HI All
I spent a great day up at Tudor Motors, Kevin Vernon's place in Market Drayton, where we fitted one of the new Suplex rising-rate suspension conversions to the front of my 1986 4/4. The kit comprises springs, shock absorbers, radial thrust bearings, adjusting collars, and spacers. The idea is that you use the adjuster to make sure that the ride height stays the same and the rebound spring remains just free - the adjustment allows the kit to deal with a wide range of car weights.
Installation is very easy. Strip out the old suspension, bung in the new rebound spring, the spacer, the radial bearing, the dinky little spring that grips the top of the kingpin, the main spring,and the adjusting sleeve. Then bolt it all up together and set the ride height. The instructions are very clear and straightforward, the way they suggest the installation is done should be pretty foolproof, if a little time consuming. Because we had the car jacked up on the 4-post lift, it was very easy to set everything up without fitting the wheels until right at the end, making access very straightforward.
And the result? Well, I knew that the developers of the kit certainly knew their suspension systems, but nonetheless the outcome is frankly little short of staggering. On smooth roads there's really not much difference over the standard setup, but on bumpy backroads, or indeed anything less than motorway/trunk road quality surfaces, the suspension just soaks up the humps and bumps. There's no harshness, no crashing, no pitching or nodding. What's really impressive is that the revised front suspension complements the rear much better than before, with the result that the car remains much more composed - definitely a harmonised package (I have the later 4-leaf rear springs, with Panhard Rod and Anti-Tramp bars).
I put the car through some pretty extreme tests on the extensively potholed backroads around Market Drayton, including one stretch we found where the road surface had been scarified off to a depth of a couple of inches, with hard steps down from and back up to the road surface proper, but only over half the carriageway, so one wheel was thudding down a couple of inches and then back up over a sharp lip whilst the other was just having to cope with the normal bumps that you find on unclassified backroads. The first time I did it, I had a fraction os a second's worry that I had overdone it (I was doing at least 40mph at the time). But no, the car just drove straight through smoothly, with no jarring whatsoever. Kevin and I looked each other in surprise, and then proceeded to repeat the exercise half a dozen times on the following scarified sections to prove it wasn't a fluke.
The price is not trivial, the kit is nearly GBP 600 + VAT, and of course fitting will require a few hours. I daresay you could rip through the job in a couple of hours, but what's the point? May as well take the time to clean out the stub axles properly, and use the opportunity to ensure everything else (tracking, camber, etc) are all set optimally. But in terms of a single simple upgrade that would transform the handling of just about any trad car, this has got to be worth considering. Kevin's only had the kits available for a week or so, and he's already fitted 2 sets, so expect strong demand - get your names down quick if you want him do you a conversion. Other suppliers are available, of course :-)
The usual disclaimer applies: I have no connection with Suplex or Kevin Vernon, apart from as a very satisfied customer.
Tim
