Hey Martin, So if I want to lower my D's rear using the adjustable shock option (with stock rear springs)... apart from setting the adjustable collar on the shocks itself, are there any adjustment I should do to the suspension setup on the car so it runs properly? And what is the minimal height the rear of the D can take before the wheel starts to hit the wheel arch when going over bumps? Cheers! John --- Martin Gutkowski - DMC Ltd <martin@xxxxxxxxxxxxxx> »¡¡G > Hi All (esp Mark) > > I've driven a lot of DeLoreans now, and more than > one with old front > springs on the rear. I also have moderately lowered > rear suspsnsion on > my own car, by about an inch with Grady's (former) > shock setup. > > 1) Front springs on the rear make the rear too low > IMO, in fact > sometimes lower than the front. Anything lower than > where the control > arms are level is a bad idea IMO. > 2) On my own car I've eaten 2 sets of back tyres in > 10,000 miles thanks > to the lower setup (toe-in is correct and although > I'm a fan of > wheelspinning, so is Chris H and he's done more > miles on one set :-) > I've got adjustable lower links on my other car and > the wheels sit > noticably straiter at the back. > 3) A softer ride on the rear makes an unbelievable > difference to the > ability to lose the back end, in a similar, but more > predictable way as > loose trailing arm bolts do. I've recently had two > cars in at the same > time - one Stage 1 and one Stage 2. The Stage 1 car > (less powerful) was > far too tail-happy. The difference was front springs > on the rear, and I > can vouch for the rest of the suspension on both > cars, and both had the > same set of pirellis. > 4) In playing with the adjustable suspension we do, > you can make the car > thoroughly dangerous (but a great drift machine, if > you're into that!) > by stiffening up the front and softening up the > rear. It's quite surprising. > > " > > The rear suspension uses the 'Second Order Lever' It > has its fulcrum and effort(spring) in opposite ends > and the load in the middle, just like a wheel barrow > set up. > > The front suspension uses the 'Third Order Lever' > The fulcrum and load are at opposite ends this time > with the effort(spring) is in the middle, such as a > shovel. > > " > I'm not entirely sure how you can apply lever > principles to the rear > suspension because as I see it, there isn't one. The > weight of the car > is passed directly to the hub carrier at one end of > the lever. The other > is just a pivot. There's no multiplication involved > unless you look at > the angle of the spring/shock which in this case is > only non-vertical to > get it out the way of the tyre, hence needing a > slightly stiffer spring > than if it were vertical, at a ratio exactly > proportional to the angle > of the spring/damper compared to the vertical (at a > guess, but it's > probably as near to no difference as makes no odds). > That's "moment of > forces" stuff and Newtonian physics, IIRC, but it's > a while since I did > my A-level Maths and Physics!). > > The front suspension is a second order lever, > although dealing with a > multiplication of effort rather than a division of > it. > > You're absolutely correct that all other things > being equal, the rear > spring can be weaker for the same effort, given the > geometry. > Unfortiunately all other things aren't equal because > someone had the > bright idea of plonking the engine over the back > wheels :-) > > http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0017416.html > > Martin _______________________________________ YM - Â÷½u°T®§ ´Nºâ§A¨S¦³¤Wºô¡A§AªºªB¤Í¤´¥i¥H¯d¤U°T®§µ¹§A¡A·í§A¤Wºô®É´N¯à¥ß§Y¬Ý¨ì¡A¥ô¦ó»¡¸Ü³£ÉN¨«¥¢¡C http://messenger.yahoo.com.hk DOC UK Website: www.deloreans.co.uk Unsubscribe: doc-uk-unsubscribe@xxxxxxxxxxxxxxx ** Unless otherwise stated, all messages posted to the group are assumed public and may be printed in the club magazine ** Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/doc-uk/ <*> To unsubscribe from this group, send an email to: doc-uk-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/