"A must always be greater than B"

[kawahonda]

In the topic of torsion bar adjustment, I noticed just by the look of other CHallenger's i've seen that some break this rule. I feel like I'm pretty much at the "limits" of not breaking this rule.

How important is this rule to follow? I'd like a little bit more lowered than it's at right now, but I want to abide by the FSM if it's for a good reason.

A must always be greater than B (FSM).
Manual calls limit at .125 DIFFERENCE BETWEEN BOTH SIDES

A = Torsion blade
B = Knuckle

BEFORE ALIGNMENT:

Passenger side:
   A: 9.33"
   B: 8.9"
   = .43" Height
   
   Fender well measurement: 24.68"

Driver's side:
   A: 9.25"
   B: 8.9"
   = .35" Height

   Fender well measurement: 24.25"

   .08" left/right difference

AFTER ALIGNMENT:

Passenger side:
   A: 9.09"
   B: 8.89"
   = .20" Height

   Fender well measurement: 24.81"

Driver's side:
   A: 9.01"
   B: 8.85"
   = .16" Height
   
   Fender well measurement: 24.68"

   .04" left/right difference

[72bluNblu]

The "rule" is just like the rest of the factory specs. They're designed for bias ply tires. When you install radials, use larger torsion bars, change out the bump stops, etc the rules are no longer relevant. The camber curves needed are different, the suspension travel needed is different, pretty much all of the geometry is different.

That said, your car it sitting really low. To stay off the bump stops you'll need large torsion bars, as in 1.12" or bigger at that height. And you can't be using the stock bump stops either. I ran my Challenger that low for awhile, I ended up bringing it up to about 25" at the top of the front fender opening to improve my ground clearance a bit for ease of use, as well as to decrease the frequency with which I was hitting my low profile bump stops.

[1 Wild R/T]

The "rule" is just like the rest of the factory specs. They're designed for bias ply tires. When you install radials, use larger torsion bars, change out the bump stops, etc the rules are no longer relevant. The camber curves needed are different, the suspension travel needed is different, pretty much all of the geometry is different.

That said, your car it sitting really low. To stay off the bump stops you'll need large torsion bars, as in 1.12" or bigger at that height. And you can't be using the stock bump stops either. I ran my Challenger that low for awhile, I ended up bringing it up to about 25" at the top of the front fender opening to improve my ground clearance a bit for ease of use, as well as to decrease the frequency with which I was hitting my low profile bump stops.

Ok.....  I guess mine must be undrivable........   I have .96 torsion bars & my measurement at the top of fender is 23.25....  It's been that way for close to 80K miles....  Oh, my bump stocks are stock.....

[72bluNblu]

The "rule" is just like the rest of the factory specs. They're designed for bias ply tires. When you install radials, use larger torsion bars, change out the bump stops, etc the rules are no longer relevant. The camber curves needed are different, the suspension travel needed is different, pretty much all of the geometry is different.

That said, your car it sitting really low. To stay off the bump stops you'll need large torsion bars, as in 1.12" or bigger at that height. And you can't be using the stock bump stops either. I ran my Challenger that low for awhile, I ended up bringing it up to about 25" at the top of the front fender opening to improve my ground clearance a bit for ease of use, as well as to decrease the frequency with which I was hitting my low profile bump stops.

Ok.....  I guess mine must be undrivable........   I have .96 torsion bars & my measurement at the top of fender is 23.25....  It's been that way for close to 80K miles....  Oh, my bump stocks are stock.....

How tall are your front tires? If they're ridiculously short, then it might not be a problem.

Otherwise you're just riding around on your bump stops.

There are also some Challenger fenders out there that have a 1" lower opening, measuring to the wheel opening isn't fool proof. That's why the factory used an LCA measurement.

[1 Wild R/T]

The "rule" is just like the rest of the factory specs. They're designed for bias ply tires. When you install radials, use larger torsion bars, change out the bump stops, etc the rules are no longer relevant. The camber curves needed are different, the suspension travel needed is different, pretty much all of the geometry is different.

That said, your car it sitting really low. To stay off the bump stops you'll need large torsion bars, as in 1.12" or bigger at that height. And you can't be using the stock bump stops either. I ran my Challenger that low for awhile, I ended up bringing it up to about 25" at the top of the front fender opening to improve my ground clearance a bit for ease of use, as well as to decrease the frequency with which I was hitting my low profile bump stops.

Ok.....  I guess mine must be undrivable........   I have .96 torsion bars & my measurement at the top of fender is 23.25....  It's been that way for close to 80K miles....  Oh, my bump stocks are stock.....

How tall are your front tires? If they're ridiculously short, then it might not be a problem.

Otherwise you're just riding around on your bump stops.

There are also some Challenger fenders out there that have a 1" lower opening, measuring to the wheel opening isn't fool proof. That's why the factory used an LCA measurement.

Tires are 26.1 tall....   Trust me, I'm no where near riding on the bump stops.... My buddies car is more than 1.5" lower than mine....   I've never thought of my car being particularly low....

On the other hand 26" at the fender is getting into bug stance territory....

[kawahonda]

Mine doesn't seem that low with these specs:

Passenger side:
   A: 9.09"
   B: 8.89"
   = .20" Height

   Fender well measurement: 24.81"

Driver's side:
   A: 9.01"
   B: 8.85"
   = .16" Height
   
   Fender well measurement: 24.68"

Very easy to drive anywhere...speed bumps, etc. I haven't looked at the bump stops as they were not mentioned in the FSM. Anyone have a pic of of them and an additional measurement to keep in mind.

I also have not checked my measurements since I installed new wheels/tires.

@1 Wild R/T

[1 Wild R/T]

Mine doesn't seem that low with these specs:

Passenger side:
   A: 9.09"
   B: 8.89"
   = .20" Height

   Fender well measurement: 24.81"

Driver's side:
   A: 9.01"
   B: 8.85"
   = .16" Height
   
   Fender well measurement: 24.68"

@1 Wild R/T

Personally I'd probably lower the passenger side a touch since it's higher then the drivers side & you know the drivers side will sit lower still when you are in the car...

[72bluNblu]

The "rule" is just like the rest of the factory specs. They're designed for bias ply tires. When you install radials, use larger torsion bars, change out the bump stops, etc the rules are no longer relevant. The camber curves needed are different, the suspension travel needed is different, pretty much all of the geometry is different.

That said, your car it sitting really low. To stay off the bump stops you'll need large torsion bars, as in 1.12" or bigger at that height. And you can't be using the stock bump stops either. I ran my Challenger that low for awhile, I ended up bringing it up to about 25" at the top of the front fender opening to improve my ground clearance a bit for ease of use, as well as to decrease the frequency with which I was hitting my low profile bump stops.

Ok.....  I guess mine must be undrivable........   I have .96 torsion bars & my measurement at the top of fender is 23.25....  It's been that way for close to 80K miles....  Oh, my bump stocks are stock.....

How tall are your front tires? If they're ridiculously short, then it might not be a problem.

Otherwise you're just riding around on your bump stops.

There are also some Challenger fenders out there that have a 1" lower opening, measuring to the wheel opening isn't fool proof. That's why the factory used an LCA measurement.

Tires are 26.1 tall....   Trust me, I'm no where near riding on the bump stops.... My buddies car is more than 1.5" lower than mine....   I've never thought of my car being particularly low....

On the other hand 26" at the fender is getting into bug stance territory....

I now recall that we had this conversation over at C-C as well, at the time you were claiming a wheel opening height of only 22.75". And I came to the same conclusion then, we aren't taking equivalent measurements. I'm not saying my measurements are right and yours are wrong, I'm just saying that our measurements are not comparable. Not sure if that's a measurement issue, a body tolerance difference or what, but they're not equivalent measurements.

I feel perfectly confident in saying that because I only have 3/4" from the 1" tall bump stop to the frame on my car. The height change at the wheel is roughly 2x the height change at the frame/bumpstop, so, even if I put my car on my shortened bumpstops the measurement at the wheel opening as I'm taking it would only be 23.5". That's a 3/4" change at the frame/bumpstop which translates roughly to a 1.5" change at the wheel.

Now, the stock bumpstops are 1-3/8" tall, so, by my measurements your car would be touching the bumpstops at a wheel opening height of only 24.25". So obviously our measurements are not equivalent.

This is one of the reasons why the factory didn't use a ride height measurement to the fenders, instead opting for a suspension height measurement (not a ride height measurement). They had different height tire options, so measuring to the the body would be different from car to car. And of course the body tolerances on these cars are not known for being spot on.

Without getting into the factory method of measurement, which can be a little tricky if you're just using a tape measure, the easiest comparable measurement to take is from the bumpstop to the frame. It's more relevant than the fender height or even the factory measurement anyway, because you can directly look at the amount of suspension travel you have. Which will help tell you if your ride height works for your torsion bar size. My car does bottom the suspension occasionally, so, with a 1.12" bar I'd say 3/4" clearance is about the minimum (I should actually use a smaller bumpstop). With a smaller bar, you'll need more travel to avoid bottoming the suspension.

[kawahonda]

I use a laser tool for my measurements. I will post pictures over the weekend on how I've been doing it.

I'm assuming that the "front" has bump-stops? I haven't seen them yet (I haven't looked at them). Your pics will help me identify them.

What is a good distance to be away from the bumpstop? 3/4"?

[72bluNblu]

I use a laser tool for my measurements. I will post pictures over the weekend on how I've been doing it.

I'm assuming that the "front" has bump-stops? I haven't seen them yet (I haven't looked at them). Your pics will help me identify them.

What is a good distance to be away from the bumpstop? 3/4"?

Must be nice! I was wondering how you were getting measurements down to the hundredth. Tape measure is all I have to use, but really with the chassis and body tolerances if you can get it within an 1/8" for ride height or suspension height you're doing ok.

Correct, the front has bump stops on the LCA's (shown in my picture) and on the frame for the UCA's as well. The LCA bump stops are the compression limiting stops, the bump stops for the UCA's are the extension limiting stops.

The distance you need between the frame and the bumpstop depends entirely on your spring rate/wheel rate. The larger the torsion bar, the higher the wheel rate, and the less suspension travel you need. For example, the factory .96" torsion bars are only 135 lb/in for their wheel rate. The 1.12" torsion bars I have in my car are 270 lb/in. Which means for the same load my suspension will travel 1/2 the distance. With a small block, power steering and no AC or aluminum parts I just barely get away with having 3/4" of clearance with the 1.12" bars.

The other thing is the factory bump stops are designed to be progressive. They have a tapered, triangular shape. What that means it a lot of people are riding on the bump stops a lot more than they think, because there isn't a big impact or shock when the factory bump stops come into play. I've talked to several people that swore up and down that their car never hit the bump stops, only to find out their car was literally sitting on the bumpstops all the time. If you aren't sure, you can put a small dab of grease on the top of the bumpstop and go for a drive. If there's a dab of grease on the frame when you come back, you hit the stops. And if you hit the stops on a drive around the block, you probably need more clearance.

[kawahonda]

Thanks for the information. Yep, my measurements pretty much reflect the bump-stop distances as well. They're darn close and should be lifted a little!

I will increase them today for .50" lift for the time being, maybe even .60" Like 1 Wild Says, give slightly bigger clearance to the drivers side.

[HP2]

A must always be greater than B (FSM).
Manual calls limit at .125 DIFFERENCE BETWEEN BOTH SIDES

A = Torsion blade
B = Knuckle

BEFORE ALIGNMENT:

Passenger side:
   A: 9.33"
   B: 8.9"
   = .43" Height
   
   Fender well measurement: 24.68"

Driver's side:
   A: 9.25"
   B: 8.9"
   = .35" Height

   Fender well measurement: 24.25"

   .08" left/right difference

AFTER ALIGNMENT:

Passenger side:
   A: 9.09"
   B: 8.89"
   = .20" Height

   Fender well measurement: 24.81"

Driver's side:
   A: 9.01"
   B: 8.85"
   = .16" Height
   
   Fender well measurement: 24.68"

   .04" left/right difference

The manual says the difference between A and B is supposed to be 1.125" +/-.125. There is not supposed to only be a .125 difference between the two. So your measurements, while being where they produce the appearance you want, are severely lowered from factory spec.

My car actual sits with zero difference between the two  points.

Fender well measurement were never used because of loose factory body tolerances and difference in tire heights.

[kawahonda]

I'm at .70 (driver) and .62 (passenger) after some quick adjustment last night. Seems right to me.