DesertSleeper

iTrader: (1)

Hello fellas,

Upgrading my suspension and have narrowed it down to these two coilover setups. There's not a whole lot of info on them since they're the non-adjustable dampening versions. I'm leaning towards the bilsteins, but wanted to get opinions from members that have them. The KWs are almost $700 more, is it worth paying the extra coin for them and why? Looking for a comfortable set up that will perform when pushed as well. Any input will be highly appreciated

MicVelo

Thread on topic: https://my350z.com/forum/brakes-and-...-bilstein.html

I've done neither but.... while doing research on suspension options a few years ago, I was left with a number of question marks in my head regarding these very same units.

As you stated, neither the Bilstein PSS14 nor the KW V1 offer adjustable dampening. Leading to my first (and most important IMO):

WHY COILOVERS THEN?

Height adjustability is one thing but unless you're going to the track and need that adjustability, well, I submit that you need dampening adjustability MORE than height adjustability. (Or, at least need the dampening to change the spring behavior when lowered to full down.)

That led to my second question - which might be answered here somewhere but I've not needed to explore further after ruling out coilovers:

Bilstein's documentation claims 30mm-50mm height adjustability by adjusting the spring perch... which also means (if going by conventional thinking on coilovers) also changes the spring pre-load and that doesn't always translate to "good". Too much spring (by decreasing height of the spring/ increasing pre-load) leads to higher dependence on the shock to control it AND typical issues with excessive spring load is a bad ride prone to tramlining and lack of civility in driving.

So the question is: What does Bilstein do right with these units to rectify this issue? They have to have an answer, right?

I don't know the answer. As stated, have done no further research in 3-4 years. If you run these, I'd sure like to hear about your experience with them in the full down position!

Sorry that this doesn't really answer the question...

DesertSleeper

iTrader: (1)

Very valid point regarding adjusting ride height via the spring perch, that is one of my main concerns. Increasing pre load cannot be ideal, and even though I would most likely have the ride height set around the mid point of their range, it would surprise me that these two brands designed a coilover that wouldn't perform ideally throughout the entire height range....

1upZ

iTrader: (4)

Adjusting the height on these wouldn't compress the spring at all. In the front you would thread the spring perch down to lower the car, if anything decreasing preload, and in back since the spring is separate from the shock preload just is what it is for the most part. Also the adjustment range only 20mm or just over 3/4" which isn't that big of a range. I'm actually installing the B14 kit on my car tomorrow actually, to replace the Stance coilovers I currently have. I was in a similar spot (looking at KW v1 or Bilstein B14) and in the end price was a huge factor for me, as I got the Bilsteins foe under $1K from a vendor on here.

MicVelo

OK, I was SO perplexed by this - because it's counter-intuitive (at least to me) - that to LOWER the car, you would move the spring perch DOWN (thereby extending the spring to it's max length; hence raising the car to full height) and.... that that the spring pre-load wouldn't suffer from this?

So I just blew up the pic of the front units and I say OHHHHHHHHHH..... I get it now.....



I now see that the height adjustment IS separated from the coil pre-load by using an intermediate spring perch for the actual oscillating coil spring and the height is adjustable (through its miniscule 20mm range) on what appears to be a helper spring, specifically made just to adjust ride height!

But I still maintain that to LOWER the car, you must move the small helper spring UPWARDS to compress it, effectively shortening the overall height of the strut unit.

Now the rears are another matter.... you HAVE TO compress the spring to achieve max low (That expression in and of itself is a oxymoron, yes? hahahaha!)

Anyhow, want to hear how it all works out for you!

1upZ

iTrader: (4)

No, nothing gets moved up, the helper spring is irrelevant. You move the bottom perch down and that allows the spring (main and helper) to sit lower on the shock body. Then the natural weight of the car will compress the strut down until the spring once again carries the weight of the car. That's most likely why there's such a small window of height adjustment, as Bilstein wants to keep you in the struts optimum range. It may still change the characteristics of the shock/spring slightly, but in theory preload won't be affected, at least not in a significant way.

terrasmak

iTrader: (8)

Well the vast majority of high end coilovers are only adjustable via preload. They may be on to something.

MicVelo

Thanks, guys, starting to get a better feel for how that all works. Still won't be convinced a hunnert percent until I actually put hands on it but I'm getting it now.

But as many know here, I'm still not sold on the need for coilovers on the street but.... they're cool to play with. (Been working on my Stance COs on my Shiro.)

DesertSleeper

iTrader: (1)

Well that just makes sense. 3/4 inch isn't a huge range. If it's not too much to ask, please post a review and pics after your install. I think I'm going with the bilsteins as well, I just can't justify paying $700 more for the kw's.

DesertSleeper

iTrader: (1)

Mickey I get your point that coilovers are not needed for street use, but look at it this way. I can keep my springs and go with a set of bilsteins b8's, which will run me about 9 bills and give me no height adjustability, or for less than another c-note scoop up the b14s and have a bit of play with the ride height, not to mention a spring and shock designed to work together. To me thats a no brainer....

MicVelo

Oh let me clarify... I was NOT trying to talk you out of them at all. I think if I were doing it all over again and wanted some adjustability, I might actually opt for either of the sets you're considering. Just playing devil's advocate.

Besides, when you put them in and report on them, we all gain from the experience!

stogey420time

iTrader: (1)

Wow reading these posts above made my reason for purchasing coils seem silly. For me, it boiled down to two choices Bilstein PSS10 (b16) or KW3. I did not consider/nor research how the spring load/preload would affect the shocks ride quality or putting the shock/strut in distress when you're on max drop. All I care about was finding the "perfect" drop height with a reputable brand that has lots of R&D... and the lifetime warranty sealed the deal.

Either way for those wondering if KW or Bilstein will drop their car "low enough", here's some insight from what I've gathered over the years... please also do your homework and take my advice with a grain of salt.

At max drop in the rear for KW, you'll have 1 finger gap and for the bilstein PSS10's (what I chose) you get no finger gap but you'll have to remove the collar in order to achieve this look. However, your wheels size may affect the outcome of this because I'm on 19" wheels and it came out perfect for me drop height wise. But those with 18" wheels may have wheel gap still even after the collar removal due to the smaller diameter wheel.

EDIT: with my really low drop setting, I'm currently having alignment issue with toe setting but I'm not going to digress and want to stay on topic.

Here are some reviews for the Bilstein line up, GL with your decision.

Bilstein PSS (b14)

Bilstein PSS9

Bilstein PSS10 (b16)

terrasmak

iTrader: (8)

You do know that there is no different in gap with properly sized tires.

275/40-18 , 275/35-19 and 275/30-20 all have different wheel sizes but the OD of the tire ( where gap comes from) will be the same.

DesertSleeper

iTrader: (1)

I know you weren't Mic, you were just offering insight on what has worked for you thus far. Your opinions and advice are always appreciated sir

stogey420time

iTrader: (1)

This is good to know! I did not know the different tire/wheel size listed above with have the same gap.

I remember Blue messaged me a while back asking how I got my rear so low and he still have wheel gap... and my assumption was he's running 18's and I'm on 19's. Also, he maybe running 35 series instead of 40 on 18" wheels.

DesertSleeper

iTrader: (1)

Thank you for the input Stogey. I have camber kits front and rear and one finger gap in the rear is fine for me, but it's good to know I can get rid of the whole gap if desired

HRMoneyPit

I came in here looking for answers cause I'm in the same boat. Springs and struts cost more then a KW V1 or the Bilstein equivalent and no need to take apart my current starts to build the new set up. Idk about you guys but that process takes forever!

But that's beyond the point cause my answer was not answered lol which one? I see a lot of talk about coils vs springs and struts

armt350z

iTrader: (6)

I actually think most people who drive on the street are focusing on the wrong characteristic between these two products. Yes there is a drop, the Bilsteins win in that category with an additional CM of lowering. If that's your thing, rock on. But for the average street driven car that wants a mild to moderate drop, either will suit your needs.

The key part that I would pay attention to is the type of springs on each of these. One uses a linear spring with a helper (B14) and the other uses a progressive spring (V1). Those are going to give different ride qualities due to the way the springs ramp up.

1upZ

iTrader: (4)

That's a good point about progressive vs linear springs. Also a note on the Bilsteins, they claim a 20mm adjustment range giving you a 30-50mm drop, but the instructions only show a 10mm range on the front. When I installed them, I ended up with the front at the upper number (smallest amount of drop) and the rears all the way down (spring perch bottomed out with lock collar removed). That more or less puts the fenders right at the top of the tires. I don't know that I can give a subjective review on the ride though because I went from Stance coilovers, and also installed Motordyne sway bars at the same time.

DesertSleeper

iTrader: (1)

Interesting....so basically to have an even drop u have to set the front at the highest setting and the rear at the lowest? Would u mind posting a picture when you get a chance along with your wheel and tire specs?