powerflex/supaflex/polymounts

[SSPPGG]

seems to be a few possibilities

for a complete chassis makeover, which type, and where from?

destined for a road not track car

[M@H]

I'd go with standard rubber for the wishbones personally - you can't fit them as easily as the polyflex ones but they are a very good bush for the job.

[M@H]

Steve Heath is doing well priced poly ARB bushes at present.

[Ant.]

Powerflex all the way, I had one of the first kits and they are still.going fine.

[Ant.]

Powerflex all the way, I had one of the first kits and they are still.going fine.

[scotty_d]

M@H said:

I'd go with standard rubber for the wishbones personally - you can't fit them as easily as the polyflex ones but they are a very good bush for the job.

This IMHO

I used the powerflex ones in my chim and i am doing my Cerb up just now but keeping standard rubber as i felt it made the chim far to hard on the road and a little skittish. If anything the roads are a sorry state and having a softer set up make your car.

1. quicker on A and B roads
2. more comfortable on A and B roads

I am doing the Odd track day in the Cerb but keeping with rubber from now on till my road Tax money goes back in to fixing pot holes!!!!!!

[Graham]

ive mixed and matched on mine after talking to a lot of people.


polys in arb mounts, and diff steve heath drop links and std bushes in the wishbones.

g

[M@H]

..same as me then Graham

[scotty_d]

Should have said like me as well then bought polly for the ARB bars and i will do the Diff in polly as well. But for wishbone i am keeping with rubber

[shpub]

scotty_d said:

This IMHO

I used the powerflex ones in my chim and i am doing my Cerb up just now but keeping standard rubber as i felt it made the chim far to hard on the road and a little skittish. If anything the roads are a sorry state and having a softer set up make your car.

1. quicker on A and B roads
2. more comfortable on A and B roads

I am doing the Odd track day in the Cerb but keeping with rubber from now on till my road Tax money goes back in to fixing pot holes!!!!!!

IIRC you also changed the shocks for GAZ adjustables, different springs and had Dreadnought raise the ride height to give better ground clearance and the Chimaera. Those are big changes to the suspension. Add to this that fact that the originals were probably worn and softer as a result so any renewal would return the car to its original stiffer stettings.

If you want better compliance, take a lb or two out of the tyre pressures - that has a BIG effect.

[TJC46]

Ant. said:

Powerflex all the way, I had one of the first kits and they are still.going fine.

This Poly bushes for me. I did consider refitting rubber but the poly ones are so easy to remove/replace in the future, that it was a "no brainer". The ride is no harsher IMO. Fitted them approx 2 years ago, and only this month removed the lower rear wishbones to replace the ARB plates. Once off just pushed out the bushes by hand, relevant welding done to the wishbone, bead blast and repaint, pop the bushes back in, job done. Would have been a lot more work and cost in removing/replacing rubber bushes.

[scotty_d]

shpub said:

IIRC you also changed the shocks for GAZ adjustables, different springs and had Dreadnought raise the ride height to give better ground clearance and the Chimaera. Those are big changes to the suspension. Add to this that fact that the originals were probably worn and softer as a result so any renewal would return the car to its original stiffer stettings.

If you want better compliance, take a lb or two out of the tyre pressures - that has a BIG effect.

I did yes over the course of 2 year i tried lots of options to set the car up but the roads are so bad in Ayrshire and a lot of the uk i driven . I took the car in to Europe and it was fantastic over there with the set up but in the UK Far too hard. The Cerb is spot on the old rubber ones as they move at least and soak up some of the impact of the surface of the moon i mean the British road

Up to the OP at the end of the day just giving you my experance's of polly bush set up on my chim and i spent a good few quid setting it up and playing with it to make it a good b road car.

[carsy]

TJC46 said:

Ant. said:

Powerflex all the way, I had one of the first kits and they are still.going fine.

This Poly bushes for me. I did consider refitting rubber but the poly ones are so easy to remove/replace in the future, that it was a "no brainer". The ride is no harsher IMO. Fitted them approx 2 years ago, and only this month removed the lower rear wishbones to replace the ARB plates. Once off just pushed out the bushes by hand, relevant welding done to the wishbone, bead blast and repaint, pop the bushes back in, job done. Would have been a lot more work and cost in removing/replacing rubber bushes.

Same for me. Couldnt agree more.

[M@H]

TJC46 said:

This Poly bushes for me. I did consider refitting rubber but the poly ones are so easy to remove/replace in the future, that it was a "no brainer". The ride is no harsher IMO. Fitted them approx 2 years ago, and only this month removed the lower rear wishbones to replace the ARB plates. Once off just pushed out the bushes by hand, relevant welding done to the wishbone, bead blast and repaint, pop the bushes back in, job done. Would have been a lot more work and cost in removing/replacing rubber bushes.

Really? - surely it would have just been cheaper to buy a brand new wishbone with the rubber bushes already in it than all the re-furb work carried out on the old ones..?

[shpub]

scotty_d said:

I did yes over the course of 2 year i tried lots of options to set the car up but the roads are so bad in Ayrshire and a lot of the uk i driven . I took the car in to Europe and it was fantastic over there with the set up but in the UK Far too hard. The Cerb is spot on the old rubber ones as they move at least and soak up some of the impact of the surface of the moon i mean the British road

Up to the OP at the end of the day just giving you my experance's of polly bush set up on my chim and i spent a good few quid setting it up and playing with it to make it a good b road car.

This concept of movement is very interesting as I tested some of the rubber bushes (admittedly on a Wedge) to see what movement there actually was. The wedge has a tie bar with two rubber bushes in it. The concensus was that the bush was needed because it allowed the tie bar to adjust as it moved in an arc perpendicular to the wishbone. If the wishbone stayed in the correct place, the tie rod length needed to adjust and this was done by the bushes moving. I was planning to replace it with rose joints. The rubber was about 4-5 mm thick and sandwiched between the two metal sleeves. It worked out that if the bush was to provide all the give it needed to move at least a couple of mm.

What I found was that it did not compress at all. What happened was that the wishbone moved sideways/twisted to compensate. I could not compress the bush itself. Yes the bush is designed to move but it twists more than compresses and so this whole idea of absorbing shock by giving seems to be a bit misplaced. It certainly allows the suspension to twist and distort its geometry but it doesn't seem to absorb through deformation.

The rubber itself has to twist and deform to allow the wishbone to pivot. The rubber is bonded to the sleeves and needs to deform to allow the wishbone to move with the suspension. This means that there is a big unknown applied to the suspension because the suspension movement has to overcome this stiction. As a result, the shocks and springs now have to compete against the bushes rather than have a free pivot movement. This is something else that is often forgotten.

Interestingly enough, rubber bushes do get soft and wear so it is possible that the worn bushes (with springs etc) are better on very rough conditions that you experience. I also live in an area of rough country roads and found that running 2 psi less tyre pressure made the car a lot more sure footed on rough surfaces. I also found that the Cerbera was a more complient car to drive anyway because of its longer wheel base.

[shpub]

M@H said:

Really? - surely it would have just been cheaper to buy a brand new wishbone with the rubber bushes already in it than all the re-furb work carried out on the old ones..?

It costs £360 for the pair with bushes from Racetech. Special clearance price - limited offer etc.

£20 to weld the plates on.
£30 to blast and powder coat.
x2 for each side.

Considerable saving I'd say.

[M@H]

shpub said:

M@H said:

Really? - surely it would have just been cheaper to buy a brand new wishbone with the rubber bushes already in it than all the re-furb work carried out on the old ones..?

It costs £360 for the pair with bushes from Racetech. Special clearance price - limited offer etc.

£20 to weld the plates on.
£30 to blast and powder coat.
x2 for each side.

Considerable saving I'd say.

Naa.. you can buy all four fronts from SC power that money - add some £ for time and hassle onto your prices and the cost of the bushes as well and I think it would be much the same.

[shpub]

I was comparing the cost of a pair of REAR wishbones that needed a new ARB plate fitted.

The rear wishbones from SC Power are £174 each which makes it £350. Bushes are extra.

If you are advocating that it is cheaper to replace all the wishbones with new ones because they come with bushes fitted then the economics still don't make sense. £750ish vs £250ish for a powerflex bush set. Ok there is a bit more work to be done but even so £500 is £500.

Edited by shpub on Wednesday 21st December 11:03

[SSPPGG]

So...back to handling characteristics.

Ive driven my car, which has had some busesh changed over the last 20 years but as the chassis is off for blasting soon, will need some replacements.

are the aftermarket bushes more or less compliant, same, or simply easier to fit.....

[shpub]

As I posted here in the Chimaera forum about 4 weeks ago


[quote]I know you bought the parts from ACT but as I also sell the Powerflex bushes and have worked with Powerflex to develop the bush sets for the S series and Tuscans, I think you need to understand what you have bought and why I think you have been misled.

The first thing is that there are poly bushes and poly bushes. There are also a lot of "chinese whispers" about poly bushes making the ride hard. However, they are several different poly bush designs that have very different characteristics. So the comment that poly bushes make things hard is a generalisation that is not applicable across the board. In other words, yes they can make the car ride harsher but that is because the wrong compound has been used.

Let me explain....

Most poly bushes are essentially a poly version of the original and the bearing is actually based on the poly moving on the sleeve. The problem here is that the poly needs to be hard enough to prevent wear but this removes the complience. This is why these bushes are available in several different hardnesses. The harder the bush the harsher the ride. Many of the Chinese whispers about poly bushes are based on early experiences where this type of bush have been used with either a soft compound (leading to wear) or too hard (leading to a harsher ride). It is this type of bush that has lead to stories that they are too hard etc, melt and so on. I don't sell this type because of this. However, it is very misleading to say that these problems apply to all poly bushes. It is like saying that because a budget tyre is hopeless in the wet that all tyres are the same.

The Powerflex bushes that I do sell are designed for road use. They use a special glacier bearing which does not rely on the poly material acting as a bearing surface. This removes the conflict with hardness that I mentioned earlier. They also provide heat shielding for the bushes that are more susceptible to heat. BTW the original rubber bushes and engine mounts are also quite vulnerable to heat so this potential problem is not just restricted to poly bushes.

In terms of handling, the Powerflex poly bush acts as a good pivot with no preload unlike the rubber standard ones. This means that the handling is more consistent because the bushes no longer act as a mini spring/shock absorber. They do not stiffen the suspension. Almost quite the opposite as the wishbones are no longer held in place by the rubber bush stiction. They hold the components in position better and thus reduce any changes in the suspension geometry caused by loading.

One final point... Powerflex offer a lifetime warranty on their parts.
[/quote]