363 replies to this topic

[techieboy]

I knew that was coming but didn't want to risk drawing attention to it, just in case everyone missed it.

[LY_Scott]

J-Turns?

[fezzasus]

Let's clear one thing up Polyurathane bushes and Ertacetal are essentially the same thing in terms of physical properties, the only difference in this application is the grooved metal inserts to retain grease. so why are they being recommended for different applications?

No.

Polyurathane and Ertacetal are not the same.

Ertacetal is hard (think like nylon), Polyurathane is soft

try pushing your finger nail into both and see what happens...

Firstly it's far from being *like* nylon, it's a very different material. I'm comparing the chemical and material properties. Polyurathane is a broad name which can cover a wide range of compositions. within that you can generate materials which have very similar properties to that of Ertacetal. Unless you have tested a wide range of polyurathane bushes you can't say they are all soft compared to Ertacetel.

The the polyurathane bushes you have seen are softer and therefore have more stiction, requiring a degree of force before they break free from the inner metal inserts, some do not because they a harder and less malleable. they are the bushes which are most similar to Ertacetal.


Furthermore wear and conformance of Ertacetal will be similar to that of the harder Poly bushes, at what point do you expect the performance of the two bush types to differ?

[Goosenka]

Let's clear one thing up Polyurathane bushes and Ertacetal are essentially the same thing in terms of physical properties, the only difference in this application is the grooved metal inserts to retain grease. so why are they being recommended for different applications?

No.

Polyurathane and Ertacetal are not the same.

Ertacetal is hard (think like nylon), Polyurathane is soft

try pushing your finger nail into both and see what happens...

Firstly it's far from being *like* nylon, it's a very different material. I'm comparing the chemical and material properties. Polyurathane is a broad name which can cover a wide range of compositions. within that you can generate materials which have very similar properties to that of Ertacetal. Unless you have tested a wide range of polyurathane bushes you can't say they are all soft compared to Ertacetel.

The the polyurathane bushes you have seen are softer and therefore have more stiction, requiring a degree of force before they break free from the inner metal inserts, some do not because they a harder and less malleable. they are the bushes which are most similar to Ertacetal.


Furthermore wear and conformance of Ertacetal will be similar to that of the harder Poly bushes, at what point do you expect the performance of the two bush types to differ?

[Scuffers]

Firstly it's far from being *like* nylon, it's a very different material. I'm comparing the chemical and material properties. Polyurathane is a broad name which can cover a wide range of compositions. within that you can generate materials which have very similar properties to that of Ertacetal. Unless you have tested a wide range of polyurathane bushes you can't say they are all soft compared to Ertacetel.

The the polyurathane bushes you have seen are softer and therefore have more stiction, requiring a degree of force before they break free from the inner metal inserts, some do not because they a harder and less malleable. they are the bushes which are most similar to Ertacetal.


Furthermore wear and conformance of Ertacetal will be similar to that of the harder Poly bushes, at what point do you expect the performance of the two bush types to differ?

why does this have to be so hard work?

I know they are not the same material, but the point I was making is that Ertacetal to feel/touch is like nylon!

as for poly, I specifically said WHAT poly bushes I was talking about - Powerflex, yes, others may well be different, but I very much doubt any of them are as hard as the Ertacetal ones.


On a more general note, I have to say people on here seem very intent on trying to poke holes into what is presented to them, if only they spent as much time actually doing this stuff themselves, we would already have some better performing VX's out there....

[siztenboots]

[techieboy]

On a more general note, I have to say people on here seem very intent on trying to poke holes into what is presented to them,

It's because we don't get rusty sills on the VElise's, so we've got to poke a hole in something. Or something like that.

Polyurethane/Nylatron/Ertacetal properties aside, I do like the design of the EP Ertacetal bushes. Makes lots of sense to do them that way (the Autobush crush tubes also have the grease retaining hatching machined into them) and really like the way the crush tube has the integral top hat. Pretty sure, when I did my refresh, Geary only did poly and nylatron bushes and those weren't an option otherwise I'd have probably used them.

[Winstar]

On a more general note, I have to say people on here seem very intent on trying to poke holes into what is presented to them, if only they spent as much time actually doing this stuff themselves, we would already have some better performing VX's out there....

Probably because quite alot of us on here are engineers and generally pokeing holes in things is what we do for a living,.Alot of us do do this type of thing for a living just not for VX's as there isn't any money in it and you already stated you don't work for free so why would we?

[fezzasus]

why does this have to be so hard work?

I know they are not the same material, but the point I was making is that Ertacetal to feel/touch is like nylon!

as for poly, I specifically said WHAT poly bushes I was talking about - Powerflex, yes, others may well be different, but I very much doubt any of them are as hard as the Ertacetal ones.


On a more general note, I have to say people on here seem very intent on trying to poke holes into what is presented to them, if only they spent as much time actually doing this stuff themselves, we would already have some better performing VX's out there....

I'm questioning this one because i've looked at the Ertacetal/Nylatron offerings before and haven't been sold on them vs. the alternatives, they just appear to be a higher quality poly bush. Have you got any information on how much longer they stay lubricated vs. polybushes without the grooves in? If you're saying they (according to the EP website) don't compromise comfort, then why are they better than poly bushes?

I know the work you are putting into Mike's car will go some way to prove these (and other) parts, but as someone who spends their whole day looking into tribological functions, I'm not seeing anything that will sell them to me.

[Scuffers]

Basically, they are significantly harder, thus much less compliance, and being self-lubricating (to a point) they can run on a smooth surfaced tube - so no significant compliance there either, they are then end-capped, so lateral compliance is contained too.

less compliance = better control of the wishbones = more about to keep the wheels pointing in the right direction/attitude.

simple as that, next step on is to go with Spherical's, but they cost £££ to do properly (although they do last a lot longer)

I have not run Ertacetal long enough to know what the wear is like, I can tell you it's well over 12 months on a road car (kind of expecting them to do better than Nylatron ones, and if fitted right, they would last years - the problem was most people just slapped them in and their design was they some needed to be fettled when fitting to get them to sit right etc)

Mikes car has Ertacetal's, let's see how they workout on his....

[cnrandall]

Road = stock bushes Track = rose joints DONE

[jameso]

Lol

[Captain Vimes]

.....
for example, this cars on new OEM bushes (and old A048's)

http://www.youtube.com/watch?v=Rq_WbFBwBrE

Enjoyed that clip. Made a lot of expensive machinery look like they were on a Sunday drive. A nice, considerate track day driving etiquette too..

I would ask what the spec was but I'm not sure this thread can take any more distractions.

[chris_uk]

whos driving that?

[LY_Scott]

Mental revs.

[Scuffers]

.....
for example, this cars on new OEM bushes (and old A048's)

http://www.youtube.com/watch?v=Rq_WbFBwBrE

Enjoyed that clip. Made a lot of expensive machinery look like they were on a Sunday drive. A nice, considerate track day driving etiquette too..

I would ask what the spec was but I'm not sure this thread can take any more distractions.

Lotus S1 Exige with SC Honda, Nothing special, built as a road car.

whos driving that?

Me.

[chris_uk]

yea i could tell by your nose lol

[The Batman]

[Bumblebee]

The porshe driver looks like he's enjoying himself going sideways Nice vid btw

[Mike (Cliffie)]

I am still quicker through Maggots and Beckets.