Powerflex on 996 C2

[POSW996]

Hi all, I'm about to fit brand new coffin arms and the adjoining control arms.

Would it be worth fitting some Powerflex poly bushes while I am at it (I like a firmer feel in the handling), to these brand new arms? Would I notice a difference? Or are they more for replacing older worn bushes?

Thanks in advance.

 

[Marky911]

Hi POS,

I'd just fit new standard parts. As you say you could fit Powerflex bushes to old arms but we experimented with some on my old C2 and they weren't very good.
Mind you we fitted the inner bushes that claimed they were 'camber adjustable" on the car. They definitely weren't and they wouldn't budge. The supplied spanner bent before the bushes rotated. Power flex were helpful and even sent a redesigned spanner, but they just weren't that good.
My Indy says they usually end up creaking as well.

The overriding fact is though, they don't feel that different and for a road car you're far better sticking with factory rubber bushes coupled with good dampers.
You want the car to ride as nice as possible with the best control over bumps and through bends.
So you want ride quality not necessarily stiffness. Taking every bit of 'give" out of the setup isn't something I'd aim for.

Refreshed standard components coupled with good coilovers or even fresh standard dampers is the way to go for road use. :thumb:


(Other opinions are available though. :wink: )

 

[POSW996]

Hi POS,

I'd just fit new standard parts. As you say you could fit Powerflex bushes to old arms but we experimented with some on my old C2 and they weren't very good.
Mind you we fitted the inner bushes that claimed they were 'camber adjustable" on the car. They definitely weren't and they wouldn't budge. The supplied spanner bent before the bushes rotated. Power flex were helpful and even sent a redesigned spanner, but they just weren't that good.
My Indy says they usually end up creaking as well.

The overriding fact is though, they don't feel that different and for a road car you're far better sticking with factory rubber bushes coupled with good dampers.
You want the car to ride as nice as possible with the best control over bumps and through bends.
So you want ride quality not necessarily stiffness. Taking every bit of 'give" out of the setup isn't something I'd aim for.

Refreshed standard components coupled with good coilovers or even fresh standard dampers is the way to go for road use. :thumb:


(Other opinions are available though. :wink: )

Thanks for that Marky. Good to hear Powerflex look after their customers! Even if you didn't stick with them.

It's not my daily driver and I prefer firmer ride, so I decided to go with the poly bushes - Helped also by finding out my local garage has a hydraulic press and popped the original bushes out for £30.

 

[Slippydiff]

Hi POS,

I'd just fit new standard parts. As you say you could fit Powerflex bushes to old arms but we experimented with some on my old C2 and they weren't very good.
Mind you we fitted the inner bushes that claimed they were 'camber adjustable" on the car. They definitely weren't and they wouldn't budge. The supplied spanner bent before the bushes rotated. Power flex were helpful and even sent a redesigned spanner, but they just weren't that good.
My Indy says they usually end up creaking as well.

The overriding fact is though, they don't feel that different and for a road car you're far better sticking with factory rubber bushes coupled with good dampers.
You want the car to ride as nice as possible with the best control over bumps and through bends.
So you want ride quality not necessarily stiffness. Taking every bit of 'give" out of the setup isn't something I'd aim for.

Refreshed standard components coupled with good coilovers or even fresh standard dampers is the way to go for road use. :thumb:


(Other opinions are available though. :wink: )

Hi Mark. Hope you're well ?

Op, I second what Mark says. I was planning on going the Powerflex route in some key places (NOT everywhere) on the car, but my suspension guys said not to do it.

One of the primary reasons was the poly bushes aren't designed to articulate in two planes, unlike a rubber bush which will twist in one plane (normally the up and down one) but also side to side to enable some deflection and shock absorbtion.

Note also that a rubber bush provides a degree of damping as it twists, good for ride comfort, though admittedly not so good for damping accuracy, as it removes a degree of response required to make the damper's internal valving function (another reason race cars use low-friction spherical bearings rather than rubber bushes).

Furthermore my suspension guys have said that once assembled and tightened up, they've seen the poly bushes bind and make suspension arms "stick", so they're not the panacea the manufacturers make them out to be.
And as Mark also says, they're known to creak unless well greased with correct type of grease.

Either fit new OE bushes or replace the complete component (ie coffin arms and rear dogbones) and more often than not you'll transform the car into something as good as the day it rolled out of the factory (if not better if you fit upgraded dampers, roll bars etc)

PS Edit to add, seemingly too late !! But if you prefer your car on the firmer side, I'm sure the bushes will be fine !!

 

[Hugh_]

I was listening to the latest 9works podcast earlier with Jethro talking (amongst other things) about his 996. That has no rubber bushes, which I took to mean rose-joints given the cars provenance (ex Poppopbangbang), but could also have meant fully polybushed, he then went on to comment that the ride is fine and not bangy or crashy.

 

[Slippydiff]

I was listening to the latest 9works podcast earlier with Jethro talking (amongst other things) about his 996. That has no rubber bushes, which I took to mean rose-joints given the cars provenance (ex Poppopbangbang), but could also have meant fully polybushed, he then went on to comment that the ride is fine and not bangy or crashy.

It's not quite as straightforward as the ride not being bangy or crashy.

My old car : :http://911uk.com/viewtopic.php?t=135064&postdays=0&postorder=asc&start=0

Had every rubber bush removed and replaced with spherical bearings in ALL the control arms, and allied to some superb Ohlins dampers, the ride was truly excellent. But what stiffer bushings and spherical bearings tend to do is introduce a certain harshness to the whole chassis.

On some road surfaces the car could be incredibly noisy as various frequencies resonated through the suspension and the bodyshell. If you didn't mind that, it wasn't an issue, but over long distances it ceases to be fun and ultimately becomes tiresome. And over really poorly surfaced roads, the degree of harshness becomes an issue for those with a modicum of mechanical sympathy.

A C2/4/4S/Turbo has a lot more sound deadening than a GT2/3/RS, along with more rubber (in standard form) in the suspension generally, all of which makes them considerably more compliant and refined.

IIRC Jethro has KW V3's fitted to his car ? which are at the more compliant end of the scale, basically a slight upgrade from stock 996 GT3 Bilsteins.
I can't remember if they come with spherical bearing top mounts ? But if they don't and the car is running polybushes, rather than full Rose joints, and is a C2, I can imagine it's probably not too bad.

But I'm guessing he doesn't use it as a daily, and when he does use it, it's more for Sunday morning hoon to CnC type journeys, rather than taking the missus away to a nice hotel for a weekend break ...

 

[infrasilver]

I've had poly bushes in my coffin arms and ARBs and I've lowered it -35mm for the last decade plus, it is slightly more crashy than standard ride height with rubber bushes but not considerably more, the whole car does feel sharper than it did.

 

[POSW996]

Thanks for the replies all... I guess it is subjective to what you want, how you use the car, and what you are used to, as to whether you should or shouldn't fit polybushes.

I was really trying to understand if a new coffin arm rubber bush (not an old worn one) would be significantly different to Powerflex purple polybush. Sounds like I would notice a bit of difference, which is good, because I want a firmer feeling/ride so I am going for that option