Question about Panhard bar and upper control arms.

[Flar]

Hey guys I just picked up a MM panhard bar for my 95 GT. I do not run a TA and probably wont be running one for a while due to money constraints and the pain of install (I don't have a welder, nor sufficient skill with one to trust myself with the job). Anyway my question is about the upper control arms with the PHB installed, on MM's website they mention nothing about the uppers with the install, however on griggs website they suggest removing ONE upper control arm once the PHB is installed. Has anyone done this? Does it help at all? Any damage to the torque boxes on the one arm that was left installed? Any input on this would be greatly appreciated. Also the car is only making about 250rwhp now and will probably never make more then 350hp to the rear wheels. Its to bad that EVM doesn't make the trilink anymore because with my power rating and givin situation it looks like it would have been my preferred option.
Thanks,
Flar

 

[ReplicaR]

I'm running factory 4 link and panhard setup from MM. The whole thing why Griggs may suggest removing one control arm is because factory 4 link has a tendency to steer itself very slightly through out the range of motion. When you install the panhard setup, the axle stops steering, but the control arms still articulate just as they did before. The likely outcome of this is destroying your upper control arm bushings in a hurry, like it happened on my car. Luckily I will not have to deal with that much longer, as I'm going torque arm in a few days.

 

[Flar]

I was thinking of buying some cheap tubular upper control arms from jegs or something and just installing one of them once the PHB is in. Since the uppers job will only be to maintain pinion angle once the PHB is installed my guess is the harder urethane in the JEGS arms will stop them from breaking down as fast as the rubber did in yours. Obviouly since the angle on the one arm is so offset it will not perform nearly aswell as it would on 05+ mustangs (looking at that suspension is what originally gave me the idea for this). But it should outperform the factory 4-link because of less bind (not as much less as a TA but still less then the 4-link). So what do you guys think? Is this 'poor mans' 3-link a viable inbetween option from the 4-link to a true 3-link?

 

[Gallows]

I put a MM panhard bar and adjustable lowers on last summer and MM said to keep my stock uppers. The FRPP uppers are the same as what the Cobra's came with I was told. Not sure what the GT's came from the factory with.

 

[ReplicaR]

I've been reading on the PM3L on corner carvers a while ago. People say that it works ok, but the car feels very weird. For one thing is the axle does is no longer as straight as it was before, so the you can expect it feeling differently from one direction to other. Secondly, what a lot of people don't realize is that upper control arm bind also serves as roll resistance, so it sort of works like spring rate or a sway bar. If you go the PM3L route, you will need to go to a different spring rate just to maintain the same roll stiffness.

 

[Blind]

PM3L works fine, I run it on my `89 currently -

MM PHB
MM HD Adj. LCA's
MM Torque arm springs
Ford racing heavy duty upper control arm, boxed, with poly bushings swapped in because the rubber ones got torn up fairly quickly
MM Bilstein shocks

I also welded in wolferacecraft battle boxes on the upper and lower control arm mounting points of the chassis, paying particular attention to the upper arm location because a lot more forces go through that spot now.

As mentioned, the car feels a little weird, mainly because there's SO MUCH rear grip, the car liked to plow a bit until I adjusted the front alignment settings, I think an offset arm setup would help out a lot to re-balance the car.

 

[blackpony]

i just installed a mm panhard, and removed one of the upper arms. i am currently running a single hpm upper arm with granatelli lowers, and turning left, the car is very snappy, but turning right, it is a little slower... i think i am going to put some fresh bushings in my stock arms, box them in, and install both uppers back in...

 

[Flar]

Which upper arm do you have removed? I have read that the car will drive differently depending on which arm is removed. I have also read that a PHB just by nature of its design will cause a car to turn differently one direction then the other because of the arcing motion it makes during its travel. I'm thinking that since the MM PHB attaches the the left side of the axle removing the upper left arm would make the turning difference a little less noticeable? Maybe to offset the slow set time of the PHB. I've got a Steeda adjustable rear sway bar in the back so I could probably tighten that thing up a bit to help maintain the same roll resistance, maybe increase the dampening on the shocks a bit as well. Car has H&R super sport springs in the rear as well as MM control arms, and tokiko illumina shocks. In the next few weeks I'm taking out the cheesy H&R/tokiko set up and putting in some Koni SA's with MM coilovers, what spring rate would you recommend for the PM3L setup?

 

[ReplicaR]

I have also read that a PHB just by nature of its design will cause a car to turn differently one direction then the other because of the arcing motion it makes during its travel.

It's actually the difference in roll center that makes the difference. Panhard bar equipped cars get their roll center from where the bar mounts on the chassis, so depending which way you are turning, the car can either raise or lower rear roll center. The difference is negligible though. I've been tracking my car with panhard setup for a while now, and I can't tell the difference.

I'm thinking that since the MM PHB attaches the the left side of the axle removing the upper left arm would make the turning difference a little less noticeable?

From what I've read, people who are doing this are removing left side upper control arm. As far as the springs rates are concerned, when you are going from 4 link to a 3 link, you almost have to go twice as stiff in the back. I'm going from H&R super race to MM track torque arm spring, and from what I've been told by MM tech, that's about the same. If you are planning on doing coil-over front and back, they also recommend 100 pound difference, to keep the car balanced.

 

[Blind]

I run with the drivers side upper arm removed, with MM Torque Arm springs in the rear.

Adding stiffer bushings to the upper control arms shouldn't be done, especially with a PHB in place unless one of the arms is removed, the 4 link is in a super bind condition with both upper arms in place, and stiffening those bushings makes it even worse.

When I removed the upper arm from my car I had the jack sitting 1/2" under the diff just in case, well the rear dropped down that full amount when I removed the bolt from the diff side! In total I think it settled down a full inch compared to when it was in bind with both upper arms attached.

 

[Flar]

Alright well this is giving me more questions then answers haha, but I think im getting a better idea of how I need to budget this build.

So far my current set up is:
Front:
Tokiko Illumina Struts, coilovers with 300# springs
rear:
Tokiko Illumina shocks
H&R super sport springs (I believe they are progressive rate 300# springs)
MM HD lower control arms
MM PHB
Steeda adjustable rear sway bar
factory sway bar

So with the PM3L im thinking of ordering some Jegs upper arms with urethane bushings and just using one of the beefer arms with the urethane bushings on the upper right control arm and remove the upper left.

Im switching the rear out to Koni SA's with coilovers, obviously with the PM3L and one day with a TA im going to need stiffer rear springs, im going to call MM to find out which rates they suggest but do you guys happen to know what spring rates my Tokiko struts can handle and what rates the Koni's will handle? I've also got some Koni SA struts (well one, one is bent) so what rates can they take since I may just pony up the dough and order one Koni strut with the shocks and run Koni at all 4 corners...

Thoughts?

 

[blackpony]

i removed the upper driver side arm... it definately feels weird... i do not like it, and will be putting the stock arms back in but before i do that, i plan to box them in to add a little strength...

 

[cntchds]

Very similar to when you put in a torque arm, you will need to run much higher spring rates to get your roll resistance back. I don't know what a good spring rate for a PM3L is, but I believe that MM's TA springs are 350lb/in.

The problem with using stiffer than stock bushings on the upper control arms is that you will be beating the hell out of your torque boxes. The rubber bushings in your old arms were very compliant, so they absorb a ton of the impact. Urethane bushings transfer a lot more of the force to the stamped steel torque boxes.

 

[wytstang]

The FRPP uppers are the same as what the Cobra's came with I was told. Not sure what the GT's came from the factory with.

The FRPP uppers are stock 94+ pieces (both gt/cobra).

 

[Flar]

You need the harder urethane when you run just the one upper because the rubber bushing will destroy itself in a very quick time from what I have read. The urethane should be alright in the upper arm because with the PHB all (not all but most of) the lateral load that the uppers were being used to stop will be handled by the PHB instead. The uppers only job will be to maintain pinion angle. Because of the gnarly angle the upper arm is at however its going to maintain that angle better during a turn in one direction then the other. Im hoping that by using a tubular upper arm with less flex aswell as the harder urethane bushings in the arm it will help minimize the amount of fore and aft flex in the single arm.

 

[Dalamar]

you'll love the TA Rep

 

[ReplicaR]

Yeah, got it installed yesterday, and having some vibration issues. I might have to get it up and reset the pinion angle. The cornering difference is quite a bit though. I can definitely tell the difference and I have not even had it on the track yet.

BTW, here is what happens to your upper control arm bushings when you run panhard with 4 link

As you can see, that's worn all the way through.

 

[Blind]

yep that's how mine looked when I pulled it too, I'm considering going with a spherical bearing on the diff side of the upper and leaving the poly on the chassis side, I think the spherical will allow freer lateral movement than the poly does