Steve Dallas

I have blown the front left shock on my Bilstein PSS9s after 2 years. Sure, I could have it serviced, but I also feel I have outgrown this mediocre setup on the track and am looking to upgrade them to one of the better setups. I have done some research and think I know which way I want to go, but I would like to weigh some experienced opinions from this forum before parting with the cash.

What I am looking for is the proverbial pink unicorn that farts pixie dust and poops skittles. I want a setup that performs as well as possible on the track that does not beat me to death. Having it be reasonably compliant on the street would be nice to have. I am tracking my car 12-15 times per year now, but also still drive it to and from the track, on weekends, on date nights, to work on the occasional nice weather Friday, etc. My price range tops out at $3,500. The tires I plan to run for the foreseeable future are Toyo R888, Nitto NT01, Potenza RE-71R.

Option 1 is KW Variant 3. I have read a lot of mixed reviews about them. People at the track also offer mixed reviews. The gist seems to be that they are very good (for their spring rates) in terms of performance, but not very durable. People are buying 2 setups, so one can be on the car while the other is being rebuilt. They are also comparatively heavy.

Option 2 is Ohlins DFV Road and Track. I don't know much about these, and there is not much information available about them as it applies to the RX-8. Miata people tend to view them favorably. The single adjustability supposedly works surprisingly well. Ohlins is a good, well-respected brand in motorsports. They are lightweight. They can be revalved to heavier springs in the future if desired, but it looks like the number of service centers is limited. I like the way the ride height adjustability works. Goodwin has them on sale for $2,300 right now.

Option 3 is Fat Cat Motorsports Custom Elite. These, I know more about. Several guys at the track have them on their Miatas and love them. I have read a lot of favorable reviews on the intertubez as well. I have never had the opportunity to drive on them, however. They represent a good foundation for future customization by FCM or one of the local Bilstein shops like Vorshlag, making them more of a mid-term investment than simply a limited-use product. They are the most expensive of the group and have the longest time to delivery.

Option 4 is Local. Speaking of Vorshlag, we have several great motorsports companies in my area that specialize in suspension. None of them are necessarily Mazda specialists like FCM, but suspension isn't rocket surgery, right? And, they have done some Mazda work. They would use roughly the same components as FCM, but may lack the skill and experience in valving and stuff, I guess. Positives are supporting my local peeps, and having local service available if needed. There is, of course, some risk involved.

For those in the know, what are your thoughts considering my options and performance parameters?

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TotalAutoPerformance

If it was me, I would go for the custom setup. No off the shelf system is going to give you exactly what you want. They work great for most people who want to get a better stance and better driving characteristics around town or on those canyon drives, but once you start really tracking a setup, thing need to be custom tailored.

I am going through a similar process now with the PSS9 on our car. Mine aren't blown, but I am trying to tailor the setup for the feel and performance I am after. Be careful with shock tuners though they aren't all created equal. It is similar to the Engine tuning world. There are a lot doing it, but only a few who are really good at it.

That is my .2 on the subject, Good luck with the build

MagnusRacing

iTrader: (2)

I have the Ohlins rebuilt for track use (higher spring rate, revalved shocks) and they have served me very well. To be fair I have not tried the other shocks you mentioned. I have my Ohlins built by Performance Shock, performanceshock.com, located at Sonoma Raceway.

Steve Dallas

^ That is another option I forgot to mention. Goodwin Racing sells them in that configuration in addition to the factory configuration as well.

How durable have your Ohlins been?

wankelbolt

iTrader: (21)

I'm in a similar boat, having older Koni Yellows and fairly soft springs.

I think the Ohlins Goodwin sells are not DFVs (or weren't when I last looked). DFV's are aimed at competing with slightly-more-pedestrian off-the-shelf setups, I think.

You don't say what spring rates you are or will run. Right now I'm 205/145. DFV's come with 458/229. I plan on going closer to 600/400 with whatever I get. Spring rates 400 and up are likely too much for the street (unless you're crazy like me).

yomomspimp06

if I had the coin, I would go FCM. I've been in a lot of 8's with different setups, and the FCM setup is by far the smoothest. On track the bumps felt smooth as glass vs the other setups

etzilon

Have you considered MCS (Motion Control)? Vorschlag works closely with MCS and can fit a set to your car. Terry is very knowledgeable. We run together with NASA TX. I seriously considered them for my track-dedicated RX8 but happened to run into a used set of Koni 2812s.

My two cents - Suspension setup is complicated. Go to someone who knows about suspension and can help you make decisions (such as Vorschlag or FCM). I did NOT do this and it has taken me lots of research and a long time to find a setup that works for me.

Steve Dallas

Goodwin sells the DFV in 2 configurations. One is stock, and the other is customized with ~725/450 Swift springs and re-valved shocks.

My PSS9 front spring rate is 370 plus a tender that is fully compressed under load. The rear spring rate is 240 progressive. That setup worked surprisingly well with medium sways (Progress Miata bars) and DOT tires. But it is swamped by RE-71Rs and anything stickier.

For the rubber I am running now and may upgrade to in the near future, I am thinking right around 500 with softer sways may be the ticket, but I am really undecided on this point. I haven't done the math yet, and really should get around to that.

In theory, either Ohlins or Bilstiens can be customized to different springs in the future. A Bilstein setup has the added advantage of local support, whereas an Ohlins does not from what I can tell.

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MagnusRacing

iTrader: (2)

I've heard great things about Motion Control as well

04Green

iTrader: (1)

I have POWERTRIX with 600/400. Car is fine on street, only a tad harsh below 20 mph. My car rides about like my wife's SUV, no worse. Do not be afraid of spring rates up to that high. What happens is body control job shifts from shocks and sways to springs. Then shocks just do dampening. Rear sway bar goes in garage. I may outgrow this setup, but not yet. This let me go with sticky tires (continental take offs). I get a little body roll, but car is stable and neutral. I am the weak link.


It is also nice to be able to adjust ride height to exactly what you want.


I was worried that I would want a better way to adjust dampers, but I do not touch anything. My street setup works well at Sebring.

Steve Dallas

I have not considered MCS.

I think you are right. I don't really know what I want to do, and don't really have the knowledge to fill in the gaps. I should defer to the experts when spending this much money.

I know Terry fairly well. I used to put a finger gun in his back and force him into my car as an instructor when I was autoXing a few years ago. Now that autoXing has become more like kissing my sister, I haven't seen him in a while. I should remedy that and pay him a visit. I should also put in a call to FCM for a 2nd opinion.

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9krpmrx8

iTrader: (46)

If you want to get nerdy.

https://www.youtube.com/user/SuspensionTruth/videos

Nathan Atkins

I use 560/392 springs on the street and its not appreciably harsher than the stock springs. Harshness I've found is a product of overdamping moreso than spring rates.




I use the OTS damping for the Bilstein B8 and body control is pretty good but they will bounce over a big undulation in the road or a speed hump at irresponsible speed. the damping is something like 55% critical, they feel glorious in the rain.
Since mine are pretty much the same thing as the fatcats they certainly get my vote if you have the $$$

Stubbs

iTrader: (1)

Another local group to look into is Hanchey Vehicle TechnologiesT(formerly AST). I had a set made by them on my miata and they were great. I'll be taking my RX8 to them in a few months.

Steve Dallas

Vorshalg update...

I spent some time at Vorshlag discussing where I am and what I want to do. Their recommendation is to avoid all of the consumer grade off-the-shelf stuff. At the lower price point, they recommend and sell what I already have (Bilstein PSS series). To get much more performance than a properly tuned car running PSS requires a step up to Motion Control or better. Everything "better" in the consumer market represents small, incremental gains that are not worth the investment. They can sell anything, and they choose to sell the PSS series.

They are not fans of KW at all--calling them fragile and mediocre at best in performance due to their twin tube design. Ohlins DFV are similar in performance to Bilstein PSS and not worth the extra $1000 according to them. They could build me some customs based on Bilstein shocks, but the cost would be higher than the value they could deliver considering what I have now, and I could build the same thing myself and have them valved much less expensively. By "what I have," they mean I already have Bilstein monotube shocks with high quality springs. It is hard to do much better than that--even if the adjuster is gimmicky--without stepping up to a true motorsports setup. And, they were quick to admit they are not Mazda specialists and are not immediately or intimately familiar with Mazda suspension design.

What Terry and Joe told me to do is have my shocks repaired, my bushings replaced, to stop worrying, to keep focusing on the driver mod, and to use my money to go to CoTA in February. If I really want to, I can change the springs and valving in the shock repair process. They said my unusual tire wear patterns on my RE-71Rs point toward worn bushings, which makes sense considering the enormous number of track days I have on this car. Changing the bushings to urethane with grease zircs costs ~$2300 for the entire car, but I can just do the fronts for now for around half that. I will definitely be inspecting those bushings the next time the car is in the air.

Interesting...

wankelbolt

iTrader: (21)

Tightening the loose nut behind the wheel is always the best fix and modification.

The most fun too.

blu3dragon

iTrader: (1)

As I mentioned in another thread, I'm very happy with my FCM setup, but I also have not tried anything comparable in cost.

I am running similar spring rates up front, but stiffer rear than the Ohlins DFV road and track that goodwin sell. At the current price, that looks like a good option to me, but from your other comments in this thread I'd expect you will be better off with stiffer spring rates, leading you down the custom path.

My own setup feels stiff on the street, but soft on the track. Go figure... however, it is soft enough for me to commute 15 miles each way on a daily basis, and I can still hang with spec miatas and spec boxsters on track, with pretty even tire wear. I do disconnect my rear roll bar and soften the front on the street, as well as running different tires/wheels and brake pads.

That is interesting, and quite possibly good advice you got. Part of what you pay for with FCM is their knowledge of valving. I'd expect their setup will be better than what you can achieve even with getting your PSS re-valved, but will it be worth the difference in cost is definitely a good point to consider.

Fatcat can probably rebuild your PSS with different internals though, so it would still be worth giving them a call just to find out what the options are if you have not already. Compare that with the cost of stiffer springs and a local basic rebuild and re-valve on your PSS and go from there...

As for bushings, that is something I have been considering as well, but I'm not sure I could live with any aftermarket options on the street. Just FYI, I have a 2010 with 57k and few more track days than you on my car and so far no tire wear issues for me. Does not mean bushings are not a problem for you, but it could just be an isolated failure you could replace with oem, or it may be that your tire wear is from the bad shock, or something else.

The other thing to consider, if you don't have it already, is a good half cage, bucket seats, harness and hans... That's currently highest priority on my list if I ever manage to justify a separate daily driver and a few more k to invest in the RX-8 as a track car.

Steve Dallas

FCM update...

I had a very nice consultation with Shaikh on the phone, and a detailed follow-up via email after I sent him a scan of my alignment settings and photos of my tire wear. I now have his recommendations to add to the mix. I also spent several hours watching his videos and reading about his approach to suspension design in an attempt to further educate myself.

The very short version is that he believes I have too much grip from the tires, which is overwhelming my current setup (if that sounds familiar, see post 1). He also thinks I probably do not have enough negative camber and that I may have some bushing wear on the control arms. Further, he thinks I am probably riding the front bump stops more than I think I have been.

He recommends spring rates of 425 front and 400 rear and going with either no rear bar or my stock rear bar and as little front bar as possible. He thinks I also need to check my control arm bushings and consider replacing them with offset units to dial in more -camber. He also thinks his ripple reduction valving would be beneficial. He thinks his softer bump stops are appropriate. He recommends moving to the BFG R1S tire, as he thinks the RE71R is more of a short run (read: autoX) tire that is not happy during extended use. Of course, a proper alignment of the new setup would also be key.

The total cost of a new FCM setup with all of the above and new mounting hardware is $3400. Reusing my existing mounting hardware subtracts $300, and omitting the ripple reducer subtracts $400.

He says he can use my PSS9s as donors at a reduced cost, but I don't have a hard number on that. The cost savings look to be substantial from what I can tell ($1700 plus springs and adapters?), but since I [stupidly] sold my OEM suspension, I would have to leave my car on jack stands for 5-6 weeks while he works over my PSS9s. I'm not sure the fetching Mrs. Dallas will go for that with winter coming. Her willingness to tolerate my driving habit is directly proportional to the amount of time she is able to park in the garage. I digress.

If you take away the normal tuning we all do, what all the above actually boils down to his valving magic. The spring rates he wants to use are very similar to what I have now. He said his calculations change the frequencies from 1.8F and 2.2R to 2.0F and 2.3R. Will that change plus his valving equal driving nirvana? I still don't know enough to answer that question.

The real question is: Is the improvement I will see worth that much money, or is the money better invested elsewhere?

Of course, it is worth noting that with those spring rates, the car should be at least as compliant on the street as it is now. That does rather exceed one of my goals.

I think I'll head back to Far North Racing's web site for more reading about shock valving now.

9krpmrx8

iTrader: (46)

Proper, prior, planning. Kudos.

Steve Dallas

I have read your other threads and know you already know what I am about to type, but it bears repeating for posterity.

[Warning: I'm about to give away the fact that I've played coy and been a little purposely obtuse thus far.]

Spring rates are not correctly determined by subjective observation. They are chosen to achieve a certain natural frequency front vs. rear once a set of variables are ascertained. Those variables are corner weights, center of gravity, roll center height, motion ratios, sway bar characteristics, loaded sprung mass, un-sprung mass at each corner, and several others. That natural frequency choice depends on certain characteristics of the tires being used. Most suspension designers like something around 2.2F and 2.5R for a track car and much lower frequencies for a street car like 0.8F and 1.0R.

However, a lot of people ignore the math in all this and just mix and match stuff that feels right, but probably isn't. (We know that everyone thinks the lap that feels fastest is usually anything but.) Even off-the-shelf kit raises questions. Why would Ohlins use the weird spring rates they chose? The rears are way out of whack. Maybe they have their reasons. Maybe they make up for it in the valving. For all the motorsports community hate the Bilstein PSS9 gets, it is actually pretty well-designed in terms of spring rates chosen for natural frequency. The adjuster is a gimmick, and valving probably suffers as a result, but they at least got the spring rates close to correct.

So, I was just spouting nonsense when guessing at target spring rates. I had not collected the data and done the math, and I didn't have to, as Shaikh did it for me. I know he has calculators on his web site, but I had not gotten around to using them yet. I was looking for casual reviews from fellow RX-8ers who track their cars before getting down to brass tacks.

We are all familiar with the three schools of thought of suspension setups among track people. There is the stiff springs / soft bars crowd, the soft springs / stiff bars crowd, and the stiff springs / stiff bars crowd. They all miss the point that they should be in the right springs / right bars crowd. They fail to understand that a suspension is a system, and that you should use whatever components work together to maximize grip. Instead, they follow an ideology that does not necessarily help them realize their goals.

I have long been of the opinion that most people over-bar their cars. Some bars are so stiff, the drivers might as well install a solid truck axle with leaf springs. Why take an independent suspension and lash it together top and bottom to force each side to stop acting independently? It makes no sense. I suspect they use stiff bars, because replacing them is simple and much cheaper than doing it right. One of the things I love, love, love at the track is when we are all standing around at 7am telling lies and discussing our MODS! and someone tells me he ripped out those crappy soft sway bars and installed the hardest ones he could find. (<-- My best run-on sentence of the day!) At that moment, I know he will be no competition to me.

What I like about FCM so far, is that Shaikh chose spring rates that create a natural frequency combination that is just softer than what many suspension engineers consider optimal for a circuit track car (probably noting my desire for at least some degree of street compliance), and that he shares my disdain for super stiff sway bars.

I still need to study up on shocks and valving to reach a conclusion as to whether there really is such a thing as magic valving, however. That is the one area of suspension that is like voodoo to me.

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etzilon

Bingo. You actually want to estimate optimal shock forces (bump, rebound) based on your wheel rate, etc. This is probably easier to do experimentally using shock pots and data acquisition equipment together with shock dyno info for your current set. I wish I knew how to do the math.

BTW, FCM spreadsheet is actually very helpful to come up with a baseline. Just double check some of his parameters... IIRC, his motion ratios are different from what TeamRX8 has previously reported among other things.

Riding on bump stops is real and annoying. I had to go considerably high on my spring rates to prevent this from happening and I run 225 tires. Use the zip tie trick to know.

blu3dragon

iTrader: (1)

I think the ohlins rates are based on running the stock sway bars, or an aftermarket set with the same front/rear ratio as stock. As such, they look to be bang on as a street/track compromise with good handling balance assuming users will not change the sway bar ratio.

The difference with the FCM setup is that Shaikh will start by picking the correct spring rates for your application, match up bump stops, and then recommend sway bars and alignment settings along with that, so you are able to fully customize the suspension rather than end up with a compromise based on leaving part of it stock.

I spent quite a bit of time doing my own research and calculations, but in the end I could have just gone with Shaikh's recommendations. He knows his stuff and was pretty much spot on with his predictions of handling balance for me. You could argue individual measurements on the spreadsheet, but I think taken as a whole it works very well. The one thing you need to decided, and give input on, is where you want to fall in the street/track compromise.

Black2010R3

iTrader: (1)

My experiences with KW V3's:

First of all I'll say that I've got KW V3's, which I chose partly because of their spring rates, reputation, dual adjustability, but also because I scored a barely used set second hand for less than any other option that I was considering. I've paired them with Hotchkis bars and I'm very happy with the handling right out of the box using the recommended settings. I don't have a lot of miles on it, so can't really comment on lifespan.

I get good even wear on my 255/40/17 NT-01's on 17x9's, but my bushings have low mileage and I run quite a bit of camber (-2.5 front, -2.0 rear) and zero toe.

My counter points/rant:

To think that there's only one way of properly setting up a suspension is pretty arrogant I think, but it can make for a good marketing strategy. Sure, he uses numbers, but whose to say that those numbers are the right ones and why would that largely mathematical method be better than the shaker rig and real world testing done by other companies like KW and Ohlins for example, which have spring rates fairly close to one another? Also, why would it be the right way for every car, every track, every driver and so on, there are far too many variables in my mind to take a one size fits all approach.

One important note on the Far North Racing recommendation for frequencies is this is based on autocross, which will reward a more oversteer biased setup than road racing, so that's something to consider for picking frequencies, maybe drop the rear a bit.

When I was shopping for coilovers I read about what spring rates and sway bars people used along with handling impressions and used the FatCat spreadsheets, but was able to download an NC version I think, updated the numbers for spring rates, motion ratios and such from versions I found here and then went about plugging in various permutations and compared the FRC's. I ended up keeping it close to my stock R3, as I felt that it had a pretty good overall balance and the overall balance stayed quite consistent. As my car gets used mainly for street use and I wanted to keep the ride quality as good as possible, but wanted it to still have enough roll stiffness to handle R compounds on track, so I went with large sway bars to help me achieve this.

Saying that large sways is like a solid axle is a fallacy and a gross over simplification. Yes, the sides are linked, but all the inherent advantages of the suspension like camber control remain. Yes, it's maybe not as good on one sided bumps, but everything's a compromise. Going with much stiffer springs and no sway bars as the other extreme will also cause the car to be upset on one sided bumps and it'll be less compliant over full with bumps as well. It's all a compromize.

Also consider this, when going to stiffer springs, the sway bars are now contributing less to the overall roll stiffness as a percentage than before. Going with larger sway bars and stiffer springs can help maintain the percentage contribution of the sways to roll stiffness. Even F1 cars with their ridiculously stiff springs still use sway bars.

My recommendation:

Get your coilovers rebuilt and re-valved. Shop around for this and I'd say don't be afraid to eliminate the adjustability, since as you say, it's mostly a gimmick and may open up new possibilities or make it cheaper. Pair it with spring rates of your choosing based on whatever the heck you want to base it on and pair it with whatever sway bars you need to in order to get the handling balance correct. If it works for you, then great, that's all that really matters.

blu3dragon

iTrader: (1)

Another opinion from the gallery here...

I just read this part, "The total cost of a new FCM setup with all of the above and new mounting hardware is $3400. Reusing my existing mounting hardware subtracts $300, and omitting the ripple reducer subtracts $400."

So, for a basic FCM setup you are actually looking at $2700. Any other off the shelf coilover set won't come with the mounting hardware - you can re-use that. For that price you are getting: custom tailored spring rates. Valving to match, set as it should be for track use and better shock internals. I think that is actually worth the money.

Yes, you should be able to get close with the OTS setup, but if you get that, change the spring rates, then end up getting them re-valved, you will be pretty close to the cost of the basic FCM option.

The remaining decisions are if you want to go stiffer than 425/400 on the springs (for a more track biased setup) and if you want to spend the extra for the "ripple reducer" in the process. My own setup pre-dates that option.

Steve Dallas

Continuing the discussion...

[BTW, blu3dragon and I have exchanged several PMs on this topic, and he has been very patient, insightful, and helpful. Thanks and kudos to him!]

The cost to rebuild my shocks to my specifications is about $225 each plus shipping if done by Bilstein. Most of the local shops I have called charge more than that and probably just send them to Bilstein anyway. Turnaround time is up to 3 months across the board (which is why I think they send them to Bilstein). I can't live with that. Let's call it the $1,000+ option. I paid $1,400 shipped for them in the first place. Ugh. (As an aside, I can buy a new set of PSS for $800 shipped with a coupon.)

I did find a shop that does the work locally, that will rebuild them for $100 each, and will turn them around quickly. They specialize in frame and suspension work, are a Bilstein authorized repair center, and should be good at this. There is some risk, of course, because I can't know how good at this they really are. They do have a stellar reputation in general, however. That is much more palatable and makes the rebuild an option. They will also repair and replace any worn bushings at very competitive pricing.

I could use that shop, buy a set of front springs (7K - 392lbs) to combine with the rears (375-445lbs 240lbs progressive) to give me something like the natural frequency I want, and trim the front bump stops down to 36mm (and the rears by the same amount) to give me a little more bump travel in combination with the slightly stiffer springs. From there, I could lower the car another 1/4" without compromising the corner balance too much, have it aligned again to max out -camber, and have the bushings inspected. All of this can be done for a total of ~$700 in time to get me to the track November 21. What I would be missing is the FCM valving. I'm still not clear on how special that really is, and I can specify the valving I want for the rebuild.

This sounds like a pretty good way to go for the next year or so. And, I would save enough money to get me to CoTA in February.

To further muddy the waters, check out this GRM review. FCM wins the shootout, but only by 0.32 seconds vs. PSS9s. Of course, we don't know what the conditions were during the test (or how valid the test really is in any respect), and changes in those conditions could absolutely dictate the outcome. Still, we are talking about a lot of money to gain three tenths of a second-even at the minimum price point to join the FCM Elite club if we assume there is some validity to the test. At my skill level, the driver mod can easily get that done, and my money is best spent on seat time. What remains to be seen is if I can get my tire wear under control with what I have plus adjustments. If not, the FCM setup would eventually pay for itself if everything goes according to plan with that.

Yet, if FCM really is the bees knees, and I can totally take suspension out of the equation and focus almost totally on the driver, does that make the cost worth it?

Hmmm...