Adjustable front sway bar .......is it worth it ?????????

[1TONY1]

Anybody have comments ? I am looking for better handling at the autocross not on the road course. Here is the link to the one Woodhouse sells.
http://www.woodhouseviper.com/store/pic.asp?stock_number=Adjustable%20Front%20Stabilizer%20Bar
I think they cut the stock bar and clamp the gold piece on and then use the stock bushings and support rod........not much for $600

 

[Tom F&L GoR]

For just autocross you'd really want something to get the rear end around, like a stiffer rear bar. Unless this sway bar really softens the front, it won't help what you want to do.

If you haven't already, stiffen your adjustable front shocks to full stiff and the rear shocks to half or 3/4 of full stiff and see if that helps. For the $600 you can buy a pretty good spring compressor, jack, ramps...

(all said with full respect for everyone at Woodhouse, they have helped me a couple of times.)

 

[1TONY1]

For just autocross you'd really want something to get the rear end around, like a stiffer rear bar. Unless this sway bar really softens the front, it won't help what you want to do.

Could you explain what you mean by the above (in dummy terms)

The front is pushing more then I want it to. I have not done anything with the shocks.......I will have to look, but it may be easier to change the spring/shock together rather than adjusting a shock......I need them loose for everyday driving/drag racing. I also have the front shims out. And, right.... nothing against Woodhouse, I'm sure it's great for the big track....just not sure about autocross.

 

[Tom F&L GoR]

The sway bar is a spring, so the more the car leans, the more load on the tire. A rear bar will add to rear tire loading so a rear tire slides first (before a front tire.) How stiff the bar or the springs are adjusts this. You can also stiffen a shock and get similar results. As the car begins to lean (the speed at which it leans over) the shock will try to slow the rate of lean. If the shock is stiff, it will greatly resist the lean and temporarily put more load on the tire. At a steady state condition (driving in a circle) the car is now not changing how much it wants to lean and the shock doesn't do anything, only the springs. While the sway bar or springs affect steady state push or loose behavior, a shock will affect transient push or loose behavior. Since sutocross is very much transient (mostly changing directions) a stiffer shock provides a significant response.

If you're pushing with the shims out, you may have other things. Are you braking when it pushes? With the front brake bias, if could be the fronts are doing too much work. Pushing at low speeds? That much camber and no forward pitching means there's not enough load on the front tire.

Since you want an AX-only fix, how about disconnecting the front sway bar at the end links? That would let the car lean a little more, but give you a looser car.

 

[Jack B]

Tom:

I had the same problem as Tony. I have done several autocross events this year. There is always a long sweeping comeback where the car just plows. This is with power and no braking. It seems as though it takes forever to get out of those.

I put in the Woodhouse bar. It also comes with the rear poly bushings. I went out to the fourth setting (stiffest), The car is now totally neutral, the plowing is gone. What is interesting it almost seems as though the springs were changed. The car is far tighter and more responsive at any speed.

 

[Tom F&L GoR]

Hi, Jack.

Well, the springs were changed. The way bar is a spring than only works when the car leans (or wants to.) So that makes sense. The rear geometrey has lots of anti-squat, so under power the front end will lighten. That hurts in those long sweepers, too. Can only slow down to get front grip, then hope to induce a little power oversteer to keep vehicle speed up. Yes, I know what you mean and the shock setting should help that a little.

Making the bar arms longer makes the sway bar softer. You said you went "out" to the fourth setting? If the front bar were softer, it is the same as more rear bar, which promotes "loose..."

 

[Jack B]

Tom:

You are right, the Instructions from Woodhouse:

"The position equivalent to the original stock bar setting will be the third hole from the end"

"The first being the most reduction of understeer"

Also kind of interesting, a comment on the new rear poly bushing "These bushings on the rear are approximately equivalent to one hole position closer to the end of the new bar"

 

[1TONY1]

Keep the comments coming. FYI.....Once again at the local autocross (short tight course) this past Sunday I had FTD (fastest time of the day) by about a 1.5 seconds. Also had FTD pax (handicap) time. I just need more

 

[Tom F&L GoR]

The poly bushings eliminate the distance the rubber bushings have to compress before the sway bar (not the "way" bar as I typo-ed above) does it's thing. By installing only rear poly bushings the rear bar would become effective before the front bar, and then for each degree of body lean, the rear bar would be twisted more, so you'd get more of a stiff rear bar effect. Sort of a middle ground as to disconnecting the front bar altogether. Interesting tuning, since I'd naturally install poly bushings front and rear.

 

[Bob Woodhouse]

Tony, Tom: I just finished reading through your thread. Interesting, and I see both of you are knowledgeable on suspension.
Also I was pleased that Jack, who owns and has tested the bar came away with what we set out to provide. That is to give a Viper an inexpensive way to balance the chassis. "I don't want drill bits, I want holes" as they say. In this case you want a car that handles well so you can go fast. This is not the only way to do that but it is an efficient way to do it.
The rear suspension bushing change is an important ingredient. To correct one statement that Jack said: he runs his bar in the end hole which "reduces" (not increases)the stiffness of the bar.
If I had to sell this bar based on time and material it would cost more like $1200. The development time is where the expense comes from. I bought and tested all the bars I could find for Viper before realizing no-one with experience had bolted and tested their product.
It is always nice to see a thread like this becuase we all learn, thank you.

 

[1TONY1]

Thanks Bob. Tom and Jack sound knowledgable but my drag racing past doesn't help much in the corners so I plead ignorant. I understand needing to "balance" the car but I don't want to loosen the back to match the front......I had rather tighten the front to match the rear. I would think one would do whatever it took to make the front and rear stick as good as possible....then balance the car. If that doesn't make sense or is wrong....it's just because I don't know whatI am talking about

p.s. Bob...sorry about the crash, I am glad you are ok. Not much heads-up time from what I saw in the video.

 

[99 R/T 10]

The poly bushings eliminate the distance the rubber bushings have to compress before the sway bar (not the "way" bar as I typo-ed above) does it's thing. By installing only rear poly bushings the rear bar would become effective before the front bar, and then for each degree of body lean, the rear bar would be twisted more, so you'd get more of a stiff rear bar effect. Sort of a middle ground as to disconnecting the front bar altogether. Interesting tuning, since I'd naturally install poly bushings front and rear.

Hey Tom, so does this mean only the rears should have the poly's? As cheap and easy as this is, even I can do it!

Mike

 

[Tom F&L GoR]

Tony,
I think Jack has "softened" the front by going to the outward most holes, which is sort of the same as "stiffening" the rear. This makes the car "loose" (rear end has more tendency to slide, opposite of push.)

It's all a big chase to keep the tires happy; to keep the tread as flat on the ground during corners and with equal load front to rear. Front tires only have to steer, so they can accept more body roll-induced load (whether from a sway bar or springs), while the rear tires have to steer (resist side load) and also push the car. Usually a car will therefore have a smaller rear bar because the outside rear tire is doing lots of work already and can't accept as much more. If it helps, think of a car cornering on three wheels - the outer front (100% side load) and the two rears (50% side load and 50% forward thrust each.)

If that made sense, then you realize that how forward thrust (power) and vehicle speed affects things like front springs or sway bars. Those dirt track cars with direct drive V-8s have a high power to weight ratio, so they have soft rear springs and stiff front roll stiffness. Front wheel drive cars need both fronts to corner and pull, so you can't afford to overload the outside front and have to install a large rear spring (and corner with a rear wheel off the ground.)

Race car shock tuning is still out of reach for me (I play with the OEM shock rebound settings occasionally) but someday. Shocks aren't there just for ride comfort, they adjust corner entry (braking to neutral throttle) and corner exit (neutral to power on) behavior.

All very cool stuff if you are reasonably close to decent handling to start with, but hugely confusing if the car is awful and you don't know where to start to fix it (my kit car Cobra of many years ago taught me an awful lot about balance.)

And Mike, the poly bushings in the rear will help loosen the car, but perhaps only a small amount, since Jack was also adjusting his front sway bar to the softer setting. But it's cheap and easy.

And to Mr. Woodhouse, who has done this for a long time, given me good advice, and has played the underdog race car role with his old Pantera (as I did with the Cobra) - I'm happy to see you visiting and finding things to do. Sounds like a good prognosis for a healthy recovery.

 

[1TONY1]

Wouldn't it be better to have aftermarket front sway bar bushings and the bushings that go in the bar stands to get full use out of the upgraded sway bar ?

Tom.....let me read through your post a few dozen times and give it some thought. tnx

 

[Tom F&L GoR]

Tony, you're right - to get the most stiffness out of the front, you would add the front bushings. But if your car is pushing, you already have enough front bar stiffness and need more rear bar stiffness. Since you can't get a stiffer rear sway bar (I've looked) the adjustable front bar gives you a position that is softer than stock. Therefore the balance of the car is such that you approach neutral handling. Don't get too hung up on thinking you're getting too soft in the front, it's the front to rear balance you're looking for.

 

[1TONY1]

Don't get too hung up on thinking you're getting too soft in the front,

Have you been talking to my wife ???????????????

 

[Tom and Vipers]

Someone needs to manufacture a REMOTELY adjustable rear bar.

Rally guys (and M3 guys I believe too) are able to adjust their rear bars while driving.

This is done by rotating the "flat blades" which are the "arms" of the sway bar.

 

[Bob Woodhouse]

Tony, those bushings in the rear are doing what you are asking, tightening the car, it will stiffen the suspension by approx 35#s per side at 1 inch of bar deflection.

Tom your idea of an adjustable from the driver seat rear bar is a good one.............but with reservation. I toyed heavily with that about three years ago. A couple of drawbacks come with flat blade style and other adjustable bars however. The flat blades tend to be non linear, ie; move a little and get no recognizeable change, then move a little more and huge change, thus self induced crashing. Next problem they bring is looseness or sloppiness, it is difficult to keep the minute amounts of free travel out of them which is so critical on cars with low compliance suspension. After talking with a number of suspension engineers I canned the idea.