[Formulabruce]

I have been helping a buddy restore his 70 Formula.
We added some hidden updates to make it more modern day friendly.
Aside from the bolt in, no mod Silversport 5 speed, I kinda pushed him into using Bearings in his suspension.
I have installed these on other cars, and his car, while the springs are too high, rides sooo nice.
Having the suspension actually Move, allows the shocks to respond to bumps much faster ( like a strut would)
This does't take away from handling.
With stock 15" wheels ( yeah its a 15" wheel Formula") and regular Bfg's
this car rides nicer than most new cars, including a newer camaro I was in recently.
This upgade was made and built in USA for many types of racing, but the Ride benefits are just amazing. You can put these in STOCK control arms, and I have.
Watch Doug Explain it. https://www.youtube.com/watch?v=dUQbcyVINL8
Rear shackles on Leaf spring cars >> https://www.youtube.com/watch?v=VA7aXTVfi48

[78w72]

That design is definitely better than traditional rubber/poly bushings... but when I saw "bearings", I was thinking bearings like a real roller bearing or something.

The del-a-lum bushings or "delrin" have been around for awhile, most suspension companies offer them, PTFB has them in their lower A-arms... Im helping a friend with a pro tour type build on a 73 formula and I steered him towards the PTFB stuff with coil over front springs/shocks and the delrin bushings. I want to change to them on my 72 firebird that has OEM rubber bushing on the lower A arms & rear springs. Good to hear they ride better than factory bushings.

[Formulabruce]

" Delrin" is the name of a type of plastic. Seems it is used in Del A Lum. But Del a Lum is the Brand Global West invented it seems.
If anyone wants to use a bigger tire with " No" sidewall, this is the ticket because it allows springs and shocks to absorb what the side walls can't, and at a very fast strut like performance.
The ride difference is huge. Old rubber seized bushings have about 2 in of twisting travel, the new ones about 4.5" of smooth as she goes.

[RocktimusPryme]

That’s interesting. I wouldn’t have guessed it would make a notable difference. And honestly I would have expected Delrin to be rougher than rubber.

I may try that on my Firebird. The front rides great with ride tech dual rate springs and quality Bilstein shocks. But the rear with repro multi leafs and cheap KYB shocks rides like a log truck

[78w72]

yeah the rubber have a lot of resistance when twisting... the delrin or GW del-a-lum bushings rotate freely allowing the suspension to work much better.

[jhein]

Last year I replaced all the bushings with Ride Tech Delrin bushings. Not exactly the same as the Global West but same result. The whole suspension just woke up. The wheels actually move up an down. The difference was dramatic and instantly noticeable. The rubber bushing were still in good shape but they were stiff. I was a little worried that the increased movement may adversely effect handling but it didn't. I think it actually handles better with a much better ride quality.

[Quad]

Originally Posted by jhein

Last year I replaced all the bushings with Ride Tech Delrin bushings. Not exactly the same as the Global West but same result. The whole suspension just woke up. The wheels actually move up an down. The difference was dramatic and instantly noticeable. The rubber bushing were still in good shape but they were stiff. I was a little worried that the increased movement may adversely effect handling but it didn't. I think it actually handles better with a much better ride quality.

It's 14 years since I replaced polyurethane bushes with delrin and still vividly remember how profound the improvement was. I did the front first & no doubt about improved handling & steering. I think a magor part of the huge ride improvement is the delrin in the rears [leafs].

I got a big improvement in handling when I replaced the badly worn rubber bushes with polyurethane but always wondered how much was to do due to badly worn rubber.

[gtospieg]

The car will definitely handle better with the Del A Lum bushings because there is Zero deflection in that type of bushing, unlike the rubber bushings that allow quite a bit of deflection. I put the Global West control arms front and rear on my 67 GTO. Another added benefit is zero wheel hop.

[twilightTA]

Originally Posted by gtospieg

The car will definitely handle better with the Del A Lum bushings because there is Zero deflection in that type of bushing, unlike the rubber bushings that allow quite a bit of deflection. I put the Global West control arms front and rear on my 67 GTO. Another added benefit is zero wheel hop.

Interesting, I was debating going with the del a lums in the rear springs especially since they can be greased a lot easier than my OEM style. I had heard some mentions in the past the the delrin could cause the leafs to bind, but not sure if that was accurate.

Have any of you bought the full shackle/bushing setup for the rear from Global West?

https://www.summitracing.com/parts/gls-108sh/reviews

[JLMounce]

Lots of people are afraid of ride quality after going to a delrin style solid bushing. Most of that fear comes from people that have never used them, claiming the ride will be harsh. It's just not the case.

The only thing I don't really agree with here is using delrin bushings in both the eyelets and shackles of a leaf spring. Yes the solid bushings help with vertical articulation of the leaf, but they hamper the ability of the leaf spring to twist, which is needed when the axle is articulating unevenly. It takes a known design flaw that introduces bind in a leaf spring car, and makes it worse. In a non-performance application, this isn't necessarily an issue, but if the vehicle is going to be driven spiritedly, those leafs need to be able to twist a bit.

Global West knows this, which is why they have the Cat 5 bushing and shackle kits of the leafs. It's a more involved installation, but it gives you the smooth vertical articulation of the solid bushings, while also allowing the leaf springs to twist. If I was going to put solids in the leafs, this is what I'd put in them.

https://www.globalwest.net/camaro-fi...4-75-76-7.html

In all cases, going to solid bushings in the suspension, effectively reduces your spring and wheel rates. This is where some of the ride quality is coming from, when you compare the same spring package to a car with rubber bushings. It does give you the ability to increase spring rates and shock valving for performance without sacrificing ride quality.

[Jack Gifford]

I'm glad I saw this thread. Good discussion of something I hadn't thought about. The ride of my '59 GMC is horrible- I'm thinking of ridding it of its four leaf springs. But I'm now tempted to give the Delron bushings a try.

[twilightTA]

+1. Thanks Jason for the cat5 info. The info you mentioned about the binding was why I avoided the delrin bushings in the leafs before. Agree if one was to go with these bushings it sounds like the cat5 setup makes the most sense.

[Formulabruce]

Jason is correct, however that twist is not really a concern unless you travel " Tail of the dragon" for fun everyday. The " Cat 5" spring set up ( reverse wound spring with leaves moved further ahead of center bolt) are NOT needed to run the cat 5 Global West joints in the stock leaves. Basically you have a " heim joint" with shafts to go to shackles or spring buckets. I have helped install a set. That said, I didn't notice much difference and they were not performance tires, and driving wasn't too " Spirited"

[Formulabruce]

Originally Posted by twilightTA

Interesting, I was debating going with the del a lums in the rear springs especially since they can be greased a lot easier than my OEM style. I had heard some mentions in the past the the delrin could cause the leafs to bind, but not sure if that was accurate.

Have any of you bought the full shackle/bushing setup

Yes, I have a couple sets here ( F body )
On this 6 sided design, the blue Aluminum piece is Pressed into the spring, and another into the rear frame rail. GW sells a tool for the frame rail thats well worth it. Note in pics the amount of slots and groves for the grease to go.

[twilightTA]

Thanks Bruce. I currently have PTFB GT leaf springs which I believe have a rubber front eye bushing and poly shackle bushings. They are a bit noisy and are really hard to lubricate given how close they are to my gas tank and no grease fittings.

I don’t think I want to go to the expense of the Cat5 setup but do you guys recommend just adding the rear GW shackle setup and leaving my front rubber bushing as is? I can’t imagine there would be any drawbacks vs my urethane shackle bushings.

Thinking to maybe finish off my suspension setup with the GW shackles and GW lower front control arm bushings and call it done with.

[JLMounce]

Rubber front eye and delrin rear shackle is perfectly acceptable. it's what I would do in your situation.

[Formulabruce]

Running the Del a Lum with stock springs is what I do. The leafs in my pics are 1972 leafs. Also, the quickness, as stated before, allows you to run bigger wheel tire combo as the fast moving suspension now absorbs what the short side wall cannot.
You'll want to grab the 25 dollar bolt press GW sells to install the aluminum core in the rear frame rail.
Enjoy the ride !

[twilightTA]

Thanks guys!

[twilightTA]

One more quick question. Do you think I can use the PTFB shackles with the Global West bushings? Not sure if I need to buy the shackle as well.

[Formulabruce]

Gw shackle kit is a kit. Shackles are welded to the bolts. Look at my pics. They are part of the kit because of the length of bolts, thicker shackles, and bearing preload. I would, and do, both ends to really make a difference..