Astra H VXR Sprint

Uprated polyurethane engine bed bushes arrived today. So a big Thank you Powerflex for supplying these bushes.

Poly Engine Bed Bushes

One area that is often neglected, along with front anti roll bar bushes, are the engine bed/subframe bushes, mainly because the bed needs to be dropped to replace them, so there is a reasonable amount of work involved. Additionally because the engine bed captive retaining nuts are floating (i.e. they can move once the subframe bolts are undone) there is a danger that once removed the engine bed could be refitted out of alignment unless the correct jig to re-align the subframe onto the car is used. Correct alignment of the subframe is essential because the wishbones are bolted to the subframe and if incorrectly aligned the chassis settings will be out, affecting the handling.

With the factory subframe mounts there is some compliance/flex in them as they are designed for road use and have a rubber core to help dampen out vibrations, however stiffer bed bushes reduce this compliance removing any flex in the bushes, ideal for improving the chassis and feel both on road and especially on track.

These front subframe mounts feature two polyurethane ‘top-hat’ style bushes that make for simple installation and durability. The bushes house a stainless steel sleeve and are supported by zinc coated steel washers at each end for increased support under load. The stainless steel sleeves should also help to prevent instqances where the bed bolts seize into the factory bushes over time.

These polyurethane uprated subframe mounts are manufactured from two material types; either 80 shore purple material or 95 shore black material. Purple is ideal for road use and black is best suited for track use.

I have chosen the black 95 shore bushes for the car due to its use on track. They are all but solid removing the flex in the bed bushes during hard use, so improving front end feel, especially during cornering and under high loads on track.

Whilst there are also some solid engine bed bushes on the market, manufactured from aluminium, they were unavailable at the time these upgrades were being carried out hence opting for these uprated 95 shore poly mounts.

All being well I will get the engine bed bushes fitted during December.

Uprated 95 Shore Black Polyurethane Engine Bed Bushes:

Black Polyurethane Engine Bed Bushes

The car is currently running the original factory anti roll bar bushes (which have now covered 88,000 miles) and these have never been changed so it is about time they were replaced. To replace them I have a pair of Powerflex Black Series track spec (95 Shore) anti roll bar bushes ready to fit.

This will be a job to do when the engine bed/subframe is dropped as I will be fitting a set of uprated engine bed bushes over the winter. Due to the location of the front anti roll bar on the engine subframe, replacing these bushes with the subframe on the car is all but impossible. With the subframe off it makes the job so much easier.

The aim is to get these fitted during December.

1 Piece Replacement Poly Bush (shown in road spec 80 shore purple material – left) and Original 2 Piece Rubber Bush (right):

Poly 1 Piece ARB Bush and Original 2 Piece ARB Bush

Front ARB Bushes in Black track spec 95 shore material:

Anti Roll Bar Bush – Black Material 95 Shore