This last weekend @ The Pomona Swap Meet I picked up a set of Hertz Shelby axle backs (GTA's)($70.00) and rear anti-sway bar (bushings and hardware intact)($20.00) off a rental with less than 1500 miles that had been rear-ended. No damage to the parts, which are basically FRPP.

I will do the install of the axle backs, but not sure if it makes sense to have a shop install the "upgraded" rear anti-sway without other suspension upgrades as well. I realize doing so will result in some oversteer, but not clear on how much and if it matters.

Can anybody offer some thoughts on all this.

 

I installed just the FRPP rear sway bar on my 06 GT, and I can tell you that just installing the rear swaybar alone makes a huge difference to the balance of the car. The install itself is very easy and I'd encourage you to do it yourself, especially if you're putting in the axle backs at the same time.

However unless you're a experienced driver who's comfortable with what amounts to an unsafe level of oversteer I'd recommend against using just the rear FRPP antisway bar. Although my case of oversteer is exacerbated by the fact that my car also 1.5 degrees of additional front camber, even a car with a stock alignment will get a much looser rear with just the rear FRPP bar. Especially if like me you're currently on winter tires... with a high output Paxton...

 

Hubec--thanks. Have owned several Porsches ('57,'65,'85) so understand the oversteer problem, although the dynamics of the rear engine/weight ratio would be different. I'm assuming that while in a Porsche a certain amount of power is needed to prevent oversteering (ie, spinning out) you have to be careful about to much on the Mustang due to the lighter rear end.

 

Well I just ordered the ford racing front and rear sway bar kit. I am hoping it will be awesome. I am not going to do struts and shocks yet, maybe down the road. Do any of you have both front and rear upgrade kit from frpp and what are your thoughts.

 

If I do it I am thinking of checking if the factory gt500 rear bar will fit. It is larger than the stock GT bar by a bit.

That way, it will retain factory style bushings with no polygraphite bushing to keep clean and lubed.

 

OK, this is where I am a real neophite....polygraphite bushings??...guess they need more care, and are they on the Hertz Cobra or I guess another way to ask is whether the GT500 and Hertz share the same FRPP anti sway bars.

 

What the heck, I am bored. Here is some history on polyurathane bushings for those so eager to use them on daily drivers. Why do I have a feeling this is going to be long.

The sway bars (and other bushings) from the factory use what is generally called "silent block" bushings. When these were originally invented (approx 60-70 years ago), they were a major advantage over previous efforts as they required no grease and stayed quiet. Prior to this, cars had metal to metal joints with bearings and grease points at every bushing. Essentially with this new rubber bushing type that was invented, there are no wear surfaces, no pivots, no greasing, quiet, etc. The number of points on a car to wear and lube decreased drasticly.

What they are is a rubber bushing. The metal part (sway bar in this case), does not move against the rubber. The rubber's flexibility is what makes the motion in the joint possible as there is no friction surfaces. Most modern bushings are like this.


Problem is, they do have some conformity depending on the durometer (hardness) of the rubber due to the nature of the design. Hence the reason the aftermarket doesen't like them. On a race car, these joints are too soft and flex too much.

Polyurathane bushings, are a very hard rubber bushing (more like plastic in alot of cases). With these bushings, the sway bar for example pivots in the bushing and is free to move and slide within it. This creates friction, wear, noise, etc, etc. But a very firm joint with no deflection which is good for performance.

So, in an effort to quiet down these noisy, now moving wear points, companies began impregnating the polyurathane with graphite, hence, polygraphite. Unfortunatly, even this is usually not enough to keep the joints quiet, squeek free. They end up squeeking and moaning, especially in cold weather.

Sooo, the next step is grease. So most kits reccomend greasing the bushings with special grease when you assemble them. However, no grease lasts forever, so many companies place grease fittings (zerk fittings) at each joint which require maintenence (greasing). But, being grease attracts dirt, and dirt is an abrasive, eventually what the joint is full of is a nice greasy, sandy, abrasive paste that wears usually the metal part of the joint believe it or not. It depends on the hardness of the metal. This contant greasing, cleaning, and eventual wearing out is why rubber bushings were invented in the first place.

So, these polyurathane bushings may be firmer, and great for the track, but are effectivly a step backwards 70 years in automotive technology as far as service and longevity.

So, is polyurathane better?? Needed?? Well, here is my take. On some older muscle cars, with improper bushing designs or ultra soft rubber, polyurathane is an improvement and worth the effort. However, in alot of cases, customers that have demanded it be installed at our resto shop are back within a short time wanting it ripped out and replaced with modern rubber. On summer only cars you stand a chance, on a daily driver, they are a PITA.

On new cars, with modern materials, I don't see the need. Not when porsches, M3's, and every other hot car you can think of is not using it. If polyurathane and nylon suspension bushings were so great and needed, they would be factory on high performance cars. The rubber bushings are not the reason our cars a bit lacking in the handling dept.

 

Thanks Classj.....now it seems the question is as you previously posted it, will the stock rubber bushings work with the FRPP anti-sway bar.

 

Blitz

IMO I would not do the rear bar upgrade without also doing the front at the same time for the reasons stated above. A degree of understeer is stable, a degree of oversteer is not. Why do you want to mess the balance of this car for the sake of bragging you have a Shelby rear bar on it?

 

RadBOSS-good point and I don't disagree (however not interested in the brag factor...@ 20 bucks it was worth the risk factor) I talked with FRPP and they don't sell seperate bars, only as a fore and aft kit (which supports your suggestion) I will now see if Ford or Shelby sells a front only. Before I put the bucks up I want to resolve the bushing question.

 

For $110 you can get an adjustable front bar from Hellwig (if you mention the Mustangsource group price). It has three adjustment positions so you should be able to perfectly match it to your larger rear bar.

 

I can't answer that one. Depends. I am sure you can cobble something together though if need be. But I would just run the poly if I were you being you have the bar already. Just be aware that it needs a bit a maintenence once in a while and keep an eye on it.


If you are an expirienced driver, I would not be afraid of a rear bar only. If you gave a mustang GT to a pro driver, the first thing they would do is add negative camber, bigger rear sway bar, and brakes. Then go from there.

It might be too much though for a daily driver, never know. Most cars are built with push to keep you safe. I have mixed feelings about it. Sometimes I want the bigger rear bar. Other times I want to keep the car comfortable and easy to corner fast on the street "safely" with a nice fat margin for error and road conditions.

 

These cars come with considerable understeer. I believe that the rear bar will help to bring the car to neutral which will be desireable if you are a good driver. If it creates too much oversteer, then you can play with tire pressure. Then, if necessary add a front sway bar.
As far as the poly bushings go, IMHO they are far superior to rubber unless you are lazy! First of all, you don't want to grease them to the point that it oozes out enough to collect dirt. Secondly, they "unbind" the suspension and let the springs do their job. If you are modding your car for better performance, greasing your poly bushings once a year isn't a big deal.

 

Blitz, I actually also had a 911, mine was the 996 model. It was much less prone to oversteer than yours thanks to Porsche's meddling with dynamic rear toe etc... But to get back to the point Mustang oversteer is a lot more fun because it's far easier to slide the car without spinning it out, and you can (almost) always catch it even if it's unexpected - assuming you're not asleep at the wheel. When a 911 starts rotating unexpectadly it's much more difficult to bring it back under control. That's why they ended up making the 996 so boring, because they wanted to prevent oversteer at all costs. But I digress again...

With my setup; 1.5 neg degrees front camber and FRPP rear bar, the car will oversteer with stable throttle and steering input at high speeds. For instance on a highway ramp. That's to say at neutral throttle at 60mph the rear wheels will slide before the fronts. Also if you do any quick lane change maneuvers you will have to counter steer to stop the car from spinning. Both of these things are obviously very unsafe and are nothing like the stock setup.

Ontop of all of that keep in mind that the car's absolute grip is now worse and it would be slower in any handling test. Though the tester may well have a big grin on his face...

 

I really think that the "bind" is insignificant considering the weight of the car and the forces involved. It is the lack of bushing squirm that makes poly bushings more effective.

It is not a matter of lazy or not. I have swapped rubber for poly and poly for rubber on many a car. The difference in feel that the sway bar bushings have made was really just down in the noise. Nothing even significant, just more maintenance and another wear point. Are they better for handling, yes. Is it a MAJOR difference that is worth the effort. Not in my opinion in most places on the car. Some places yes.

They do make a difference in places such as rear control arms with problems such as wheel hop (which oddly enough my car does not have). But the wear and maintenence comes along with it. I have seen quite a few guys replacing their poly bushings on S197 cars already back there. Not to mention complaints of axel whine, etc transmitting to the body. But the performance difference is worth it at the track.

 

Does anyone know if steeda's billet sway bar brackets will work with the frpp front sway bar. The front bar looks exactly like the ford, so I am thinking they are the same upgraded bar. I would like to purchase but would like to know if they fit first. Has anyone tried this?

 

What diameter is the FRPP rear sway bar? The GT500 rear bar is 24mm and the stock GT bar is 20mm....

 

It is also 24mm.

 

So, does that suggest the front anti-sway bars are the same on a GT500, the forthcoming Shelby GT and the Hertz??

Also, what does one do and use to lube the polycarbonite bushings??

 

I think maybe you like it to be unstable like a 911 Porsche ... you had one too long. Or maybe your just into that power slidding thing?