Lapping Jefferson Extension

I had the MINI at Summit Point this past weekend on the extended Jefferson circuit and it ran great. I really like the new Bilsteins. Very predictable weight transfer, good grip, and nice ride-height. Currently riding about 40mm lower than stock in the back and 50mm lower than stock in the front. Could go another 10mm lower but don’t see the need currently.  (Interestingly, the current height is 20mm lower than H&R Sport Springs on Konis.) The car isn’t slammed and the tires aren’t rubbing, but it is fairly low. I did have to not use the 5mm spacers I normally run on the street to avoid rubbing the rear arches (the wheels are 17 x7 with offset 37.)

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Here’s a lap I filmed behind a student.

Bilstein PSS B14

Two years ago, we tried using the budget-priced Speedtech coilover suspension for MINI at the track. The suspension is the bargain cousin of the KW v1 coilover. Similar spring and (non-adjustable) dampening rates, a bit heavier construction, and a limited 5-year warranty. On paper, it’s a good trade-off of function vs price, but it wasn’t robust enough for heavy track use.  We blew out the right front damper the first season, and the left front the second.  For the street performance driver who wants to significantly lower the car without a harsh ride, we would still recommend it, but not for a car that will see a lot of track time.

Our favorite non-height adjustable suspension for the MINI is a set of B6 struts over H&R Sport Springs.  By far, that’s the best combination of predictable track performance and road comfort. The only major limitation for a trackcar is the size of the front springs which limits the amount of negative camber that can be dialed-in. The spring perches on the Bilstein struts are a bit lower than Konis so the car sits about 10mm lower on the same springs. Since we wanted to go just a bit lower than that, we started looking for heigh-adjustable coilovers.

This season we’re trying the Bilstein B14 Performance Suspension System (PSS). Bilstein offers five suspension options for the first generation MINI and the B14 PSS is second from the top (but the top is almost double the price).  At the low end, are the B4 struts for use with stock springs; followed by B6 struts to use with stock or lowering springs; the B12 kit which are B6 sport struts with Eibach Sportline Springs; B14 PSS described here; and the top of the line is the B16 PSS10 Adjustable Coilover Kit.  The goal of this experiment is to see if we can dial-in just the right set-up using just height-adjustment, camber settings, and adjustable swaybars.

The car goes for an alignment on Tuesday then it’s off to the track on Friday so we’ll post an update next weekend.

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