THE REAR

Now that the front is done, lets tackle the rear. It's only fair to let you know that the rear is more difficult to do than the front. Even though there is less to undo, the lower control arm is tricky to get back in and get the bolt through. Having two jacks helped a lot.

Jack up your car and remove your wheel. Secure the jackstands and ensure you are working safely.

Don't tap on threads with a hammer to push these balljoints out. Use a puller. You can rent them for free at most quality auto parts stores.
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Start by removing two upper bolts for the rear shock.
The bottom of the shock is held in place by a single bolt. Once you remove it, the entire shock can be removed.

Next, we need to start removing the bolt that holds the end of the lower control arm to the rear cradle. You'll only be able to get it out so far before...

You run into this- the rear exhaust is in the way. So we'll need to either drop it, or do what we did- raise it just enough for the bolt to *almost* clear. This is where the second jack came in handy. We simply raised the exhaust enough for the bolt to come out. It's still tight, but a bit easier getting the bolt out than dropping the exhaust.

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This picture doesn't show it too well, but the top arrow shows how the lower control arm is seperated from the cradle, the the lower arrow shows how the control arm is actually dangling down. Once it is down, you can remove your old spring in preparation for your new one.
Remove the old lower spring rubber. In this photo, we used some spray lubricant and ran the new spring inside it. It was a bit easier getting it on this way.

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Now install the upper collar into the spring, and then the spring into the car. With this kit, there was also a rubber gasket that goes between the collar and the body. You'll need to remove the rubber spacer that the stock spring was sitting in because you won't need it.
With the spring installed, you can install the rear shock.

Now that the spring and shock are installed, you can install the lower control arm.

Some tips on installing the lower control arm.​

• It might be easier to put back into place without the shock installed. It can go in last if needed.
• Using two jacks may help. In our case, we kept the exhaust raised up for the bolt to be pushed back through the lower control arm.
• You might need a pry bar to help maneuver the control arm in place. Just be careful, remember you are probably on jackstands.
• Use a screwdriver or something to put through the hole, so if you need to lower and re-position the jack, you won't have to start from scratch.

 

Interested in knowing how to adjust the coilovers? Lets start with the front.​

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Using the supplied spanner, loosen the lower tightening ring (1). The idea is to thread up (2), the bottom adjuster part of the strut. This will shorten the length of the strut, lowering the car. If you want to raise the car- thread it down, to lengthen the strut and make the strut longer.



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I took all three rings and locked them together. This made it easy to use the spanner and turn the entire strut in the direction I needed it to go to extend or shorten it.


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Here is the strut in it's lowest position. Take the bottom ring and lock it down to the lower mount.

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To explain this another way-
- upper gold collar adjusts preload
- lower gold collar locks upper preload collar
- lower mount in blue adjusts ride height
- collar in red locks blue lower mount in place.

Ideally you just want the gold collars barely snug against the spring. If you add preload and start to compress the spring, you will have a very very tough time adjusting ride height while the shock is on the car. This is because you are supposed to spin the shock body up or down in the blue lower mount. If the gold collars are pushing too hard against the spring, they won't let the shock body spin, and you won't be able to adjust ride height.

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What about using the rings to lower the car by bringing the spring down? That's not how this system is designed. The two top rings used for the spring are to pre-load the springs. Lowering the car by adjusting the springs will damage the system. In simplest terms, it may allow the dampers to bottom out- exactly why we paid money for a high performance suspension system versus using factory parts- so it doesn't bottom out. Don't do it!

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What is pre-loading and how do you do it? Loosen the lock rings and take all the preload off the springs till they hang loose and you can move them up and down between the perches. Then move the spring perch up, turning with just your thumb and index finger till you feel some resistance and cannot turn any more easily. Secure the lock ring and that should be a good starting point. This would be 0 preload.

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Setting a higher preload gives the Magnum less of an initial dive/pitch under braking or acceleration. This is good to have as you want to keep the car as even as possible. You dont want to take weight off the wheels that you want to keep down during heavy acceleration or braking.

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When you put the weight of a corner of a car (probably around 700lbs) over your spring it compresses to absorb that weight. With 400lb spring, it will compress about 1 3/4". So, if you start with the lower collar so that it is just tight enough to hold the top of the spring against the upper perch this would be 0 preload. Raise the collar 1 3/4", and you now have 700lb's of preload. (arbitrary #'s for the sake of illustration.) Since you have preloaded the spring, the same weight as the car's corner, when you put the car on that spring, it will not compress at all, and will simply sit on top of the spring. If you were to hit a bump, the force would still compress the spring the same amount it normally would if you had set the spring to 0 preload. Now if you set the spring to say 900lbs of preload, when you hit the bump (say its a bump that generates around 250lbs of upward force), the spring will compress much less b/c the spring is already beyond the load specified to absorb the bump. Since there is only 50lbs beyond the preload, the spring will only compress about 1/8th inch, and the car will likely be launched over the bump.

You will likely never ever preload a spring beyond the weight of the corner of the car it is on for that exact reason. Springs are there to absorb bumps, if there are any bumps at all, this is a bad idea.


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What good is preloading the spring then?

It can provide you with more suspension travel in certain situations. In the ideal world, having the spring at 0 preload would place the piston inside the shock exactly halfway through it's stroke (middle of shock) once the car's weight is resting on the spring. This is almost never the case. By preloading the spring, you can adjust the amount of rebound, or compression travel you have in the shock. If you preload like 200lbs, this will give you more compression travel, and will help keep your Magnum from bottoming out when cornering. You have to be careful though, because you don't want to sacrifice too much rebound travel, or you could cause all sorts of other problems.


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Almost everyone recommends a preload of 0 for general street use.



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Now lets look at the rear.

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1: Remove the shock. Two bolts up top, one in the bottom.​

2: Loosen the upper locking ring.​

3: The lower ring will be the one that is moved to raise or lower.​

4: Move the lower ring in this direction to lower the car. Move it in the opposite to raise it.​

5: Install the shock again. Adjust it so there is no slack- meaning that once the bottom bolt is put through, adjust it so the top is already sitting up with the shock tower. You shouldn't need to use the bolts to suck it all together.


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Remember to take measurements of how one side is done, then duplicate this on the other side. Make sure both sides are equal in everything you do.


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How to adjust the firmness of the ride.

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Each shock and strut comes with these handy dial adjusters. They are pretty self explanatory. Set them hard for the track or soft for the street. They have 30 different adjustments. Whatever you set it as, just make sure you count them off and make them the same on the front and the same on the rear. Each axle needs to be the same.


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How do I have my suspension set up?


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1: I have my lower mount adjusted as far up as it will go. This is the shortest position for the strut, so the lowest my front will go.​

2: I have a distance of exactly 2 ¼" between the very bottom of the spring, and the very top of the lower mount. This preloaded my spring to a 0 at least, because I can still turn it with my hands, although it's pretty stiff.​

3: For driving around town, having my dampness set at the softest was ok. When I took my car on the freeway, it bottomed out on a couple of bridges. I played with the settings, and right now I have them set at this- start at the softest- and I turned them 13 clicks to the hard side- both fronts.This stiffened up the ride a bit, and we're still playing with these settings.


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The distance between the ground and the wheel well (top, tires at 35PSI, 275/40/20" tires) is 28½", exactly for both front wheels.



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The Rear:


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In my car, I have the rear set up like this. I have a 1¼" space between the bottom of the bottom ring to the bottom of the rear collar.


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The distance between the ground and the wheel well (top, tires at 35PSI, 275/40/20" tires) is 28¼", exactly for both rear wheels.

The above measurements are only to reference MY ride height.
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Here is the car at it's maximum height.

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Here it is at it's minimum height.​

Measurements from the center of the hub to the top of the wheelwell.
STOCK SUSPENSION:
On Ground Rear= 17.5"
Off Ground Rear= 21.75"
On Ground Front= 17.75"
Off Ground Front= 21.75"

BCRacing Coilovers (MAXIMUM HEIGHT)
On Ground Rear= 16"
Off Ground Rear= 20.5"
On Ground Front= 18"
Off Ground Front= 21"

BCRacing Coilovers (MINIMUM HEIGHT)
On Ground Rear= 13.5
Off Ground Rear= 18.5
On Ground Front= 15"
Off Ground Front= 18"

Now we needed to find way to get at the adjusters in the rear. When we had the shocks out, we drilled a small pilot hole up through the top shock mount. It put a small hole in the plastic in the back. Then we took a 1 1/4" hole saw and made two holes. Then we took some sandpaper and cleaned it up. Now we can make adjustments to the rear shock dampness when we need to from soft to hard. Then we bought some 1 1/4" metal plugs to put in the holes for a cleaner look.


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With all of that, here is the final stance.



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If you felt these posts were helpful, feel free to send some rep points. A lot of work went into this and it's still not done.

BCR is changing the rears on my recommendation to allow for the car to go higher in the rear to match the front.

Now for my official review of what we have so far. Ready?



The fit and finish of the parts are great. This was the first time they were put in a car (these are the prototypes) and everything went in smoothly. The black and brass theme that BCR uses looks great. It looks more performance oriented than flash and show.

I've been able to put some drive time under this suspension. I just wanted to give everyone a quick update on my feelings on them.

Let me explain it in one word- SMOOTH. My car glides along the road and it feels like I'm just gliding along. Bumps in the road don't bother me anymore like they did with springs only. Same with coming on and off bridges on the freeway. I have the rear set at max soft and the fronts either at max soft, or at 15 clicks in (which is right between max soft and hard). It just feels like it "should". I have a performance suspension, and can make it feel "performance" with a few clicks of the dampers. But I don't have a Hemi, (and AWD no less) so I'm not much of a performance oriented guy (although I have a new Diablo enroute- YAY!). I'm for comfort and cruisability. My car is a joy to drive again, because I can put my wife in, and my 5 and 7 year old in, and cruise, without worrying about bounce, harshness, and wondering if my wife is secretly complaining about driving the Magnum instead of the Envoy or the kids can't nap in the car without getting jarred around. I don't feel sketchy and worry about people wondering if my car is on hydraulics because it's bouncing up and down the road. I don't feel like I'm hammering the snot out of my car with a harsh spring-only ride. We took the car on an errand today, and my wife even commented on how smooth it is now. That made me feel good, because she's not really a car girl (more of a comfy SUV girl), so when she makes a comment like that, it's substantial. These BCRacing coilovers have bridged the gap for us AWD guys and put us in line with the RWD crowd. We finally have options. I have no idea what KW's are like, I've never been in a car with them. But I can and will vouch for the BCR Coilovers. I would recommend them any day for anyone looking at AWD suspension.


Conclusion:

Great product. Finally, something for the AWD crowd that won't break the bank. The estimated price for this full set should be around $1200 and will (should) be available for the consumer market in February 2010. It's such a HUGE improvement over springs alone for us AWD guys who want to bring it down like the RWD guys. It's truly like night and day in terms of the ride quality compared to springs alone.

 

very nice love the info

 

Wow, thats one heck of a write up, that must have taken a long time, beans to you my friend !!!!!! I paid to have my prokit and dampers put in, i chickened out

 

Wow that's a long read . . . and I have to admit I did not read it all in detail but glad you got them coilovers on finally!

You were showing the measurements from the top of the tire to the wheel and I am not sure what exactly for but keep in mind the front wheel well is larger and sits higher than the rear wheel well. A suggestion to anyone measuring ride height in order to set your preferred stance (level, raked etc.) would be to measure from the ground to the rocker panels since it will give you a much better representation on how she sits.

Oh and not to deter anyone from coilovers but in my experience (and I have heard this from others as well) but given the design of the rear suspension the coilovers back there become more difficult to adjust after they settle in. The last time mine were adjusted the strut had to be removed and the rear cradle bolts had to be loosened all the way in order to relieve enough pressure to adjust the coil.

Nice work being the guinea pig on a new product for the AWD!

 

Mighty nice wright up Rob. Looks like they did a good job making them.

 

Well I just red it all and this "preload" thing intrests me. . . it is a very different design than the KW's or Eibachs as they have a single ring located where your "preload" ring is . . but it doesn't compress the spring nor extend the shock body . . . I am confused. haha

 

Sorry the pics are so large. I cut this all from my website.

 

I guess I beaned ya b4 says I have to spread the love, but thanks for the looking out for the AWD's

 

lookin great man
this just a proto?
KW already makes some awd coilovers
i just cant afford the near 2k for em

 

Yea, these are prototypes. These should sell for $1200 versus the $1800 or so for KW's. I can't afford KW's either.

 

are they worth it for a 2in drop?

 

Yes. I grew weary of the lack of quality suspension for AWD. I grew weary of the low quality of my ride from springs alone. My car feels smooth again. No bounce, no harshness, and I'm not jarring the snot out of my car. It's an 05 with less than 30K on it and I take good care of it. I don't want everything to shake loose because of springs alone.

I didn't pay full price, I got a steep discount as the tester.

 

It won't let me bean you again, but I will once I find someone first to bean.

 

Bean Deaddog, then Deaddog bean Salvatore, then both of you bean me! :lmao:

 

Excellent info, I'll be savin it for future reference. I think I ALMOST have the guts to attempt this myself now. Maybe I'll do a 1.5" drop if you're rubbin on a 2" drop.

 

I think I ALMOST have the guts to attempt this myself now.

You can do it. The fronts are pretty easy. The rears are tricky, and it takes a bit longer, but absolutely nothing you can't handle.

The first time I did the rears when I just installed my DZ springs (in red) I dissembled the entire rear linkage at the rotor end. Now THAT took a while. This time I just did the one bolt on the other end of the control arm. MUCH, MUCH easier and faster, by far!

I did these instructions to help. i seriously think almost anyone can do it. I just want to stress safety working with jacks and jackstands. I jack up my car then shake it. If it's unstable, I'll know before I climb under.

 

Great write up Rob! The stance looks fantastic. Mean and Agressive just like it should be!

It's not always very easy to do the work and at the same time capture it with detailed pictures.
Love the pictures and all of the details.

 

Ok, heres some side on pictures as requested.

 

Wow, now that is a great stance! And yeah when your front is that low you have to start being careful. I clipped mine really good a few times right after lowering it and had to cut down my aggressive driving habits haha.

I guess the extenders look like what I was trying to explain, are the removable after you make the adjustments?

 

so for a drag racing standpoint, these would be better right? If/when I go to 20's next year I want to drop it a bit, but still have enough height for racing.

 

These would be better IMO, because you can adjust the firmness of the suspension. Soft for the street, hard for the track.

 

Quick update- the extenders (like shown a couple of posts above) came today. I'm going to install them- but I have an all new rear setup being shipped. The rear spring adjuster has been redesigned to allow the back to come higher, and they said two new shocks are coming- probably a bit longer to allow for the higher rear.

As soon as it arrives, the rear of my car will come back apart, I'll install these new parts, and jack my car back up to it's max height and take measurements/pictures.

The extenders will need to stay on once they are installed. I'll explain it all and show why when I do this work. Stay tuned.

 

Thank you a bunch for all this work Rob!

 

Replacement parts came today to let the rear come up more. Let me get my kiddies off to bed and I'll hit the shop and get these bad boyz in, take measurements and then hopefully this stage is done!

 

Ok, I have made some changes to the setup.

In February 2010, We decided to finally install our rear shock adjusters. The BCR coilovers have adjusters to firm up or soften the ride by turning the knob on the top of the shock. It has 30 levels of adjustment from nice and soft for the street to rock hard for the track.​

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Naturally, we jacked up the car removed the wheel.

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When we originally installed these, we didn't know there were rear adjusters. We cut a 1" hole to allow adjustment, then found out these adjusters were available. We used some steel plugs to fill in the hole. However, with these adjusters, we just drilled a hole through the plug to allow the cable to come out. If we had known about these adjusters , the large hole wouldn't have been put in.

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We didn't need to pull the shock right out. We just un-did the top bolts and compressed it down to install the adjuster.

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After that, we needed to cut to size the inner cable and outer sheath. This cable is just like a brake cable on a bike, just a lot larger.

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In that last picture we put the plug back in. Once that is all done, repeat for the other side. Lastly is as simple as installing the adjusting knob. Just be sure it's snug when you tighten the small hex screw in. We have checked our final sizes and are happy with the results.

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Here are the final results. Now we can make fine tune adjustments to our suspension firmness right from the trunk even easier than before.

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