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| BMW Strut & Spring Guide |
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 Vorshlag sells camber plates for various E30, E36, E46, E90/92, and E82 chassis BMWs, and each model has dozens of strut and spring styles to choose from for our matching upper spring perches. Vorshlag camber plates must include new upper spring perches for a perfect fit. The first section of this page shows the common BMW strut end types that are available, sometimes multiple types from the same shock manufacturer (which is where it gets tricky). The next section shows the various spring styles and sizes that are available. Lastly, we list the seven basic upper spring perch designs that are further configured to work with the various strut shaft sizes and ends.
This may seem a bit overwhelming to you, a buyer of camber plates - just imagine designing and building all of these variations! Instead of making one camber plate to work with all struts (one-size-fits-all), we accept nothing less than a perfect fit. Perfect fits mean no slop, no noise, no unnecessary wear, and no returned parts! Due to this, we make customized spring perches with matched bushings to work with each different strut manufacturers mating surfaces and diameters. This ensures that you have the most options for your BMW, and many worry free miles on your track or street car. These perches all have a heavy duty, sealed axial bearing and the appropriate spool piece adapters for the shaft diameter, length and shoulder for the struts you are using. The extra effort to verify this strut information is well worth your time in the long run, as this gets you the right parts. The end result is a customized spring perch assembly that works with all of these variables. There is no 100% fool proof way for us to know what you have on your car without seeing your suspension up close and apart, so we hope this page helps our buyers (and other BMW enthusiasts) become better informed when they are buying camber plates.
Exploded views of the main Vorshlag spring/strut camber plate set-ups (click to enlarge):
Bilstein w/ OEM Springs |
Koni w/ OEM Springs |
Koni w/ 60mm Springs |
Note: If you are putting a new set of springs and/or struts on your car before installing camber plates, then please take a look at the parts while apart to verify strut shaft diameter, shoulder style, and spring type/size. If you do not have your suspension apart to verify these issues, and are about to order camber plates - don't worry. Contact us and we will likely know exactly what you need. We have sold hundreds of sets of camber plates and know what works 95% of the time, just from strut brand and year they were built. This guide is mainly to verify those handful of cases where there are potential unknowns or unusual components.
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BMW Strut Styles
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Strut design has a lot to do with the spring perch selection, namely: inverted strut or non-inverted, what diameter upper strut shaft is used, what type of strut end "shoulder" the perch will land on, and upper strut nut diameter. The first variable to determine is the brand of strut you have, which helps determine many variables (sometimes everything). In some situations it helps to know the upper strut shaft diameter and strut end shoulder style. There have been a few changes over the years within the same strut manufacturer, and sometimes a visual verification is sometimes needed in order to get the right spring perch. The pictures below show you exactly what to look for.
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Koni Square style strut end. 14mm diameter shaft with square shoulder. Similar to many Moton and AST non-inverted struts. This is usually what is found on Konis purchased before 2006. Pic 2 - Pic 3
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Koni Square Strut End with 16mm diameter shaft and square shoulder. Somewhat rare, GC Advanced Design Koni struts use these larger 16mm square shouldered shafts. Please order perches for 14mm Koni style square struts and in the notes section specify that you have Advanced Design struts. AD's work with 2.5" diameter coilover spring perches, unless you have had them custom made for 60mm springs.
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B&G Coil-Over with 12mm diameter shaft and square shoulder fits B&G "PS2" coil-over struts for BMWs. This B&G is fairly new (late 2006) and uses a smaller 12mm shaft diameter on the common Koni square shoulder. One of our dealers sells B&G so we made the parts to be able work with our camber plates. Please order the 60mm perches for Koni style and note the 12mm B&G shaft in your order. If your struts have this 12mm upper strut shaft diameter and use 2.5" perches, order the Koni style 2.5" perches and note the 12mm shaft size in the order.
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OEM (or later Koni) Tapered Strut End. 14mm diameter shaft with tapered shoulder. Similar to most stock BMW struts, these are easily spotted by the tapered top washer that is used with the stock struts. BMW (OEM), Sachs, Boge, and even some newer Konis typically have this shoulder. If you purchased Konis after 2005 you need to double check your struts to see what you have (or contact us if you cannot disassemble your strut before ordering camber plates).
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Bilstein Sport Inverted struts (non-adj/non-PSS9) with 14mm Strut End. Inverted struts with a very short 14mm diameter shaft and Bilstein specific square shoulder. Bilstein, H&R, and other "inverted style" coil-over kit struts will usually have these ends. We have perches to work with these struts and OEM style springs or those that have been modified for use with 2.5" or 60mm coilover springs (a somewhat common conversion). There are also a few 16mm shaft Bilsteins out there (rare). We sell a LOT of kits for Bilstein Sports...
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Bilstein E36 PSS9 (adjustable valving, not Bilstein Sport) coil-over struts are fairly common (read: cheap) and made for several generations of BMWs. The E36 models have a 14mm diameter shaft with a square shoulder (similar to Koni square shoulder) and use a "unique" coil-over spring from Bilstein that has a 60mm lower diameter but the upper spring diameter is made for an OEM style upper perch. If you want to keep the included tapered springs Bilstein provides in these kits, order the camber plates with an OEM-style Vorshlag upper spring perch option for your appropriate year car. You can also take the extra step and convert to real 60mm coilover springs and ditch tapered Bilstein supplied springs. Using real coilover springs gives you hundreds of rate and length options to choose from, lowers unsprung weight, and allows more negative camber adjustment (larger diameter springs limit camber travel to the strut tower). See entry below for more.
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Many if not most of the E46 PSS, PSS9 & PSS10 applications and some KW coilover kits all use an a similar "tapered" spring design as the E36 PSS kits, which again has a 60mm inner diameter at the bottom but grows to fit into the large OEM upper spring perch/bushing at the top (see picture above). This is not a true "coilover" spring design, which would have a constant 60mm or 2.5" inner diameter. This "big headed spring" causes problems in both sourcing alternate spring rates (there are none in this style) as well as for limiting camber travel, but we can and do make OEM style upper perches for use with Vorshlag camber plates. Remember: The E46 M3 and E46 non-M cars use a different upper perch, but we make models for both. The E46 M3 PSS series uses a taller spool piece, but we'll know how to build it when you order your camber plates - just make sure to mark the model of strut and style of upper perch set-up car has (OEM non-M, OEM M3, or 60mm upper - we've seen these struts sold various ways).
If you would like to convert your PSS/PSS9/PSS10 or KW struts that came with a "tapered" spring to a true 60mm coilover spring, we can also help you source springs plus point you to the correct upper perch that can work with Vorshlag plates. This is a very popular and common upgrade for our customers with PSS series struts.
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As you can see there are a number of options for struts, just for 3 series BMWs.
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BMW Spring Styles
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The other part of the camber plate formula is the spring style and diameter. By spring "style" we mean stock or stock style (with "pig-tailed" or tapered spring ends) versus coil-over style springs (which have a constant spring winding diameter). Vorshlag's camber plate design uses a sealed bearing in the upper spring perch, making a specific Vorshlag upper spring perch assembly be sold with our plates. We make upper spring perches to fit the 3 main spring types sold for most 3 series BMWs, including:
60mm Coil-Over Springs
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Here is a picture of a commonly available 60mm "coil-over" style spring. This 60mm measurement is of the inner diameter, and is usually part of a spring makers part number. Being metric, the spring rate is usually shown in Newtons/mm (this one is rated "70" N/mm). We also like to measure in Fig Newtons, but this measurement system hasn't really caught on yet... Lastly, the free (uncompressed) spring length is shown in millimeters, with the spring shown at left being 170mm long (6.7"). 60mm coil-over springs come with many european sourced aftermarket "coil-over" struts that have adjustable height spring perches. These are the smallest diameter springs commonly found on modified BMWs, and have huge array of spring rate and free length choices. Vorshlag stocks and sells a limited number of 60mm springs.
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2.5" Coil-Over Springs
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Here are pictures of a 2.5" "coil-over" style spring (and they do look very similar to a 60mm spring). This 2.5" measurement is also of the inner diameter (which is 63.5 mm). This is the other popular aftermarket coil-over spring commonly available for BMWs and other cars (domestically sourced). Being a non-metric size, the spring rate is usually expressed in pounds-per-inch of travel, such as 500 pounds/inch. This is commonly referred to as a "500 pound" spring. No, the spring doesn't weigh 500 pounds, but it would take 500 pounds of force to compress the spring by 1 inch. The proper way to order springs like this would be to know the free length of the spring (5, 6 or 7" is common), the diameter (such as 2.5"), and the spring rate (such as 500 pounds-per-inch). (Note: we do not address 2.25" dia, 2" dia and other odd diameter coilover spring sizes at this time)
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Stock Style Springs
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 Here are pictures of various stock BMW spring and "stock style" aftermarket spring sizes. The upper spring perch needed is a modified OEM perch made to use a double row sealed axial bearing (which is twice as strong as the stock unit); see the perch section below. Stock Style aftermarket springs include dozens of popular lowering springs that many BMW owners tend to go to "first", before they get serious about racing and/or feel the need for higher spring rates (and the larger number of rate choices) that coil-over style springs allow. Being a stock style spring, they typically do not work with adjustable height spring perches and take up more room under the fender (slightly less camber adjustment range). These types of springs also tend to come in much softer spring rates, and are often variable rate (the first inch of travel is soft, and they stiffen as they compress). There are dozens of brands, rates and free lengths to choose from, and several pig-tail end sizes for the factory springs made for BMWs (and the aftermarket has lots more), but most are covered by the "stock style" perches manufactured by Vorshlag, as shown in the perch section below. We have full coverage for E30, E36 and non-M E46 stock style springs.
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Above are a few more pictures showing various stock style and coil-over springs and struts, for relative sizing. The picture at the far right shows rear springs and shocks as well. Now you can figure out what springs you have - it is easy to visually check and/or measure, even while still mounted onto the car.
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Vorshlag Spring Perches
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As stated above, Vorshlag Camber Plates require a very specific upper spring perch be used, and the choice depends on the type of spring and strut design you have. If you have followed the sections above, hopefully you know what strut brand/shaft diameter/end style you have as well as the spring size and type used. We make the upper spring perches below to work with most struts and spring combinations, and there are a lot. The year and model of your BMW can also dictate the style of the spring perch (stock style springs, 60mm or 2.5" coil-overs) as well as the spool piece that adapts our spherical bearing with the strut shaft's shoulder and diameter. As usual, pictures tend to help. Here are the seven basic Vorshlag upper spring perches, each having several optional bushing inserts (spools) to work with the various strut diameters and strut shoulders:
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 95 M3 OEM style - fits 1995 M3 and all E30s, with stock style springs. The upper perch kit is sold with the necessary axial bearing and spool pieces pressed into place, as well as upper spool pieces.
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 96 M3 OEM style - fits 1996-99 M3 with stock style springs. The upper perch kit is sold with the necessary axial bearing and spool pieces pressed into place, as well as upper spool pieces.
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 E36 non-M OEM style - fits E36 318, 325, 328 (1992-1998), with stock style springs. We stock and sell these regularly, but many people that race non-M E36 cars tend to use M3 style struts & springs (which has a different swaybar mount) or go right to coil-overs.
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E46 M3 OEM style - This works with all 2000-2006 E46 chassis M3 models, with stock or stock style springs (H&R, etc). This uses a modified OEM steel E46 M3 perch and our bearing. We stock and sell these regularly. As mentioned elsewhere, the OEM style upper spring perch is used on various Bilstein PSS and KW coilover kits.
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E46 non-M OEM style - This works with all '99-04 E46 chassis 323, 325, 330 non-M models, with stock or stock style springs (H&R, etc). This uses a modified OEM aluminum E46 perch and our bearing. We stock and sell these regularly. As mentioned elsewhere, the OEM style upper spring perch is used on various Bilstein PSS and KW coilover kits.
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 Vorshlag 60mm upper spring perches are made to fit non-inverted strut coil over applications using the 60mm diameter coilover springs. These can be made to fit struts with 14mm square shoulders (Koni, AST, others), 14mm tapered shoulder (OEM struts, Boge, Sachs, newer Koni), 16mm square shoulders, or 12mm square (B&G), with various press-fit spool piece adapters.
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 Vorshlag 2.5" upper spring perches are made to fit non-inverted strut coil over applications using the 2.5" diameter coilover springs. These can be made to fit struts with 14mm square shoulders (Koni, AST, others), 14mm tapered shoulder (OEM struts, Boge, Sachs, newer Koni), 16mm square shoulders (GC Advanced Design), or 12mm square, with various press-fit spool piece adapters.
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60mm Bilstein Sport Coil-over - fits either 14mm (most common) or 16mm inverted strut coil over applications using the 60mm coil-over springs. These are for people that take a Bilstein Sport, cut the lower perch off and make a 60mm spring coil-over strut out of them. This is a very common conversion.
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2.5" Bilstein Sport Coil-over - fits either 14mm (most common) or 16mm inverted strut coil over applications using the 2.5" coil-over springs. These are for people that take a Bilstein Sport, cut the lower perch off and make a 2.5" spring coil-over strut out of them. This is a common conversion.
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 Bilstein Sport struts with stock style springs - we have OEM perch kits for all E30, E36 and non-M E46 set-ups using this strut and OEM style perches. Uses the same big sealed double row axial bearing that is on other OEM perch kits, plus our custom M14x1.5 (E36 & non-M E46) or M12x1.5 (E30) "long reach" topnut. Since this set-up comes with a Vorshlag designed long reach upper strut nut, installaiton wrench, and a tube of thread locking compound, there is an upcharge over other OEM perch kits.
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Once you know what you need, head on over to the Online Catalog and order up a set of camber plates!
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