Optical TDI

iTrader: (2)

After some research I'm considering the Mazdaspeed shocks and springs. But I'm also considering the Bilstein/Eibach or Koni/Eibach set up.

I'm looking for any opinions for those who have knowledge about these. I'll be doing a couple of HPDE events per year. Thanks.

devildog1679

I have the full MS set-up and track my car atleast 6 times during the summer. Nice set-up. I'm sure they all are great just go with the one that's most economical.

Jedi54

iTrader: (7)

Kwescott has the MS suspension and has been very happy with it. (he autocrosses monthly)
Your car going to hit the track?

Are the MS struts adjustable?

I have Koni + S-Techs; love the setup and love the fact that the fronts are easily adjusted. (rears need to be removed to adjust but I doubt I'll ever need to do that)

PhotoMunkey

I have the Bilstein HDs and Eibach Pro-Kit springs, and I don't consider the Bilsteins to be very good. Yes, they're an upgrade from the stock shocks, and have better control over the rebound, but their compression setting leaves much to be desired. I expected them to be better. It's like the crossover point for the low-speed upwards movement and high-speed upwards movement isn't set well for this car's weight. The LA freeway expansion joints really kick the car upwards, though the shocks do eventually control the motion.

Lest you think I'm just grousing, I had Bilsteins for my Porsche 944, which was a similar size, and less weight, and the valving was spot on! You could drive over all sorts of bumps, and feel very little from the driver's seat, yet body roll was perfectly controlled. These Bilstein HDs, by comparison, feel like cheap gas-charged shocks bought from Pep Boys.

BTW-I believe the Konis just control rebound, and not compression. The Konis can be revalved though to make the compression softer without purchasing additional parts (going stiffer requires new parts). It all depends on what sort of ride you're seeking.

Net result, I'm not happy with Bilstein right now... The Eibach springs I like just fine though.

LionZoo

Interesting. Thanks for crossing the Bilstein HDs off my list. Now I'm really interested in the Bilstein PSS9s, but nobody seems to have them.

VarneyMazda

Believe me from experience, there's enough members on here if they isn't many people using them there's probably a reason

Razz1

I have no problems with my KW Variant 3's

LionZoo

When nobody has been able to report anything at all, it just feels like there's a lack of momentum more than anything else. The PSS9s get good reports from other users, but it seems the RX-8 community barely knows they exist.

Razz, how's your ride quality with the KWs?

connor@tirerack

I think the best way to go is the Bilstein PSS9 kit. They are fully adjustable shocks and spring perches for height. This would give you the best of all worlds. You could compress the springs and stiffen the shocks for track days and they expand the springs to your taste and soften the shocks for everyday use. I have driven them on our test vehicles (not an RX8) and the difference in handling was amazing when combined with upgraded sway bars. I currently have the PSS9 kit in stock for 1332.00.

ThecdnRX8

I think the reason for not much interest in the Pss9 for the RX8's is the spring rate ratio between the front and rear that Bilstein decided on seem to be very different then stock and what every other maker uses.

For example
OEM
Frt 156 lbs/in
Rr 113 lbs/in
Ratio 1.38

Mazda Speed Coil Over
Frt 400 lbs/in
Rr 275 lbs/in
Ratio 1.45

PSS9
Frt 370 lbs/in
Rr Progressive. Working range: 375-445 lbs/in
Ratio 0.986 - 0.831

To me it seems like they are set up to work with a front swaybar. Otherwise you would have a car with more over steer.

Below is an e-mail I received when inquiring on these coil overs from Bilstein

Good morning! The PSS9 kit for the Mazda RX8 is GM5-B029-H0. The Front
spring rate is: 370 lbs/in (main), 145 lbs/in (tender). The Rear spring
rate is: Pregressive. Working range: 375-445 lbs/in. Please let me know if
you have any further questions.

Thank you,
Rebecca Kellerman
BILSTEIN Shock Absorbers

As far as the HD here is another review.


https://www.rx8club.com/showthread.p...ht=bilstein+hd

LionZoo

Based on TrackAddict's review, I wonder if PhotoMunkey got a bad shock or something...

swoope

iTrader: (5)

i think it is a shock to spring thing..

the drop on the rb springs that ta runs is .5 inch.. the eibachs 1.25.

i have been for a ride in ta car on the track. it does very very well..

note it was a very smooth track...

beers

crimson-rain

I have the MS springs/shocks setup. I can't tell you how they perform on the track or in autocross (haven't been able to get out much, getting married on March 20!!!). But as far as drivability on the regular street, they're just fine. My fiancee rides with me all the time and doesn't complain. My dad didn't really have an issues either when riding in it.

I've pushed my car a little on some back rodes and on-ramps here and there and I will say this setup feels VERY CONFIDENT. Less roll (no swaybars yet either), less pitch and dive, my car seems like it's "squating" on all four wheels instead of diving the nose when braking hard. Anyone have this feeling when braking hard in the 8? All in all, I can't wait to drive my at the track.

ThecdnRX8

The HD's are not designed to work with lowering springs. Bilstein's suggests to use the sport version if you intend to lower your car. But guess what they don't make it for the RX8.

So very good point made up above. If you what to go with lowering springs HD's would not be recommended.

LionZoo

PhotoMunkey's issue could be him hitting the bumpstops over the expansion joints, though to be honest LA expansion joints shouldn't force a suspension to hit the stops.

PhotoMunkey, next time you're in LA you want to give me a ride in your car?

PhotoMunkey

One of the techs from Bilstein called me back and told me "the HDs are designed to be used with stock springs." If that's the case, why bother to call them "HD" then? I'm considering going with JIC-Magic's street/track setup with the 8kg/mm and 5kg/mm front and rear springs. With my K-Sport setup, I had 10 kg/mm front and 5 kg/mm rear springs to start, but the rears were too short and bottomed out. Now they make them with 6.5 kg/mm rear springs, which are slightly taller. I have to say that I think the K-Sports on full soft were better than my Bilstein/Eibach setup is right now. Barely, and mainly only during compression.

I do believe that it might be an interaction with a too-short spring and a too-tall shock. Compared to stock, the Bilstein shock bodies are significantly shorter though. Some people might not consider it bad, but I know what good Bilsteins feel like (and KW systems, and well-tuned Koni systems, etc) and these sure don't hit the mark on the street. If the Racing Beat springs are .75" taller, that 20mm would make a big difference in feel in the front. The rear is a longer-travel design anyway, and I don't think I'm getting into the bump stop there. The "harshness" I feel seems to be in the front. This weekend I might try swapping back to my OEM front shocks, just for grins, and see what sort of difference that makes.

That's on the street though... not on a smooth track. I think the HDs would be very good on a track. BTW-body roll to me indicates that I'm NOT bottoming out the spring... No coil-binding marks on the wider gapped portions of the Eibach springs.

BTW-I heard once that the Mazdaspeed pieces were actually made by Eibach as private-label stuff for Mazda. This is NOT to say that they're the same as Eibach's own stuff.

ThecdnRX8

HD stands for heavy duty. I have never seen them advertised as sport shocks for lowering in any application.

LionZoo

Just getting back to this, but have you thought about trying the HDs with the stock springs?

philsbluerx8

can anyone give me a certain answer of my question: Are MS shocks and springs also good for daily drive use???? are they gonna be too stiff to reduce the comfort?

eddybear

I am highly confused, I am coming from the world of rally and I am already missing the confidence i have cornering hard that I had when driving the Evo V...

Do the sway bars or upgraded suspension fix this or both...

The other thing (and yes i'm a noob) .. but the precise steering comes from the sway bars right ? the feelin when i jerk the steering to avoid the road bumps/holes etc?

If that is the case, I see everyone rocking the RB sways for front & back, so I assume thats the way to go..

Please advise, very interesting thread..

staticlag

"precise steering" is mostly good tires.

You could have the greatest suspension in the world, but if you don't have good tires it will be nothing.

Welcome to the world of RWD sportscar. Takes more skill than AWD and computer assist YAW, Pitch, and roll system.

Spinning Sushi

iTrader: (21)

I've been searching for the exact numbers of the Mazdaspeed Shocks and I don't know if I got the accurate measurements for it. Can anybody confirm this for me? Can someone also provide numbers instead of percentage values?

eddybear

But what I am experiencing now is more of less responsiveness to steering inputs, how do I increase that so that I get more turn from less steering input ?

devildog1679

I have the full MS set-up, if you drive on roads like that of NYC then it may be a bit to much. If not they are just fine for daily use.

LionZoo

Change your steering rack (good luck!). It's less responsive to each degree of steering input because the ratio of the rack that Mazda uses for the RX-8 is higher than the ratio of the rack that Mitsubishi used for the Evo. No amount of suspension tuning or tire upgrade is going to change the ratio.