99se5speed

iTrader: (8)

So i've finally decided that i want coilover instead of struts/shocks so i can lift the car during the winter time if need be. I've read alot about the different coilovers for the max and decided i want to go with BCRacing.

I just wanted to know what is recommened i change while im doing the coilovers. Do i need to take anything of my stock setup and put it on the coilovers? I know i need front camber plates, and i need to change some bushings, which do i really need to change? In general can someone let me know what i should do while changing out my suspension? Thanks for the help with this newb question!!

Zack342

iTrader: (89)

http://www.bcec.com.tw/

99se5speed

iTrader: (8)

what was the link for? that they are made in taiwan? i did not know that but have heard/read alot of reviews by 350z/g35 owners and they praise these coilovers. I heard (how true this is i don't know) that bcracing makes coilovers for many diff companys that relable them as their own. Bcracing then made their own coilovers using the best specs from the many different suspensions that they have built. So it's either tein of bcracing...

- 30 way single adjustment dampening force
- Mono-Tube Design
- 46mm Piston / 53mm Housing
- Front Camber Plates
- Rear Pillow Ball Mounts
- ADJUSTMENT ****- Allows for adjustment without the use of any special tools or hex head
- Seperate Height & Preload Adjustments

seems like really good specs, plus i just noticed it already comes with the front camber plates....opinions??

JSutter

iTrader: (46)

Dont bother with coilovers in the winter. Chances are you will blow them and/or corrode them making adjustments a royal pain.

BTW most full coilover set for the max are built with crap dampers. The only brand I would run is Progress. Even those are going to need rebuilds on a regular basis. Winter driving with just make it worse. Ksport and D2 include camber plates & rear mounts. Tien & Progress do not include camber plates.

Honestly the best adjustable setup is shortened Konis and G/C. Konis are the best damper we can get.

BLACKonBLACK98

iTrader: (42)

i think that needs a little clarification. not sayin you're wrong but theres some important facts left out, as well as mention of jic.

progress is a moot point since they are no longer available. tein are of reputable quality as well but the downfall of both these designs is that they are not total length adjustable, meaning as you lower the car you lose suspension travel. same with koni/gc but the shortened koni's offer somewhat of a solution to this issue.

i'd put jic over anything else available with the only con being price.

---
anyways, to the op's actual question; you should not have to change out anything with the bc racing coilovers. from what i can tell they are a drop in design since they appear to include camber plates w/ pillow ball mounts.

JSutter

iTrader: (46)

jic are not all they are cracked up to be

Grand_hustle17

iTrader: (22)

^^^ i think the same but i never owned a pair so my point's invalid

MorpheusZero

iTrader: (10)

Unfortunately you can only shorten the Konis so much. IIRC I was bottoming out when I was "slammed" but then again I was testing the car driving briskly on very uneven, patched up roads.

Here is how I see it.

Advantages of JICs over GC/Konis:
1. They come with camber plates
2. Full-tap so you can go lower without bottoming out
3. No work to assemble
4. 2-way adjustable instead of just rebound (although my setup rides just fine)

Disadvantages:
1. Inferior damper design, longevity and dynos (debatable but we will see how long it takes my konis to blow)
2. Atrocious customer service
3. Price

BLACKonBLACK98

iTrader: (42)

definitely like to hear some elaboration on that one.

can't argue with the price (yet ), but what inferior damper design are you reffering to? warranty is something that could be added to the cons (koni's lifetime is hard to beat). never had a problem with service, although i'm sure they treat me a little differently. i hope that all my customers would disagree as well.

Bonka

iTrader: (13)

BCRacing = Megan = D2 = KSport = etc, etc, etc...

Bor Chuann uses the same design (note similar spring rates, 30 some odd damper settings, pillow ball mounts) for all the coilovers they build. They Relabel them and use a different colour (if you search on Ebay you'll find many sellers selling the same looking (and likely same design) under different brands).

You mind as well buy D2 or KSport. At least you know the customer service is there.

maximumobsesion

iTrader: (36)

check over on nyc maximas their are a couple guys running the bc coilovers and they have nothing to say but good things. as far as jic sucking ask anyone with the flta2 im sure they will COMPLETELY disagree they are said to be the best coilovers for the maxima period.

MorpheusZero

iTrader: (10)

How long have they been running them?

Have they dyno'd them?

Any problems?

Many people assume JICs are the best thing out there because they're the most pricey. In general you do get what you pay for but not always.

JonBlz

iTrader: (11)

BC racing are good *** coilovers hands down

BLACKonBLACK98

iTrader: (42)

and many who can't/choose not to afford them say they're not all they're cracked up to be.

my personal stance is they are the only full featured coilover of reputable quality available for the 4th gen. that's why i sell them.

when you have a coilover that is compression/rebound adjustable, camber adjustable, and total length adjustable you are only limited by your ability to dial them in to your liking. of course the same thing can be said for most of the coilovers on the market (tein basic being the exception). the difference being build quality.

i had a great conversation with brain catts about a year ago concerning coilover options. this was when the progress coilovers future was still uncertain. what made the progress so great was that they were designed specifically for the application and the margin for user error was reduced. as long as you didn't try to slam the car to the point of ruining the geometry you couldn't go wrong. setting any fully adjustable setup to similar specs will yield similar results.

as far as shock dynos, k-sport is the only company that i know of (with a relevant application) that offers them. given k-sports track record that leads me to believe that there's not much value in them.

MorpheusZero

iTrader: (10)

I haven't heard of k sport offering dynos, but I have seen a dyno that demonstrates their inconsistency.

There is more to a shock than its dyno, but that doesn't make dynos irrelevant.

mowgli29

iTrader: (21)

i don't want to continue debating whether or not JIC is the shiznit....rather, let me say this:

JIC may be good. hell, they may be AWESOME coilovers for the maxima.

BUT, I believe the koni's to be better dampers, and even if we give JIC the benefit of the doubt and say that they are the BEST for the maxima (which may or may not be true) they can't be (and probably aren't) much better than koni+GC.

And when I can get koni+GC for $677 (yes, that's what I paid.), there's no contest. That leaves plenty of money for camber plates, helper springs, and any other blring you want them to have. isn't the price on JICs around the 2k mark?! there becomes a point when its silly to sink SOOOO much money into the suspension of a MAXIMA. yeah I want my fwd family car to handle well...but not for 1500+ on coilovers alone. there is so much more to a good suspension setup than just coilovers...

and if anyone wants to argue that you can't slam your car with konis...if you're getting them for performance, not looks, you don't want to slam the car anyway! all that will do is give you massive amounts of bumpsteer and make you gain positive camber on turn in. slamming a maxima has one purpose - looks.

/rant.

back on topic...how long has BC racing been making coilovers for the maxima? is there any proof that they are the same ol' stuff as ksport/D2/etc?

BLACKonBLACK98

iTrader: (42)

brand names side here's how i feel:

sleeve coilover/oem replacement strut combo - on the plus side you have cost and availability of quality parts. however, it has been determined that lowering a maxima ~2" or more ruins the suspension geometry directly affecting performance. without total length adjustability you approach limited suspension travel before the 2" point. in this scenario i don't see the point in height adjustability at all vs. a static spring setup unless you are wanting a drop of less than 1", which can't be accomplished through aftermarket offerings.

sleeve coilover/shortened strut combo - same pros except this setup deals with the shortened suspension travel by being a type of total length adjustment. the "2 inch rule" is still in affect for optimum performance. what has changed is you have altered the suspension geometry before you even swapped springs. let's say the entire assembly is .5" shorter, now you only 1.5" of drop before you are out of tolerance. once again; easily accomplished without coilovers of any sort.

total length/camber adjustable full coilover setup - this setup offers full suspension travel through the height range. the camber curve is related to the angle of the spindle to the lca so adding negative camber can be used to correct suspension geometry as well, within reason of course. the downside is you have either low quality, unproven, or high cost options to choose from.

nwell2k3

iTrader: (1)

I wish I would of known this topic was going to come up.

I was doing a google search in 2006. I typed in A32 coilovers and came across Bc website in taiwan . So I sent them an email and they responded back asking me if I was interested in being the importer or their coilovers. I didnt have the money nor the space needed to order what they required. I questioned them on the design and quality and thats when they stated that, they sold coiliovers in the USA under Apexi, Meagan Racing, and I think the other company was Hks. The difference between their coilovers and the ones they make for the other companies is the locking collar and thicker shaft(pause lol)..

Qnz's max has been using them for a few months in Nyc with no issues so far..

The G35 and subie guys have been running them since late 06... And they are reporting positive reviews.

I am going to hold off until maybe next year. But I still would like to get the now out of production progress coilovers...

MorpheusZero

iTrader: (10)

A few things:

re: suspension geometry, that is a bit of a blanket term but the geometry that is fubar'd here goes beyond travel. Toe curve, camber curve, toe steer/roll steer, bump steer, ackerman etc etc (you know this but I am stating for clarification). These are the geometry issues more pertinent to performance (bump steer and roll steer are relevant to safety as well). Bottoming out is more of an issue with ride, to the DDer less so an issue of performance but still an issue.

re: shortened struts, I am not sure where you are getting this but shorten a Koni .75" (about what you can shorten them) and you gain .75" of compression travel and lose .75" of droop/extension travel, which is most likely fine for stock cars, let alone lowered ones. Shortening a strut does NOT affect ride height, only threshold of travel.

So in terms of strut travel you will have the same compression travel if you are lowered 2" than if you shorten Konis and lower to 2.75". Other geometry issues will be much more pronounced however, and at that point you will probably be rubbing fender or fender liner before you bottom the strut out (I was at ~2.5" lowered).

I was thinking that it would be cool to futz around with this, use camber bolts to set as much positive camber as you could and then camber plates to adjust to whatever you desire--that would help the camber curve, but the toe curve would still be ***, possibly more so.

And the camber curve is related to the angle between the lower ball joint and upper strut mount, not the spindle angle.

Unfortunately no one has really "proven" any of the coilover setups for A32s, or any Maxima for that matter. Really it is just based upon hearsay and personal experience, and to that effect no one really knows the objective truth as no one has lived with all of the setups on a daily basis.

And yes, the Koni leg humpers will always be there to endlessly and incessantly contradict you.

BLACKonBLACK98

iTrader: (42)

before i go any further i'd like to make it perfectly clear that i do not consider myself a suspension expert by any means. i'm into being low, consequences be damned. however, i have done a fair amount of research on the subject. not much hands on experience, some things taken on faith and some backed up by math which i could make sense of.

some of these i am familiar with and some could not quite wrap my head all the way around. however, in the examples i listed i stayed within the "2 inch rule" where these issues are supposedly within tolerance (taken on faith).

an equal drop with equal camber should have equal geometry, regardless of how it is acquired.



maybe i have misunderstood the whole process and it's purpose but i was under the impression that the value of "shortened konis" was the "short" part. i.e. achieving a greater drop while retaining stock suspension travel by shortening the total length of the strut assembly. assuming i am correct i would say shortened konis would most definitely affect ride height.

exactly my point. where do you suppose that extra .75" came from?

this is where the question "why ground control?" comes in. assuming the goal is maximum performance, you are bound by the "2 inch rule" to keep the geometry issues in check. subtract for the length lost by shortening the konis (unless you can convince me otherwise) and you are in the aftermarket spring drop neighborhood. at this point what good does the adjustability do?

tomato, tomato. (doesn't work in type)

it is the same angle.

proven referring to durability. it's my stance that any fully adjustable (damping, total length, and camber) can perform equally when set equal. the only variables are build quality and the user's ability to dial it in.

i think you missed the point. i'm questioning the necessity of ground control more than koni. a shortened koni/eibach setup should put you at the edge of the "2 inch rule". i don't see a point in paying for adjustability when you can't use it, from a performance perspective of course.

mowgli29

iTrader: (21)

at first glance...it does seem that way. but if you stop and think about it, you'll see why shortening the konis doesn't affect ride height. Basically, it's because they are inserts. You shorten the inserts so that they sit lower in the housings and you therefore gain travel.

BUT, the height of the spring perch (in relation to where the housing bolts to the knuckle) does not change, and therefore ride height does not change.

also, GCs aren't necessary, but they do have more than one purpose. stiffer springs limit body roll, and if you were to get custom spring rates(raise the rear rates), you could use them to your advantage in trying to making the FWD beast a little more neutral...

eibach/koni should only be around 1.5"
you'd need GCs to get to the 2" mark if you wanted...but like I said, some people want stiffer than eibach, AND you can get custom rates.
yes, you could get to the 2" mark with crap s-techs or something, but the GCs would give you a quality product meant for performance AND still allow for the adjustability.

BLACKonBLACK98

iTrader: (42)

took me a couple times going back and forth from the picture to the description, but i get it now.

so yeah... i can see the gc/koni setup being a viable option, but i still wouldn't trade my setup.

*edit - in response to your edit, you can also get custom rate eibachs and h&r, but still... i'm sold on the fact that there is some adjustability and therefore some value.

BLACKonBLACK98

iTrader: (42)

dang morpheus, you've been typing for so long the conversation passed you up. hurry up so i can go to bed.

mowgli29

iTrader: (21)

to each his own!

I just want to say, you have valid points. There are plenty of good reasons for people to choose JIC over our frankenstein koni/GC setups. It really just depends on what that person is looking for... and I'm simply not someone looking for the benefits of the JICs.

if nothing else, at least now we have a little better perspective of the reasoning behind each others' positions.

now THAT is a statement we can agree on!
silly engineers....blackonblack, I have a feeling we're gonna go when we attempt to read his technical response, lol

BLACKonBLACK98

iTrader: (42)

for sure. honestly, as everyone knows, i am not a performance guy. i mod more for style and owning/desiring to own the top of the line products (not necessary better or worse) is just something i do.

however, even with mind made up i always like to understand how things work though i may have zero plans for implementing my knowledge.

i stick by my statement that a set of jics can do anything a gc/koni setup can do and more, but it's definitely on the individual to decide worth.

MorpheusZero

iTrader: (10)

I'd be more than happy to go over them all if you are interested, but what is relevant to the discussion is that the suspension was only designed to operate at a certain ride height, and that goes beyond just bottoming out--just to be extra clear, we are talking the way the struts, tie rods, LCAs etc all fit together and dynamic alignment issues here, i.e. static toe in and camber are in spec but when you compress the suspension or turn the wheel, what happens? At stock ride height, very little, but as you lower further and further things that would make any suspension engineer cringe start to rear their heads.

and
Negative. Move the upper strut mounts inward and you fawk with the camber curve (in a good way), consequently messing with most everything else as well. You can do this while keeping the static camber the same if you use camber bolts AND plates, i.e. add a degree of negative camber with the plates and a degree of positive camber with the bolts. Follow me? This would create a more acute angle between the strut arms and the LCAs resulting in a more favorable camber curve. How beneficial it would be remains to be seen, but it was just an idea I had.



Peep those pics closely. The lower spring perch is in the same position relative to the spindle attachment points in both cases, meaning spring geometry is not changed, but the Koni is moved lower in the housing. What this means is that the springs can compress further without bottoming out, all this is doing is moving the regular position in the stroke travel of the strut.

We are NOT shortening it to shorten the total length of the strut/spring combo, we are shortening the strut insert only and shoving it further down the casing. This does not affect ride height at all, rather only affects the strut stroke position relative to the spring position.

So:
length of koni insert (not piston or rod): shorter
length of strut casing: same
ride height: same
therefore there is more room for compression travel at any given ride height. It is basically analogous to adding .75" of preload to a full tap coilover and then raising up the ride height .75" to keep it at the same height.

First: coilovers and ground controls do NOT change geometry (camber/toe curve, etc), these elements of the front end geometry are identical to a strut/spring setup of the same ride height; the only way to change this geometry is to get extended ball joints, tie rod end relocators and/or custom LCAs (or the aforementioned camber bolt/camber plate trick which honestly would not do very much compared to these remedies).

Second: there is NO length lost by shortening the konis. I really am not sure where you are getting this notion but the only "length" that's changed in a bad way is the fully extended length.

Damping properties are also important. Without going too in depth here, a good example would be the k sport dynos that Josh (mowgli) posted up. Cheap adjustable dampers are typically not adjustable across a very wide range nor matched very well, and the ksports that they dyno'd were impossible to match to each other left-to-right, i.e. the left was softer on full firm than the right was on full soft. This is a bad thing. Having said that, I haven't actually come across a dyno of the Konis made for A32s so I can't preach their "superiority" firmly on this trait alone.

The advantages of GCs over Eibachs are threefold:
1. much higher rates (approximately twice the spring rate, with standard GC rates) and custom rates available
2. ride height adjustability
3. (to a much lesser extent) weight savings and less protrusion into the wheel well, allows for slightly better wheel fitment and less backspacing headaches

Hope this clears up a few things.

MorpheusZero

iTrader: (10)

you fawkers

i had to go back and edit stuff when i realized what your mistake re: shortened konis was... and i was watching pulp fiction

mowgli29

iTrader: (21)

sorry mang. you know we <3 you.
in an entirely heterosexual way...

that post wins by the way. your knowledge>*

BLACKonBLACK98

iTrader: (42)

good stuff none the less. after i grasped the concept of the shortened konis other things fell into place.

the examples i posted in the beginning were assuming constants of ride height and camber accross the board.

you lost me on the camber bolt/plate thing but that's probably because i do not know how camber bolts work. either way, when i was looking into camber curves i saw a thread on one of the bmw forums i believe that broke it down to the point where i could understand it. i believe we are talking about the same angle, just different ways to affect it.

MrDicks95SE

iTrader: (23)

man that was some good readin. i <3 tech talk.

MorpheusZero

iTrader: (10)

I guess my post will stay there as a resource

Gotcha.

Camber bolts are primitive and ugly. Basically a smaller diameter bolt to put in a larger hole (the strut-to-spindle hole), allowing for more play before you crank them down to hold it in position.

Bottom line is after thinking about it a bit I doubt my "idea" would make much of a difference to the camber curve.

As for the angle, yeah we are talking about the same angle, I guess the more precise way to describe it is the angle formed by the LCA plane and the line between the upper strut mount and lower ball joint. But since the strut kind of goes out of the way of that line and the spindle isn't at the same angle (although they are related) it is hard to visualize and a bit misleading if you refer to it as the spindle or the strut angle. Maybe that is just me though.

I can always go over the other properties (camber/toe curve, etc) tomorrow just for ***** and giggles if anyone is interested.

BLACKonBLACK98

iTrader: (42)

cool.

i'm going to see if i can get my hands on any shock dynos directly from jic. if not i may see into doing some 3rd party testing, as long as it's available locally and doesn't cost a grip.

MorpheusZero

iTrader: (10)

So, dynamic alignment issues.

The idea here is that the front end of the car isn't ideal, and the LCAs, strut arms (everything connecting the upper strut mount to the lower ball joint) and tie rods move in different arcs as the suspension compresses and rebounds, and the front end is engineered for the arcs to match when the car is at a certain ride height; rather, they don't match perfectly but it is "close enough" to do the job pretty well.

The A32 was not designed to ride with the suspension compressed an extra 2" (lowered 2"), in fact that's about where it bottoms out normally. So they don't really care how the car acts when the suspension is that compressed as it will very rarely happen. So, you can see that when compromises are made as they must be with a limited budget, limited space and a macpherson strut design, this realm of travel of the suspension is ignored. When your car is this low you will generally have problems, whether you notice them or not depends on how perceptive you are.

First, camber and toe curves.

The camber "curve" refers to a plot representing dynamic camber of a wheel depending on suspension position. I mspainted up about what it looks like for an A32:



So as the suspension is compressed, it gains negative camber until the curve levels off at about 1.5" compressed, then starts gaining positive camber.

Now, I have referenced it at static camber being lined up with stock ride height, but the curve is all relative, so if you set the camber at 1" lowered to be 0 degrees and then raise the car back up to stock ride height, it will be at +1 degree of camber. Think of it as you being able to move the y axis (or the camber axis) up or down to set the camber to a certain value at a certain corresponding suspension position, but the x axis and the curve stay the same.

So, with all that being said, let's discuss the stock geometry. As the suspension compresses, negative camber is gained. This is good as the outside wheel will go under compression when you turn, and you want that wheel to have as much negative camber as you can.

Now take a look at it when it's 2" lowered. At that point you gain POSITIVE camber/lose precious negative camber as the suspension is compressed. Now it's not going to compress the same amount since a) the springs you're running should be significantly stiffer and b) you will probably run into the bump stop if you're on stock length struts. But the fact remains, the behavior is the exact opposite of what you want to happen. Your outside wheel loses negative camber as the wheel is compressed, which is when you need it the most. Not good.

Toe curve:
So you get why they call it a "curve" now, and the toe curve is just the same thing as the camber curve--a plot of relative toe in/toe out based on suspension compression. This changes a bit as you change toe since you're basically changing the length of the tie rod and that means that the tie rod arc changes, and it changes when you change camber, but it's a similar effect: basically, around stock ride height the toe curve is pretty straight, so when you compress the suspension you get about the same toe as stock, and when you extend the suspension you get about the same toe. However, at 2" lowered the curve has a positive slope, so when the suspension is compressed, you gain toe-in and your tires scrub. When the suspension is extended, you gain toe-out which translates to a lack of immediate steering response.

You may think "big deal, my toe changes which I don't really notice anyway" but consider this: left and right suspension are not always in the same position. So, if you hit a bump with the left side of the car and not with the right, as the left suspension compresses the left front tire will point inward, effectively steering the car to the right. Two things happen here: a lot of this energy goes into jerking your steering wheel to the left, but the car steers to the right as well. This is called bump steer and it's no fun.

Roll steer is another problem, basically a positive reinforcement loop on your steering wheel when you are traveling at high speed. When you turn left, the body of your car rocks over to the right--standard body roll. The left suspension extends and the right suspension compresses. Can you see what's coming? The left wheel gains toe out, pointing outward (left) and the right wheel gains toe in, pointing inwards (left). So you steer left, and as the car rolls to the right it starts to steer itself more and more to the left. I have only noticed this when doing naughty things at highway speeds, because the car rolls about the same amount and the wheels turn themselves about the same amount, but you don't notice it if you're only going 30mph since you're already turning the wheel so much. If you're going 100+, you are turning the wheel just a tiny bit to corner hard and all of a sudden that smallish "self-steer" toe angle becomes very noticeable.

Ackermann: ackermann is another property of the steering, it's basically a curve of the toe versus steering wheel position. This is necessary basically for the same reason a differential is necessary. When you're in a tight turn, the left and right front wheels are turning at different speeds and are turning different radiused arcs--the inside wheel is turning slower because it is traversing a smaller radiused, or a tighter arc. This means that the inside wheel must have a greater steering angle than the outside wheel because it's turning a tighter circle.



It is sort of hard to see here but the inside wheel is turned a bit more than the outside to compensate for running a tighter circle. The funny thing is that most race cars run anti-ackermann, that is the outside wheel turns in further than the inside wheel. This is because when cornering hard, most of the weight is on the outside wheel, and a tire with more load on it can take a higher slip angle before it starts to slide. Thus, if you have a race car that keeps its tires parallel (parallel steer) as it turns, the inside wheel will start to scream, losing grip, while the outside tire does not as much. Anti ackermann is more effective on fast tracks with less of a steering angle though, typically closer to parallel steer or even ackermann steer is effective on tighter tracks so the wheels don't scrub.

Now, intuitively it seems to me that the effect of lowering on ackermann is nil, as long as you keep the toe the same. However, I have noticed my inside front screaming for help on hard cornering when I had my softer Progress springs that lowered the car about 1.8-2". I have not noticed the same effect with my current setup although it is entirely possible that the ackermann on our cars just wasn't set up for performance driving (less ackermann, closer to parallel steer) but instead for economy (less tire scrub around slow corners, more ackermann)

The best way to add ackermann to a setup by angling the steering arms inwards or towards the center of the rear of the car (as they are in the picture), whereas anti-ackermann is added by angling them outwards or towards the center of the front of the car. This is not something we can adjust at will on a street car.

The only way to get rid of these problems if you insist on being low? Custom extendable ball joints AND tie rod relocators. Bump steer kits with just tie rod relocators do not solve the problems as toe is very sensitive and the camber curve won't be affected without extendable ball joints, thus still throwing off the toe curve (possibly in even more funny ways). You must recreate the stock ride height geometry in order to do it right.

So, Matt, if you're out there, make those damned custom LCAs.

mowgli29

iTrader: (21)

MrDicks95SE

iTrader: (23)

if only the LCA market and aftermarket in general is in high supply for the maxima...

we chose tough cars.

MorpheusZero

iTrader: (10)

Nah, we are just a tough demographic.

QNO_A32

iTrader: (7)

mind = blown

MorpheusZero

iTrader: (10)

I wonder how many people will actually read that.

jg_98max

Should this be a sticky? Suspension geometry 101?

mowgli29

iTrader: (21)

^^ I vote yes. This is info that everyone who's into advanced suspension/handling needs to know. Mods?