Front Suspension

Lowering the shock position and fitting coil over kit to Mk2 Astra McPherson struts.

This is relatively easy to do and having adjustable front means you can always get a better look by winding the front up and down to suit the height of the rear. You see a lot of people lowering the front more than the rear and in my opinion it looks amateurish... low and flat is the way to go and for performance low and the front a little higher than the rear helps on the track.

Remove the spring plate off the strut. Being careful not to cut into the strut tube. This is where you would cut the Strut tube to shorten it to match the shock absorber length, then later will be covered by the threaded tube for the coil over system.

Drill out the bottom of the strut with either a hole saw or large drill and die grind
the excess material so it is smooth inside.

Machine a new stop and weld it onto the end of the strut tube.

The maximum length I set Strut Tube extension was 34mm from the cast hub.
This can be played with but you have to consider 2 things:

1. to be able to remove the CV from the strut
2. the CV boot touching the strut tube

Cut the strut tube bellow the thread at the top of the strut tube and shortened it to match the shock length then weld back together. This is important to weld properly making sure you don't get any penetrating weld that will stop the shock going down the tube. I use a Brass tube machined to fit inside the strut tube with about 1mm clearance... this allows me to make sure I don't get too much penetration.

It wouldn't be the end of the world as long as you can die grind the inside if you had a problem. When completed I paint it then slide the threaded coil over tube over and do a few small weld to keep it in place... it doesn't need much weld and make sure no welding splatter gets onto the threaded tube.

  

Cut away the top of the steering arm keeping the cut away part for the stiffening part, then plate the hole with flat 3mm sheet metal and fully weld.

  

Stiffen up the steering arm on the lower side to retain the strength. Then fit the coil-over kit with small welds at the bottom of the thread.
On rally car struts I uprate this to make it stronger but not needed on a street car.

Doing these 2 things allowed me to lower the shock by 25mm plus by stiffening the steering arm and removing the original steering arm support it allowed me to have a spring another 50mm or more lower to the original place. This does not change the position of the steering arm.