SoundGuyDave
This Space For Rent
- Joined
- Apr 9, 2007
- Posts
- 1,978
- Reaction score
- 28
First off: I do NOT have a Watts on my race car. However, I have driven (and raced, as in competition license raced) a LOT of S197s, with Watts links and Panhard bars on track, so I think I have a decent perspective on this.
1) I personally don't "feel" enough difference on a full-sized track comparing right and left turns to dismiss the validity of a ROD-END Panhard.
2) I do not autocross, so have no exposure to slalom-type corners, and will fully admit that a Watts may be superior in quick alternating transitions.
3) The Watts is, hands-down, heavier and more expensive, and with like bushing construction, doesn't present any drastic improvement in axle location.
What I *THINK* is happening with a lot of the "Watts Links are awesome, Panhards are devil-spawn" posts and threads is a lot of different factors going into the judgement, which like tolerances, can stack up...
1) There is usually no comparison made with setups using like-material bushings. IOW, apples-to-oranges. Stock PHB sucks; going to ANYTHING will be an improvement!
2) There is some confirmation bias involved: It's only natural if you just dropped a grand or more into locating your axle to mentally perceive SOME improvement.
3) I've never seen any comparison where all other factors were eliminated: Bushing compliance and roll center being the biggies.
4) With the exception of Terry Fair, I don't recall any "non-learning" driver weighing in on the debate. Not intended as a slam to the less-experienced, but unless you can consistently grind out laps within a couple tenths of a second per mile, the mechanical advantages of any hardware will be lost in the "noise" of lap time variance, which is directly related to driver input errors.
5) Combining #2 and #4, you easily get more "driver confidence." If you typically use between 80-90% of the "grip budget" of the car, the "OMG I have a Watts!" factor can allow a driver to narrow that variance somewhat which will be perceived as "Watts is better." Never mind that the REAL change was all mental.
6) Possibly the most telling, the Watts is typically NOT installed in isolation, but is credited with all the change... Watts, shocks, LCA's and springs are a "normal" package to install in the rear, but for some reason the Watts gets all the credit. I would argue that shocks make a LOT more difference than any of the rest of it!
I can't comment on the street aspects of Watts versus Panhard. To me, though, I have a couple of points to raise as food for thought.
1) Mathematically, we've established that the Panhard allows around .080" of lateral axle shift over a "normal" range of suspension deflection (with Heim joint ends). We're talking on the order of 1/16" and that's just not enough to even talk about compared to the 1" or more of tire carcass deflection.
2) There seems to be no chatter whatsoever about the differences in Watts designs. Fays2 mounts the prop bolt on a subframe which effectively doubles the vertical shift in RC location compared to a PHB in pitch. The Cortex/Griggs Watts mounts the prop bolt on the diff, which locks the RCH, but does still allow twice the variance in lever-arm length to the chassis compared to the PHB.
Please note that I have NEVER said that a PHB is superior to the Watts, only that thought needs to be applied to the decision, not just a knee-jerk "OMGz!!1!!!!1!" reaction. If you're complaining that a stock rear suspension setup kinda sucks, I'll agree with you. If you throw good shocks, springs, LCAs and a Watts at it, you'll have a drastically improved tractive capability, period. If that leads you to push the edge of traction more consistently, then you will also be faster (lower lap times). Don't for a minute, though, think it's all because you pulled one bar off the car and replaced it with two bars, a football and a fixed prop bolt, because it just isn't the case. I will argue that with a rod-ended PHB eliminating the bushing deflection issue, there just isn't enough of a difference in LATERAL AXLE LOCATION to be worth the expense, complexity and extra weight that comes with a Watts link. If you want to talk about altering the roll-center location, then that's a whole different story. I just really hate categorical statements without anything to back them up!
In closing, I will NOT say that the Watts doesn't present some advantages over a PHB, even with like-material bushings, because that just wouldn't be true. All I will say is that there just isn't enough of a difference in "feel," or more importantly lap times, to warrant the change in my situation. If you're autocrossing, then the rapid transitions in the slalom sections may put the Watts higher on the list than it is for the big track. When it boils down, there are just too many FAST S197s that run PHB's to categorically state that the Watts is light-years better on the open track. Much better to focus time/money/attention on the lower-hanging fruit: better dampers, and most importantly, the driver-mod!
1) I personally don't "feel" enough difference on a full-sized track comparing right and left turns to dismiss the validity of a ROD-END Panhard.
2) I do not autocross, so have no exposure to slalom-type corners, and will fully admit that a Watts may be superior in quick alternating transitions.
3) The Watts is, hands-down, heavier and more expensive, and with like bushing construction, doesn't present any drastic improvement in axle location.
What I *THINK* is happening with a lot of the "Watts Links are awesome, Panhards are devil-spawn" posts and threads is a lot of different factors going into the judgement, which like tolerances, can stack up...
1) There is usually no comparison made with setups using like-material bushings. IOW, apples-to-oranges. Stock PHB sucks; going to ANYTHING will be an improvement!
2) There is some confirmation bias involved: It's only natural if you just dropped a grand or more into locating your axle to mentally perceive SOME improvement.
3) I've never seen any comparison where all other factors were eliminated: Bushing compliance and roll center being the biggies.
4) With the exception of Terry Fair, I don't recall any "non-learning" driver weighing in on the debate. Not intended as a slam to the less-experienced, but unless you can consistently grind out laps within a couple tenths of a second per mile, the mechanical advantages of any hardware will be lost in the "noise" of lap time variance, which is directly related to driver input errors.
5) Combining #2 and #4, you easily get more "driver confidence." If you typically use between 80-90% of the "grip budget" of the car, the "OMG I have a Watts!" factor can allow a driver to narrow that variance somewhat which will be perceived as "Watts is better." Never mind that the REAL change was all mental.
6) Possibly the most telling, the Watts is typically NOT installed in isolation, but is credited with all the change... Watts, shocks, LCA's and springs are a "normal" package to install in the rear, but for some reason the Watts gets all the credit. I would argue that shocks make a LOT more difference than any of the rest of it!
I can't comment on the street aspects of Watts versus Panhard. To me, though, I have a couple of points to raise as food for thought.
1) Mathematically, we've established that the Panhard allows around .080" of lateral axle shift over a "normal" range of suspension deflection (with Heim joint ends). We're talking on the order of 1/16" and that's just not enough to even talk about compared to the 1" or more of tire carcass deflection.
2) There seems to be no chatter whatsoever about the differences in Watts designs. Fays2 mounts the prop bolt on a subframe which effectively doubles the vertical shift in RC location compared to a PHB in pitch. The Cortex/Griggs Watts mounts the prop bolt on the diff, which locks the RCH, but does still allow twice the variance in lever-arm length to the chassis compared to the PHB.
Please note that I have NEVER said that a PHB is superior to the Watts, only that thought needs to be applied to the decision, not just a knee-jerk "OMGz!!1!!!!1!" reaction. If you're complaining that a stock rear suspension setup kinda sucks, I'll agree with you. If you throw good shocks, springs, LCAs and a Watts at it, you'll have a drastically improved tractive capability, period. If that leads you to push the edge of traction more consistently, then you will also be faster (lower lap times). Don't for a minute, though, think it's all because you pulled one bar off the car and replaced it with two bars, a football and a fixed prop bolt, because it just isn't the case. I will argue that with a rod-ended PHB eliminating the bushing deflection issue, there just isn't enough of a difference in LATERAL AXLE LOCATION to be worth the expense, complexity and extra weight that comes with a Watts link. If you want to talk about altering the roll-center location, then that's a whole different story. I just really hate categorical statements without anything to back them up!
In closing, I will NOT say that the Watts doesn't present some advantages over a PHB, even with like-material bushings, because that just wouldn't be true. All I will say is that there just isn't enough of a difference in "feel," or more importantly lap times, to warrant the change in my situation. If you're autocrossing, then the rapid transitions in the slalom sections may put the Watts higher on the list than it is for the big track. When it boils down, there are just too many FAST S197s that run PHB's to categorically state that the Watts is light-years better on the open track. Much better to focus time/money/attention on the lower-hanging fruit: better dampers, and most importantly, the driver-mod!