The downside of being the first in North America to modify the BMW 135i Coupe is that we were sometimes the guinea pig for various parts. On a few occasions, where no instructions were available, we made an educated guess about how parts might fit. Generally, we guessed right but we admit to a few errors. So in this update we plan correct a few wrongs and install some new parts.We hoped the longer H&R springs...
We hoped the longer H&R springs and strong Turner Motorsport end-links would resolve our 135i's problems
As You May Have Read In Our Blog Posts At eurotuner.com, we snapped both sway bar end-links holding our H&R sway bar in place. To be honest, the stiff 135i shell and firm H&R Street coilovers from Turner Motorsport (TMS) meant the car remained driveable, but it needed to be resolved.Since we were among the first to install H&R's 27mm front bar, there was some uncertainty about the cause of the breakage. So we obtained adjustable front sway bar end-links from TMS. These ball-jointed rods were both stronger and allowed adjustment to accommodate a range of sway bars.
Before we took them to BMW specialist, BMS in Santa Ana, CA, we were advised that the problem was possibly caused by incorrect location of the H&R front struts. It appears the aftermarket units don't have a locating tab to ensure they fit into the spindle clamp as the OE parts do. Therefore, it's relatively easy to misalign the struts, causing the end-link brackets to be out of position. This would explain the stress our stock end-links suffered, resulting n inevitable failure.
To avoid similar problems, we were advised that the locating slot in the spindle clamp must be 47.5° (+/- 2.5°) away from the vertical edge of the sway bar bracket. To achieve this, take a straight edge from the sway bar attachment point and make a mark on the seating ring. From that mark, measure 18mm round and make another mark. This second mark must line up with the center of the slot in the spindle clamp!
 Chris Welch from BMS can do...  Chris Welch from BMS can do this job sitting down! |  Our snapped OE end-links and...  Our snapped OE end-links and the rose-jointed and adjustable TMS replacements. Adjustment used on racecars when they're corner-weighted |  When fitting the front struts,...  When fitting the front struts, you need to ensure they're properly aligned to avoid stressing your sway bar end-links. To do this, measure 18mm from the sway bar bracket. The second mark should align with the slot in the spindle clamp |
Fortunately, Chris Welch from BMS knows his way around a BMW and was easily able to rectify the problem. H&R now includes an alignment template with its kit. And since he was re-aligning the struts, we also asked him to fit new front springs.
We had also installed the first coilover kit and nobody was sure how it would work. As it happens, the ride comfort is exceptional, but the ride height was a problem. We love a slammed car but the front springs didn't give us enough clearance. We were constantly scraping the belly and air dam on curbs and speed bumps. We also encountered problems fitting our 19" wheels, since the front tires were tucked, even with the coilovers in their highest setting, causing them to rub when we turned.
To resolve this, H&R supplied another pair of front springs, which Chris fitted. However, they didn't make a huge difference and again had to be raised to the max setting. But we can now turn the 19s, so hopefully these new taller springs will be supplied in the H&R coilover kits.
 17 and 16mm wrenches needed...  17 and 16mm wrenches needed to replace end-links. Ensure ball-joints are parallel to bar before tightening to allow full movement |  BMS was able to undo front...  BMS was able to undo front struts from top mounts and remove springs without undoing bottom pinch bolt. These springs weren't under tension, so didn't need spring compressor, but this is not always the case, so take care. We loosened bottom fixing on driver's-side to rotate strut so sway bar bracket was properly aligned for end-links |  As you can see, H&R 135i Street...  As you can see, H&R 135i Street coilover spring v2 (on left) is barely longer than original, but its seems to have raised car "just enough". When installing, ensure springs are properly aligned and located in their perches to ease subsequent adjustment. To set ride height drive car to settle springs, measure each corner and adjust perches |