Notices
993 Forum 1995-1998
Sponsored by:
Sponsored by:

Sway bar diameter question - 20mm vs. 21mm for front

Thread Tools
 
Search this Thread
 
Old 08-22-2016, 10:45 AM
  #16  
jskylarwilson
Rennlist Member
Thread Starter
 
jskylarwilson's Avatar
 
Join Date: Aug 2013
Location: Phoenix, AZ
Posts: 506
Likes: 0
Received 60 Likes on 35 Posts
Default

Thanks all for the insight! I'm driving the car on the street and in canyons for the most part. I'm so hesitant to track it, although we have a great track here in Utah. It'll probably stay on the road, and I'll get something dedicated to the track eventually.
Old 08-22-2016, 11:02 AM
  #17  
Martin S.
Rennlist Member
 
Martin S.'s Avatar
 
Join Date: May 2001
Location: Solana Beach, CA
Posts: 9,621
Received 535 Likes on 349 Posts
Default If you want to see what your car can do...

With no possibility of hitting a school bus full of nuns, running over a pedestrian of bicyclist, getting a $$$ ticket, the potential for a head on collision:
Canyons have consequences where you can encounter all of the above including guard rails.

Take it to Miller for a DE day. Go out with an instructor and get to learn your car. Have Les Long set the car up for you...he has/had a shop at Miller. http://airpowerracing.com Les is one hell of a fine driver on the ground and in the air

Miller as I understand it, has lots of run off in case you make a mistake. I'd love to drive that track but it's at least an 18 hour tow each way. In closing, I always discourage people from high speed canyon driving, too many opportunities for "failure", if you know what I mean. Canyon driving is a big deal in SoCal...I have never participated, never will.

Last edited by Martin S.; 08-22-2016 at 07:45 PM.
Old 08-22-2016, 12:14 PM
  #18  
Kika
Nordschleife Master
 
Kika's Avatar
 
Join Date: Feb 2007
Location: Torrance, CA USA
Posts: 5,633
Received 80 Likes on 61 Posts
Default

Originally Posted by Martin S.

I forgot how comfortable a street 993 can be...got a ride in a pal's Carrera S last year, mighty sweet.
Here here!! I test drove a sweet OEM Stock 96 C2 with low miles a few months ago. down to the stock ride height, it was basically off the showroom floor. light bouncy clutch, everything just fresh!

very comfy...BUT, that isn't how I like my car set up, as in my signature. That is the beauty of customization, no one else really has to like the way my car rides and handles, as long as I do.

Having said that, I have the 22/21 ARBs with the M030 springs and Bilstein HD shocks. and I love the way my car handles. It is definitely on the aggressive side, but my wife will still ride and drive it...(I'm lucky, my wife digs sports cars AND can handle a manual tranny.)

I do not recommend taking someone else's word regarding suspension, everyone has different needs, driving abilities and comfort tolerances. At least drive another car set up with said equipment, and/or know what your objective is, (reduce/increase oversteer/understeer) etc...

Martin's recommendation for DE is also very sound advice, but I have to slightly disagree with the canyon driving remark, or at least comment on it. I do love a good canyon run now and then, but I prefer to do it by myself or very small groups, of no more than 3. I keep the speed reasonable and ALWAYS with plenty of margin with respect to my ability and vision of what is around the next corner.

I think of our good friend and Renlist brother Halycon (RIP) EVERYTIME I am in the canyons. KEEP IT UNDER CONTROL! enjoy your cars, and the beauty of driving, but BE SAFE! and certainly wary of others.
Old 08-22-2016, 02:19 PM
  #19  
nile13
Addict
Rennlist Member
 
nile13's Avatar
 
Join Date: Jan 2004
Location: Boston, MA
Posts: 8,554
Received 95 Likes on 61 Posts
Default

Martin, as expected, is absolutely spot-on in his advise on street driving vs. DE. I heartily second that advise.
Old 08-22-2016, 03:04 PM
  #20  
Juha G
Rennlist Member
 
Juha G's Avatar
 
Join Date: Aug 2006
Location: Finland
Posts: 2,528
Received 63 Likes on 31 Posts
Default

Originally Posted by Martin S.
Here is the real world. The 993 RS 5 position front bars are not as easy to adjust as the 3 position rears. I generally leave the front bar in the middle setting, same with the rear. However if I am on a twisty track and I want to throw the rear end around a bit, I move the setting to full stiff in the rear, leave the front alone.

If I am on a very fast track such as California Speedway, or Willow Springs, I move the rear bar to the full soft position...

And sometime just for s#@ts and giggles, I'll run one of the faster tracks with the rear bar in the center..get a little tail action.

General rule, if the bar is too stiff on the front, you'll be picking up the inside wheel...always better to have four wheels on the ground. I had TRG front bars before I went to 993 RS...they were about 25mm, maybe even 26mm...can't recall. They were adjustable, but I could never get them right, always picking up a wheel, breaking drop links....since I went to the 993 RS bars and Tarrett adjustable drop links a few years back....problems over.

General the adjustment of the bars is reciprocal, that is, if you are up to messing with the front bar. Tighten the front bars loosen the rear bars, loosen the front bar, tighten the rear.

In conclusion, if you are adjusting your suspension with a butt dyno, your intuition may be way off. You need a data logger with wheel sensors if you really want to know what's going on, but that's a topic for another day.
Here's the catch; I know Skylar and we had this discussion in person last winter when I was in SLC. I was driving his stock 993 C4S while we were having the discussion about how his car feels to drive.

Skylar is not looking at improving lap time or even making the car any faster, he just wants it to feel more planted and more aggressive.
His car was rolling A LOT, very soft and not so involving. As you'd expect from a 100% stock 993.

Now he has the Bilstein PSS10s and the next natural thing to change (to make the car FEEL better, not necessary make it faster) is to beef up the swaybars.
For me at least driving on the street is more about the feeling than anything else. I never race anyone on the street so who cares if the car is fast or slow. It is all about the driving experience. The more planted and involving the car feels and the better it sounds, the better the experience. Fast or slow, doesn't really matter as no one is taking lap times. Simple as that.

So why RS bars? Well, Porsche designed the pinnacle of the normally aspirated street going 993s and that was the 993 RS. Why do you think it is a bad choice to go with stuff Porsche designed and built specifically for this application?
The 993 RS is a STREET car, not a race car by any means. I am sure Skylar will not be adjusting the swaybars before every drive. He will find the setup he likes and keep it there. Again, no lap times or competition to beat, just to have the best feeling when driving the car.

If I were to build a street 993 and would start from a scratch, I'd do RS everything.
Old 08-22-2016, 04:58 PM
  #21  
Bill Verburg
Addict
Rennlist Member

 
Bill Verburg's Avatar
 
Join Date: May 2001
Posts: 12,398
Received 579 Likes on 398 Posts
Default

Originally Posted by Juha G
*******
If I were to build a street 993 and would start from a scratch, I'd do RS everything.
That's the best advice I've seen in a while, but you have to start at the bushes and go all the way to the tires to get the full benefit

The RS suspension is what every 993 should have had stock oe fitment.
Old 08-22-2016, 05:06 PM
  #22  
PCA1983
Rennlist Member
 
PCA1983's Avatar
 
Join Date: Apr 2014
Location: Orlando burbs
Posts: 3,042
Received 462 Likes on 314 Posts
Default

For similar sway bars of the same design, stiffness goes up as the diameter squared. So yes, the 21 mm bar is going to be 10.3% stiffer than the 20 mm bar, If it's otherwise the same basic design. .
Old 08-22-2016, 05:22 PM
  #23  
NYC993
Drifting
 
NYC993's Avatar
 
Join Date: Apr 2013
Location: Nothern NJ
Posts: 2,286
Received 11 Likes on 6 Posts
Default

Originally Posted by Martin S.
With no possibility of hitting a school bus full of nuns, running over a pedestrian of bicyclist, getting a $$$ ticket, the potential for a head on collision:
Canyons have consequences where you can encounter all of the above including guard rails.

Take it to Miller for a DE day. Go out with an instructor and get to learn your car. Have Les Long set the car up for you...he has/had a shop at Miller. http://airpowerracing.com Les is one hell of a fine driver on the ground and in the air

Miller as I understand it, has lots of run off in case you make a mistake. I'd love to drive that track but it's at least an 18 hour tow each way. In closing, I always discourage people from high speed canyon driving, too many opportunities for "failure", if you know what I mean. Canny driving is a big deal in SoCal...I have never participated, never will.
+1. The most dangerous part of the track weekend is going to the track and driving back home. Most variables at the track are controlled by me. Most variables on the public roads are controlled by somebody else.
Old 08-22-2016, 07:51 PM
  #24  
Martin S.
Rennlist Member
 
Martin S.'s Avatar
 
Join Date: May 2001
Location: Solana Beach, CA
Posts: 9,621
Received 535 Likes on 349 Posts
Default I need to get off this string....

But lastly from me, I was thinking (Dangerous???), Skylar, have you driven the car with the new PSS10s and stock sway bars? Maybe you don't need sway bars? If it has uncomfortable body roll...and you have new shocks/struts, then you do need sway bars. If it doesn't have uncomfortable roll, then "if it ain't broke, don't fix it!" Just saying.....
Old 08-22-2016, 09:31 PM
  #25  
clib
Rennlist Member
 
clib's Avatar
 
Join Date: May 2004
Location: Minnesota
Posts: 697
Received 118 Likes on 65 Posts
Default

Reminded of the PSA of why the track is safer than the street for going fast

https://m.youtube.com/watch?v=VruWHHEnZGw
Old 08-23-2016, 02:40 AM
  #26  
Juha G
Rennlist Member
 
Juha G's Avatar
 
Join Date: Aug 2006
Location: Finland
Posts: 2,528
Received 63 Likes on 31 Posts
Default

Originally Posted by clib
Reminded of the PSA of why the track is safer than the street for going fast

https://m.youtube.com/watch?v=VruWHHEnZGw
WOW! Hadn't seen that before. I wish all youngsters (and older hoonigans too) would see this video. It really makes the point clear IMHO. No racing on the street!!!

Racing aside, there is a time and place for a little spirited drive. I think it's safer to do that on a deserted canyon road vs. texting or browsing the internet on your phone while taking your daughter to school. etc.
Old 08-23-2016, 06:26 PM
  #27  
jskylarwilson
Rennlist Member
Thread Starter
 
jskylarwilson's Avatar
 
Join Date: Aug 2013
Location: Phoenix, AZ
Posts: 506
Likes: 0
Received 60 Likes on 35 Posts
Default

Juha is right on with what I'm looking for. Even with the PSS10s, the car still feels like it has too much understeer and body roll. Although the PSS10s make the car feel better, the sways are too small. He's who made me realize that the car is lacking confidence on the street.

I'm not looking to track or reduce lap times. I'm not a hooligan in the canyons, but I want the car to corner better than not. No street racing, no overly reckless driving, just better.

RS sways are just so damn expensive! I love and hate you all for draining my bank account
Old 08-23-2016, 06:51 PM
  #28  
NYC993
Drifting
 
NYC993's Avatar
 
Join Date: Apr 2013
Location: Nothern NJ
Posts: 2,286
Received 11 Likes on 6 Posts
Default

Btw, you have c4s so you should have 19mm turbo bar in the rear not 17mm.

I have RS bars and went from full soft to full stiff in front. The result is that car's rear doesn't come out as often. I can't tell any difference on the street, granted our streets are crap and crowded.

I'm not sure that the 1mm stiffness in front will transform the ride of the car. Not confidence inspiring could be just a feel thing. Do a DE or car control clinic or autocross and see what the car does, before saying it's not confidence inspiring or that you need a stiffer bars. When I bought my car, it didn't feel confidence inspiring at all...until I did a few DEs and a couple skid pad and slalom sessions. Btw, RS bars are not that expensive, they are less than 1k with hardware plus new rear drop links.
Old 08-23-2016, 06:52 PM
  #29  
Bill Verburg
Addict
Rennlist Member

 
Bill Verburg's Avatar
 
Join Date: May 2001
Posts: 12,398
Received 579 Likes on 398 Posts
Default

Originally Posted by jskylarwilson
Juha is right on with what I'm looking for. Even with the PSS10s, the car still feels like it has too much understeer and body roll. Although the PSS10s make the car feel better, the sways are too small. He's who made me realize that the car is lacking confidence on the street.

I'm not looking to track or reduce lap times. I'm not a hooligan in the canyons, but I want the car to corner better than not. No street racing, no overly reckless driving, just better.

RS sways are just so damn expensive! I love and hate you all for draining my bank account
The car should be set up w/ springs and then tweaked w/ sways
PSS9/10(225/250-400/685)are only slightly stiffer than RoW M030(186-286) and more importantly the difference between front and rear 185 for PSS 100 for M030 changes the handling characteristics, bigger difference means less understeer.

For fast street use you want ~150 to 220 difference, RS(246-457) is 211
For track use ~100 to 150

for street use i'd look for springs in the 400-450 lb/in front and 550-600 lb/in(for a 150 difference), w/ RS adjustable sways or w/ M030 front and tt rear non adjustable sways

If the car won't turn try adjusting the front shocks softer and/or the rears stiffer, front tire pressure higher and/or rear lower, add a spacer in front, softer sway in front/stiffer in back, wider wheel or tire in front
Old 08-23-2016, 09:54 PM
  #30  
Edward
Addicted Specialist
Rennlist Member
 
Edward's Avatar
 
Join Date: Jun 2001
Location: So.CA
Posts: 6,141
Received 359 Likes on 201 Posts
Default

Originally Posted by jskylarwilson
...
I'm not looking to track or reduce lap times. I'm not a hooligan in the canyons, but I want the car to corner better than not. No street racing, no overly reckless driving, just better.
Great, yet another responsible adult behind the wheel! He actually wants to enjoy his sports car feel, and doesn't even care about dropping his lap times ...because he has no lap times, and it doesn't phase him! And he simply wants to drive canyons like the mature adult he is, and yet wants to experience the visceral joy of a sports car without driving like an adolescent hyped up on testosterone. Next thing you're gonna tell me is he has a family and actually cares about getting back home to them.

RS sways are just so damn expensive! I love and hate you all for draining my bank account
OR, there are the M030 sways which measure 22mm/20mm which are plenty good and, in concert with a properly set up PSS10 system, will result in flatter cornering and more sporty feel. Or better yet, the RoW M030 from the TT that measure 22mm/21mm, which does even more to reduce understeer, yielding a crisp-handling sports car ride with neutral balance.
1. Far less pricey than all the alternatives, incl the RS
2. Perfect fitment, bushes, links, and all ,making for the easiest installation
3. OE quality because it is OE.

There is no shortage of ways to spend more money ...heck, doing so even allows you to talk faster about how much faster your car goes. Then again, excellent alternatives that yield excellent results do exist. And that's not even thinking outside the box. Have fun, all.

Edward


Quick Reply: Sway bar diameter question - 20mm vs. 21mm for front



All times are GMT -3. The time now is 02:50 PM.