Rear sway bar vs 140 rear springs Options

[Geezer914]

Would installing a set of 140# springs be the same as adding a rear sway bar using stock springs?

[charliew]

No it will be a LOT stiffer in the rear.

[naro914]

springs and sway bars do very different things. In ultra simple terms, springs affect the stiffness at that particular corner, sway bars affect how each corner handles with relation to the other. Sway bars do not really affect the ride at all in a straight line, springs do.

[jmill]

Installing the anti sway bar will affect body roll. Beefier springs will make it a bit more difficult to roll just because they're stiffer. Keep in mind that you will trade ride quality for stiffness. Really, to get it all right, you need to match your springs with your shocks and sway bar. They all have a piece in your cornering ability. Too stiff will make it tail happy.

[jhadler]

Sway bars work by coupling the left and right suspension through a torsion spring. You loose some degree of independence of the suspension as a result. This is not necessarily a bad thing,but it is worth noting. On rougher surfaces, the two wheels will not respond with complete independence.

Too much spring can be as bad as too much bar. Too much bar, and you couple the left and right sides so much that compression of the outboard suspension lifts the inboard wheel. This can possibly result in undesired wheel spin depending on how the rest of the suspension is set up.

Adding more spring, or more bar, will reduce your understeer and help the car rotate better. Too much though, and you just spin...

-Josh2

[sean_v8_914]

rear sway bar is typically reserved for more agresive non stock set ups at the hands of an experienced skilled driver. I know many here will argue this but evaluate teh source of a comment to determine validity....very few great handling 914s have teh rear bar connected. LSD, a $3000 option, and rear bar work well together.
for suspension setup think balance, weight transfer management. it is not wise to greatly stiffen one end and not the other.
those 140s will improve cornering, wil work with stock front torsions but wil need a front bar to balance out the 140s in teh rear.

it would be best for us to know a little bit about you and your desired driving style. How will you use teh car? what shocks do you want to run? tires? competition? AX? street/ AX?

[sean_v8_914]

OT: Bob, I enjoyed that off track adventure shot of Papa Smurf

[naro914]

sean,
avatar updated (IMG:style_emoticons/default/smile.gif)

[sean_v8_914]

sweet. did everything turn out OK after your off-track excursion?

[naro914]

oh yeah. I never slowed down. and didn't realize I cracked the front splitter until later.

It's turn 1 at VIR. Went a little hot into the turn, and came through a bit wide... oops... the fact that someone got a picture is amazing..

[r_towle]

Geezer, what are you trying to accomplish? That is reall the first question to ask prior to designing a good solution for suspensions.

Track? autox? Street? a combination of all of those?

Rich

[sean_v8_914]

tell us more about your car so we can give you better recomendations. you dont want to end up like papa smurf up here mowing the lawn at VIR. your lucky the grouds keeper wasnt union.

[naro914]

tell us more about your car so we can give you better recomendations. you dont want to end up like papa smurf up here mowing the lawn at VIR. your lucky the grouds keeper wasnt union.

Wow...harsh! Actually, the suspension on Papa Smurf is about as good of a set up as you can ever get on a 914: ERP 935 front control arm set up with Fox remote resevoir shocks, 375 lb springs all around, camber boxes, reinforced trialing arms. It normally sticks like glue, I can run down a lot of car in turns and braking...

What happened at VIR is the 993 I had been chasing for about 4 laps decided to brake way too early into 1. It surprised me (I was probably about 1 foot from his bumper) so I dodged right and jabbed the brakes...but missed the brake pedal...which of course now made me go back and jab it again...waaay too late. Never spun or locked them up, just went through the turn a bit wide. I passed him going into the turn and stayed ahead all the way around.

Here are a few suspension pics (and yes, the underside of the car looks terrible)

[sean_v8_914]

do you run lsd? rear bar?
that is one fine setup. although rules currently limit that type of setup for us (for now) they do allow chris' rear suspension point relocation. he says the improved geometry helps him accelerate out of corners.

if we talk about suspension set up here we can avoid a full blown thread hijacking, right

[naro914]

I run in PCA GT class, so suspension is free. No lsd...yet. No rear bar. My understanding, and I'll confirm once I get lsd, is that you should run without a rear sway if you don't have lsd, run with rear sway if you do.

I ran with a rear sway forever. Then someone told me to take it off and see if it was better, which is was.

Back OT about this thread, I kind of asked a similar, but more broad question back a while ago. More of a "what should I do" in general for my other 914 - Huey. I asked here and on Pelican Parts. Here is the thread on Pelican:
http://forums.pelicanparts.com/porsche-914...tml#post4936570

The post that really helped me - though I've done nothing yet on Huey - was the one from Dan:
>>21mm front torsion bars, Koni adjustables (yellows), 21 or 22 mm sway bar.
180# rear springs, Koni adjustables (or bilstein sports so you can get the car lower), no rear sway bar.
that is what I had on the Puttputt and it worked extremely well for street/AX/Track duty...
Also had this same basic suspension set up on a 914-6 with 2.7RS motor and it worked very well. This is a very old tried and true suspension setup for a track/street 914<<

[sean_v8_914]

180 rear sounds light for that stiff front end...to me . I currently run 22mm hollow frt torsions, 19mm hollow Tarret front sway @ 50% (the 22mm was way too stiff) 200# rears w/ adj spring perches, no lsd, no rear bar.

those 140s will work well on Geezers street/AX ride if he has a front bar and stiffer shocks. KYBs, while a bit crude, provide additional damping required to manage the extra energy storage capacity of a stiffer spring. KYB aka "kill your back" are also fairly cheap $.

rear 140# is the cut-off point for stock front everything. you can get away a stock front bar if you add adj bar levers

[rfuerst911sc]

This is an interesting post as I also have 140 lb. springs on my car but not running yet. Here is my current setup:
Stock front torsion bars
Elephant Racing polybronze bushings all 4 corners
Stock Boge front strut inserts
H&R 19mm adjustable front sway bar
Rear Koni shocks set to firm with 140 lb. springs. Stock spring perches.
No rear sway bar
Boxed swing arms with GT chassis stiffening and Engman kit.

This is a 1975 chassis with a 911 3.0 engine. Car will be street/AX/DE car. I " think " this will be a good neutral handling setup but won't know until I actually get the car running. I believe having the chassis a little soft will work out better overall but time will tell. Any thoughts on my setup ? I apologize in advance if this is a hijack of the thread.

[sean_v8_914]

here's the 10Jereen 914/4 120hp-under 1700#. TTOD winner over 100+ cars. Giant slayer.

OK I read your Pelican post. Huey's front bar is way too stiff

[sean_v8_914]

rfuerst911sc. your car is soft but balanced. set the rear shocks to full soft to start. all mods must be considered dynamic to the load(weight). the set up that works in a 914/4 is not allways gonna work in a heavier six. even if the six car is substantially lightened, dynamic weight transfer in the center of the car is greater as is foward weight transfer under braking. a stock six had bigger stock front torsions

start the front bar at 50%

poly bronze bushings reduce net spring rates 25-50# so your car is soft!

[davesprinkle]

here's the 10Jereen 914/4 120hp-under 1700#. TTOD winner over 100+ cars. Giant slayer.

What's the story with these wheels? Widened Pedrinis? Who did it and how much? Do tell.