Street Beast rear suspension setup - springs and shocks

[ziggy75]

As many of you already know, I inherited a Street Beast and recently began working on it. The rear end of this car will utilize an axle from a 94 Mustang GT. Yesterday, I pulled the axle to pressure wash and will give it a coat of Eastwood rust encapsulator and Eastwood chassis satin black. I am also planning on replacing the upper and lower control arms. While removing, I realized that the shocks were junk and one spring was broken. I believe my dads intent was to just bolt it on and replace later. Anyway, what I would like to know is what style spring should I go? If I were to go stock, I would need to purchase a set of used springs. Either Fox or SN95. If I go aftermarket lowering, then I would need to find a place that sells just the rear. Also, what style shocks should I go with? Ideally, I would rather go with a coilover setup but at this point, I am focusing my resources elsewhere.

[YerDugliness]

Ziggy, as I looked at the photo of the frame and differential I could not tell if the diff was mounted onto the frame or the frame was just set over it.

What you have looks to be just the factory live axle/differential with stamped steel control arms for a regular Mustang GT. If that mounts to your frame, you can just go to a salvage yard and get whatever parts you need from a Mustang GT. That would be the best, IMHO, because factory parts are readily available and inexpensive compared to specialty parts. If the assembly does mount onto your frame that means the kit was engineered to use those parts...if it doesn't you'll have to go about getting a differential assembly mounted, and that can mean fabricating custom bar-mounting points on the differential as well as on the Street Beasts frame.

Here's an idea if the parts do fit onto the frame you have...there is a company named Factory Five Racing (FFR) who makes a kit that is designed to use the Mustang as a donor, so it is engineered to use the parts you have already. If you contact them they may be able to give you some idea about springs to use, what spring rate, that sort of thing---and you may be able to buy the parts from them, as I think they sell their wares to anyone needing go-fast parts for the Mustang FOX/SN95 based products. If you are interested in improving your kits handling and ride, there is the option to replace the factory control arms with tubular ones from FFR...and perhaps the option to use coil-overs as well. I know you stated a preference to use the factory parts due to budgetary issues...IMHO it will all depend on whether the kit was designed to use the factory diff/control arm assembly or not.

My kit has a parallel 4-bar rear suspension with a Panhard rod. When I bought the car the urethane bushings were so brittle that they fell to pieces within 500 miles. It too me over a year to find replacement busings...but when I did find them the repair was inexpensive and easy. My chassis was built by Ron Godell Racing out of Tulsa, OK and was engineered for the setup I described....there's no telling what your Street Beast chassis was engineered for unless you can find a build manual.

Just a historical perspective....Street Beasts was the Phoenix that rose from the ashes of a different component car manufacturer. There may be others on the forum who have cars made by that defunct company and can help you. Perhaps a web search will yield the information regarding the "parent company"...as I recall the end of the parent company was not pleasant, with many paying customers not getting things to which they were entitled...but Street Beasts attempted to resurrect the product line. I could be wrong about all this....after all, at my age the memory isn't so good, so if you find out that the history I mentioned is not accurate, I apologize, I'm just trying to retrieve long-ago acquired information that was not really needed, so perhaps not remembered correctly? If you do find the parent company...check out the "manufacturers" forums to see if there might be a brand-specific forum.

[EDIT--I surfed into your profile and see that you have found the information to which the previous paragraph referred. CMC...if you'll look in the "Manufacturers Forums" section I think you'll find a forum for CMC products...if so I'll post a link. Good luck!]

I don't really think this is the company, but it's the closest I could find in the Manufacturers' Forums....just don't be surprised if it isn't the company from which Street Beasts arose...I think the Contemporary Classics are quite highly engineered, well built component cars in high demand...IIRC CMC (the company from which I believe Street Beasts arose) stood for Classic Motor Carriages. Anyway, if you'll read a few posts in this forum you'll figure out if CC and CMC are different, as I suspect is the case:

Contemporary Classic Forums - Club Cobra

Good luck...getting what we call a "basket case" means getting a frame with a "basket" of parts with no instructions...kind of the situation in which you find yourself and we all know how difficult that can be, so keep posting and asking questions.

Cheers!

Doug

[joyridin']

Just a suggestion, but you may want to rethink using that rear end. The 94 and newer 8.8's were wider than the 93 and earlier due to the ring on the axle for the anti-lock brakes. This means the rims will have to be offset further out. You can put the earlier axles in, but then you would have to ge with drum brakes. To keep the disks, you need the narrower axles out of a Ranger and new offset caliper mounts from NorthRaceCars.

[ziggy75]

Thanks guys for the information.

The frame is set up to accept a factory live axle from a Mustang. This means that all components bolt to the frame as they would with a stock Mustang. The axle was mounted to the frame in that picture. The bolts were there holding it in but it was not torqued down.

I will probably go with new control arms, springs, and shocks.

Joyridin' - you bring up a good point.. I am sure my dad thought of this when he decided to go with a 94-95 setup. What i will need to do is get the rims installed on the axle and measure and compare with the body. I had no idea there would be an issue with this...

[YerDugliness]

Welcome to the "joys" of owning a "component car", Ziggy.

Running across issues that you had no idea would arise will be a common experience as you proceed on this build...wait until you start on the electrical system

...oh, and people have probably forgotten to mention...the fun continues even after you have the car on the road...forget about being able to go to the parts store and get almost ANY part unless you know the specific year, make and model of car the damaged part is from...and all the specifics such as engine size, AT/MT, etc. It can make shopping for ball joints and that sort of thing a very frustrating experience.

But....and we'll all tell you this....it's part of the existential experience that defines owning one of these "detuned" race cars and attempting to use it for everyday purposes. Most of us wouldn't give it up for love nor money...well, maybe for enough money...but only enough money to start on the next project

Cheers!

Dugly

[joyridin']

I probably missed the part about already having rims. The old CMC had a pretty narrow wheel well and you could put about an 8" wide tire, since the molds were the same, I assume the Streetbeast is the same. They were designed for a Mustang 2 rear axle width to give the rims some offset. If you go wider, it might look a bit odd.

I had the same set-up as you. I chopped off the upper spring mounts and made my own mounts while using coilovers. I then had the 1994 axle narrowed 2.5" on each side and put new shorter axles. I could then put an 11" rear tire under the car.