26/02/2024
I ran a car and van parts company mainly for German vehicles for around 20 years and supplied many suspension components for including lowering solution’s. The following article was my response to someone asking what these straps (travel limiters were for) and someone’s response about the prevelence of “crap” springs out there. My answer includes observations of different spring designs and maybe of interest to anyone considering lowering their vehicle.
The springs “crap,” mentioned exist because of owners obsession with modding, the emphasis of form over function and being overly sensitive to price.
VW Transporter T4s (and other vehicles) were not designed by the vehicle manufacturer to be very low. To achieve the look that a significant number of people want without the likelyhood of the springs falling out can be achieved in a number of ways.
1. Keep the springs as long as possible achieving lowering by the spring being weaker. The problem with that is the springs becoming coil bound all or most of the time. People go for this because it is cheap. Also the ability of the van to carry loads is severely compromised. The greater the lowering the greater the compromise on load capacity, handling and comfort.
2). Use variable gauge springs. Commonly called pigtail springs. Vw themselves use that design on the transporters at the lower end of standard ride height. Also H&R and Eibach use this design. The disadvantages. With that are price and that the tendency for them to snap at the ends where the gauge becomes thin. Springs like this for the T4 tend to be more modest in the amount they lower the van by.
3. Use a shorter stiffer spring along with that limiter strap as in the picture or shorter dampers. This is a good idea but the compromise here is only that common to all lowering attempts is that the potential suspension travel is decreased. While the strap prevents over extension, compression is limited by the damper bottoming out and or hitting the bump stop with much less suspension travel occurring than envisage by the engineers at VW. In the event of bottoming out specially if it is the hard bottoming out that occurs when the damper reaches the end of its travel, both comfort and handling is severely compromised.
Vw designed the suspension as it is for good reason. I recall T4s R is used to have green - 80 springs they used to hate selling and would always warn that the van would drive rubbish but people bought them regardless.
Markets provide what customers want to buy and are prepared to pay for. Engineering is about juggling compromises. People’s obsession with modding, form over function and thinking that cheapest is best underlies the tendency to result in poor outcomes. People would do well to research the compromises in the original design and the re ranking of those compromises that a “mod” will logically entail.
