Rear suspension

[churchy]

Hi, I have a Sierra base S7 and this is about the only job I have been putting off for some time.

The rear suspension, at the moment I am running  is a Sierra set up with standard Sierra shock absorbers(new) with springs inboard on the rear subframe these springs are not standard but I have no idea what they are. I love the ride height of the set up at the moment and the wheels sit nicely filling the wheel arch but when riding along the rear is too soft and over pot holes and large bumps the suspension bottoms out .

My question is what's the best way to sort this out with keeping the ride height the same and not going too hard, any advise will be gladly appreciate.

Cheers Andy

[MarkBzero]

It's been a while but I thought Protech did a conversion kit so you can use traditional coilovers with adjustable nuts.

[Jez Morton]

When I had my S7 with standard Sierra springs and shocks I added towing/caravan spring assisters in the the rear springs and this stopped it grounding. This would be a quick cheap fix but I doubt you'll get them nowadays. 

[Peter Bell]

Could any one measure the diameter of the wire used on the Sierra rear springs? mine are 14.6mm and they are from a 1300 car. I wondered if there is much difference through the model range; I expect the estates were stiffer.

I have added the spring assisters which help but it's still soft.