What is the difference between a Torque arm and a Panhard bar?
Prowler
go to (what parts to use) set up a road race suspension? TIA
Carl S.
89 Mustang GT
77 Camaro
Greg Banish
> How does each one act on the suspension? What would the best way to
> go to (what parts to use) set up a road race suspension? TIA
A torque arm controls axle twist from acceleration and braking moments and
the panhard rod (bar) controls side to side location and force transfer of
the axle. The torque arm runs from the carrier forward under the
driveshaft to a pickup near the vehicle's center. A panhard rod runs
parallel to the axle, but usually behind it and connects to the axle on
one side and the frame on the other.
When using this type of setup for a road race suspension, the stock upper
control arms are removed. The addition of the torque arm and panhard rod
replaces their original function, with better geometry. Also, the stock
quad shocks are removed too, since axle twist is now limited by the
bushing at the front of the torque arm (if there is one).
It is also a good idea to at the very least do a spring change from stock
when going to this setup to reduce the rear roll rate. Torque arm setups
on a car with good tires and plenty of power can actually pick the inside
front tire up off the ground exiting a corner if they don't have enough
roll stiffness. This can be done with either stiffer springs or sway
bars.
~gb
'93 LX
I can be emailed directly at ban...@saoa.com during the week, but this
address doesn't work for newsgroups posts yet.
John Guzik
Prowler wrote:
>
> Would a torque arm/panhard rod be a better set up than changing the
> upper and lower control arms?
>
It would be a world of difference however comma you NEED to change, at a
minimum, the lower control arm bushings to poly, if you don't put
aftermarket pieces themselves on.
Griggs would be the obvious choice for Torque arm-they also sell panhard
bars. But maximum motorsports sells them too. You also need to:
Upgrade springs to 350 or 400lb rear.
remove upper control arms
remove quad shocks
I've got a torque arm sitting in my closet, I still need to get control
arms and springs, which I almost bought, but really wanted a dvd player
instead, so it'll wait-besides it's too cold to put that stuff on right
now. The panhard bar alone is great, but some say it's self defeating
since it causes the rear end to bind. Don't know about that, it's great.
Steve Lilly
Prowler wrote in message <78629f$b98$1...@winter.news.rcn.net>...
>Thanx for the info. But you opened a can of worms by replying. ;)
>Now I'm really curious about using a torque arm/panhard rod setup. I
>was planning on going to a road race suspension this summer and I was
>going to swap in the BBK upper and lower control arm kit. But now I'm
>thinking of using the TA/PR. I was also thinking of using Eibach
>springs and Koni red shocks/struts. But I'm not sure what rate
>springs to get. If you don't mind, I'd like to ask you a few more
>questions.
>Would a torque arm/panhard rod be a better set up than changing the
>upper and lower control arms?
Properly done, definitely.
>With a TA/PR set up would you have to change the lower control arms?
Not necessarily. Stiffer control arms would probably be beneficial. Best
to ask the tech support at the company you buy from.
>and last but not least ..... What company do you recomend, that has
>experience with these type of suspensions and will give you honest
>advice with which parts complement each other?
>
Griggs Racing is probably the best.
>Carl S.
> 89 Mustang GT (only looks stock)
> 77 Camaro (Bone Stock 305)
>
One more thing to consider: a torque arm/ panhard bar setup is going to be
considerably more expensive, and the installation is probably not a job you
want to tackle yourself.
Steve
Prowler
Now I'm really curious about using a torque arm/panhard rod setup. I
was planning on going to a road race suspension this summer and I was
going to swap in the BBK upper and lower control arm kit. But now I'm
thinking of using the TA/PR. I was also thinking of using Eibach
springs and Koni red shocks/struts. But I'm not sure what rate
springs to get. If you don't mind, I'd like to ask you a few more
questions.
Would a torque arm/panhard rod be a better set up than changing the
upper and lower control arms?
experience with these type of suspensions and will give you honest
advice with which parts complement each other?
Carl S.
Jared Rude
>Prowler wrote:
>>
>> Would a torque arm/panhard rod be a better set up than changing the
>> upper and lower control arms?
>
>minimum, the lower control arm bushings to poly, if you don't put
>aftermarket pieces themselves on.
>
>http://www.griggsracing.com
Yep, Griggs is the best in my opinion. I know Central coast Mustang makes
Griggs copies, but they are a little different. I bought the Griggs arm
since:
1) Griggs parts have been used for 20 years with good results
2) It was used, and therefore cheap (half price of new)
>Griggs would be the obvious choice for Torque arm-they also sell panhard
>bars. But maximum motorsports sells them too. You also need to:
MM's panhard rod is about the least expensive for what you get. It's $299.
>Upgrade springs to 350 or 400lb rear.
>remove upper control arms
>remove quad shocks
>
>I've got a torque arm sitting in my closet, I still need to get control
>arms and springs, which I almost bought, but really wanted a dvd player
>instead, so it'll wait-besides it's too cold to put that stuff on right
>now. The panhard bar alone is great, but some say it's self defeating
>since it causes the rear end to bind. Don't know about that, it's great.
I have my torque arm sitting in my living room at this point in time. I am
going to order the panhard and MM LCA's probably on Friday. Also need a T/A
cover, gasket, and differential fluid and springs.
The only thing that worries me about the torque arm, is having it or the
crossmember bang against the stock H-pipe. Will it? I don't know, I'll find
out in a few weeks. Either way, I planned on headers and X-pipe this summer.
Does anyone know if the BBK H-pipe for long tube headers will fit with a
Griggs Twin Tube torque arm? I know Central Coast Mustang sells a Bassani
X-pipe specifically for torque arms, but I'll bet it big bucks. The other
option is that a shop down here can build me an X-pipe custom to fit. I
already priced them and they are $399.
--
Jared Rude
1990 LX 5.0
remove "nospamforme" to reply
Prowler
>The only thing that worries me about the torque arm, is having it or the
>crossmember bang against the stock H-pipe. Will it? I don't know, I'll find
>out in a few weeks. Either way, I planned on headers and X-pipe this summer.
Could you post results after you get everything together and take it
for a test drive or two? (any problems during installation, ride
quality, cornering ability, etc.) I want to know as much as possible
about a good road race set up for a daily driver. I want to get the
right parts and set it up right the first. As soon as I get the cash
(read : after I get the credit card down) I want to do my suspension.
And maybe go to one of those racing schools. I'd like to go to the
Bondurant school but Arizona is a little far from New York. Oh well.
"Ya can't always get what ya want"
Greg Banish
> The only thing that worries me about the torque arm, is having it or the
> crossmember bang against the stock H-pipe. Will it? I don't know, I'll find
> out in a few weeks. Either way, I planned on headers and X-pipe this summer.
On my car, the H-pipe rests directly against the crossmember for the
Torque Arm. However, mine is a custom, self made piece where the cross
piece is about 2.25" in diameter. The exhaust presses against it firmly
so it can't rattle and noise/vibration transmission into the passenger
compartment from this contact is neglible. I'll probably end up having a
custom 3" dual exhaust bent for the car next year that fits the turbo
outlets perfectly and clears the panhard bar better, though.
Greg Banish
> It would be a world of difference however comma you NEED to change, at a
> minimum, the lower control arm bushings to poly, if you don't put
> aftermarket pieces themselves on.
Well, usually. But you can get away without getting them for a while if
you're only using the car for the street.
> I've got a torque arm sitting in my closet, I still need to get control
> arms and springs, which I almost bought, but really wanted a dvd player
> instead, so it'll wait-besides it's too cold to put that stuff on right
> now. The panhard bar alone is great, but some say it's self defeating
> since it causes the rear end to bind. Don't know about that, it's great.
Actually, the stock non-parallel four link is what binds. Since the stock
upper control arms are angled like they are, body roll induces bind in
them. Eliminating these arms frees up the suspension movement, and the
panhard bar gives positive location to the axle.
sbest
for a 92 Crown Vic. The usual Vic owners are not into this sort of
thing. If you want performance answers you guys seem to be the gurus!
In spite having the "police" rear bushings, my 4 link suspension is
pretty sloppy. Most noticably on bumps on corners, even with "Z" rated
BFG TAs it will jump and slide. I suspect that a panhard bar might
help this but have no experience with adding them. I notice as well
that the latest Crown Vics now have a Watts Link on the rear, so
obviously the factory thought they could use some better lateral
location.
My question is what sort of problems does a panhard rod fix on a 4
link rear suspension? Is there any side effects like increased
oversteer or rear bump steer?
Steve Best, Nova Scotia,
4x4 van website:
http://www.glinx.com/users/sbest
John Guzik
sbest wrote:
> My question is what sort of problems does a panhard rod fix on a 4
> link rear suspension? Is there any side effects like increased
> oversteer or rear bump steer?
It prevents side to side movement of the axle. It creates oversteer-but
believe me, you get used to it the first time you turn the wheel. My car
just shoots to the left or right when I turn it now.
sbest
wrote:
Would that just be transient oversteer John, like when you put
firmer rear shocks on?
or would I have to readjust the balance of my swaybars?
I think I can see how it would improve steering responsiveness.
I never though of that. (improvement needed!)
How does it do with sharp bumps on fast corners?
Jared Rude
>"Jared Rude" wrote:
>>The only thing that worries me about the torque arm, is having it or the
>>crossmember bang against the stock H-pipe. Will it? I don't know, I'll
find
>>out in a few weeks. Either way, I planned on headers and X-pipe this
summer.
>
>for a test drive or two? (any problems during installation, ride
>quality, cornering ability, etc.) I want to know as much as possible
>about a good road race set up for a daily driver. I want to get the
>right parts and set it up right the first.
Sure, I planned on posting the results anyway.
>As soon as I get the cash
>(read : after I get the credit card down) I want to do my suspension.
>And maybe go to one of those racing schools. I'd like to go to the
>Bondurant school but Arizona is a little far from New York. Oh well.
>"Ya can't always get what ya want"
I know the feeling on the: cash and "can't always get what you want" parts.
Prowler
>Griggs would be the obvious choice for Torque arm-they also sell panhard
>bars. But maximum motorsports sells them too.
I was checking out the torque arm at the Griggs page and the GR-40
Street set up caught my eye. Comes with everything and then some.
Now I just have to find the $2100 to buy it. For now I'll just have
to dream about it.
Maybe I can get my girlfriend to buy me it when she's done interning
and gets a paying job. Nah .....who'm I kidding. She has her eye on a
'99 Cobra. Oh well ....time to start saving my pennies.
Jared Rude
>John Guzik wrote:
>
>>http://www.griggsracing.com
>
>>Griggs would be the obvious choice for Torque arm-they also sell panhard
>>bars. But maximum motorsports sells them too.
>
>I was checking out the torque arm at the Griggs page and the GR-40
>Street set up caught my eye. Comes with everything and then some.
>Now I just have to find the $2100 to buy it. For now I'll just have
>to dream about it.
>Maybe I can get my girlfriend to buy me it when she's done interning
>and gets a paying job. Nah .....who'm I kidding. She has her eye on a
>'99 Cobra. Oh well ....time to start saving my pennies.
Look for the GR40 stuff used on the Corral. There's a guy in North Carolina
(I think it's NC) who has adverised the his entire GR40 rear suspension set
up for $1400. You'll just have to spend some time on the web (the Corral
specifially) to find his ad in the suspension section. I remember seeing it
advertised once a long time ago. I saw it again about a week ago. I
remembered it is the same ad since he had the whole setup powdercoated red.
If he's having problems getting rid of it, that means the price is
negotiable.
Buying used stuff (that's still relatively new and in good condition) saves
a lot of money.
Or, just assume ownership of your girlfriend's Cobra after she buys it.
Possibly the cheapest way out.
Greg Banish
> Would a torque arm/panhard rod be a better set up than changing the
> upper and lower control arms?
IMHO, yes. It's not the most economical way to go, but the results are
superior in the long run.
With a TA/PR set up would you have to
> change the lower control arms?
Not necessarily. If the setup is only being used on the street, stock
LCA's are fine. If you're racing, I'd look into serious Control arms from
Edelbrock, Maximum Motorsport, Griggs, BBK, etc...
and last but not least ..... What
> company do you recomend, that has experience with these type of
> suspensions and will give you honest advice with which parts complement
> each other?
Both Griggs and Maximum Motorsports have a good background with these
setups.
Prowler
>Look for the GR40 stuff used on the Corral. There's a guy in North Carolina
>(I think it's NC) who has adverised the his entire GR40 rear suspension set
>up for $1400.
>Buying used stuff (that's still relatively new and in good condition) saves
>a lot of money.
I'll have to look into that. Thanx
>Or, just assume ownership of your girlfriend's Cobra after she buys it.
>Possibly the cheapest way out.
I just might have to do that. I could always say the car didn't sound
right ..."let me take it out for a test drive to make sure it's ok" ;)
Greg Banish
> All right, please excuse me guys for asking this here but this is
> for a 92 Crown Vic. The usual Vic owners are not into this sort of
> thing. If you want performance answers you guys seem to be the gurus!
>
> In spite having the "police" rear bushings, my 4 link suspension is
> pretty sloppy. Most noticably on bumps on corners, even with "Z" rated
> BFG TAs it will jump and slide. I suspect that a panhard bar might
> help this but have no experience with adding them. I notice as well
> that the latest Crown Vics now have a Watts Link on the rear, so
> obviously the factory thought they could use some better lateral
> location.
Perhaps your bushings are worn. How many miles are on the car? Boxing
the stock control arms by welding plates across their open bottoms will
also help. Adding an anti-squat bracket to the rear LCA pickups will also
generate more bite off the corners by lowering the position of the bushing
1" or so.
Ford's addition of the Watt's link was more to correct wind drift for the
old folks than for performance, but it does work. Problem is, it's not an
easy retrofit for anything. Trust me, I asked the development engineer.
> My question is what sort of problems does a panhard rod fix on a 4
> link rear suspension? Is there any side effects like increased
> oversteer or rear bump steer?
The PB gives solid side to side location of the axle under the car.
Usually, they end up lowering the rear roll center (the PB height becomes
roll center height) and make the car looser (oversteer more). Side
effects are limited, but if too much travel is involved, they bais the
suspension. This makes the car feel different turning right than it does
turning left, but only happens if the bar is too short or travel is too
long.
I don't see why it would be too hard to fabricate on for a Vic, since
there's way more room under there than on a mustang. If you have access
to a maching shop and welder, it should be straight forward, just make
sure you don't end up with interference with the sway bar, inspection
cover, fuel filter or exhaust.
sbest
Excellent stuff Greg, gives me a good idea of what to expect, thanks!
Tons of miles on the 92 squad car, original rear bushings but in
good shape. Front bushings were destroyed and I replaced them with OEM
"police" bushings where polyurethane were not available. The bushings
could be soft, but no poly rears available so the PB may be the only
way to go to get rid of the loose feel. The Watts link is cool but not
a practical swap and I think I can get lots of length and there is not
much travel involved.
Not hard to find lots of room and good solid attachment points on
the Vic. Roll center was something I was concerned about. The usual
goal in the front is as low as possible but I realize a bit higher is
better in the rear. I was thinking of keeping it at the same height as
the stock but I have no idea just how high that would be! I was
intending to use the Mustang aftermarket bars as a guide.
Any suggestions?
Jared Rude
> Not hard to find lots of room and good solid attachment points on
>the Vic. Roll center was something I was concerned about. The usual
>goal in the front is as low as possible but I realize a bit higher is
>better in the rear. I was thinking of keeping it at the same height as
>the stock but I have no idea just how high that would be! I was
>intending to use the Mustang aftermarket bars as a guide.
>Any suggestions?
Does your Crown Vic have upper control arms like a Mustang? A Mustang has
the upper control arms closer together at the differential housing than at
the body.
Basically, on a Mustang, the rear roll center is at the intersection point
of the two upper control arms (if a straight line is drawn through the
center of each upper arm and extended out until the lines hit each other).
The intersection occurs somewhere inside or above the gas tank. If you have
the upper arms and a Watts link, then the roll center would still be at the
intersection of the upper arms. The Watts link was probably chosen over a
panhard rod with upper arms since the Watts link will not cause the
suspension to bind with the upper control arms, and the panhard rod will in
many cases.
If you don't have upper control arms, but do have a Watts link, the roll
center is at the point where the Watts link mounts to the rear end. This
requires a method to keep the axle from rotating around it's own axle
centerline though. Normally, the upper control arms perform this function.
This function can also be performed by a torque arm, ladder bars, etc.
So, if you have both upper control arms AND a Watts link, then yes, you have
two roll centers. However, since the upper arms control axle rotation, they
will be the dominant roll center which the body rotates around.
Now, if you have upper control arms and the Watts link, you can remove the
driver's side upper arm and the roll center will move down to the point
where the Watts link mounts to the rear end. The passenger's side upper arm
must be retained though, in order to control the rotation of the axle.
Basically, you will have a true three link with a Watts link controlling
lateral axle location.
Prowler
Is there any ground clearance problems with the addition of a torque
arm and panhard bar?
Greg Banish
> Tons of miles on the 92 squad car, original rear bushings but in
> good shape. Front bushings were destroyed and I replaced them with OEM
> "police" bushings where polyurethane were not available. The bushings
> could be soft, but no poly rears available so the PB may be the only
> way to go to get rid of the loose feel. The Watts link is cool but not
> a practical swap and I think I can get lots of length and there is not
> much travel involved.
Check the shocks while you're under there. If they're leaking at all,
pitch them and get some better ones. Otherwise, new bushings will
certainly help.
> Not hard to find lots of room and good solid attachment points on
> the Vic. Roll center was something I was concerned about. The usual
> goal in the front is as low as possible but I realize a bit higher is
> better in the rear.
Well not really. A low front roll center gives more head toss when
cornering and poor suspension compromises under roll. Plus, I don't think
this is really adjustable, so it's a moot point. Having a low front roll
center and high rear roll center means that the roll axis (the line
between these two points) is seriously inclined. This is both good and
bad. It means the car will understeer, a lot. While this is good for Joe
Average car driver, loosening the car up will allow better cornerning.
> I was thinking of keeping it at the same height as
> the stock but I have no idea just how high that would be!
The stock rear roll center is tough to describe because of the
non-parallel four link, but trust me when I say it's about 3" below the
upper contol arm height, give or take. Where ever you place the panhard
bar's center will become the new rear roll center. So if you want the car
to get a little looser, place it lower than the stock roll center location
(about axle level works perfect for mustangs). This might turn out to be
a packaging issue though, so prepare to make a compromise here.
> I was
> intending to use the Mustang aftermarket bars as a guide.
> Any suggestions?
The maximum motorsport piece is nice too.
good luck!
Greg Banish
> Does your Crown Vic have upper control arms like a Mustang? A Mustang has
> the upper control arms closer together at the differential housing than at
> the body.
Yes, the crown vics (pre 98 1/4) have the same non-parallel four link as a
mustang. (98 1/4 and later units have a parallel four link and watts
link)
> Basically, on a Mustang, the rear roll center is at the intersection point
> of the two upper control arms (if a straight line is drawn through the
> center of each upper arm and extended out until the lines hit each other).
> The intersection occurs somewhere inside or above the gas tank.
Getting close here... actually, you take that point from the UCA's and
connect line to the point where the LCA's intersect (way out in front of
the axle). Where this imaginary line intersects the axle's vertical plane
is the rear roll center.
> If you have
> the upper arms and a Watts link, then the roll center would still be at the
> intersection of the upper arms.
Nope, with the parallel four link (and softer, nonbinding bushings) the
watt's link dominates the roll center location. Putting it at the pivot
point of the watt's link, since the car is not free to shift side to side
about this point, it must roll about it.
> The Watts link was probably chosen over a
> panhard rod with upper arms since the Watts link will not cause the
> suspension to bind with the upper control arms, and the panhard rod will in
> many cases.
True, unless the bushings are soft enough to prevent binding in the UCA's.
> If you don't have upper control arms, but do have a Watts link, the roll
Thi setup doesn't exist on panther (crown vic) body.
> So, if you have both upper control arms AND a Watts link, then yes, you have
> two roll centers. However, since the upper arms control axle rotation, they
> will be the dominant roll center which the body rotates around.
Nope, see note above.
> Now, if you have upper control arms and the Watts link, you can remove the
> driver's side upper arm and the roll center will move down to the point
> where the Watts link mounts to the rear end. The passenger's side upper arm
> must be retained though, in order to control the rotation of the axle.
> Basically, you will have a true three link with a Watts link controlling
> lateral axle location.
Yup, this is how the Baer/Bart's Works mustang three links basically work,
except they use a panhard rod for lateral control and the upper link is
moved so that it is longitudinal to the vehicle.
Reference: "The Automotive Chassis" by Heller (IIRC)
Greg Banish
>
> Is there any ground clearance problems with the addition of a torque
> arm and panhard bar?
My cats scrape first, even with a larger torque arm than the Griggs piece.
I wouldn't advise going through deep ruts that have a lower clearance only
under the center of the vehicle though, since this is where the torque arm
is. If the TA does get lodged on something, it will lift the rear axle.
But that hasn't been a problem for me ever, even with the lowering springs
on the car.
Greg Banish
(snip)
> >> If you have
> >> the upper arms and a Watts link, then the roll center would still be at
> the
> >> intersection of the upper arms.
> >
> >Nope, with the parallel four link (and softer, nonbinding bushings) the
> >watt's link dominates the roll center location. Putting it at the pivot
> >point of the watt's link, since the car is not free to shift side to side
> >about this point, it must roll about it.
>
> with less bleary eyes I'm beginning to question it as well. I have to go
> check my Machine Dynamics and Vehicle dynamics text books. Also, another
> reason to not post at 2:00 AM.
No, the lateral locating device will always dominate rear roll center
location as long as the other bushings don't bind too much.
> >Reference: "The Automotive Chassis" by Heller (IIRC)
> Don't have that one. Who published it? Maybe I'll order it from Amazon or
> SAE. I have "Race Car Vehicle Dynamics" by the Millikens.
Now that I think of it, I'm pretty sure I have the wrong author. It is an
SAE publication though and the title's right. I just can't find my book
right now for the life of me, I think I loaned it to my father last month
and haven't seen it since. Hmmm, maybe the author was something like
'Steimpel' it's a european book that was translated to english and uses
all european examples for the figures and examples. This was nice since I
was able to read all about my shocks/struts that I work on in it. (Sachs
is the biggest supplier of these in Europe.)
Jared Rude
>Jared Rude wrote:
>> Basically, on a Mustang, the rear roll center is at the intersection
point
>> of the two upper control arms (if a straight line is drawn through the
>> center of each upper arm and extended out until the lines hit each
other).
>> The intersection occurs somewhere inside or above the gas tank.
>
>Getting close here... actually, you take that point from the UCA's and
>connect line to the point where the LCA's intersect (way out in front of
>the axle). Where this imaginary line intersects the axle's vertical plane
>is the rear roll center.
Oops, I forgot the lower control arms aren't parallel to the vehicle
centerline. You're correct. I've got to stop posting stuff at 2:00 AM.
>> If you have
>> the upper arms and a Watts link, then the roll center would still be at
the
>> intersection of the upper arms.
>
>Nope, with the parallel four link (and softer, nonbinding bushings) the
>watt's link dominates the roll center location. Putting it at the pivot
>point of the watt's link, since the car is not free to shift side to side
>about this point, it must roll about it.
Did you mean non parallel four link? This makes sense. Rereading my post
with less bleary eyes I'm beginning to question it as well. I have to go
check my Machine Dynamics and Vehicle dynamics text books. Also, another
reason to not post at 2:00 AM.
>Reference: "The Automotive Chassis" by Heller (IIRC)
Don't have that one. Who published it? Maybe I'll order it from Amazon or
SAE. I have "Race Car Vehicle Dynamics" by the Millikens.
--
sbest
<jr...@nospamforme.bellsouth.net> wrote:
>Does your Crown Vic have upper control arms like a Mustang? A Mustang has
>the upper control arms closer together at the differential housing than at
>the body.
><MUCH INFO SNIPPED>
>Jared Rude
Thanks Jared, for the insight.
4 arm suspension much like a Mustang. Watts link only on the latest
models, which is not mine unfortunately.