Opinion: Suspension Setup

[DTFE30]

Looking for your professional opinion on choosing the correct suspension for my use...

Background:
I do mostly HPDEs with it and some "spirited" driving on the weekends. As for the future, I think spec e30 would be something I might consider a long time down the road.. Also, I don't care at all abt street ride quality since I don't DD it.

Current Setup:
My e30 has all urethane bushings, eibach sway bars, and an off brand weld in coilover setup in it now and I am not happy with the coils.

Would you:

A). Run a conventional setup such as H&R race / IE3 with billy sports and a nice set of camber plates (something similar to the setup Turner sells http://www.turnermotorsport.com/p-41...nsion-kit.aspx)

B). Purchase the GC coilover setup with either single or double adjust. price really isn't a concern. They are quality products.
Trying to get an idea of what to run from guys who have "been there, done it"

Thanks in advance!

[TobyB]

I am not happy with the coils.

What part? The nice thing about a conversion to 2 1/2" springs is that
you can now change springs to whatever stiffness and height that you want.
The damper's still a damper, and can be anywhere from stock to quite aggressive
to match the spring. Adjustability is nice if you're changing springs or road/ track conditions.
For example, Seattle is faster with a softer setup, Portland can be run very stiff...

The upper mount is a bit harder- the GC all- metal adjustable mount's very nice indeed.
But it'll be noisy, relative to something soft. And they do take occasional maintenance.

...to get things started...
t

[matthugie]

As someone who has redone their suspension a few times, my suggestion is to figure out what your end goal is and build in that direction. If you think it'll become a Spec E30 car down the road then just get yourself a spec suspension. There's no sense in getting GC's if in a year or two you have to take them off and do something else.

I can say that I had all urethane bushings with IE3's and billie sports paired with Kmac camber plates for a couple years and they were fantastic. Being swapped I can't run a spec series so I ended up going for a stiffer setup, but the ride was pretty good all told and the car handled very well. Great setup for a car that sees both track and street.

[DTFE30]

What part?
t

Specifically the rear. I went through 3 iterations with the company and still the final set they sent was improperly matched spring and damper. I put a 700# gc linear coil in the rwar and have been messing with damping on the streets but theire poor customer service and lackluster quality really left a bad taste in my mouth and I want to cut my loses for something of quality construction and performance.

Sent from my SAMSUNG-SGH-I317 using Tapatalk

[Bimmerman325i]

Do it once and do it right: buy the highest quality shocks you can afford. If you're only looking at GC, then I would strongly encourage you to look at the Double Adjustable (DA) setup, and to also investigate TC Kline's suspensions.

There are other fantastic brands (JRZ, MCS), but the GC DA is a very good price/performance setup. You don't mention a budget, but unless you plan on doing competitive time trials/wheel to wheel racing, there's not much need for something beyond GC or TC Kline's DA kit.

Since your car is swapped (based on your avatar), SpecE30 is out of the question, so go proper coilover.

The damper is honestly the most important component as you've begun to realize. Having separate compression adjustment is amazing and makes a huge difference on your setup possibilities. That said, it's also another setting to screw up and make the car worse. The single adjustables are a great setup as well, and leaves a couple track days' worth of funds left over vs the DAs.

If you've been doing HPDEs, and you have a cheapo coilover kit now, get the GC or TCK Doubles (not the GC Advanced Designs unless your car is trailered) and be happy.

Hope that helps! I really liked my TCK DAs; for an HPDE car I think they are pretty much perfect.

[UDMRacing]

Also, after you have dialed in the ride height to your liking, find someone with some scales and have it corner balanced. I wasn't so sure that it would make a difference, but after getting it on the track there is no doubt that it is a requirement from now on. Here's a good link that will explain how and why. Enjoy. http://grassrootsmotorsports.com/art...orner-weights/

[blatant]

I'd recommend TCK DA.
Which coilover setup are you currently running? Posting the name will help others avoid the company.

[DTFE30]

Did you run the shortened housings and m3 style end links?

Do it once and do it right: buy the highest quality shocks you can afford. If you're only looking at GC, then I would strongly encourage you to look at the Double Adjustable (DA) setup, and to also investigate TC Kline's suspensions.

There are other fantastic brands (JRZ, MCS), but the GC DA is a very good price/performance setup. You don't mention a budget, but unless you plan on doing competitive time trials/wheel to wheel racing, there's not much need for something beyond GC or TC Kline's DA kit.

Since your car is swapped (based on your avatar), SpecE30 is out of the question, so go proper coilover.

The damper is honestly the most important component as you've begun to realize. Having separate compression adjustment is amazing and makes a huge difference on your setup possibilities. That said, it's also another setting to screw up and make the car worse. The single adjustables are a great setup as well, and leaves a couple track days' worth of funds left over vs the DAs.

If you've been doing HPDEs, and you have a cheapo coilover kit now, get the GC or TCK Doubles (not the GC Advanced Designs unless your car is trailered) and be happy.

Hope that helps! I really liked my TCK DAs; for an HPDE car I think they are pretty much perfect.

[DTFE30]

Thanks guys. I really appreciate the advice!

[DTFE30]

I'd recommend TCK DA.
Which coilover setup are you currently running? Posting the name will help others avoid the company.

Not trying to bash companies, but it was ISC. I would suggest avoiding them and spending the extra money on something of higher quality if possible.

[Artful Dodger]

Im gonna chime in here a bit. I have spec suspension on my swapped e30. It works well all around. but by no means is it great. Spec suspension is off the shelf components that the organizers deemed would be used to try to keep the cost of building the car down.

If you want a non adjustable suspension, I would go with the Turner J-stock suspension. it is much stiffer than the spec suspension and the shocks/struts are custom valved to match the spring rates.

If you are looking at an adjustable set up (coilover), Ground control is a great company. Just be sure to get the proper shocks in the rear, or you will have to remove the shock from the car to adjust the rebound.

Of the higher end companies, Motion Control is making its mark as the new guy in town. The kits are expensive, but in this case I say you get what you pay for.

good luck in your decision.

[lcoleman]

Better dampers are probably what you're looking for. Is there a way to add a better strut to the setup you have now? Just replacing one part is much cheaper than replacing the whole thing, obviously.

Otherwise: SpecE30, GC, TCK, AST or Ohlins, MCS in ascending order of price (I think).

[matthugie]

I will amend my original opinion and agree with Dodger here. I thought you were still M20 powered if you were thinking Spec E30. If you have a swapped car then don't go with a spec suspension. I swapped out my IE3's and billie sports for a J-stock setup and it's one of the best things I've done to the car. That said, if the roads around you are rough and/or you drive to and from the track over rough roads it can be a bit much after a while. J-stock also is hard to find (except the dampers, Turner still sells them). If you want adjustability then go with a good coil over kit.

[Jaxx_]

To me it seems crazy to redo the entire suspension setup if you have swappable coils and adjustable sway bars. I assume you cannot adjust compression/rebound on the current coilovers? Is the concern about mismatched spring rates and shock valving because of ride quality?

I have nearly spec e30 suspension (missing SE30 sway bars) and it's not bad, but not fantastic. It handles everything pretty damn well in my 318, and matching sways and tires appropriately will make up for the imperfections in my opinion. Over harsh bumps it is easy to tell that the springs were not designed to match the valving of bilstein sports.

With all of this said, I think that even with mis-matched dampeners and springs in the rear your car could handle fine. Does the car under or oversteer into or out of a corner? Some of these issues can be fixed simply with sway bar setup(or even alignment!), even if the car is neutral mid-corner.

[Bimmerman325i]

You can change the spring rate until the cows come home, but if the damper isn't up to snuff, then you're just wasting your time and alignment funds. The damper is the most important component in a suspension, not the springs, not the sways, not the bushings.

Case in point: I went from TC Kline Doubles to Motion Control Doubles at the same spring rates, and the difference in handling was eye opening. The car was so much more composed over bumps, each click of rebound or compression made a noticeable difference in feel, and the car didn't feel like I was driving a pogo stick down the road. Responsiveness of the car, car chassis movement damping and control, and car balance have all been drastically improved....and that's saying something considering the TCK DA suspension is pretty damn fantastic on its own, especially compared to a stock car.

Compare that experience to the ASTs I had, or the Bilsteins/Eibachs: the car was incredibly uncomfortable, harsh over bumps, bouncy, and just utterly uncompliant and unforgiving. People who don't know better associate stiff and harsh ride with good handling and quick responding suspension but that could not be farther from the truth.

Another data point: we installed a set of JRZ race shocks (with silly high spring rates) on my friend's street Evo MR, to replace the still-good stock Bilsteins. Bone stock car otherwise, sticky street tires, nothing else except the JRZs now. Immediately, without doing any setup tuning, the car was smooth and controlled over bumps and broken up pavement, handling bumps with control and aplomb rather than unsettling the chassis, turn in was dramatically improved, over/understeer balance was improved, the car gripped so much nicer, and ride quality was even improved. The magic here is in the shock, not the springs, not the sways, not in any other part of the suspension.

ISC coils aren't BC or Megan or JOM levels of garbage, but they are still $1k coilovers. The dampers aren't consistent nor even all that good at blowing off bumps and absorbing shocks. If his issue is unsatisfactory handling, the single best thing he could do is swap the dampers for something better.

rant over: having the ability to change spring rate and anti-roll bar rate has little to do with improving ride quality when the primary culprit is poor damper quality and unsatisfactory functionality. You get what you pay for with dampers, so don't skimp.

As far as J-Stock idea goes, I would favor an adjustable coilover. Not being able to adjust springs, ride height, nor damping means the car is easier to set up and forces the driver to focus on driving and not tuning (great for lower-level HPDE), but you eventually will outgrow it. It is a great setup but it is honestly not designed for swapped and modified E30s, with different weight biases, different max/min weights, power, tire, etc. I would instead get a good adjustable suspension, set it to the baseline specs provided by the retailer, and then do a few HPDE before you twiddle knobs. Once you get used to how the car reacts with the new suspension, then start fiddling with it to dial it in to your driving style preference (over/understeer, trail braking, stability, etc). Again, a good damper makes setting up a car easy and simple. A bad damper leaves you chasing your tail and frustrated. It all comes back to the damper.