Mike,
I'm not sure why the Spyder Zetec +2s all seem to display this ride height anomaly.
The most frequently used Tyres are 185/60x14 so the 55 aspect ratio tyres on Jerry's car could highlite this problem a bit.
Nevertheless it should be possible to dial this out by lowering the spring platforms.(However see below)
The Spyder Zetec tubular chassis does differ from the standard +2 Spyder tubular chassis. The differences are, as far as I know, limited to the rear end to accomodate the Sierra differential. Also the central tunnel provides more room for the MT75 g/box & oval section tubing is used in the diagonals towards the rear of the front "Y" split.
I expect that this is now standard irrespective of Zetec or Twincam application.
I did my S4 Zetec conversion on a tubular chassis but that was before Spyder started making Zetec specific space frames.
The Spyder Zetecs also use their "Double wishbone" rear suspension & in most cases their own front uprights, all to accomodate the Sierra brakes.
At the time I bought the Spyder space frame I also bought their rear suspension set up & front adjustable spring seat dampers & springs.
Assemling the springs to the dampers was a frightening experience.
The amount of compression required & the resulting closeness of the coils gave me a "funny feelin' in me water".
When fitted to the space frame the massive difference in the rear "wishbone" lengths just didn't look right to my eyes & would, I thought, cause massive camber changes.
The result of this was reverting to the rear struts using TTR damper, 2.25" springs & adjustable platforms. A pair of matching TTR front springs were also fitted ( a darned sight less hairy to fit)
Sorry to have rambled on but these were some of the things that I had noticed, changed & could possibly have an influence on ride height.
In a previous mail I mentioned the sump height problem.
If Spyder use an unmodified Mondeo sump they may have decided that the increased ride height was/is necessary in order to provide the necessary ground clearance.
Someone also mentioned an additional central silencer. This would also be ground clearance/ride height factor.
Dear purists, I hope you've been looking in another direction during all of this Zetec splurge
To the Rivet counters I have generalised a bit in places just to prevent this mail turning into "War & Peace"
Cheers
John