Just wanted to share with those who've been talking about bumpstops and sport (non-c/o) springs lately:
I've wanted to get the BMW PS springs for over a year to go with my koni's. I didn't want the whole 'new' PS kit because of how lousy my oe zsp dampers were and just figured the koni's would have better (and adjustable) damping than whatever BMW provides w/the PS kit. The PS kit dampers were engineered to be used with runflats and I've been off of those for 3 yrs and have <19 lb wheels. The PS springs have been available for over 2 years but you couldn't get the front PS bumpstops seperate from the kit (I've been asking Tischer for over a year). The rear PS bstops have been available. Lot's of folks have added the PS springs to the 'original' or V1 PS kit but that kit was engineered to be used w/zsp springs. Anyway, I didn't want to mismatch springs and bumpstops, so after 1-2 yrs of waiting I contacted Dan@UnitedBMW (1addicts vendor) ; he contacted BMWNA about getting the front PS bstops seperately and voila-1 month later I've got 'em
I want to thank a few of you guys that have the new V2 PS kit for answering some questions
I've read a few threads where people are installing PS or aftermarket sport springs and wondering what to do about bstops. I think jwong77 and luckyu have used the E36 M3 front and Z4 rear bstops and are happy with the results (this might be what Dinan uses for their E9X susp kits). But if you're going to install the PS springs, why not use the bstops engineered to work w/those springs? They're used as a secondary spring after all. The p/n is 31 33 6 789 540. For comparison's sake I measured the height of the old v1 and new v2 PS bstops and the zsp bstops. The v1 bstops feel alot firmer than the other 2 and are taller; the front v2 bstops are firmer and shorter than zsp; the rear v2 bstops are shorter than zsp and feel close in firmness. I have no way to measure density or rate with these bstops but here are the measurements:
From left to right are: ZSP F-2 3/4", V1 F-3 1/16", V2 F-2 3/8", ZSP R-2 7/8", V1 R-3 1/8", and V2 R-2 5/8"