snub disphenoid

I'm not trying to start a flame war, I'm just trying to see both sides of this disagreement.

Most people these days seem to shoot for the high-priced "JDM" coilovers (i.e. TEIN, Zeal, JIC, Silkroad, etc.). These are obviously quality pieces and while I had them my car was actually faster than me. I liked them, but they were very expensive, and I'm not sure if the price was really justified.

There's also a fledgling idea that I've heard, mostly in the second gen. forum (the folks that don't have all that much money to throw around) that "JDM" coilovers are overrated. These folks say that a simple setup like Ground Control "Coilovers", adjustable shocks, and camber plates are just as good, and also cheapers (Shocks - $400, springs and perches $350, camber plates $300-$400). Another upside would have to be the ability to customize your spring rates. You can choose if you want a soft street setup for springs, or you can make your car a super-stiff racemobile that shakes your teeth out.

I'd like to get a discussion going here - what's better, and what's better for the money? A custom hybrid setup or the seemingly tried and true "JDM" coilovers? Suspension experts chime in, please.

rynberg

The cheaper "JDM" coilovers suffer the same exact drawbacks as the Ground Control kit -- the spring perches are not independently adjustable. Therefore, ride height determines length of suspension stroke and spring pre-loading. This is not ideal. The better quality coilovers have independent spring perches so full suspension stroke is retained.

Theoretically, a designed coilover will have the shock valving set up perfectly for the included spring rates. This may not always be the case. However, the GC kits are just that -- kits. You use your off-the-shelf Konis or Illuminas or Bilsteins or Gabs, and combine them with Eibach linear springs. The shocks are not valved specifically for the spring rate. So, theoretically, a designed coilover package will have a more controlled motion through all of the different types of suspension loading than a GC kit.

Also, some of the higher quality "JDM" coilovers come with much higher quality dampers (bigger diameter monotube) than the Konis/Bilsteins/GABS, and especially Illuminas.

bradt

what he said^^^^^^^

BicuspiD

Plus, a coilover setup (IMHO) should be used primarily to dial in the corner weighting of a car. When you are that level/need for adjustment, then you can truly take advantage of being able to swap in different spring rates/lengths, shock valving, camber change, and the other benefits that coilovers give. A simple shock/spring setup can give great results though, if its designed for the car in mind and not a "one kit fix all" solution

That being said, I am still using KG/mms and Bilsteins, simply because my driving ability hasn't compromised the performance increase/price point yet.. (ie im not that good) Hopefully some day I'll need external reservoir transverse mounted units

snub disphenoid

That's what I was thinking. High priced coilovers have specifically valved dampers paired directly to the springs. Also, the JIC's I had had independently adjustable spring perches so that I could go with a significant drop in ride height without sacrificing suspension travel. Still, the JIC's blew pretty quickly, which raised an eyebrow about the durability issue.

snub disphenoid

That's another thing I was thinking. Most people that buy coilovers seem to buy them so that they can say they have a certain brand of coilovers, not because they're racing at such a level that they'll really need them. I know I wasn't at that level when I bought my JICs. I played with the compression/rebound maybe...twice at most the entire time I had them. It was just that I wasn't so good that I would say that it was my suspension that was limiting me, rather than my driving ability. I imagine that most street driven/occasionally autocrossed cars don't really need full blown name-brand coilovers.

RETed

Yep, it's JDM envy.

When it comes down to it, spring handles compression - damper handles rebound.
The system needs to work together to produce good handling performance.
Of course, that is a VERY simplified explanation of what's going on.

So what does Tein / JIC / Silk Road / HKS / A'PEXi / Cusco does that KYB / Tokico / Bilstein / Koni don't?
Nice fancy advertising...
Nice colorful anodizing...
A complete adjustable system...

When it comes down to it, it's still spring has to handle compression, and damper has to handle rebound.

Adjustability is nice, but it's not absolutely necessary.

I'd put a set of converted custom double-adjustable Koni yellow's against ANYTHING the Japanese is pumping out, and I put money the Koni's will smoke them on the track.
The one thing the Japanese haven't really started selling is independently adjustable compression and rebound dampers.
Ask any real racers what the advantage is...



-Ted

artowar

iTrader: (1)

Aside from the other factors mentioned, if you are going to spend the money on adjustable racing dampers, then you should also take maintenance into consideration:

- Are they rebuildable?
- Are spare parts available?
- Are rebuilding services available?
- What is the typical service turnaround time?
- What are the prices for parts & service?

Ground Control and Advance Design are in California. Konis can be rebuilt and serviced by Truechoice in Ohio. Of course, Penske has domestic service.

JRZ, Moton, Ohlins, and the Japanese brands? I don't know much about these companies or whether they have good U.S. domestic support, but if I were interested in their products I would definitely check first.

snub disphenoid

Tein has a few double-adjustable coilovers available, but prices start around $2400, so forget that.

DamonB

What artowar says is what counts. "JDM" doesn't account for anything when it comes to performance. I can assure everybody that the Japanese do not have the market cornered when it comes to performance parts. JDM is just as likely to be over priced crap as it is to be good; it's no different than anywhere else.

I guarantee 95% of the people on this forum with true coilovers don't understand what a coilover is really used for and have no idea how to set them up properly.

RETed

If you look at what the Japan / Asia F3000 series cars are running, it's not Japanese dampers.


-Ted

Falcoms

^ Please explain more in depth!

I am considering a coilover setup (yes, I know how to use/adjust them for conditions) being that my shocks are all the original AAS stuff on the GXL with 150k miles on them. I don't want to go for a good name, but rather quality and adjustability, as well as reputation (read: on road course scene, not ricer (i.e. street) scene). I've been looking at whats available, and it's honestly not looking like Japanese equipment is where it's at at all. I remember a site that (don't quote me on this) Silverbullet from the FD section made that went through all his research on coilovers. The only problem is, though, that his research info stopped about half way through after he settled on one brand. I'll try to find the link for you all.

Falcoms

http://www.silverbulletrx7.com/coilovers/coilovers.html

here it is!

dis1

Yea, thats my site. I've been reading this thread with interest. Sorry you think my research stopped before it should have. I think you can do very well with a GC setup with some shocks from a brand like koni. In fact I know you can because many of my friends run this setup and are much faster on the track than me. (Its not because of the coilovers though.) Anyway I like what I have better and it was not that much more money.

I'd also disagree about what DamonB said about 95% of people here don't know how to use their coilovers. I'm sure it is a high % but I wouldn't go that high Maybe ... 85%.

Falcoms

^ I agree on the percentage comment, and I also appreciate your input on this threa, being that you went through the search for coilovers. I'm not sure about the GC setup comment, though. To me (read: my opinion only), they seem like they are not part of a complete system, but rather just a glorified spring. They don't allow height adjustment without adjusting spring preload from what I've read, and they are sloppy when the suspension starts to go to the extremes of its travel.

Well, I guess it's time for me to say what I think I'm going to be going with. After much research (thanks to dis1 for helping it along!), I finally decided for a street/track setup, I am going to go with the buddy club racing spec (possibly the P-1) coilover set. They give me the adjustability that I need, and they also are rebuildable, and I have heard more good things than bad about them (I am open to any and all comments that will sway me away from these).

I think that this is a very large investment that goes in a place that could me life or death for myself and possibly others if they fail. Therefore I belive that thourough research is the only way that a wise choice will come from.

RTS3GEN

well, I'll chime in on the experience side of the debate. I have run GC coilovers for years on a set of Tokico 5 way illumina's now and have slowly run into a stroke issue. As I have become a better driver(I am a Porsche club, Audi Club and BMW club instructor on long course Drivers clinics) I am out driving the stroke on the illumina's because the GC limits the shock piston by about 2 inches. I am switching over to a set of Tein Flex's with the edfc to take advantage of the appropriate matching of spring rate and stroke of the coupled unit. Don't get me wrong for 80% of the guys/gals on the forum the GC and Tokico/Koni etc setup would be great for street and occasional track use but if you are going to eventually track the car I would recommend going with the complete coilovers sold as units. With the RX7 or any car for that matter, you get what you pay for(BTW, the Tein's Flex dampers with upper pillow mounts are under 1500 bucks complete, w/o the edfc.)
Art

DamonB

Explain? I don't understand what you're saying.

37FC3S

I was looking for JDM coilovers and have settled for modifying my KYB AGXs with GC coilovers. I did not want to spend $1500-$2000 for a set of coilovers that would have to be sent out for 2-8 weeks if one needed rebuilt and possible miss a track day. I will be able to replace a damper myself within a week and it probably costs less. For daily driving and occasional track use I think I would have been over spending on suspension that I can’t take advantage of yet.

owen is fat

I think you've made the right choice.

37FC3S

Thanks “Owen is fat”. I almost did get the Tein flex coilovers but wanted something a little stiffer. I will have 375lb front springs, 250lb rear springs, front adjustable camber/caster plates, rear camber adjusters, and rear polyurethane shock mounts. This should be a good compromise between street and track I hope. I will see how it is on Buttonwillow raceway in March. I want to start passing more of those Porsches!

ARD T2

iTrader: (22)

I've always found the ride quality to be much worse in a GC/damper setup. In both the FD and FC. Also had issues with the "aluminum" pieces wearing down. Not to mention they can be noisy as well. I do see serious benefits from both a performance as well as a "comfort" standpoint with several integrated units from personal experience. While I agree with many of you I still feel that an end user can appreciate certain benefits to an integrated short stroke setup.

RTS3GEN

Well, since the GC coil sleeve is located up about 2 " above where the original spring perch on the Tokico's are, the shock piston rod, bottoms out much sooner than it would if it were sitting on the stock spring/upgraded spring. Since there are several area's of the tracks I drive(HPT and MAM) with slight dips and bumps, I am bottoming the shocks out with the shorty springs and GC coilovers and thus upsetting the balance of the car, she starts to bounce out of the dips and distributes the weight incorrectly. As I have gotten faster thru several of the sections of these tracks where dips are, the problem is compounded when I have to hit the dip and then start braking immediately following, then the car tends to dive more harshly and is more difficult to handle thru the corner or difficult to apply full speed exiting!
Art

artowar

iTrader: (1)

It sounds like you're describing coil bind (i.e., the spring is compressed to the point where one or more coils touch), not bottoming out the damper.

RETed

Hmm...
Doesn't the shorter springs imply less damper travel?
If you're using GC stuff (or almost any other coilover kit), you're most likely using significantly stiffer spring rates?
Stiffer springs rates would almost eliminate the damper to compressing further than if they were using stock or stock-replacement springs?


-Ted

DamonB

That's the fault of running a too short spring. You have to raise the collar way up to make up for the short spring and when the spring coil binds you run out of suspension travel. Buy longer springs.

Just FYI the Tokico is known to not like springs much stiffer than stock.