WHAT ARE THEY?Aftermarket replacement suspension component bushes made of tough polyurethane instead of the OEM rubber and with specifically engineered steel crush tubes where appropriate. But because this is one of those mods which you cannot see and which takes time and hence costs you more to fit, are poly bushes something you need?
SuperPro Bush features:
http://www.superpro.eu.com/whysuperpro/features.aspx^ Product quality is beyond question - They inspire confidence in their durability and retention.
POLYURETHANE vs RUBBERThe OEM suspension bushes are made from a hard rubber substance which over time will deteriorate and will almost certainly need replacing one day on a high mileage car. Also, the OEM bushes are less resilient, increase their hardness (durometer) when compressed, losing elasticity, and so lower their ability to perform well with other aftermarket suspension mods. This doesn't mean that OEM bushes are rubbish but that they are designed for the unmodified car and to be production cost efficient in the car's lowest common denominator marketplace.
SuperPro polyurethane is manufactured using cold pour/thermo setting processes and will return to and retain its original shape. It is also resistant to oil, petrol, salt, and other airborne contaminants which a car is subjected to. Rubber isn't.
On a tuned performance car with modified suspension, rubber is not man enough for the job in the longer term. I know quite a few folks who have swopped out their rubber bushes for polyurethanes just to achieve a more improved and integrated suspension for better roadholding and without waiting for any signs of the OEM rubber deteriorating.
WHY NOT REPLACE OEM BUSHES WITH OEM BUSHES?The illustration below shows all the suspension bushes on a Mk5 Golf. You can doubtless appreciate that changing all the bushes is labour intensive and especially when some of the high mileage OEM bushes become difficult to remove, as is very often the case. Pass me the lump hammer!
Therefore it is the same in labour costs to replace them with polyurethane bushes and gain their advantages and longer life, as it is to replace them with OEM rubber bushes.
^ Full SuperPro kit for Leon Cupra [Tsfi_Mike]
Okay, so that's enough about polyurethane and rubber products but what do SuperPro polybushes contribute to the enjoyment of driving?
THE DRIVING EXPERIENCE:Even with handling mods such as KW V3 coilovers, WALK, Quaife diff, UNIbraces XB and UB, Eibach ARB's, VWR engine mounts and front poly bushes already done, to my surprise I instantly felt a further improvement in the handling of the car. Fitting polyurethane bushes tightens up every connection in your chassis, thereby removing what are small amounts of play but which add up collectively to something bigger. I performed several heavy emergency braking tests and the whole car felt rigidly planted with hardly any nose diving and the car keeping absolutely straight - My car has AP Racing front brakes and S3 rears resulting in very evenly balanced braking. Fitting SuperPro poly bushes may not be a mod which you can see but it is a mod which you can feel.
When driving hard and fast on twisty roads the car feels extremely well planted. It felt well planted before this mod but the poly bushes take it a step further. Taut, tactile, and now tight. I can't wait for my next drive.
ALTERNATIVES:Similar poly bushes are offered by PolyBush and by Powerflex and I have their Front Wishbone Bushes (number 1 on the illustration).
^ The purple bush is by Powerflex and fitted by VWR to balance my WALK. The WALK consoles have yellow polyurethane bushes.
^ Powerflex bushes (Front Wishbone).
I don't know how SuperPro compare with either the Powerflex or the PolyBush polyurethane bushes.
PolyBush Review by h4rdy:
http://www.mk5golfgti.co.uk/forum/index.php/topic,30593.0.htmlSOURCE:AKS Tuning:
http://www.facebook.com/AKStuning Alex of AKS arranged a Group Buy on the forum with generous discount:
http://www.mk5golfgti.co.uk/forum/index.php/topic,49608.0.htmlAs I already have aftermarket Eibach Anti Roll Bars (with their own poly bushes) and also WALK with Powerflex wishbone bushes, I only needed the SuperPro rear kit.
^ Mk5 Golf Rear Kit - Separate and specific SuperPro kits are offered for many brands of car - They are not universal.
INSTALLATION:Being very methodical and applying patience is the key in all workshop practices. I don't own the tools, workshop, or have the expertise to do mechanics etc myself so I went to JKM who I regularly use and trust implicitly. To allow enough time for any tricky OEM bush removals and to have my car properly aligned afterwards, JKM asked for one and a half days and were able to lend me a new Volkswagen Polo.
^ Typical removed OEM bushes [photo courtesy of Alex @ AKS]
^ Rear Trailing Arm - Bush number 8 on the Golf Mk5 illustration.
You can see how the OEM bush designs compare badly with the SuperPro poly bush designs.
ALIGNMENT:It is very important to have alignment professionally done after installation. Mine was done on a Hunter Laser Rig.
PLUS POINTS:- Polyurethane's inherent properties and ability to return to its original shape.
- Each SuperPro bush is individually designed to achieve the optimum performance for its location on the car.
- Eliminates problems where the OEM rubber bushes are prone to failure.
- Improved roadholding.
- Significantly improves the feel of the car when driving hard by tightening up the suspension.
- More responsive steering - Not something I noticed but probably because all my front poly bushes were already fitted.
- Increased tyre life is claimed - Surely not to the extent of being significant, but we'll see and every little bit helps.
- Longevity.
- 3 years or 36,000 miles warranty.
MINUS POINTS:- In spite of manufacturer's claims to the contrary, I immediately noticed a tiny bit more vibration and an even greater sense of what the road surface is. But all very much in a good way as far as I am concerned. No noise increase though.
- A relatively expensive mod but costs can be spread by buying and then installing later. Alignment adds to the cost but is very necessary.
- If you plan to put your car back to standard before selling, it would involve significant labour costs as well as the cost of buying new OEM rubber bushes. Pointless returning bushes to OEM, in my opinion.
SUMMARY:With handling mods such as KW V3 coilovers, WALK, Quaife diff, UNIbraces XB and UB, Eibach ARB's, VWR engine mounts and front poly bushes already done, I had serious doubts how much improvement I would feel and I fitted the SuperPro's principally because at over 100k miles I knew I would need to replace the OEM bushes sooner rather or later. Alex at AKS was offering a forum Group Buy with generous discount and so it became a no-brainer.
My car was an absolute joy to drive before and it's even more of a joy to drive enthusiastically now. Jim of JKM, who is known as a very talented fast driver, told me after his 20-mile test drive that my car
"feels very well planted" and I have since heard that he told someone else that
"it drove well". He already knows my car very well so it was good to hear his valued opinions and that I was consequently not suffering from any placebo effect - So very easy to do immediately after installing a mod. At this time of writing I have driven about 300 enthusiastic miles on fast twisty and roller coaster roads.
If your car is performance tuned with suspension mods and you plan to keep her, then I wholeheartedly recommend SuperPro poly bushes as a mod.
The phrase
"VW Golf - Designed And Built By German Craftsmen, Modified By Mad Englishmen" comes to mind.