Please share your BC coilover feedback. -ride quality, comfort, impressions

[softopz]

Had mine for 2 years now love them!!

[iFari]

I just wanted to add to this old outdated thread. I just order these from JPNGARAGE. I would strongly advise anyone looking into these to go ahead and give them a call/email. they are very convenient and knowledgeable. I need to have mines sooner than their usual lead time since i am doing my build in rented space and they were very good at accommodating me. 

[madkaw]

I guess I need a 101 class on how these adjust, install , etc...

Keep looking but can't find much info

[seattlejester]

I'm pretty sure I have done this earlier in this thread or the sister thread, but....

 

 

To adjust height you undo the locking collar on the very bottom. Grab the bigger wrench and turn the very top collar, this rotates the body down or up.

You can find a bunch of videos online, almost all coilover systems of this style are identical in this fashion. Once you get the adjustment required, lock the very bottom perch. Notice you never undo the ring in the middle right under the top collar. 

 

To install you undo your stock system, cut the strut, weld on the adapter tubes, thread on the tube and reinstall reverse of how you un installed.

 

I have a terrible video series if you have about an hour to waste that goes over installation. It really is quite simple.

 

For spring rate I wouldn't go above 5k which is 330lb/in. Stock is 85-100 or something of that nature and an agressive setup is 200F/225R. If you plan on staying low then a higher spring rate will help, but going much above 300lb/in or 5k you are going to have suspension that is harder then your chassis flex, which means the chassis will absorb bumps at stress points over the suspensino.

 

For 3 bolt vs 4 bolt. If you go anywhere near low (2-3 inch drop) then you will have to max out the camber plates to positive on the 3 bolt setup and that will still yield quite a bit of negative camber -1 to -2. The 4 bolt will give you a little more room, but will require drilling another hole. The camber plates themselves are not possible to adjust on the car, you have to drop the struts to do so. Not terribly difficult if you unhook the sway bars and use a jack to lower the suspension it is possible to do with relative ease, but as mentioned these will pretty much be pegged at positive anyways. At positive they will not clear the factory center strut hole so it will need to be lengthened or you will have to use a remote adjuster. 

 

For dampening these are a simple valve as in only one adjustment for both rebound and compression. As a general rule, start in the middle if you chose your spring rate reasonably this will be stiff, but compliant. With wider tires I was rubbing, so I stiffened it 5 clicks in the rear. That caused the car to porpoise as the stiffer shock caused the rear to oscillate less causing the front to oscillate more, the plan then is to adjust the front stiffer until the porpoising goes away. These adjustments really aren't that difficult due to their simplified nature. Make it too stiff via the shocks and you will hurt the life expectancy, similarly make it too soft and you will hurt their life expectancy.

 

For regular vs extreme low. If you plan on hitting stock height in your realm of use for people who prefer to make the car look lower with flares while maintaining ride height, you want the regular. They will max out from what we have seen at about 2 inches or so below stock height. The extreme low is suited for those looking for more then a modest drop. If you want there to be a one finger gap or less between the wheel and the fender this kit is most likely more suited for you. You won't get the height adjustment to go up to stock height, but you can go low enough that you will high center on the most modest of speed bumps. I have the extreme low on my 240z and found that even with adjustment to go 2 inches lower, I high center on my garage lip. Going over a 1 inch steel plate on top of a curve made me dent my fuel cell cover. 

[madkaw]

Thank you for taking the time to lay out some basics - not a coil over guy.

Questions though. Where is the rubber insulation at in the top hats? I looked at pics trying to make out the construction , but fail to see this.

So camber plates are not needed with these and all camber adjustments are done by dropping struts? Or can you use both ?

My confusion on install is that I thought there was not cutting involved or welding, but now I understand that the original strut housing is removed and BC is installed, welded , on. So really it's the same amount of work as section ing struts ?

[seattlejester]

If I was being semantical, technically you are a coilover guy unless you are running leaf springs or torsion bars, the stock system is a coil over shock aka coilover .

 

No worries, I looked into a lot of this stuff before I ordered so it is still pretty fresh.

 

There are no rubber insulators. Part of most coilover conversions save for I think mckinney which offers a stock top option forgo the insulator in preference for a pillow ball. Basically a spherical bushing in a plate. The rubber insulator in addition to absorbing NVH helps the strut flex a bit for and aft, the pillow ball setup takes this job in most coilover systems.

 

The BC coilovers have camber plates. However to adjust camber due to the small size of the strut hole one has to drop the strut, as in physically remove it from the car (undo the 3 nuts), from the top to snake an allen key to undo the bolts to adjust them. If you had traditional camber plates from places like Sakura garage, TTT, GC or others you would adjust camber via the top without having to drop the strut, however those systems are not bolt in. As most coilovers run a sliding system I don't think you can run both, although you could slot the top 3 holes I suppose to increase a bit of camber adjustment. Best bet would be to convert to something like mckinney's top mount if you needed lots of camber adjustment.

 

Originally there was talk of making it a complete bolt in setup as they do make bolt in setups for AE86's that have brand new cast and machined front spindles, but it was noted that we would also need rear hubs, which is quite a task to cast and machine, other manufacturers I believe make a setup by welding pieces, but that whole conversation ended up being that they could potentially do it, but it would be at a much higher cost point, I think it boiled down to the fact that if someone wanted a full bolt in setup they would go for TEIN or something and the R and D to do it wasn't financially worth it so we have what we have now.

 

It is less work. A traditional TTT/GC coilover setup requiring sectioning struts usually involves:

Removing strut

Grinding off spring perch

Cutting out a section

Welding on new 2.5 inch spring perch

Welding the housing together

Grinding down the weld to fit the spring

Cutting strut mount out of car (unless you have a drill and bolt plate which requires I think 8 holes drilled)

Welding in slotted camber plate (or bolting in the camber top if you have a bolt in style)

Reinstall strut

 

In a BC setup it would be:

Remove strut

Cut off strut top

Fit adapter

Weld in adapter

Screw in coilover into adapter

Reinstall strut

 

^Much shorter list

 

To be fair for a couple hundred more, you could buy a premade setup from TTT that would essentially bolt in minus the camber tops for the GC style coilover. 

[madkaw]

I will have to go back and search, but I thought part of the attraction on the BC was there was a non- pillow ball option that had top hats that were insulated by rubber.

For me- no more NVH is desired. I'd like to have better ride options as far as adjustable shocks. "Coil over " with smaller springs would be nice for bigger wheel options , but not ready to sacrifice any more on ride quality .

[seattlejester]

I believe that is mckinney which offers that option. Similar in a lot of ways, so the confusion could be easily made.

 

The concern on my part is that those top mount insulators are old. One side completely crumbled when I removed it, I can't imagine they are doing much NVH dampening at that point. 

 

With shock options in mind a GC/TTT setup might be a better option. You can literally run whatever fits in the housing. With the BC/Mckinney/Sakura you are more or less limited to what shock comes with the unit.

[theczechone]

The benefit of BC coils is really that the whole strut assembly moves up and down with the ride height. For setups like T3, and GC you are compromising shock travel with ride height. Hence why most people section the struts. 

I think what's important to note is that sectioning the struts with those setups is completely optional. If you are not looking to go very low with your car, and are only looking to add some clearance for larger wheels you can just modify the stock spring perches install the threaded sleeve and the 2.5" springs. This will give you a little adjustment in ride height but will provide clearance to the wheels, also if you are clever this can be done with zero welding. I think the T3 top hats will work with the stock rubber insulators so if you are looking to leave those in, you can. 

[Jason]

Sorry for the revival, but my resto is about 2 years behind yours 😛

 

Could you mix BC coilovers with camber plates that bolt to the top of the shock tower? Like these from T3?

T3 240z-260z-and-280z-cut-and-bolt-camber-plates

 

Saw a lot of Zs at the Atlanta ZCON using BC coilovers but it will annoy me to have the camber adjustments BELOW the shock tower, and thus virtually inaccessible. I do NOT want to drop the perch to adjust camber... let alone the initial setup.

[wheee!]

I used CX Racing coil overs and did the shock tower mod to accommodate the camber adjustment.

[seattlejester]

^That is very well done.

 

For your concern though, I'm not sure what you think you will be doing, but camber is pretty much a set and forget type situation. Unless you plan on tweaking it often and have toe/camber plates at home you really don't revisit it very often. Even if you did, the 1 degree or so that the bolt in style gives is not the most useful range, adjustable control arms would get you more or adjustable cross member. If you needed to drop it it is 3 bolts plus the sway bar end link. 4 bolts. Not the end of the world really. 

 

The T3 ones or the 4 bolt have a larger range so that would make more sense to use. You would have to find out the shock diameter and length. I have the number 14 or 17mm in my head for some reason. 

[LLave]

That looks great. I did something similar recently with my 4 bolt BC's. Just not as nice looking. Hah. 

 

[wheee!]

Nicely done! Mine is partly for aesthetics. 

[Jethoncho]

I’m doing a conversion to S14 front spindles, 5-lug hubs and brakes to my 280Z.  BC was very helpful, they sold me a 280Z upper coilover that the fitted a S14 lower mount to.  I have it all mocked up in the car but I am still looking for a solution to my tie rods being too long.  Don’t want to hijack this thread but I wanted to mention BC was very helpful with this project...great tech support and customer service.  They quoted me 4 weeks for the custom build, the coilovers arrived on my doorstep 4 days after I ordered.  Would be great if other companies performed like this!

Edited October 30, 2018 by Jethoncho