Astra H VXR Sprint

The first track outing for the car was Thursday 26 July 2012; a track evening at Snetterton on the 300 circuit. The majority of the changes had been made to the car namely the Intercooler rework, addition of the Pro Alloy water radiator, turbo rework to K06 specification, the front brakes have been enlarged to 356mm, additional front brake cooling added and the front suspension bushes upgraded. The car has also had a 4 wheel chassis alignment carried out. The car ran on factory dampers with DAP road springs and the standard front seats and 3 point seat belts were still fitted along with the factory spec 278mm rear brakes.

This was an ideal opportunity to give the car a shake down and see how it performed, prior to further modification work.

The car performed faultlessly over the sessions run, it was a hot sunny July afternoon with the ambient air temperature at around 24 degrees C. Despite the heat coolant an inlet air temperatures were kept well under control and the front brakes were superb, offering excellent stopping ability. Looking forward to the next track day and the future mods.

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

On Track @ Snetterton

Track Evening organised by OpenTrack www.OpenTrack.co.uk
Thanks to Tony Harrison for the on track shots © Copyright Terms: http://creativecommons.org/licenses/by-nc/2.0/deed.en

The car came fitted with Alcon Monobloc 4 Pot calipers with single piece 345mm EBC discs. The discs are somewhat past their sell by date, as can be seen from the picture! Badly lipped and the grooves have been completely worn away.

Original One Piece 345mm Disc with Alcon Caliper

I decided that since the discs need replacing and that to fit the 345mm single piece discs the original brackets had been turned upside down and spaced out with washers (which I felt was not be ideal for track use left alone road use!) something different is called for.

So instead of using the Alcon 343mm discs and bells I will switch to a 356mm disc and alloy bell set up which would need a new single piece calliper mounting bracket. So to have the calliper mounting brackets machined, a piece of T6082 material is required:

T6082 Aluminium

Once the calliper was mocked up onto the new discs using the original brackets and some spacers to allow accurate calculation of dimensions:

Alcon Caliper and 356mm Disc

the new aluminium brackets were CNC machined:

Brake Caliper Mounting Brackets

New Bracket (bottom) with Original Bracket (top)

Brake Caliper Mounting Brackets

New Caliper Bracket:

Aluminium Caliper Mounting Bracket

New Bracket Trial Fitted to hub:

Bracket Mock Up

356mm disc and bell added:

Alcon Caliper and 356mm Disc

And all fitted, with a lovely brand new set of Pagid RS29 pads:

All Fitted

Almost back together ready for the first track evening at Snetterton at the end of July.

Slam panel to refit and coolant to be added:

Engine Bay Nearing Completion

Coolant required to top up:

Engine Bay Nearing Completion

Finished for now, ready for track:

Finished for Now

Finished for Now

The car has covered about 85,000 miles, and since it is being used on track an upgrade to the factory rubber bushes is in order. Whiteline Polyurethane Front Wishbone Bushes are being used, and at the same time due to the age and mileage of the original ball joints and drop links they are also having a refresh at the same time whilst everything is apart.

So here are the Whiteline front wishbone front poly bushes, new genuine original equipment (OE) drop links (anti roll bar links) and new genuine OE replacement bottom ball joints:

Poly Bushes, New Drop Links and Bottom Ball Joints

Poly Bushes come as a replacement bush in two halves for easier fitting with a heavy duty central metal sleeve. The Whiteline poly bushes below are the front wishbone rear bushes which give a small caster change, to improve positive caster for better turn in.

Whiteline Black Poly Bushes

Whiteline poly bushes have a shore hardness of around 85-90, and so are much stiffer than factory rubber bushes.

New wishbone to engine bed/subframe nuts and bolts:

Wishbone Retaining Bolts

Front Wishbone removed from the car, the bushes will be knocked out along with the removal of the ball joints:

Front Wishbone

From the factory the original bottom ball joints are riveted onto the wishbone, so to remove them the rivets on the OE ball joints are drilled out using suitable sized drills first (wear protective goggles!):

Removing OE Bottom Ball Joint

Then supported on a suitable old socket or similar the rivets can be tapped out allowing the ball joint to be removed from the wishbone:

OE Rivets Removed

Poly bushes have been fitted into the wishbone and the new genuine bottom ball joint has been fitted and secured with the supplied bolts and stover type lock nuts and is a perfect fit:

Bushes and Ball Joint Fitted

Front Wishbone from another angle showing the caster change bush fitted:

Camber Adjust Rear Poly Bush

Eibach camber adjustment bolts to allow some additional negative front camber to be added:

Eibach Camber Bolts