Sway Bars and balancing a suspension

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Bleyseng
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Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 4:44 am

Here are a few pics I have of 914's and the effects of front sway bars and stiffer rear springs.
1. This is a prototype pic of a 914 cornering and notice the wheel lift.
2. A 914/6 lifting the front wheel and rear suspension compression
3. Front pic of my 914 hard cornering with front sway bar and stiffer T bars plus HD rear springs. Almost flat body.
4. Rear shot of my 914 under hard cornering
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Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Bleyseng
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Re: Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 4:46 am

Race 914/6
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Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Bleyseng
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Re: Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 4:47 am

Front of 914
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Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Bleyseng
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Re: Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 4:57 am

rear shot
Now one object of setting up a suspension is to try to keep as much as all 4 tires in contact with the road. This way you have a much grip as possible while cornering. The negatives of this setup is it's a very harsh ride for the street but fine on the freeway at 100mph.

For a bus, too much front and rear suspension stiffness would be awful IMHO as it has such a high center of gravity that rollover could occur. In my 914 when you reach the limit you either 4 wheel slide or 360 snap spin. I don't think that would happen in a bus, I think you would have the rear slowly come around until it was in front of you like the early 911's or if the speed was high enough rollover.

So what are the limits of modifying a buses suspension? A HD front sway is easy to add but something must be done to the rear to balance that addition. My answer was to add stiffer rear shocks but to keep the oil filled front shocks so the front isn't too harsh in normal driving.
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914 76 cornering.jpg
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Amskeptic
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Re: Sway Bars and balancing a suspension

Post by Amskeptic » Fri Apr 04, 2014 8:10 am

Bleyseng wrote: Now one object of setting up a suspension is to try to keep as much as all 4 tires in contact with the road. This way you have as much grip as possible while cornering.

For a bus, too much front and rear suspension stiffness would be awful IMHO as it has such a high center of gravity that rollover could occur.
I think you would have the rear slowly come around until it was in front of you like the early 911's or if the speed was high enough rollover.

So what are the limits of modifying a buses suspension? A HD front sway is easy to add but something must be done to the rear to balance that addition. My answer was to add stiffer rear shocks but to keep the oil filled front shocks so the front isn't too harsh in normal driving.
The factory did not want too much in the way of grip. They limited tire sizes and required lower front and higher rear tire pressures, to ensure a proper breakaway (loss of traction) well before the center of gravity could leave the wheel base (that would be "flipping over"). DO NOT SCREW WITH THEIR FORMULA.

Please explain this:
A HD front sway is easy to add but something must be done to the rear to balance that addition.
Here are a few quotes from over at the Shop Talk forums, excellent thread.

h[url]ttp://www.shoptalkforums.com/viewtopic.php?f= ... 9&start=15[/url]

"We use a nonadjustable 19mm rear bar, or an adjustable 22mm Whiteline rear bar, and sometimes, no rear bar at all. It all depends on the track. A rule of thumb is the faster you go, the less oversteer you want, and on our type of car, rear bars promote oversteer."

"The thicker a sway bar, the more roll resistance it offers. But more is not always better. Porsche learned back in 1959 that decreasing the rear roll resistance made their cars handle better. VW followed suit on this in 1967 with softer rear torsion bars."

I already explained this, the car *has to lean" to pick up the inside front tire to promote understeer. I personally believe that it is the height if irresponsibility to suggest a rear stabilizer bar on a Volkswagen bus. Most of the "explanations" I have heard about better "handling" is subjective sensations of improved directional control. This is irrelevant in an emergency.
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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Bleyseng
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Re: Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 8:50 am

I have never recommended a rear bar on a bus or even a bug/ghia.
VW set the front tire pressures lower because the front of VW's are so light. Too high a pressure and they handle terrible! (try it sometime as the front end feels like its on ice). A soft front tire keeps the tire contact patch as big as possible. I do remember the Zbars VW installed on the later bugs/Ghia's to help with rear wheel tuck do to the Tbar rear suspension issues. ( Unsafe at any Speed Bullshit). The 69 switchover to independent rear suspension solved all those issues.

Okay, any change in a suspension must be at both front and back. Balance is the key unless you want to drive around like those dirt track cars with the rear end hanging out in the corners. Increasing the front sway bar means increased front stiffness so this must to accounted for in the rear. I don't like a rear bar on a bus so stiffer shocks is a easy way to balance the car. Adjustable koni yellows would be my dream but I haven't seen those around nor rear shocks with springs.
Tires are important too, so too stiff a sidewall or too sticky a tire (like the ones we AX with) would make a bus drive really harsh as it's so heavy! I like the Hankook's are they are a decent soft sidewall tire but not too soft like a passenger tire. Tread design should be looked at as mudder tires are great in mud but on the road they suck.


If you change from stock, you must consider the whole package or you can get yourself in trouble!
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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Amskeptic
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Re: Sway Bars and balancing a suspension

Post by Amskeptic » Fri Apr 04, 2014 2:11 pm

Bleyseng wrote: Tires are important too, so too stiff a sidewall or too sticky a tire (like the ones we AX with) would make a bus drive really harsh as it's so heavy!

Honda Accord 3,238
Ford Taurus 3,316
Volkswagen Westfalia 3,350
Toyota Camry 3,400
Mercedes E350 3,927
Chevrolet Caprice Classic 4,200
Honda Odessey 4,370
Mercedes S600 4,817
Volkswagen Bus Gross Vehicle Weight 4,982
Dodge Ram pick-up 5,532
GVWR Toyota Sienna 5,995
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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Bleyseng
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Re: Sway Bars and balancing a suspension

Post by Bleyseng » Fri Apr 04, 2014 6:26 pm

As I said, a loaded Bus or Campmobile is quite heavy, nearly 5000lbs gross. Proper tires with the correct inflation and a well setup suspension is the ticket to pleasurable safe driving. How you set it up for your driving style is up to you.
Geoff
77 Sage Green Westy- CS 2.0L-160,000 miles
70 Ghia vert, black, stock 1600SP,- 139,000 miles,
76 914 2.1L-Nepal Orange- 160,000+ miles
http://bleysengaway.blogspot.com/

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