Why can't a Mustang run a torque arm?

[y5e06]

I gotta idea ...

Finds complete parity...

Eliminates the need for directors, rules lobbying even the internet.

I got a good one too! How about CMC?
just CaMaro Challenge? then we don't have to worry about the disadvantaged fords. we can leave the 3rd gens out too. oh, and no LS1s because everyone should have to deal w/ the crapti-spark. oh toss the firebirds too since it is a ridiculous pain in the rump to find body parts.

I'm glad I don't visit the forums often enough...

hmmm, pass the popcorn

[ShadowBolt]

From the Maximum Motorsports web site.

•Never replace rear upper control arm bushings with urethane, due to induced binding, and resulting chassis damage.
•Upper control arms must rotate and pivot with axle motion, and rubber is the only material that sufficiently allows for this twisting without chassis damage.

I knew this but I thought with only one arm in place (using the PM3L) that I could get away with it. Boy was that a big mistake! I never had any damage at all until I switched to Urethane. I hope it drives the same using the left side upper than with the right side. For whatever reason (I'm sure Richard can tell us) everyone says to run the right side only when doing the PM3L.


Several of you are not understanding what Michael and I are saying. We don't want tube chassis. We are not pissed and we are not going to take our toys and go play somewhere else if we don't get our way. The question to us is why would the Mustang be better than the Camaro with the same items that are on the Camaro? I do understand (now) that the stock torque arm on a Camaro may be a POS and adding a aftermarket t/a to a Mustang would be some kind of advantage but I never knew or had heard that before reading it here in this post. I assumed that if you put both cars at the same weight, same track width, both with torque arms and coil-overs, and at the same power that they should be the same or at least very close. Are we sure that the Mustang would be any faster at all with these mods? This is the reason I wanted Glenn to run Boudy's car this year. I would have been glad to help with the money for him to get the car set-up to his liking. If he goes out and by the end of the year he is as fast as he was in the Camaro then all us Stang drivers shut the crap up from now on! If he can't beat Jay and I then something is out of whack.

JJ

[RichardP]

For whatever reason (I'm sure Richard can tell us) everyone says to run the right side only when doing the PM3L.

Since you asked...

The screwed up bias of the offset arm sort-of, kind-of tries to compensate for the inherent solid rear axle bias due to driveshaft torque. In other words, it should put down power better with the arm on the right...


Richard P.

[marshall_mosty]

Has anyone tried a spherical bearing on both sides of the PM3L upper link? Would that maybe provide the degree of motion needed to keep from twisting the mount?

Do NOT put spherical bearings in both ends!!! The shorter upper control arm travels through a different arc than the longer lower control arm. This is why the factory lower control arms had the oval bushings. The soft rubber will allow the fore/aft deflection in the lower arms and not cause any more bind than 100% necessary.

Once you go to polyurethane in one end of the lower and then a rod end in the other end, the lower basically is a rigid link. That is why the PM3L uses the stock rubber bushing on the frame end. This is the "last link" that will allow for that different arc travel.

[mitchntx]

OK ... all joking aside ...

So the way I understand it is the bushing is removed altogether from left side UCA so that bind is eliminated as the solid axle moves through it's range of motion.
And it's the left side UCA that is causing all the issues with the mount.

Not 100% on top of it all, so if that's a true statement, then ...

Why not allow removing the left UCA altogether? If it serve no purpose other than it's a factory suspension piece and it causes major relibility problems, nix it.



If that's not the case and its the fact that all loading is directed to one mount instead of shared between two, then ...

... adding a TA similar to what a an F-Car has will be just moving the problem.

The TA in my car has been systematically tearing and ripping the floor pan out of my car for several years.
Most any 4G will show signs of the spot welds being pulled through on the floor in front of where the passenger seat bolts.
I had to repair the trans mount at one point. Its a common problem.


I think what gets lost in these kinds of discussions is that we are taking these platforms to a level of loading no one ever intended them to go. Think about it ... there is suspension loading being transmitted to a pick-up point that is spot welded to 14 gauge molded steel pan. And the expectation is that will endure repeated G-loading seen coming off the banking at TWS? Hopping curbs through Rattlesnake at MSR-C? the washboard at ECR? The canyon exiting T6 at Hallett? And we do it year after year. Not even custom built tube chassis cars can last through that kind of punishment.

I think we generally expect too much of these platforms.

[BryanL]

From the Maximum Motorsports web site.

•Never replace rear upper control arm bushings with urethane, due to induced binding, and resulting chassis damage.
•Upper control arms must rotate and pivot with axle motion, and rubber is the only material that sufficiently allows for this twisting without chassis damage.

I knew this but I thought with only one arm in place (using the PM3L) that I could get away with it. Boy was that a big mistake! I never had any damage at all until I switched to Urethane. I hope it drives the same using the left side upper than with the right side. For whatever reason (I'm sure Richard can tell us) everyone says to run the right side only when doing the PM3L.


Several of you are not understanding what Michael and I are saying. We don't want tube chassis. We are not pissed and we are not going to take our toys and go play somewhere else if we don't get our way. The question to us is why would the Mustang be better than the Camaro with the same items that are on the Camaro? I do understand (now) that the stock torque arm on a Camaro may be a POS and adding a aftermarket t/a to a Mustang would be some kind of advantage but I never knew or had heard that before reading it here in this post. I assumed that if you put both cars at the same weight, same track width, both with torque arms and coil-overs, and at the same power that they should be the same or at least very close. Are we sure that the Mustang would be any faster at all with these mods? This is the reason I wanted Glenn to run Boudy's car this year. I would have been glad to help with the money for him to get the car set-up to his liking. If he goes out and by the end of the year he is as fast as he was in the Camaro then all us Stang drivers shut the crap up from now on! If he can't beat Jay and I then something is out of whack.

JJ

We all know you are just looking for an advantage for the 55 over the 24.

You know I understand where you guys are coming from. I don't like the Fox having to do bodywork for the track width either. But all the platforms are just different. I don't think getting the cars closer in weight, track width, TA's etc. will get you closer because there are too many other variables like wheelbase, suspension points, and lots of other engineering things that I don't understand. I don't think its possible to have it perfect but I think its pretty close. If Mosty would just put a racing steering wheel in his car and fix his handling issue then he might be untouchable. I'm all for narrowing my track width so the Fox doesn't have to do bodywork but what about the SN95 track width or do I then get a weight break? I don't think I'll be any slower without the spacers. I believe (and think others have proven) that if you prep a platform, test, test, seat time, seat time, great setup, fresh tires then any of the platforms would be the best.
Are you wanting someone to say that the Mustang would be better with the same items on the Camaro so therefore the Camaro has an advantage?

[ShadowBolt]

OK ... all joking aside ...

So the way I understand it is the bushing is removed altogether from left side UCA so that bind is eliminated as the solid axle moves through it's range of motion.
And it's the left side UCA that is causing all the issues with the mount.

Not 100% on top of it all, so if that's a true statement, then ...

Why not allow removing the left UCA altogether? If it serve no purpose other than it's a factory suspension piece and it causes major relibility problems, nix it.



If that's not the case and its the fact that all loading is directed to one mount instead of shared between two, then ...

... adding a TA similar to what a an F-Car has will be just moving the problem.

The TA in my car has been systematically tearing and ripping the floor pan out of my car for several years.
Most any 4G will show signs of the spot welds being pulled through on the floor in front of where the passenger seat bolts.
I had to repair the trans mount at one point. Its a common problem.


I think what gets lost in these kinds of discussions is that we are taking these platforms to a level of loading no one ever intended them to go. Think about it ... there is suspension loading being transmitted to a pick-up point that is spot welded to 14 gauge molded steel pan. And the expectation is that will endure repeated G-loading seen coming off the banking at TWS? Hopping curbs through Rattlesnake at MSR-C? the washboard at ECR? The canyon exiting T6 at Hallett? And we do it year after year. Not even custom built tube chassis cars can last through that kind of punishment.

I think we generally expect too much of these platforms.

Mitch,
the current thought on the PM3L is to run air (no bushing at all) in the upper chassis side arm on the left and a rubber bushing on the right side upper chassis side. When I went from rubber to polyurethane it tore the right side upper chassis mount out of the car in two events (Michael has been running this bushing without issue on the upper but he is tearing up his lower torque boxes). The lowers are a lot easier to fix. I assumed with no bushing in the left side there was no bind (I did not know the problem was as Marshall describes above. I just found out a few minutes ago we Mustang drivers have another issue that is going to hit us all. When I was running the arm with the rubber bushing on the chassis side (the bushing comes installed in the arm, you don't install it yourself) I would go through two in a season. Ford Racing (and Ford) stopped producing these so the only place I can find them are Maximum Motorsports at $200.00 a set!

JJ

[RichardP]

Do NOT put spherical bearings in both ends!!! The shorter upper control arm travels through a different arc than the longer lower control arm. This is why the factory lower control arms had the oval bushings. The soft rubber will allow the fore/aft deflection in the lower arms and not cause any more bind than 100% necessary.

Once you go to polyurethane in one end of the lower and then a rod end in the other end, the lower basically is a rigid link. That is why the PM3L uses the stock rubber bushing on the frame end. This is the "last link" that will allow for that different arc travel.

Huh??? If you are running both upper arms, spherical bearings in both ends is a very bad thing to do. If you are running only one upper arm, spherical bearings in both ends of the upper arm would be the best from a suspension geometry/bind standpoint. The spherical bearings could transmit more impact load into the chassis mounts and accelerate their destruction. The rubber bushings aren't strong enough to get the job done, though. Pick your poison...


Richard P.

[ShadowBolt]

Are you wanting someone to say that the Mustang would be better with the same items on the Camaro so therefore the Camaro has an advantage?

This is the $64,000 question that I don't think anyone knows the answer to. If a top driver switched platforms, by the end of the season you would know the answer. Either Michael would be faster in your car then he is in his Mustang or not. Hell, they may be as even as we can ever get them but how do we know......just because someone spends lots of time and tons of dollars and wins in a Mustang, that means the cars are equal?

JJ

[rpoz27]

Do NOT put spherical bearings in both ends!!!

You can run sphericals in all 4 ends...in fact, I would recommend it over the PM3L. Call Wolfe Racecraft in Arlington who puts 1500hp through the stock design. http://www.wolferacecraft.com/detail.aspx?ID=267 I think their claim to fame is 7's on the stock 4 link. Since bushings are open, install a heim in the stock UCA and go to town. You are going to get a TON of gear noise and you will need to up your rear spring rates to account for the lack of bind but the PM3L guys are already doing that.

You guys are over thinking this and just need to run the right bushing setup that isn't overtaxing half of the stock design and just gusset the pickup point as the CMC rules may allow. Problem solved and you keep $750 in your pocket.