Suspension BC coilovers installed (how-to & feedback)
#552
09-17-2012, 07:45 PM
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Preload allows for softer or stiffer springs, but at the cost of suspension travel. More preload provides a stiffer spring (more compressed spring), but less shock travel in the shock body, basically the throw of the rod is closer to the bottom of the end of the shock. Less preload provides softer springs (less compressed spring), with more shock travel in the shock body, as the throw of the rod is farther away from the bottom of the shock.
This video on BC Racing website, shows how to adjust preload and says the 4mm of preload is good for a track or street car.
http://vimeo.com/28427984
However, I hear that 5mm of preload is stock for BC Racing BR Type COs. I also hear that this should be as-is when you are shipped your COs, and that there's no need to adjust them. Then again, I hear that some people need to adjust them as they were not set at 5mm of preload. I adjusted mine to 4mm, then when I read that factory setting is 5mm, I re-adjusted to 5mm, because I removed my COs so that I could re-adjust ride height.
When I get the import shop to re-adjust my ride height and preload, I am going to tell them that I would like preload at 4mm according to the video.
This video on BC Racing website, shows how to adjust preload and says the 4mm of preload is good for a track or street car.
http://vimeo.com/28427984
However, I hear that 5mm of preload is stock for BC Racing BR Type COs. I also hear that this should be as-is when you are shipped your COs, and that there's no need to adjust them. Then again, I hear that some people need to adjust them as they were not set at 5mm of preload. I adjusted mine to 4mm, then when I read that factory setting is 5mm, I re-adjusted to 5mm, because I removed my COs so that I could re-adjust ride height.
When I get the import shop to re-adjust my ride height and preload, I am going to tell them that I would like preload at 4mm according to the video.
#553
09-17-2012, 07:49 PM
Gotcha - thanks. So basically reducing preload would somewhat offset the general stiffness of the COs? This particular car will almost never go to the track anymore, so I don't really need a massively stiff ride, so I suspect I should look into reducing preload?... wonder how much of a difference it will make.
#554
09-17-2012, 08:05 PM
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As for a 1mm difference, this will not really make a difference. Something also to keep in mind, if the preload is not the same at all four corners, but your ride height is according to the counting of threads which is a ridiculous way to measure or using a digital caliper or a measuring tape, your car will sit at different heights. By compressing the spring or decompressing the spring, this will in fact affect ride height even if the ride height according to the CO is the same.
I learned this the hard way, that's why I had to re-adjust preload, because ride height was correct, but preload was not so my right side was higher then my left side.
If you are thinking about adjusting preload, I suggest finding a friend or someone else that has BC COs and seeing what they have their preload set, before messing with it by yourself, unless your are getting a shop to take care of it.
I don't track my car, but I think I will go with 4mm. My ride is rougher than stock, but maintaining that line as your turn on the twisties going 60 in a 40 and go even faster on turns and not worry about the wheel lifting off the asphalt is worth it to me.
As for the dampers, I have the front set at 16 from the soft setting and 12 in the rear from the soft setting.
I learned this the hard way, that's why I had to re-adjust preload, because ride height was correct, but preload was not so my right side was higher then my left side.
If you are thinking about adjusting preload, I suggest finding a friend or someone else that has BC COs and seeing what they have their preload set, before messing with it by yourself, unless your are getting a shop to take care of it.
I don't track my car, but I think I will go with 4mm. My ride is rougher than stock, but maintaining that line as your turn on the twisties going 60 in a 40 and go even faster on turns and not worry about the wheel lifting off the asphalt is worth it to me.
As for the dampers, I have the front set at 16 from the soft setting and 12 in the rear from the soft setting.
#555
09-17-2012, 08:07 PM
Preload lets you fine tune the spring rate / weight to the actual application.
And to fine tune its intended usage.
It is actually a fairly long and involved topic as ALL suspension is a compromise.
But to show you 1 instance. if you carried lots of weight in the boot ... you could balance that a bit by increasing the preload.
Our race cars are corner balanced and if one corner weighs heavy the preload can be increased to move weight to other corners.
I promise without very delicate equipment you would not feel the difference between 4 and 5 mm.
They say the BCs are pre set and I have been told aprox 5mm .
However the many units that I have sold they never seem to be set the same. I sell them and install them.
With my pre install check you will know that the preload is correct AND that the lock nuts are tight. (You will not ever need to adjust that again in most circumstances)
I can do the check and preload adjust in 10 min for all 4 .
This from my race motorcycle set up tutorial ... but the concept is the same.
By adjusting the preload, we adjust the “sag” of the bike on its front and rear suspension components. Sag is the distance the bike settles on its suspension when subjected to load. The term “free sag” is used to express the compression of the suspension under the weight of the bike alone. Free sag assists in preventing your suspension from topping out as the fork unloads toward full extension. Without it, the suspension would have insufficient upward travel with which to work. “Static sag” is used to express compression from full extension when the rider is on board. Sometimes this is also referred to as “race sag”. Do not read too much into the word “race”. Race sag does not strictly mean the correct sag for racing purposes. Rather, the terms “race” or “static” sag refer to the suspension travel achieved when the motorcycle is laden with rider(s), riding apparel, and any luggage and/or gear. Let me mention at this point that, depending on the source, these terms are not absolute and are sometimes interchanged. The term used is not as important as the concept.
@jbourne. I do understand not wanting to drill holes for the rear and some balance can be obtained from adjusting the fronts.
However to fully maximise the potential the rear adjusters make a big difference. Also they can be adjusted by jacking up the care and removing the 2 top bolts ... then move by braile .
If I was to set up a non adjusted rear I would not go a hard as you have chosen as HARD increases compression and slows rebound. I would suggest 5 to 8 from soft.
And to fine tune its intended usage.
It is actually a fairly long and involved topic as ALL suspension is a compromise.
But to show you 1 instance. if you carried lots of weight in the boot ... you could balance that a bit by increasing the preload.
Our race cars are corner balanced and if one corner weighs heavy the preload can be increased to move weight to other corners.
I promise without very delicate equipment you would not feel the difference between 4 and 5 mm.
They say the BCs are pre set and I have been told aprox 5mm .
However the many units that I have sold they never seem to be set the same. I sell them and install them.
With my pre install check you will know that the preload is correct AND that the lock nuts are tight. (You will not ever need to adjust that again in most circumstances)
I can do the check and preload adjust in 10 min for all 4 .
This from my race motorcycle set up tutorial ... but the concept is the same.
By adjusting the preload, we adjust the “sag” of the bike on its front and rear suspension components. Sag is the distance the bike settles on its suspension when subjected to load. The term “free sag” is used to express the compression of the suspension under the weight of the bike alone. Free sag assists in preventing your suspension from topping out as the fork unloads toward full extension. Without it, the suspension would have insufficient upward travel with which to work. “Static sag” is used to express compression from full extension when the rider is on board. Sometimes this is also referred to as “race sag”. Do not read too much into the word “race”. Race sag does not strictly mean the correct sag for racing purposes. Rather, the terms “race” or “static” sag refer to the suspension travel achieved when the motorcycle is laden with rider(s), riding apparel, and any luggage and/or gear. Let me mention at this point that, depending on the source, these terms are not absolute and are sometimes interchanged. The term used is not as important as the concept.
@jbourne. I do understand not wanting to drill holes for the rear and some balance can be obtained from adjusting the fronts.
However to fully maximise the potential the rear adjusters make a big difference. Also they can be adjusted by jacking up the care and removing the 2 top bolts ... then move by braile .
If I was to set up a non adjusted rear I would not go a hard as you have chosen as HARD increases compression and slows rebound. I would suggest 5 to 8 from soft.
Last edited by COR BLMY; 09-17-2012 at 08:25 PM.
#556
09-17-2012, 08:12 PM
...
I don't track my car, but I think I will go with 4mm. My ride is rougher than stock, but maintaining that line as your turn on the twisties going 60 in a 40 and go even faster on turns and not worry about the wheel lifting off the asphalt is worth it to me.
As for the dampers, I have the front set at 16 from the soft setting and 12 in the rear from the soft setting.
I don't track my car, but I think I will go with 4mm. My ride is rougher than stock, but maintaining that line as your turn on the twisties going 60 in a 40 and go even faster on turns and not worry about the wheel lifting off the asphalt is worth it to me.
As for the dampers, I have the front set at 16 from the soft setting and 12 in the rear from the soft setting.
I think my preload might be fine, so I think I won't mess with it. I'll measure my ride height once I do an alignment and get my summer wheels back on and go from there, I think. I know it's a lost cause to reduce stiffness with COs, but always worth a shot exploring. Anyway - I'm coming from Eibachs and stock shocks, which was bounce country - so anything is better. (and the stock ride on MCSs is actually surprisingly rough for the comparatively little handling that it provides).@jbourne. I do understand not wanting to drill holes for the rear and some balance can be obtained from adjusting the fronts.
However to fully maximise the potential the rear adjusters make a big difference. Also they can be adjusted by jacking up the care and removing the 2 top bolts ... then move by braile .
If I was to set up a non adjusted rear I would not go a hard as you have chosen as HARD increases compression and slows rebound. I would suggest 5 to 8 from soft.
However to fully maximise the potential the rear adjusters make a big difference. Also they can be adjusted by jacking up the care and removing the 2 top bolts ... then move by braile .
If I was to set up a non adjusted rear I would not go a hard as you have chosen as HARD increases compression and slows rebound. I would suggest 5 to 8 from soft.
#557
09-18-2012, 09:04 PM
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The lowest I went in the rear was 10 and it felt pretty bouncy. 12 feels pretty good, except for going over tall but in length wise short bumps in the road. When the setup is like this it feels like the rear is pulling underneath from me. Then again I would rather have this, then be bouncing around like a bunny.
Regardless, for good measure I will adjust the rear to 8 and see how it feels, then update you guys.
Regardless, for good measure I will adjust the rear to 8 and see how it feels, then update you guys.
#558
10-15-2012, 08:02 AM
#559
10-15-2012, 08:06 AM
Well - so much for that. Ran on mine for all of three weeks before my dampening adjuster broke (tried to rotate it for the first time since the wife was complaining it was too stiff, it got stuck, and now it freely spins). BC says its "user error"... :P the previous owner of these c/o's broke the left front adjuster in exactly the same way, and now the right front went. I'm not so sure about this "user error" excuse. They want $125 to ship a new shock body. And the coilovers have barely 3,000 miles on them.
#560
10-15-2012, 08:14 AM
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Well - so much for that. Ran on mine for all of three weeks before my dampening adjuster broke (tried to rotate it for the first time since the wife was complaining it was too stiff, it got stuck, and now it freely spins). BC says its "user error"... :P the previous owner of these c/o's broke the left front adjuster in exactly the same way, and now the right front went. I'm not so sure about this "user error" excuse. They want $125 to ship a new shock body. And the coilovers have barely 3,000 miles on them.
#561
10-15-2012, 03:18 PM
The downfall has always been the threaded-body shock... the front knuckle of the MINI is too narrow and considering BC uses the same shock just in a variety of sizes and valving, they didn't want to make a shock specifically for that application, so the shock body was limited by the fact that it cannot actually go into the knuckle itself, where other shocks and OE shocks could utilize that extra few inches for internal travel allowing for more shock travel overall.
So.. 6kg if you want, but you're going to bottom out like crazy... $.02
#562
10-18-2012, 11:32 AM
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The lowest I went in the rear was 10 and it felt pretty bouncy. 12 feels pretty good, except for going over tall but in length wise short bumps in the road. When the setup is like this it feels like the rear is pulling underneath from me. Then again I would rather have this, then be bouncing around like a bunny.
Regardless, for good measure I will adjust the rear to 8 and see how it feels, then update you guys.
Regardless, for good measure I will adjust the rear to 8 and see how it feels, then update you guys.
So 8 in the front and 5 in the rear feels pretty darn good.
#563
10-18-2012, 06:17 PM
@ "speed..." Glad you are trying settings closer to my recommendation, and that they are working.
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
I would be interested to see the break point. If you screw counterclockwise . then past the indent you just start unscrewing the adjuster shaft, clockwise it locks the threads ... you would need to really force it to then break / damage .
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
I would be interested to see the break point. If you screw counterclockwise . then past the indent you just start unscrewing the adjuster shaft, clockwise it locks the threads ... you would need to really force it to then break / damage .
Last edited by COR BLMY; 10-18-2012 at 06:26 PM.
#564
10-18-2012, 06:20 PM
@ "speed..." Glad you are trying settings closer to my recommendation, and that they are working.
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
Sigh.
#565
10-19-2012, 09:23 PM
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@ "speed..." Glad you are trying settings closer to my recommendation, and that they are working.
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
I would be interested to see the break point. If you screw counterclockwise . then past the indent you just start unscrewing the adjuster shaft, clockwise it locks the threads ... you would need to really force it to then break / damage .
I have tested different springs .
I found that anything lighter was just too soft. Even for street only use.
On our race cars we run 8 front and rear. (the 8 front is not a " bee hive " just straight . not had any binding)
I have installed and sold lots of these (many also for other vehicles) I have only once had an adjuster issue. and that was on a MINI that the fellow who installed used the extender but only drilled a 1" hole. (rear installation nor followed correctly)
The arc movement was greater that that would allow and the cable kinked and broke.
I would be interested to see the break point. If you screw counterclockwise . then past the indent you just start unscrewing the adjuster shaft, clockwise it locks the threads ... you would need to really force it to then break / damage .
Last edited by SpeedRacer0212; 10-20-2012 at 10:23 AM.
#566
10-19-2012, 09:33 PM
#567
10-20-2012, 08:08 AM
#568
10-20-2012, 10:28 AM
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Well, I am going lower than I am now on Monday and a shop is adjusting preload and ride height as I did not want to mess with it again. They only quoted me for adjustment and alignment. They are a really busy Soobie, Evo, and Mazda shop, as I scheduled this 5 weeks out, so I doubt they will have time to remove the rear and add the damper switches, so next time I will have them add the extenders. But as I have said before (and got from Cor) 8 in the front and 5 in the rear feels real nice and really comfortable. I might take the front to 7 or 6, but I am happy with the rear at 5.
#569
02-26-2013, 07:19 PM
I asked this in a Megan thread. Now I'm asking you guys, because I think BC will be a better choice for me.
So, here's where I'm at: I have an '05 S with about 82,000 miles on it. I've noticed that the ride is getting pretty harsh, so I know my struts are shot. There's no wallowing, but the ride has gotten worse over the miles. I'm now hearing a loud squeaking sound out of the right strut tower when I go around corners. I looked at the top mounts and both are broken in the front. If I put my hand on the body where the struts are bolted to and someone turns the wheel, I can feel the vibration from the squeaking. I figure, I might as well spend a little extra and get Megans or BCs, as apposed to replacing all 4 struts and top mounts. I have always wanted to do that anyway. I have some questions:
1. If I'm only going to lower 1" and I want to be conservative on the camber, it's my daily driver, can I wait and get adjustable rear arms in the future?
2. With the above parameters, will I have to do any trimming to the front mounting holes in order to properly tighten things up?
3. I really want adjustability in the rear. Is drilling for adjustment cables a bad idea in any way? I Also have the OEM amp back there.
3.5 Do the adjustment cables have to stick up through the interior, or can I keep them short and access them through the little doors on each side?
4. Are there any other parts or anything else I need to know. Money is a little tight right now, so I want to do it as cheaply as I can.
5. I'm running 205x55x15s with 40 offset wheels, will I need any spacers in the front wheels?
Thanks for all your help,
Shawn
So, here's where I'm at: I have an '05 S with about 82,000 miles on it. I've noticed that the ride is getting pretty harsh, so I know my struts are shot. There's no wallowing, but the ride has gotten worse over the miles. I'm now hearing a loud squeaking sound out of the right strut tower when I go around corners. I looked at the top mounts and both are broken in the front. If I put my hand on the body where the struts are bolted to and someone turns the wheel, I can feel the vibration from the squeaking. I figure, I might as well spend a little extra and get Megans or BCs, as apposed to replacing all 4 struts and top mounts. I have always wanted to do that anyway. I have some questions:
1. If I'm only going to lower 1" and I want to be conservative on the camber, it's my daily driver, can I wait and get adjustable rear arms in the future?
2. With the above parameters, will I have to do any trimming to the front mounting holes in order to properly tighten things up?
3. I really want adjustability in the rear. Is drilling for adjustment cables a bad idea in any way? I Also have the OEM amp back there.
3.5 Do the adjustment cables have to stick up through the interior, or can I keep them short and access them through the little doors on each side?
4. Are there any other parts or anything else I need to know. Money is a little tight right now, so I want to do it as cheaply as I can.
5. I'm running 205x55x15s with 40 offset wheels, will I need any spacers in the front wheels?
Thanks for all your help,
Shawn
#571
03-25-2013, 06:23 PM
[QUOTE=CynMini;3687443]I asked this in a Megan thread. Now I'm asking you guys, because I think BC will be a better choice for me.
So, here's where I'm at: I have an '05 S with about 82,000 miles on it. I've noticed that the ride is getting pretty harsh, so I know my struts are shot. There's no wallowing, but the ride has gotten worse over the miles. I'm now hearing a loud squeaking sound out of the right strut tower when I go around corners. I looked at the top mounts and both are broken in the front. If I put my hand on the body where the struts are bolted to and someone turns the wheel, I can feel the vibration from the squeaking. I figure, I might as well spend a little extra and get Megans or BCs, as apposed to replacing all 4 struts and top mounts. I have always wanted to do that anyway. I have some questions:
1. If I'm only going to lower 1" and I want to be conservative on the camber, it's my daily driver, can I wait and get adjustable rear arms in the future?
YES
2. With the above parameters, will I have to do any trimming to the front mounting holes in order to properly tighten things up?
I have had luck lately setting using the markers on the camber plates and not needing to adjust after install at all. Some have had luck using "ball alens" or switching to a hex bolt for the camber adjustment.
3. I really want adjustability in the rear. Is drilling for adjustment cables a bad idea in any way? I Also have the OEM amp back there.
Have had zero issues on lots of installs and my own cars and racecars.
3.5 Do the adjustment cables have to stick up through the interior, or can I keep them short and access them through the little doors on each side?
NO ... they can bend and be behind the cubbie doors
4. Are there any other parts or anything else I need to know. Money is a little tight right now, so I want to do it as cheaply as I can.
You should be good ta go .. but budget an alignment
5. I'm running 205x55x15s with 40 offset wheels, will I need any spacers in the front wheels.
I have done that install and NO
Thanks for all your help,
Shawn
...
So, here's where I'm at: I have an '05 S with about 82,000 miles on it. I've noticed that the ride is getting pretty harsh, so I know my struts are shot. There's no wallowing, but the ride has gotten worse over the miles. I'm now hearing a loud squeaking sound out of the right strut tower when I go around corners. I looked at the top mounts and both are broken in the front. If I put my hand on the body where the struts are bolted to and someone turns the wheel, I can feel the vibration from the squeaking. I figure, I might as well spend a little extra and get Megans or BCs, as apposed to replacing all 4 struts and top mounts. I have always wanted to do that anyway. I have some questions:
1. If I'm only going to lower 1" and I want to be conservative on the camber, it's my daily driver, can I wait and get adjustable rear arms in the future?
YES
2. With the above parameters, will I have to do any trimming to the front mounting holes in order to properly tighten things up?
I have had luck lately setting using the markers on the camber plates and not needing to adjust after install at all. Some have had luck using "ball alens" or switching to a hex bolt for the camber adjustment.
3. I really want adjustability in the rear. Is drilling for adjustment cables a bad idea in any way? I Also have the OEM amp back there.
Have had zero issues on lots of installs and my own cars and racecars.
3.5 Do the adjustment cables have to stick up through the interior, or can I keep them short and access them through the little doors on each side?
NO ... they can bend and be behind the cubbie doors
4. Are there any other parts or anything else I need to know. Money is a little tight right now, so I want to do it as cheaply as I can.
You should be good ta go .. but budget an alignment
5. I'm running 205x55x15s with 40 offset wheels, will I need any spacers in the front wheels.
I have done that install and NO
Thanks for all your help,
Shawn
...
Last edited by COR BLMY; 03-25-2013 at 06:29 PM.
#572
03-25-2013, 06:34 PM
#575
05-22-2013, 10:22 AM
I have had mine on for about three weeks. I have Swift springs 8k in the rear and 7k in the front, with stock sway bars. I run the fronts 5 clicks softer and I get great bite and turn in on the front and the whole car rotates nicely. I can run the rears on full hard and the fronts 5 clicks softer and the ride is only a little harsh on cracks in the road. If I go 5 clicks softer from that, it's not harsh on cracks or anything. If I run it at full soft,the ride is soft, but it's controlled and doesn't wallow.
I am very happy with this setup. And you don't have to tear the interior completely apart to safely drill the rears for adjustment.
Do yourself a big favor: Upgrade to swift springs. My installer talked me into it and I'm very glad he did.
I am very happy with this setup. And you don't have to tear the interior completely apart to safely drill the rears for adjustment.
Do yourself a big favor: Upgrade to swift springs. My installer talked me into it and I'm very glad he did.