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Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

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Old 04-23-2008, 05:52 PM
  #11  
Sam Strano
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

ORIGINAL: kcmarti

Apparently, I do not need a Watt's Link rear - maybe just change out the stock shocks/struts. Are "dampers" the same as shocks and struts? Most folks on this forum talk about Koni Sport and Tokico D-Spec shocks/struts/dampers. Can I use either of these with my stock springs? Anyone know where to get them at a reasonable price? Once again the main thing I want to accomplish is to decrease (hopefully stop) the rear end from kicking out over bump in corners - is that what is referred to as "bump steer"?
I can help you out with either the Koni's or the Tokico's as I sell both. I think my prices are pretty much inline with most others, but there is always some clown on Ebay with no overhead or experience undercutting....

What you are getting is not bumpsteer. That's a front happening that has to do with how the steering knuckle moves relative to up and down motion. What's happening to you is simply the fact the rear shocks don't do a good job of dealing with sharp bumps. I get to see this every day as my car has Koni's, but my girlfriend'scar has stock shocks (same springs, same bars..stock GT stuff) and her car is a lot more jumpy in the rear than mine is now. But you have to remember that you are talking about a solid axle car, not a lot different than a pickup truck. Solid axles are more upset by bumps than anything, as what happens at one side effects both tires. The dampers will help and help quite a lot.

And I agree with the PHB vs. Watts.... There isn't anything wrong with a PHB, it's not as cool as a watts link,and it's not the cause of your issues.
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Old 04-24-2008, 03:43 PM
  #12  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

ORIGINAL: houstonnw
The Grand Am Mustangs seem to do a good job against the IRS Porsches with a simple Panhard Bar rear suspension.

I've done 13 track days with my '07 and the only things I've changed are the tires and brake pads. I had an American Iron instructor ride with me last time and he suggested new shocks/struts and camber plates.

IMO, you can't (or shouldn't) be able to feel the difference between a Panhard Bar and Watt's Link on the street. I don't think that I could on the track and I'm well beyond the newbie stage.
Hi houstonnw,

Yes the GS Koni Challenge FR500C's are competitive with the IRS carseven with the lowly Panhard bar rear end. But they are racingona trackwhich isfairly smooth whichmeans that the suspension travel is naturallylimited compared to the real world roads. As you increase the suspension travel the amount oferror in the axle movementincreases and the advantages of the Watt's link become more apparent.

Also note thatas you reduce compliance in your suspension bushings you will get more feel for what the wheels are doing under the car.If you are on a stocksuspension with all of the squishy bushings all over the suspension and overly stiff compresion damping you won't feel the Panhard bar working. As you replace the bushings and control arms with stiffer control arms and bushings that can actually transmit the informationback to your butt and hands you can start to discern the difference between a good stiff Panhard bar with firm bushings or rod-ends and a Watt's link. What you believe you can't feel you probably can't feel with your car the way it is currently setup newbie or not.

HTH!
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Old 05-01-2008, 10:40 PM
  #13  
houstonnw
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way


ORIGINAL: F1Fan

ORIGINAL: houstonnw
The Grand Am Mustangs seem to do a good job against the IRS Porsches with a simple Panhard Bar rear suspension.

I've done 13 track days with my '07 and the only things I've changed are the tires and brake pads. I had an American Iron instructor ride with me last time and he suggested new shocks/struts and camber plates.

IMO, you can't (or shouldn't) be able to feel the difference between a Panhard Bar and Watt's Link on the street. I don't think that I could on the track and I'm well beyond the newbie stage.
Hi houstonnw,

Yes the GS Koni Challenge FR500C's are competitive with the IRS cars even with the lowly Panhard bar rear end. But they are racing on a track which is fairly smooth which means that the suspension travel is naturally limited compared to the real world roads. As you increase the suspension travel the amount of error in the axle movement increases and the advantages of the Watt's link become more apparent.

Also note that as you reduce compliance in your suspension bushings you will get more feel for what the wheels are doing under the car. If you are on a stock suspension with all of the squishy bushings all over the suspension and overly stiff compresion damping you won't feel the Panhard bar working. As you replace the bushings and control arms with stiffer control arms and bushings that can actually transmit the information back to your butt and hands you can start to discern the difference between a good stiff Panhard bar with firm bushings or rod-ends and a Watt's link. What you believe you can't feel you probably can't feel with your car the way it is currently setup newbie or not.

HTH!
My main point was that you shouldn't be driving hard enough on the street to feel the difference.

However, you talk about the amount of error in the axle movement.

The original post was about the rear end on bumpy roads. I hope that you will agree with me that the rear end "skipping" on bumpy corners is a function of the live rear axle and a Watts Link will not fix it.


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Old 05-02-2008, 05:51 AM
  #14  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

I think the original post spoke of improving the ride as well as the handling. While stiffer sta-bars don't carry with them the same ride penalty as stiffer springs or too much bump damping in the shocks/struts, they don't by themselves actually improve the ride. Though it certainly is possible to improve the ride at least in some cases with stiffer bars if you also reduce the spring rates.


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Old 05-02-2008, 01:59 PM
  #15  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

ORIGINAL: houstonnw
My main point was that you shouldn't be driving hard enough on the street to feel the difference.

However, you talk about the amount of error in the axle movement.

The original post was about the rear end on bumpy roads. I hope that you will agree with me that the rear end "skipping" on bumpy corners is a function of the live rear axle and a Watts Link will not fix it.
Hi houstonnw,

HUH? Why do you think you shouldn't be driving hard enough on the street to feel the diference? If youwere drivingmy caryou could feel the difference at 10MPH when making tight turns under power and the difference only goes up from thereon as corner exit spped and power application rises. I'm getting a bit gray but I'm not driving a golf cart around the home yet.

Carefully read my previous post #7 where I posted that a Watt's link does and does not do. The problem with the rear end skipping through bumpy corners or even going in a straight line is not due to the live rear axle per sebut the unsprung mass of the suspension and the poorly selected stock damper rates which are heavily over dampened in bump andequally under dampened in rebound for someunknown and unknowablereason.

HTH!
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Old 05-03-2008, 04:43 PM
  #16  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

There's na dynamic going on in the rear end with a PH bar that no one seems to be taking into consideration, which to me is far more detrimental than the very slight lateral movement. There's more lateral movement in the tires, the bushings, and under hard cornering load with fat sticky tires, if you're still runnung factory hardware, there's a ton of slop in the mounting holes themselves, and the bolts are moving more than the PH bar in their respective holes. What's actually happening with a PHB is, as soon as the bar gets past horizontal under a cornering load, it wants to act like a pogo stick. In a left hand turn, especially with cars with the factory ride height or any setting with the chassis end of the bar already abovehorizontal, the bar is trying to lift the inside of the car. On a right hand turn, it's the opposite...it's trying to push down on that point. The bar will try and swing on it's pivot point untill the load is perpendicular (typically parallel with the road surfac) to that pivot point. On a car where the suspension travel is less due to being lowered and having stiffer springs, and where the bar is horizontal at static ride height, this effect is minimized, but still there. The lateral movement of the chassis due to the sweep of the bar, IMO, especially in a lowered car with the above ocnditions I mentioned, with ALL the other dynamics occuring at the same time, isn't something I believe anyone could possibly detect. The effect the bar has on roll rates and weight jacking can't be overlooked, and impart more handling instability and inconsistancies than anything else involved with a PHB suspension. The other thing happening in the rear end is the rediculously short UCA and the geometry changes that occur with the slightest suspension movement.
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Old 05-03-2008, 07:20 PM
  #17  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

I think a sensitive driver might be able to pick up differences and/or changes in the rear axle roll steer.


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Old 05-03-2008, 08:53 PM
  #18  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

ORIGINAL: Norm Peterson

I think a sensitive driver might be able to pick up differences and/or changes in the rear axle roll steer.


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I wouldn't disagree if that was the only change or dynamic going on.
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Old 05-03-2008, 09:15 PM
  #19  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

ORIGINAL: steelcomp

There's na dynamic going on in the rear end with a PH bar that no one seems to be taking into consideration, which to me is far more detrimental than the very slight lateral movement. There's more lateral movement in the tires, the bushings, and under hard cornering load with fat sticky tires, if you're still runnung factory hardware, there's a ton of slop in the mounting holes themselves, and the bolts are moving more than the PH bar in their respective holes. What's actually happening with a PHB is, as soon as the bar gets past horizontal under a cornering load, it wants to act like a pogo stick. In a left hand turn, especially with cars with the factory ride height or any setting with the chassis end of the bar already abovehorizontal, the bar is trying to lift the inside of the car. On a right hand turn, it's the opposite...it's trying to push down on that point. The bar will try and swing on it's pivot point untill the load is perpendicular (typically parallel with the road surfac) to that pivot point. On a car where the suspension travel is less due to being lowered and having stiffer springs, and where the bar is horizontal at static ride height, this effect is minimized, but still there. The lateral movement of the chassis due to the sweep of the bar, IMO, especially in a lowered car with the above ocnditions I mentioned, with ALL the other dynamics occuring at the same time, isn't something I believe anyone could possibly detect. The effect the bar has on roll rates and weight jacking can't be overlooked, and impart more handling instability and inconsistancies than anything else involved with a PHB suspension. The other thing happening in the rear end is the rediculously short UCA and the geometry changes that occur with the slightest suspension movement.
Hi steelcomp,

That dynamic you are talking about can easily be felt once you remove allthe soft bushings and ge a setof tires that actually have some grip. Allof a sudden allthat axle movement can be felt and the loading and unloading of the lateral loads the Panhard bar is pushing or pullinginto thechassis. Most folks just don'tnotice it because they havesquishy bushings andtires that are not capable of generating seriousgrip no matter what the tire ads say about their 60,000 mile tires. The other thing is that most people have no idea how to even get close to 7/10ths ofwhat their tires can generate. All that loading and unloading of the chassis is the problem and the way the geometry works is why you can feel the jacking going on. Why do you think I switched to a Watt's link?

The issue with the UCA is less an issue than you migh think. I used to havea good set of drawings I made of the rear 3-link using measurements I took off a stock car on a drive up alignment rack.A stock rear suspension is not a badthing and lowering the car has a benificial affect on the sideviewIC in terms of the IC moving around but of course is reduces th rear grip somewhat. But I've lost that notebook in my garage remodel so I don't have solid numbers to give out anymore.

HTH!


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Old 05-05-2008, 05:41 AM
  #20  
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Default RE: Watt's Link Rear Suspension - Is there a better (i.e., less expensive) way

F1Fan, Your other post (https://mustangforums.com/fb.asp?m=5019989) on the Watt's Link adds to my confusion. It sounds like on this post, the Watt's Link is not what I should be looking at, but on the other one, you somewhat describe a "change", which I thought the Watt's Link (Saleen or JDM, not sure about the Steeda) would do. Is the caveat then, that I need to have other suspension upgrades in place for the Watt's Link to matter? Thanks.
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