Gsedan35

iTrader: (10)

I do not own these, I'm just posting the infomation because Terry at Fortune auto was kind enough to send me the dyno's.


Front


Front Hysteresis


Rear


Rear Hysteresis

Basic product description:
Monotube, adjustable damping (rebound) full height adjustable, true coilover rear design
Spring rates 448/336


Pro:
Mild damping
Mild spring rate (front)
Serviced in the states and not just with core swaps, revalving avaliable**
Lack of insane damping levels

Con:
Adjusting them stiffer doesn't really add much low speed control, but it does keep some from messing things up really bad
A little too mild in the front, would like to see about 75lbs more compression by 10 inches per second
Underdamped and oversprung in the rear
?What about those of us that will NOT run true coilover rear setups?

Here's my biggest concern, that the rear is oversprung and underdampned.

Compression at low and high piston speeds are fine. When I overlay these dyno's with other* dyno's that I have they match up quite well. For a setup that works with much softer rear spring rates. IMO, based on these dyno's I would not run the rear spring rates the kit ships with. I also see running a softer rear spring as a plus front to rear roll couple wise.

Here are some numbers to better explain my concerns about the rear.

Let's take apart the kits spring rates and show how much spring actually makes it to each front and rear wheel to perform work (wheel rate)

Out of the box the setup comes with 448/336 spring rates
448 x .688 x .688 = 212 front wheel rate
336 x .97 x .97 = 316 rear wheel rate
^ High rear roll couple

A 316 rear wheel rate equals 750lbs rear spring run in the oem rear location vs on the rear damper.

IMO I would drop the rear rate to
224 x .97 x .97 = 211 rear wheel rate
500 x .649 x .649 = 211 (spring rate needing if running a spring in the oem location vs on the rear damper)
^Equal front to rear rool couple


*Other shock dyno files being oem revised 2004.5, Koni sport full soft, 4 and 6 sweeps and Bilstein Pss9 full soft. All of which dampen a 180lbs rear wheel rate quite well (Koni's can cover up to 211lbs )
On the whole, I had hoped for greater control ranges, especially in compression. To me these are more about being a comfort biased setup that IMO is oversprung in the rear and in need of a bit more highspeed compression in the front.

**Given the dyno's shown, product may or may not be able to acheive your desired force levels or curves in a revalve situation. By all means inquire with the company.

SoCal07HR

iTrader: (17)

Glad this info is out there. Thank you.

VQ35deMax

iTrader: (6)

Wonder how the new 510 Coilovers would compare

SoCal07HR

iTrader: (17)

Over sprung and under damped isn't all that bad when it's using a 9kg true type and the company offers different rates at no charge. What rear spring rate d you recommend for these? Maybe 6-7kg/mm?

Jackson0927

interesting, i just ordered 500's yesterday

terrasmak

iTrader: (8)

Probably 4k or 5k rears

Zazz93

iTrader: (2)

Oversprung and underdampened is pretty much the aftermarket, save a few, so that's not too surprising. Honestly, I expected to see some real issues, and I pleseantly surprised (relative to this unit's competition). The 2ips range is well lower than I would like, but like you say they seem well suited for comfort (especially with a little less spring out rear).

Gsedan35

iTrader: (10)

Look at the math again. It is bad.

True rear types leverage almost 100% of the springs power to the wheel to perform work.

If the spring is in the oem location, a whole lot less of the springs power gets leveraged to the rear to performa work.

Over spring and underdamped is bad. I've run, and tested with shock dyno's way too many setups. I know.

I show in the math the rear rate I recommend based on the dyno's

As stated by Terry in his email to me reguarding this thread, they can supply the softer rear rate or they can revalve. Only concern would be,....revalve to what? I've been down that road before and it didn't end well and I was dealing with a very respected outfit working on a Bilstein product. And a hard lesson it was

Gsedan35

iTrader: (10)

Relative to the spring rates in the kit, I totally agree. IMO, more buyers in the market for a cheap coilover are more likely to not track their cars, so to me these are more suited to their market. Course their will always be those folks that aim to track on a cheap setup. To them, they'd be better served with a bit more front spring and more damping in the 0 to 3ips range with degressive blow off from their (more knee). I would have concern's that this products valving setup would be able to deliver on that.

Voboy

iTrader: (58)

thanks for the info.

Vivid Racing

iTrader: (67)

Thanks for posting this, Gsedan. I can tell by your post that you're knowledgable with suspension but would you mind sharing what your "credentials" are or what experience you have?


The hysteresis and cross talk (or lack of) looks great to me, especially considering the price and their competition. A bit more low speed damping would be nice in the 0-3ips area, but overall these are a GREAT coilover for the money. The fact that Fortune Auto has NO problem making dyno plots public should go to show how they feel about their product.

Zazz93

iTrader: (2)

Man...I can't think of a dampener in this range that offers a knee like you described, except maybe some Koni yellows. Its seems all the manufacters had decided to let the high speed dampening run rampid.

Duckeee

iTrader: (7)

couldnt have said it better, Scott.

if I was in the market for coilovers in the $1k market, i would choose Fortune Auto over Megans, Stance, BC Racing, Ksport, or any of those brands.