I was going to call the guys at AWE to ask about the differences between the PSS9's and 10's. Apparently the PSS9's are still available.

 

i don't track my car, but i studied physics. it takes more torque to spin a 19" wheel than it does to spin an 18" wheel. this is because moment of inertia (like mass for things that spin) varies by the *square* of the radius; small changes in the distance of the wheel barrel from the center point make a big difference in moment of inertia.

so, ignoring tire weight, and just considering wheel barrel weight, you need to reduce barrel weight by around 11% to compensate for the increase in moment of inertia when moving from 18" to 19" wheels.

 

When done properly, the radius/diameter of the 19's will be just about the same as 18's. Also, with a quality wheel the weight will not be any greater.

 

Hey, what type of wheels? I live down the road (Cape Girardeau) and am looking for wheels. Can you send me an email to myvette@charter.net?
Thanks,

 

Vick- so in other words, buy a set of Dymag 19's... LOL

erubin- you may want to compare pricing on the KWv3 coilovers. Absolutely phenominal street ride, progressive spring, triple adjustable, outboard gas resevoir, stainless body, etc. -
I like the PSS series but have been much more impressed with the KW's performance. Check the Group Buy forum there's an active thread from 6speed sponsor.

 

let me challenge you on this... what tests have you done, data do you have that led you to be "much more impressed"?

 

In my case I've found the combination of PSS9's, 19" wheels/tires plus the fact that my car is a cab has resulted in a harsher overall ride but I'm ok with that.
For me the trade off of between comfort and performance is not an issue.

Cheers,
Stan

 

Not much to challenge really- Just my personal experience / opinion, which I will post up in case it is of value to anyone. I've posted in several threads here along with a writeup following my install last year.

Before making my buy desicion I test rode / drove 996's with H/R coilovers, and PSS9. I also looked into the various OEM upgrades like X74, etc.
I then researched member opinions and asked questions on numerous threads here, at rennist and at renntech.

Was initially leaning towards PSS9 because most felt pleased with the result, and was also contemplating JIC.
A friend of mine who sponsors a couple of BMW race teams and owns a performance shop told me about the KW's and how he was really impressed with how they performed on the 996 both for track and for DD, and suggested I look into them since the price point was not too much more than PSS9. He basically told me "just buy them and you won't regret it", and I tend to trust his opinion.

All the research I looked up on KW3's on the net was positive- Loved the article about the turbo 996 setting a speed record at Nurbergring, running KWv3's. Feedback from members here / rennlist who run them were 100% positive "you gotta buy them" opinions. Not one single negative comment.

Some build points of the KW's seemed to make common sense to me as far as potentially providing a superior ride:

1. Stainless construction = no corrosion, long service life (in case I move back to Hawaii, this would matter)
2. separate low-speed bump settings and rebound settings with outboard gas reservior construction. HR / PSS9 do not have separate bump / rebound settings.
3. special fixed "high speed bump" designed to soak up sharp bumps, this is separate from the low speed bump. Not present on HR / PSS9
4. progressive spring vs. linear spring of HR / PSS9
5. can possibly dial in lower drop than HR or PSS9 (2nd-hand info)
6. wider range of settings for rebound / bump than HR / PSS9
7. look at a set of KW's side to side with PSS9's (I did) and you can see that they look superior in construction and finish.

Combine the above with a good 6-speeder price from Dan at vivid and I bought them, and have been impressed ever since. IMHO the ride is better than PSS9 or HR, at least as far as the comparison rides I experienced.
I got to ride in a 996 with JIC's installed, and while they were spot-on flat for handling I thought it was kind of harsh / bumpy on city streets.
With the KW's, I get flat handling and high-speed control along with a reasonably cushy ride. I can dial them go-cart tail-sliding solid or OEM-cushy. Presently I run them somwhere in the middle slightly towards the cushy end.
It's a very nice combo of options / features / ride for the price.

Again JMHO, AFAIK, IIRC, YMMV, et al... and all that.

I have no idea how the PSS10's ride, my above notes are based of my research last year.

Have you ridden in any pcars with KW3's?

 

I considered KW3s when I had my E46 M3, but ultimately decided on the TC Klines so the answer is no on the 911.

What I have learned over the years is that street adjustable coilovers are just that - all are for the street and they rarely have enough of a diff over the other to make any sort of objective difference at the end of the day. More adjustability isn't necessarily better because suspension tuning is black magic and that really only applies to the serious track guys out there who can even begin to think about wheel-to-wheel racing.

So when people come on car boards and strongly pick one flavor over the other, it raises a flag with me. The PSS9s are proven on the 911 - a popular choice. This doesn't make the KW3s worse or better, it's just the common suspension lingo around these parts.

Where the difference really comes to even begin to worth noting outside of the typical list of features is when you start spending ~$1K per corner (Motons, JRZs, Ohlins, etc). Outside of this, all the other adjustable aftermarket coilovers, so long as you stick a a known brand like Bilstein/KW etc, you're good to go and to even begin to advise someone pick this one over this one! is somewhat of a misnomer.

But again, I have no data to support the general recommendation I'm making above. My bottom-line statement is... KW3s, PSS9s, PSS10s... you'll get a better ride than stock and you can adjust the crap outta them but reality is, most of us want to set it and not worry about it and just enjoy the drive to work, on the local twisty road, etc.

P.S. You're from HI, eh? No wonder you seem cool.

 

yep yep- all good points. I think any of the noted brands will provide a strong improvement over stock.

I can advise the KW's based on my own experience / opinion / personal prefs, which is what we all kinda do here at the six- and since I am far far far from any sort of pro driver or wrench, it's definitely an "AFAIK" "YMMV" situation. To me, based on my research and current driving experience, and my particular driving style, the KW3's seem to be a better bang for the buck. They also are a proven suspension choice for 996 cars, but apprently not as mainstream for US sales like PSS9's. Better presence in Europe. I'd like to see the KW's get a bit more press in the US.

i'm kind of an eternal tweaker on my cars so it's been value-add to me to have the added adjustability of the KW3's.
You brought up a good point about adjustability, I believe the KW's may have a wider range of usable adjustability than the others in this particular category. No data to back that up, basing my thought strictly on the extreme difference in the KW's on full firm or full soft. It is very extreme in range, more than I would expect. Also, if I adjust the bump or rebound by say two clicks, this small of a change is noticeable. This really helped me to tune the car to my personal liking.
If you have a chance to demo a pcar with KW's you'll probably be impressed. Considering you're familiar with TC's you'd have a better feel for the comparative quality.

 

Totally cool, my man. Glad you're enjoying the KW3s. Realistically, I don't have the time or energy or INTEREST to split hairs between street coilover systems as the ride on my PSS9s that have never been adjusted except for height (set in the middle) has served me well for the past 15K miles that I've driven my Pork4S.

 

Well, yeah...probably more hair splitting than neccessary. but you brought up the question Ben so DEAL with the long drawn out answer

You been out to the islands? I'm hitting Maui and Oahu in a few weeks to visit family / surf / chill and soak up some local mana.

 

+ 1

There is no performance advantage (only disadvantages) for 19's (vs 18's) on the 996.

Do it for looks if you like, but don't have any illusions about a performance benefit.

 

i dealt - you got no data just a lot of marketing bullets.

i was out in maui for my cousin's wedding in lahaina (kapalua bay)... awesome awesome and then my ex-gf grew up in honolulu (white chick) so i visited with her and had the time of my life. the food is so good there. i love poke and leonard's malasadas (sp?).

 

Nice try, but the radius stays the same with the decrease tire profile.