Here’s my most recent suspension change; Bilstein SPs with JCW springs.


I’ll save the evaluation for later, right now is the installation story. The only thing I had known about these struts previously was their reputation for stiffness (and they are), after my first attempt installing the front struts, I learned about their steering knuckle insertion obstinacy. This couldn’t happen at a worst time with a storm approaching and a strut stuck in the knuckle I had to go Neanderthal on them. After the Bilstein was extracted I took measurements (Bilstein 52.4mm diameter, Stock 52mm), paint had to be removed from the base to get it started and more paint removed from certain areas.


Once again it became lodged and wouldn’t budge with help from chisel or pry bar. By now the storm had arrived and time had run out. I discovered neither a spring compressor nor assistant is needed to remove and install JCW springs; even without an adrenalin overload.

I began to plan for the next attack on the install and found this was not an isolated occurrence. Unfortunately it was the first MINI specific sale by the distributor I purchased through so it was a learning curve for both of us. After receiving a few tips and a vague tool suggestion by Bilstein (couldn’t get the Facom tool in the U.S. from a conventional source), I found an alternative tool and thought I was prepared to try again. More paint came off and I tried a BMW suspension spreader (socket with nub, insert and turn 90 degrees), but no luck, so it was time to get aggressive with a drum sander.


I polished the surface with various grades of emery paper and put the spreader back in.



In the mean time I made more observations, notice the welds under the spring perch on the troublesome right front strut (on the left), it had a silver sticker too; I wonder if it’s a rebuild with two coats of paint. The driver’s side strut also had a smaller diameter of 52.1mm so I thought I would get a break on installing that strut.


With the hole in the steering knuckle reamed out, the spreader in place, and both surfaces smeared with anti-seize, in goes the strut. An inch down the BMW spreader falls out because the strut has widened it further. Bilstein had suggested a ¼ inch drive (insert and turn 45 degrees) to spread the gap but before it wouldn’t fit, now it did and that helped inch it in. I don’t know how the strut will ever come out again because there also was a jack lifting from below (completely lifting the vehicle) and I was applying force to the chassis from above (ProMini’s suggestion).


Here’s a close-up of the two suspension spreaders, the “shade tree” version on the left and BMW's on the right.


The driver’s side only required a polishing with a fine grit drum sander & emery paper, plus a little edge dressing with a file to prep, more anti-seize, the BMW spreader, the jack from below, and me bouncing on the chassis.

Here are some fun facts. Bilstein designs in some fluid seepage to keep the swipe moist. I think the leakage is excessive on one of the fronts (no photo) but it was suggested to install any way to see if it will moderate later.


See how large the shaft is on the front strut.


That’s because the piston is in the shaft and it’s really an upside down design, with the bump stop incorporated within the lower body. The rear shafts are larger also. The rear spring perch is 5mm lower than stock and the front’s are 7mm lower; now that the fronts are on, the forward rake I’m so fond of has returned.

 

i had the same issue. love the dampers though and mine are paired with h&r's. anyway i removed the paint, coated them with corrosion X, then got them in as far as they would go, put the wheels back on and lowered the jack so the weight of the car (maybe with alittle bounce or two, i dont remember for certain) got the the rest of the way in. when i had to get them out once i used a baseball bat set in the mount next to the strut and hammered on the handle. a 2x4 will split. BTW i didnt notice any seepage on mine.

 

A combination of removing the paint and the tool worked perfectly. They went in and out easier than stock. I love the sports with H&R.

 

Oh yeah, gotta love all that paint on those bad boys... I had the same issue - and that squared off bottom doesn't help get it in there, either.

 

And I thought I had a rough day with my suspension project! Creativity and persitence...

 

lol i had the same problem with the billstein front struts. i used a bigger hammer and knocked the knuckle onto the strut. slowly but shurely it went on. poor design let me tell you.and i used about a half can of wd40

 

The front SP struts were stiffer than I could enjoy during daily drives so I sent them off to ThyssenKrupp Bilstein of America for a change in valving. Unfortunatly, the strut bodies were damaged during return shipping due to poor packaging. Bilstein responded with great customer service; instant pick-up and rapid return. The internals of my custom valved struts were installed in new updated bodies. I would like to think it was my feedback on MINI specs a few months ago that prompted the changes but that only matters to my ego; the important thing is Bilstien’s willingness to accommodate.

The lower section of the new strut has .4mm machined away to facilitate fitment. The diameter is 52mm just like the stock strut although un-tapered. The demarcation line can be seen between the two tabs.


Another nice touch to ease insertion is the removal of the former square shoulder by machining a 35 degree angled bevel on the outer edge of the lower strut body.


The specs for the custom valving are about midway between the SP and HD variants. The head tech told me care was taken to retain the standard SP’s anti-roll characteristics while softening the initial jolt that would be felt when encountering sudden road irregularities like expansion joints. For sure the ride can not be mistaken for a sedan, and true to engineering intent, body roll is very limited; I’m reminded of the ride the previous installed fat front sway bar provided and that’s a good thing.

 

Did you only do the fronts? What was the cost and how specific did you have to get with the request?

 

Only the fronts were re-valved for $65 per strut; the rears already performed well with the stiffer rear springs and increased rear weight bias I’m running, without being too rough on bad roads http://www.bilstein.com/services.php...9b7b60afae3387 . There is service request form that must be completed and sent along with the struts; current and desired behaviors were spelled out as well as specs for the springs (both stock and JCW).

 

Keith,
What an ordeal. It takes someone with your persistance and patience to sort these things out. Good work and thanks for posting. You'd think that the manufacturers would get it correct before they release the product to the market.
Installed my Leda struts last Winter, with no problems what so ever. The company subsequently went into receivership. So, these aftermarket products have their down sides.

Track day today, Yippee.

John Petrich in Seattle

 

...hmm, Bilstein and H&R seem to have similar problems...H&R Sportcoilover utilize Bilstein inverted dampers. Mine are officially gone.

The lack of a step in the dampers is a big problem - mine moved 1/4" after hitting a pothole - thankfully the brakehose flange stop this one from going any farther. And the sanding and grinding...as you stated John, should not be part of the install - the H&Rs were no different. In addition, the welds along the pinch bolt flange required a fair amount of grinding. Otherwise the flange would not fit in the knuckle.

 

I have enough road time on the custom valved fronts with the standard rears to make a ride report. Slow speeds over railroad tracks and rough roads are still a bit harsh, but on the roads where cornering prowess holds precedence, the struts perform masterfully. It’s not only the expected aspects of wheel and body control that have seen an improvement but the reaction to steering inputs have quickened as well. I must add alignment settings have been altered so the steering changes can’t all be attributed to the SPs. For the current setting I dialed back negative camber & toe in the rear, and as a result of lower wishbone bushing replacement, front camber was reduced; steering response is very sharp without feeling tail happy. With the amount of added rear weight my car carries I wouldn’t have describe it as feeling light on its feet before, but lately it reminds me of a Jack Russell Terrier with the way it shows a willingness to dart about. No more lost energy due the front sloshing around.

One of the advantages of the SP design is increased travel up front. Our poor MINIs have about two inches with which to absorb road energy on conventional front struts and often the bumpstops are carrying the load especially with reduced block height springs. The front SPs have an internal bumpstop and a shorter neck above the lower spring perch that allows more travel so the spring can do the work it was designed for. When I hit a dip at the bottom of a hill, that increased travel makes itself appreciably known; of course the stout damping slows things down also.

As with just about any performance oriented modification, the SPs are not a one size fits all situations and sensibilities, but I can’t help thinking many are looking to coilovers when a well designed non-adjustable strut can provide the same kinds of benefits.

 

are there posted spring rates for the jcw's? also about how much lowering do they claim. im running the standard sp's with h&r's. thanks

 

No published rates; keep in mind there are three versions for the JCW springs so comparisons of wire diameter, outside diameter, and unloaded height can be used to get in the ball park. This sounds counter intuitive but a shorter spring height with similar other measurements usually means a greater rate according to the head tech at Bilstein’s service center.

The claimed drop for the JCW springs is 10mm, combine that with a 7mm lower spring perch in front and 5mm lower in rear for the SPs results in about ¾ inch drop once settled; the reality is a little more than that on my vehicle.

If you want to take some edge off the front rates mine were revalved to 174 rebound over 57 compression, standard SP valving is 141 over 96 expressed in Nm @ .52/sec.

 

Did the increased rebound help control some of the oscillations on bumpy roads?

 

I didn’t have oscillation before the valving change and none afterwards. There was body movement over slow stuff before but I attribute that to stiffness; the chassis followed the road in close relation to the wheels instead of being stably independent. It’s still not perfection but it is very good.