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GTV Powerflex vs OEM

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18K views 94 replies 18 participants last post by  Freds GTV 2001  
#1 · (Edited)
I know this has been discussed before but I need to fix my rear end from rattling and was considering Powerflexing the rear end.

My Alfa Mechanic (Alfamotive) in Sydney has quoted $500 AUD (234 GBP) to supply and fit everything being a Powerflex dealer also.

However reading on the forum here I have found the following advantages and disadvantages
of both :

POWERFLEX
1) Cheaper
2) Lasts Longer for the life of the car
3) Better firmer handling
4) Rear stiffness increased by 10-15%
5) Better than any worn out knackerd OEM suspension
6) Considered an "improvement" and upgrade when selling the car
6) Loss of rear wheel steering
7) Hardness and skipping over bumps

OEM
1) Keeps the original OEM geometry and rear wheel steering
2) Specifically designed OEM bushes done for this reason
3) Does not last very long (or not as long as Powerflex)
4) People swear it is the best way to do it saying they hate the feeling of Powerflex and
have gone back to OEM saying its much better.

Ive seen on the AlfaWorkshop website that I can get the OEM Bushes Alfa Romeo GTV Bushes

But which ones will I need ? Do I need the "Rear hub bush" x 2 ? 166HBUSH
and do I need the "Rear Spring Pan Arm Bush"x 2 SPP2 (2 supplied for one side)?

I dont know what I'll need as all I know is that I have the rattling in the rear but assume you would have to replace everything on both sides.

I just wanted to find out what the costs was before deciding on which way to go.

Thanks guys
 
#2 ·
Mine was bought Powerflexed, hated it. GTV's are a firm ride anyway, all Powerflexing seemed to do to it was make it even firmer. On any surface other than glass smooth then the difference between that & OEM is significant.

The only reason I'd choose to go the Powerflex route again was if the roads I use were v smooth or I was tracking the car a lot. Neither of which apply to me.

Cheers,
Hedge
 
#4 ·
I had power flex bushes fitted to the GTV I had for eight years and also to my current Spider.

I noticed no change in the ride whatsoever (still like a kart) and I drove on the original bushes for a year so I had something to compare it to.
The geometry was not affected (measured) and I could notice no difference when cornering so it seems the rear wheel steer effect was not altered.

Given the above it was a "fit and forget" situation with the greatest upside being that by the time my GTV finally died it had done 120k miles on these bushes and they were as good as the day they were fitted in driving terms.
 
#5 ·
Not sure - I've taken some polyurethane bushes out because they were stuffed, and some because they made the ride too harsh. I think you have to be careful where you fit them. I turned up at a suspension specialist years ago with a handful of poly bushes and he looked at the car and said fit those ones, they'll be fine, but not those - they'll be hopeless.

If you have a knock, might be better to have a look under the car and see what's causing it, rather than assuming all the bushes need replacing. Might be the exhaust?
 
#11 ·
Not really, Alfa never sold the bushes separately. The Alfa workshop sell replacements for the spring pans but depending on what needs replacing there are a lot more bushes.

The page you've linked to is actually only the 2 rear spring pan bushes. The Merc bushes (first bush on the page) only cover the outer bushes on the spring pan and the transverse trailing arm. Alfaworkshop can supply the inner springpan but only when you buy the outer from them (the last bush set on the page that includes the first). The remaining cannot be bought, or not that I'm aware of.
 
#12 ·
Hmm - I see best to ask my mechanic exactly what needs replacing. Looks like I will have to go down the poweflex route just because of the cost.

Should I just powerflex the bushes that have worn out and leave the rest OEM ?

Which of the bushes wear the most or do they all wear out ?

Assume anything you replace should be done symmetrically on both sides
 
#13 ·
I chose superflex bushes for my car, I just did the whole rear of the car using the lemforder merc bushes on the outer arms of the spring pans and the rear trailing arm, the rest were done with the superflex bushes. The merc bushes allow for movement as the suspension moves as they are spherical and can pivot so I'd recommend doing that. I did the whole rear as part of my rebuild, did they all need doing definitely not. If there is play replace them both sides but you could probably get away with just doing only the bushes that need doing. It all comes apart quite easily so not difficult to get in and replace any other bushes later.
 
#15 ·
i heard most if not all just powerflex the rear only, not sure why. maybe someone can elaborate on why people only do the rear on the GTV.
 
#18 ·
I think the front is too hard when Powerflexed and not very good. Also its relatively cheap to just replace the front arms with OEM (which is what I did)
Previously, due to some mis-information, we/I incorrectly posted that the fronts on 916s can 'pop' out, they can on 156/147s, but the 916 has 'lips' that prevent this from happening. Unbeknown to me, until recently, my Cup-a-Like had polybushed fronts & that had the best feeling front end over any other 916 I've had/got or driven.....it also had 8J 18s, Eibachs & new std fr shocks so might not have all been down to the bushes. The other reason most don't polybush the fronts is that it's the wishbones' outer ball joint that normally wears first so it's not really worth it.

As for the feel of the rear, to me, it's the same & I've had + currently got a mixture of 916s with part poly bushed, 'full' polybushed & std OE rears. Not had the top wishbones of any that have been polybushed though....or not as far as I know!?

I've just bought a V6 Spider with Koni Sports etc etc & the owner/seller told me it had been completely polybushed....when I looked underneath it had new std rear doglegs & not a polybush in sight!!

Some people seem to think poly bushing is an upgrade, to me it's a replacement....cheaper & longer lasting so I only do it when needed & in at least matching pairs side to side.

It's the rear suspension's geometery that creates rear wheel steering, fitting polybushes doesn't affect the geometery....all the suspenion arms are the same length so no change.

Quite often when people change the bushes they also change other things at the same time, shocks/springs/tyres?, 'feel' can be.....................psychological?

How many times have we heard people say a Q2 has transformed their GTV/GTA? Recently there's been a few people posting that they don't know, & can't tell, if their car's got one fitted!!??

Clive
 
#19 ·
1. I can clearly feel the Q2 in my car. It works. And with the way I drive, it works hard. You can feel it in the steering wheel on wet roads on bumpy surfaces when under power. And while it is working during hard cornering. You can even feel drive shifting from wheel to wheel through the steering wheel.
2. With Polybushes the suspension firms up and resists most of the rear wheel steering geometery changes which gives you that linear effect when cornering at high speeds. The effect is limited and feels benign, deffinitely not as active as a stock set-up.
3. The stock bushes allow for more movement in the rear suspension which is why they wear more but reduce the amount of impact and road vibration transmitted to the chassis as well as allowing for more movement during a rear wheel steering moment. It feels more settled in a corner especially when combined with konis and eibach springs which are firmer.
4. When encountering a severe dip midcorner, the oem bushes when worn do cause the car to wiggle it's tail but quickly settles in and sorts itself out. New bushes do not have this issue. In this situation polybushed rear ends might skip or bump which sometimes unsettles the car badly.

This is in my experience. I have a stock rear and will always replace with stock bushes. For better ride comfort and handling over wider road conditions.
 
#20 ·
1. I can clearly feel the Q2 in my car. It works. And with the way I drive, it works hard. You can feel it in the steering wheel on wet roads on bumpy surfaces when under power. And while it is working during hard cornering. You can even feel drive shifting from wheel to wheel through the steering wheel.
2. With Polybushes the suspension firms up and resists most of the rear wheel steering geometery changes which gives you that linear effect when cornering at high speeds. The effect is limited and feels benign, deffinitely not as active as a stock set-up.
3. The stock bushes allow for more movement in the rear suspension which is why they wear more but reduce the amount of impact and road vibration transmitted to the chassis as well as allowing for more movement during a rear wheel steering moment. It feels more settled in a corner especially when combined with konis and eibach springs which are firmer.
4. When encountering a severe dip midcorner, the oem bushes when worn do cause the car to wiggle it's tail but quickly settles in and sorts itself out. New bushes do not have this issue. In this situation polybushed rear ends might skip or bump which sometimes unsettles the car badly.

This is in my experience. I have a stock rear and will always replace with stock bushes. For better ride comfort and handling over wider road conditions.
I wasn't saying that 'you' can't feel ANY difference....just that most don't.

What set up were you running when this happened!?..see pics below.

Clive
 

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#22 ·
Polyflex main advantage is their durability. GTV set up seems to be very harsh on the OEM bushes meaning many original owners saw big bills on relatively low mileage cars and if they ignored the clunking even bigger bills on suspension rebuilds.
Any other claimed advantage I think is more marketing than fact.
My understanding on the passive rear steering design is that bushes should have little or no influence unless they are worn.
 
#23 ·
I have never experienced a GTV with OEM bushes but I know the difference between a properly setup GTV rear and a poorly setup one.

When I first got my GTV the rear had powerflex bushes on the dogleg arms and the springpans only. The upper arms still had OEM bushes and it had a set of lowering springs fitted with KYB Gas-a-just dampers. I thought this handled well but the ride quality was appaling. It would crash through every bump/hole and bottom out the rear suspension so easily.

When the rear subframe broke I ripped the whole lot out and found that the powerflexes hadn't been fitted with the right washers at the hub end and none of the bushes had been lubricated with copper grease as you are supposed to do. All of the pivot points in the rear suspension was seized solid and it just wouldn't move if you tried to bounce it.

I reasembled it with a full set of brand new powerflex bushes. I lubricated each bolt, bush and crush tube well and I ground back the rust on the hubs so that it would accept the washers correctly. I also fitted normal springs and replaced the upper wishbone bushes with Powerflex items too.

The difference was like night and day. It was so much smoother going over road imperfections and felt far more confident in the corners, I could finally feel the line tightening in corners when you press on as you should.

Based on this, I would recomend that if you go powerflex then do the whole lot on the end of that car. Don't just do the springpans. Do every arm. Yes it is a tough job but if you do it properly first time (and don't forget the copper lube) then you shouldn't ever need to do it again. My rear suspension can now be described as Firm but comfortable.
 
#24 · (Edited)
Thanks guys for all your responses.

Im starting to think more towards OEM at this stage. Talking to my Alfa Mechanic he says I need "Lower Inner and Outer Swing Arm Bushes" as one side is worn on my car. He also said the uppers should be fine and dont usually wear as my car has only done 80,000 Kilometers or 49,000 miles.

So I guess he means (Rear Spring Pan Replacement 'metal rose joint bushes') from AlfaWorksop ? :

Alfa Romeo GTV Bushes
Spring pan bush replacement

Therefore I would need 2 of them for each side costing ÂŁ69.04 x 2 would this be right ?

Also I have Koni sport shocks (which I already like at 50% Firm) and 18" wheels on my car so I think there is already enough "firmness" in the car. Also if they wear out in another 50,000 miles or 80,000kms Ill just replace them again with OEM.
 
#31 ·
Had mine done a couple years back and iirc it was a little more expensive than that for the powerflex alternative. Then again, I have no idea where my Alfa specialist sourced them from so you could probably get a better price online somewhere.

Also, just some food for thought, look at Strongflex bushes, not just powerflex. They are also PU bushes but are generally cheaper (made in Poland I think) and are really well regarded. They also offer bushes of various hardness (red is closer to OE, yellow is more track/motorsport oriented) and would definitely be worth investigating as an alternative to Powerflex or OE bushes.

GTV & Spider 95-05 - STRONGFLEX Polyurethane Components
 
#34 · (Edited)
Ok after much research on every Alfa website I could find around the world I have decided on getting OEM bushes from Jim Spackman at Alfaholics. They are the easiest and cheapest all round the world. (I have bought other stuff off Jim as well)

916 GTV Rear Suspension Bush Kit

Tried to buy the same parts from another well know Alfa supplier (who will remain nameless) but they just had no idea what they were doing and what parts I needed. I couldnt believe it ! anyway thats another thread.

Its also interesting that the OEM bushes have recently become available. A year ago or so they werent which is another reason why people just bought the Powerflex as it was cheaper than buying a complete spring pan arm.

Anyway I have weighed up the evidence. There are some people for and against powerflex. However there is NOT ONE COMPLAINT about OEM Bushes. No one has said OEM are terrible and Im going to Powerflex. Where as the opposite is mostly true with several people saying Powerflex is terrible and Im going to OEM. So for that reason Im going with OEM. And once they wear out in the next 50,000 km Ill just change them again ...

Get them installed next week and will report back then :)
 
#35 ·
Ok after much research on every Alfa website I could find around the world I have decided on getting OEM bushes from Jim Spackman at Alfaholics. They are the easiest and cheapest all round the world. (I have bought other stuff off Jim as well)

916 GTV Rear Suspension Bush Kit

Tried to buy the same parts from another well know Alfa supplier (who will remain nameless) but they just had no idea what they were doing and what parts I needed. I couldnt believe it ! anyway thats another thread.

Its also interesting that the OEM bushes have recently become available. A year ago or so they werent which is another reason why people just bought the Powerflex as it was cheaper than buying a complete spring pan arm.

Anyway I have weighed up the evidence. There are some people for and against powerflex. However there is NOT ONE COMPLAINT about OEM Bushes. No one has said OEM are terrible and Im going to Powerflex. Where as the opposite is mostly true with several people saying Powerflex is terrible and Im going to OEM. So for that reason Im going with OEM. And once they wear out in the next 50,000 km Ill just change them again ...

Get them installed next week and will report back then :)
The link shows 1 pair for springpans & 1 pair for 'control' arm....not 2 pairs, inner & outer, for complete rebushing of springpans.

Clive
 
#38 ·
Hybrid solution...

Hello...

I went with P'Flex inners and Delphi spherical-joint outers.

My reasoning was that the 'give' of the PU bushes might absorb some of the shock going through the spherical joints and so help extend their life a bit. Also the outers are easy tio source cheaply.

So far, it seems to ride nicely with no noticeable wind-up/side-loading going on and the rear steer working noticeably.

Apparently, it is little known but the PU bushes should be 'bonded' (e.g. using one or other of the non-permanent Loctite-type products) in the suspension part they serve, with only the stainless through bushes (supplied) lubed up with the copperslip.

Think I read that on the P'Flex website somewhere... :thinking:
 
#42 ·
Gotta love a greasy bush...



Yeah, they are quite snug...

However, I think the PU bush is meant to rotate around the stainless inner bush, which would itself actually be held tight in the subframe once bolted up.

If the stainless bush was able to rotate around the bolt, then surely it would wear the subframe lugs and, to do so, would also have to have some lateral clearance and would then possibly also 'knock' as well as wearing both itself and also the bolt?

Which, I think is the reason why the PU bushes should be 'bonded' in, to also stop them wearing out inside the suspension arm.

Just thinking aloud here, really - I will find the info' online and post it if possible...