Also any pictures of the underside of the car where the staggered shock mounts to the floor?

Thanks

Chappy said:

Snakepilot -

What spring rate are you using on the rear springs? How much power are you putting to the ground and what type of tires?

Also any pictures of the underside of the car where the staggered shock mounts to the floor?

Thanks

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250lb springs. That sounds heavy but Flex-a-Form must measure the rate differently. They do not feel stiff. How much power? It's a "mild" Genesis aluminum sideoiler 482FE, 500HP/525Tq going through a TKO600. Tires are BFG KDWs 275/40/17.

Crappy picture of the upper mount, I just slid under there to take it. I will get better pics next time it is on the lift.

Thanks for the information. Would love a better picture of the body side of the mount when you get a chance. I'm assuming there is a bracket or something that you made that is welded to the frame there for extra strength?

I'm looking for rear suspension ideas for my 70 with a 03 Cobra motor with 500rwhp/500rwtq going through a T56. I'm going to be running a slightly larger (295 or 315) and more sticky tire (drag radial) on the rear. So I might have more chance for wheel hop.

Chappy,

Here's some pics of an original mount and a link to a guy who makes reproductions:

stagger

I didn't use his parts but it looks similar. My upper panel doesn't have the tabs on the edges, it's welded directly to the trunk floor/sides for a more seamless look and the lower panel is not two piece since I didn't have to worry about frame variation. Also the hole in my lower panel is smaller and welded to the upper panel shock mount.

Wow, great information! Thanks. Did you just use a stock shock mount from the front side welded on the back side for the actual mount?

Chappy, it's all custom fabricated. Check out this link:

67 GT500R 9", Staggerd Shock, Traction Master, Rear Disc Install PICS - Vintage Mustang Forums

That answers all of my questions. Thanks for the help. Something else to add to the list of jobs to do.