What sort of ground clearances are normal. I've positioned bottom of my sump about 30mm below the chassis. Is that normal and going enough to carefully negotiate speedbumps etc. I haven't set my ride height or even got any shocks yet. I'm a bit paranoid and thinking about making sump guard.

4" front chassis to ground, 4.5" rear is pretty normal, do not bother using a tape measure, cut a couple of blocks of wood to size, its much easier and more accurate.

[Edited on 1/9/13 by mark chandler]

75mm minimum below sump is a good starter. Lived with that for 10 years or so with no issues. Sump is about 60mm below chassis tubes.

Ok good to hear - long as I don't need to move the engine. I put solid spacer bars where the shocks go just to roll it in and out of the garage and was worried when it struggled getting over a small lip but its pretty low so I guess with proper length shocks will be fine.

I have about 100mm between the road and the bottom of the bellhousing (the lowest point under the car) - and I still hear the occasional slight touch as I go over speed bumps...