lzhmax

Thanx mate,
i might go for pss9 then. Are they much better than stock(R3's bilstein shocks)?
Cheers
BTW, i'm Max too.

chiketkd

iTrader: (5)

Nice to meet you Max. In case you didn't catch my name before it's Chike.

Yes - the PSS9's are definitely a huge step up from any OE suspension available for the RX-8! But the R3 bilstein shocks could be revalved to perform better. FatCat Motorsports now has the ability to revalve "crimp top" OE Bilsteins, so that's another option you could consider. Honestly, if I had 3K to spend, I'd get the double adjustable FatCat Bislteins (based off of the Bilstein HD shocks). However, I went with the PSS9's as they can be revalved later to perform like a 3K shock. FWIW, Rick Jung's Evo VIII won STU last year (in the hands of Tom Kenna iirc) on revalved PSS9's. This is in a class where 3-4K shocks aren't out of the ordinary (Ohlins, Motons, etc).

Once I switch to the 7K Swift front springs, my plan is to revalve all four shocks this winter to make the front & rear adjusters more biased to rebound. I'm also thinking of going with a slightly shorter front bump stop to increase front bump travel.

Looking to fine-tune my "big bar, soft spring" set-up to hopefully get into national-trophy fighting form by the 2011 season. But we'll see, I've set some short-term goals which I'll hopefully be able to accomplish this season and then continue to grow as a driver from there...

lzhmax

Hi Chike
Thanks for the reply. I can see you are really a pro!^^
My main use of the car is a daily drive and around 10 track days per year. so 3k-4k might be unnecessary for me. lol
i'm also looking at TEIN type flex or monoflex. What do u think?
Cheers,
Max

chiketkd

iTrader: (5)

Ha ha. Far from being a pro. I'd like to consider myself as more of an up-and-comer. I'm just not afraid to ask questions to people who are knowledgeable.

I wouldn't be the best person to get feedback on Teins as I've never run these shocks. I would say that from my research, I wasn't impressed with their damping -- and heard similar statements from Strano. So Tein, Stance, etc were never on my list. The PSS9 was recommeded to me as being the best coilover available for under 2K.

My humble $0.02...

S0l08

iTrader: (1)

Looks like your lifting the rear a litle in that pic Chike. I think the stiffer springs would help out. Going to a stiffer shck setting might put a bandaid on it for now. Ever tried to go up on the sways?
I would love a local test and tune, but that never happens around here. And I don't get to race that often due to work.

chiketkd

iTrader: (5)

I agree Max. Stiffer front springs would definitely help reduce inside rear wheel lift as there will be less weight transfer to the front of the car. I've now done 4 events (1 T&T, 3 regular events) on the stock PSS9 coilovers. I'm definitely ready to try the Swift springs (up front). I might be able to do the swap as soon as this Saturday night (before Sunday's event), but if not, I'll have to wait until the following weekend.

I've thought about trying the stiffest swaybar setting, but when I tried it previously (on the street), it induced more understeer than I would have liked. Since I have the 7K Swift springs already, I'll throw them on and go from there.

Until then, I'll try the stiffer shock settings (F&R) as a bandaid.

lzhmax

Thanks Chike
I read that some of u guys bought it from shox.com, does it do international order? as i live in Australia.

stewiefied

idk what my alignment is i believe it was set close to stock..... what do you recommend for sways and alignment oh btw my tires are oem Dunlop SP Sport 2050 i think thats what they are

S0l08

iTrader: (1)

Alignment kind of depends on how serious you are. I'm running 2.7/2.2 f/r. Chike I think is at 2.5/2. This is awesome for autox, not so awesome for dd. I just had to flip my star specs after about 8k miles. Insides were almost bald and the outsides were almost full tread
As far as bars go, we are running Hotchkis front and Eibach rear bars, both from MX5.

chiketkd

iTrader: (5)

An unknown alignment definitely doesn't help things. No point spending ~$400 on F&R swaybars when a $60 alignment could solve your issue. A good compromise for an autocross/daily driven RX-8 is -2F/-1.5R with 0 toe all around.

Max and I run more, but we probably buy more tires each year! I'd also invest in a set of better tires (Star Specs, RS-3's, etc)

stewiefied

ok i found the alignment sheet i was given when it was done the front is set at -1.5 and the rear is at -1.4

chiketkd

iTrader: (5)

That's not ideal (should run at least -2.0), but not horrible either.

The big 'underlying' issue could be your tires. If you plan to get more serious about autocrossing, it's time to upgrade.

S0l08

iTrader: (1)

That alignment will give you a good bit of oversteer. We all run .5* less camber in the rear. And my *** is easy to hang out at will.

stewiefied

ill take it in to get an alignment and see if she'll be a good girl next time lol

S0l08

iTrader: (1)

http://www.stuscully.com/Motorsports..._5PrUd-L-1.jpg
You can see from this pic that I am getting a lot of roll also.

chiketkd

iTrader: (5)

That's a great pic Max. I would agree that there's a decent amount of roll in our cars. Were you on the middle setting for the FSB and the soft setting for the rear?

chiketkd

iTrader: (5)

...for the droop travel vs bump travel of the PSS9 coilovers.

Side Note: When starting from your static ride height, your droop travel is how much the shock can extend before the tire looses contact with the ground. Bump travel is how much the shock can compress before the bump stop prevents the suspension from compressing any further.

I posted these pics earlier in thread:

Total front shock travel (~5.5")


Total rear shock travel (~6.0")


From the PSS9 manual, these coilovers come with 44mm bump stops F&R -- which means that ~1.75" of each shock's total travel is taken up by the bump stop.

The rough measurements I got for F&R droop travel were as follows:

Front = 2.25"
Rear = 3.0"

From this my calculated F&R bump travel are as follows:

Front: 5.5" - (2.25" + 1.75") = 1.5"
Rear: 6.0" - (3.0 + 1.75") = 1.25"

So when our front and/or rear suspensions compress by ~1.25 - 1.5" we are into our bump stops. The rear isn't too concerning too me (due to the progressive spring used on that end), but I would definitely like more bump travel up front (before the spring rate effectively goes to infinity when we hit the bump stop).

The pair of 7K Swift springs I'll be installing will improve things, but I'm seriously considering ordering a pair of shorter bumpstops from Fat Cat Motorsports (36mm are the next step down, or I could go with a 12mm race version). As I still drive the car on the street (weekends), I might go with a pair of 36mm bumpstops, which will increase my front bump travel by ~1/3"...

S0l08

iTrader: (1)

Yes middle/soft f/r. Shocks at 5 all around.

Kennetht638

iTrader: (2)

Just as a note, this isn't entirely true. When you run out of droop travel at one wheel, that wheel doesn't necessarily lift off the ground. This would only happen if the vertical load at that wheel goes to zero. Otherwise, the slightest turn would roll a kart over. What it does do though is effectively move your roll center to the contact patch of the wheel that is out of droop travel and double the roll rate of that axle. I'm not yet sure how to use this, but there are some track guys out there that run a "zero-droop" setup and claim that it offers more responsive turn-in at the expense of high speed and braking stability.

Anyway, I've been following this thread with great interest as I'm interested in Bilstein dampers, and I really appreciate the work that you guys are putting into sharing this information.

chiketkd

iTrader: (5)

Doh! Double post.

chiketkd

iTrader: (5)

Great post. I was definitely using the simple definition of droop & bump travel to get a rough estimate of what I was working with. At my last event, it felt like my car was getting into the bump stops, and after these rough measurements I took, I'm not surprised. I like the fact that the Fat Cat Bumpstops are linear so if I get into them, the car will still handle predictably up to a point.

I like these coilovers a lot! I definitely feel like I can "fine tune" them to work like a top dollar shock.

MilesJ

It looks like I'll be getting my set of PSS9's this week!! It'll be nice to finally have a good set of dampers for the car. I never truly liked the Koni's on my car and I always seemed to PAX better on the stock suspension. Shorter bumpstops are on my list of things to get as well. Can we change the rear bumpstops on the PSS9's?

S0l08

iTrader: (1)

Can't change the rears. They are built into the inverted shock.

chiketkd

iTrader: (5)

Congrats Miles.
Correct. The end-user won't be able to change the bumpstops, but if you get your rears re-valved, they can install your alternate bumpstops at that time.

chiketkd

iTrader: (5)

I did Points event #1 with the DC region today. STX ran in the morning, when temps were in the mid 50's, skies cloudy and a cool breeze was blowing. To make things even more interesting, about 50% of the lot was recently re-sealed and was VERY slick in these cooler temps! The 2wd cars were struggling to put any power down (even on the straights) while awd had a solid advantage.

I ran pressures of 39F/37R which felt good in these cooler conditions, however, my initial shock settings of 3F/4R were too stiff. Car was skating over the surface on my first run. Softened the fronts by two clicks and the rear by one, and that improved things greatly. I ended up third in class behind two solid drivers who were co-driving a well-developed WRX (both drivers have multiple trophies in STX at Tours and Pro Solos in the car).

When I left, the afternoon session hadn't begun yet, but for the morning group the STX class winner (Travis) PAX'd in the top ten, while his co-driver (John) was 18th and I was 20th. Speaking to my friend who ran in the afternoon, temps got warmer and the sun came out, which improved the grip of the lot significantly. I'll probably be lucky if I end up top 50 in PAX at this event (out of 250+).