chiketkd

iTrader: (5)

Miles,

I'm also curious about the valving as well. One thing, these coilovers are compatible with Eibach ERS springs, so it is possible to change the spring rates if you so desire.

Unless I can get custom springs made for my konis at the rates and ride height I desire, this will be the route I'll go. I'll probably run the coilovers as delivered for a few events before changing springs, etc.

Peppy@kacework

Let me see if I can dig up the paperwork that came with them. Not sure if I still have it, may have been lost in my move.

the_duke313

Whats the spring rate on these? and what is the equivalent shock that bilstein sells for our cars?

the_duke313

bump?

LionZoo

The spring rates are listed earlier in the thread. Bilstein sells a Bilstein HD standalone damper for the RX-8, but it's damping curve is different from the PSS9 curves as that damper is valved for standard RX-8 springs.

GeorgeH

iTrader: (2)

The other day, I talked with of John @ Bilstein tech support about revalving the PSS9s for autocross duty (STX). One of the first things I brought up was the spring rates as reported in this thread, and he told me the rates reported here are incorrect. This is what I learned about the RX-8 PSS9s:

Front spring rate: 340 lbs/in, 80 lbs/in tender
Rear spring rate: 240 lbs/in, didn't ask about the tender

Seem like reasonable rates to me.

FWIW.

the_duke313

thanks for the info

ThecdnRX8

The rears don't have tenders. They are progressive as seen in the pics.

LionZoo

Quite interesting. With the lack of a tender, any idea what that does to rear droop travel? As you know, droop travel is what I'm having the most issue with.

Peppy@kacework

They need to work on getting their employees the correct information. I called 3 times and was given the rates that I had posted earlier in the thread each time. The numbers you were told seem more in line with all the other brands of coilovers for the RX-8 in regards to front/rear spring rate ratio.

Just out of curiosity, did you happen to talk to the East Coast or West Coast headquarters?

GeorgeH

iTrader: (2)

It was west coast. Again, I spent 15 minutes on the phone, talking about custom revalves, etc. He even looked up the damping values for me, but I didn't write them down so I'm not going to post them here (I recall the range being fairly tight, as in you will not experience a huge difference from full soft to full stiff). And, as I said, when I first told John about the rates, his response was "That doesn't sound right - let me look it up."

I agree, it is frustrating to get different data.

As for the rears, since they are progressive springs, there shouldn't be a need for tenders, as was stated above.

Peppy@kacework

Ya, I had talked to the east coast, maybe they just make up rates cause they are too lazy to look it up, lol. Regardless I am extremely happy with my PSS9's. They are exactly what I was looking for. Comfortable for every day use, but more than capable for DE track events. I have no interest in Auto-x so I wasn't looking for higher spring rates. I have noticed results from the adjustments I have made on track, even if the damping range is small.

GeorgeH

iTrader: (2)

Good to hear. If you are tracking it and are not having oversteer problems, I am inclined to believe the rates I reported above as opposed to the rates you heard from the east coast office.

And, I'm sure you will feel a difference between clicks, just not HUGE differences. There seems to be two schools of thought on damper adjustment - big steps with very obvious differences between clicks, vs. more subtle changes for each click. I prefer thre later, as it allows you to more precisely tune the car.

Of course, the advantage of having a wide damping range is that it makes it easier to fit stiffer springs. This is probably the only drawback to the PSS9s. But as you say, the rates are probably ideal for the typical dual-use car as-is. Even for STX autocross, conventional wisdom (right now) is that you wouldn't want to run much higher.

Peppy@kacework

I haven't had any issues with excess oversteer. I'm sure the rates you were given are the correct ones. Right now the car is very neutral. I have my front sway in the middle setting and my rear in the soft setting. I had started out with the stiffest settings on my shocks but found the car to be much more stable under braking and a little less on edge in high speed turns when I softened up the rear. My original settings were 1 in front and 2 in the rear(1 being stiffest, 9 softest), my settings now are 3 front and 6 rear. My next track weekend May 2, will be my first on my NT-01's. I'm sure I'll be messing around with the settings a bit more with the extra traction and braking of the R comps.

GeorgeH

iTrader: (2)

Excellent to hear that, as your report is consistent with how they wanted to set me up with the custom valving. Basically, once you tell them your spring rates, they set the valving so that the middle of the range corresponds (more or less) to critical damping and then you tweak from there to get the balance you want. Sounds like the stock valving is set up the same.

LionZoo

Hmm...

If I had known those were the rates beforehand I'd probably have gotten the PSS9s instead of trying to build my own. Nonetheless, I have no regrets as the process I've been through has been incredibly educational.

Peppy, about how long are the rear springs? If possible, can you take pictures of the rear at full droop?

Peppy@kacework

Lionzoo - I'll measure the springs and take a picture of the rear at full droop for you tomorrow.

91 Impulse RS

Hi, was just wondering if you recall whether your PSS9's were shorter in extended length than the stock shocks, or were they the same.
thanks.

chiketkd

iTrader: (5)

Time to bump this old thread...

I'm in the market for a set of coilovers in the coming months and the Bilstein PSS9's are near the top of my list.

From the spring rates George was quoted, it seems like Bilstein used similar rates as the MX-5 PSS9's:

http://www.good-win-racing.com/Mazda...-1070pss9.html

Front: Linear 343 lbs/in + tender (80 lbs/in?)
Rear: Progressive 242-282 lbs/in

These seem very close to the figures George was quoted.

I'll definitely want to up these rates for autocross use, and Good-Win-Racing sells a nice adapter for the rear coilovers:



http://www.good-win-racing.com/Mazda...t/61-0196.html

After I get an accurate understanding of what spring rates the RX-8/MX-5 PSS9's can handle, I'll probably look into a revalve and getting some 2.5" Swift/Eibach springs.

GeorgeH

iTrader: (2)

I was told that the PSS9s have a fairly narrow damping adjustment range, and will require revalving for most spring rate increases. They reccomended that I run them for a while with the stock rate to get an idea of the rates I wanted, and then send them back to be revalved for the stiffer rates once I had a target established.

chiketkd

iTrader: (5)

George,

That's my understanding as well, but Jung is willing to give me technical assistance with revalving and sorting out my set-up along the way. He's also given me the contact info for the person he uses for revalves at Bilstein in Poway, CA.

I'm pretty sure they'll do a revalve for me right away. I'm still gathering info on spring rates and I'll be interested to see what rates Isley used on his car @ Nats with his motons.

From the info I have currently, my front spring rate "revalve range" will be around 550-400 lbs/in, while the rears will be around 350-250 lbs/in. Eibach, Swift and Hypercoils will all work with these coilovers and I'll probably pick up several different sets/combos.

As Nats probably won't be in my cards next year, I want to spend my time sorting out my suspension and wheel/tire set-up.

-Chike

LionZoo

I wouldn't recommend those adapters. As detailed in my Bilstein thread, I can't figure out a way to make an adapter for a 65mm springs in the rear that won't result in rubbing and someone else later chimed in that the adapter as used on his friend's NC had rubbed all the finish off the damper. On the RX-8, the rubbing can only be worse.

chiketkd

iTrader: (5)

Are their any other adapters out there?

I've been e-mailing back-n-forth with an engineer at Bilstein in CA, and iirc he mentioned that the fronts accept 70mm ID springs and the rears take 65mm ID springs (recommended Swift springs).

ULLLOSE

iTrader: (1)

Same type of part on the Moton, works fine.

chiketkd

iTrader: (5)

Looks like I'll be able to get custom valved bilsteins from the Poway, CA office for $125 per shock (if requested they'll include a dyno graph of the performance change @ .52m/s). Once I've selected a vendor, they can do the revalve for me prior to shipment.
Where did you get your adapters for your rear motons? I'm wondering if the quality of some adapters are better than others...