Hotchkiss "TVS" system, or Calvert Cal Track?

[MxRacer855]

I'm trying to decide what to put on my '68 in the rear. Hotchkis' "TVS" system covers the entire car while Calvert's Cal Track is only a rear setup, but with that being said, I'm just working on the rear end now. I just want a car that handles really well under aggressive driving.

Does anyone have any experience with a Calvert Cal Track system?

Jeff

[Ghoste]

Cal-Tracs are more about drag racing.

[MxRacer855]

I saw an article in Mopar Muscle Magazine where they discussed them, and that's pretty much the impression that I got as well.

[Ghoste]

Which doesn't necessarily mean they would be detrimental to road handling in any way.  Like much of that it depends on what you really want.  We can improve these cars but they are never going to match a 911 on the skidpad.

[MxRacer855]

I hear that! According to Hotchkis... the "TVS" kit allows your old muscle car "to have that modern sports car handling". 
I'm just looking for a rigid, stiff handling setup. I'll sacrifice plushness and a smooth ride for a greater sense of feel and control. I have every intention of building my 440 to put out around 700hp, so I really just want suspension that will be able to handle that and keep the car upright coming around corners. I hate that feeling of it bottoming on the opposite side in a corner (if you make a right, the left side compresses).

Jeff

[WHITE AND RED 69]

I hear that! According to Hotchkis... the "TVS" kit allows your old muscle car "to have that modern sports car handling". 
I'm just looking for a rigid, stiff handling setup. I'll sacrifice plushness and a smooth ride for a greater sense of feel and control. I have every intention of building my 440 to put out around 700hp, so I really just want suspension that will be able to handle that and keep the car upright coming around corners. I hate that feeling of it bottoming on the opposite side in a corner (if you make a right, the left side compresses).

Jeff

Don't laugh too much. It may not be super car handling but it's a HUGE improvement over the stock setup. Just look at the hotchkis equipped cars, they keep up with the professional big money builds at all kinds of events with bolt on parts. 

What are you going for on your car? Lowered look? Stock? Drag? The hotchkis rear leaf springs will lower the car almost 2" so be ready for that if you decide to go that route. If you are looking for decent handling on the rear just get a great set of shocks like bilstein, a decent set of leaf springs, and an adjustable rear sway bar. With your car having 700 hp I'd check out firm feels quadra shock setup. I've never had any experience with it but firm feel makes great parts.

  http://www.firmfeel.com/QuadShock_b.htm

Or if you have the bucks ditch the leaf springs and go with a four link for the rear.   

[War wagon]

I run cal tracs on my car, while they do tighten the rear in normal street use IMHO they are mainly for getting that 700hp to hook with slicks at the strip.
Can make a significant difference in your 60ft time and that's where races are won or lost.
I don't think they would help much on a road course, they basically wind up the spring to prevent wheel hop and put pressure on the contact patch. That could get sketchy in a corner depending on diff choices.

[1970Moparmann]

I haven't bought any kit, just put together my own per say as money would allow.

The front I did new upper and lower control arms and a sway bar from Hotchkis - huge improvement.   In spring, I plan on adding the following to the rear

-http://www.hotchkis.net/rear_sway_bar_set_6670_bbody.html

I am also running the discountinued Edelbrock IAS shocks. 

It all depends on how radical you want to go......  Have you driven a 700 HP B body yet?   Mine is 550 and it's fun as hell.....

[MxRacer855]

Thanks for the advice guys! Exciting stuff!

1970Moparrman, I have NOT driven a "B" body with more than a stock 440 (what I've got)... but believe me, I AM PUMPED ABOUT IT!!!  Unfortunately, I've got to wait another year to get the money for that. I'm building everything in advance, then leaving that for last. I already ordered the Dana 60 rear end with 373's for my '68. I'm hoping to get the full Hotchkis "TVS" kit with sub-frame connectors, torque boxes, and maybe the Cal track system as well (since that provides an element that Hotchkis' "TVS" kit does Not). Rome wasn't built in a day... UNFORTUNATELY! Damn Romans set the bar for patience for the rest of us!!!!!

Jeff

[HPP]

The Cal-trac system was developed by  a Ford racer in an effort to duplicate the Mopar SS spring action for his Mustang used in stock class drag racing were mounting points alterions are severly limited. What has resulted is that is is still a leaf spring suspension system, but it allows some tuning range of instant centers in a manner that is easier than what can be done with stock leaf mounts. It also provides the opportunity of reducing weigh by using the split mono-leaf as compared to a multi-leaf set up.

Is this better or worse than the oem set up in a handling application, I'm not too sure. It certainly will provide a different loading curve to the tires which may help corner exit or may radically overload the tires at throttle application. I can't say which, as I've never done much analysis on it. With 700 hp, its safe to say you can overpower any suspension set up out there, whether it is a link, leaf, or coil. There will not be a magic bullet that will allow you to mash the throttle unabashadly.

[Calif240]

My entire rear end is Hotchkis and I'm very pleased. I've got the rear sway bar, heavy duty leaf springs and shackles. I've got big tires and a Dana and could tell a good difference when installing the new leaf springs and then when installing the Sway bar, could feel even more. Very happy with all of my Hotchkis parts. Car rolls less than most new cars. Also, Hotchkis matches their front and rear so if you're doing the rear, thinking you might do the front later or some portion of the front, you'll want to consider that.

Terry

[myk]

I hear that! According to Hotchkis... the "TVS" kit allows your old muscle car "to have that modern sports car handling". 
I'm just looking for a rigid, stiff handling setup. I'll sacrifice plushness and a smooth ride for a greater sense of feel and control. I have every intention of building my 440 to put out around 700hp, so I really just want suspension that will be able to handle that and keep the car upright coming around corners. I hate that feeling of it bottoming on the opposite side in a corner (if you make a right, the left side compresses).

Jeff

Don't laugh too much. It may not be super car handling but it's a HUGE improvement over the stock setup. Just look at the hotchkis equipped cars, they keep up with the professional big money builds at all kinds of events with bolt on parts. 

What are you going for on your car? Lowered look? Stock? Drag? The hotchkis rear leaf springs will lower the car almost 2" so be ready for that if you decide to go that route. If you are looking for decent handling on the rear just get a great set of shocks like bilstein, a decent set of leaf springs, and an adjustable rear sway bar. With your car having 700 hp I'd check out firm feels quadra shock setup. I've never had any experience with it but firm feel makes great parts.

  http://www.firmfeel.com/QuadShock_b.htm

What is considered to be a good leaf spring other than Hotchkis?  Also, I've always wanted to get a rear sway bar as well, but I've read conflicting reports both here and elsewhere stating that arbitrarily installing a rear bar without factoring in other suspension factors can actually make the car handle worse in some situations.  What's the deal with that?

[Ghoste]

Eaton and Espo both make excellent leaf springs.

[HPP]

The leaf springs, sway bars, and T-bars all work together to produce a "rate" that is applied to the wheels. These rates are not applied equally to all four wheels but must be in a percentage front to rear that is then a percentage of the weight front to rear. If you apply too much percentage to one end or the other, then you create an imbalance. The end with the greatest imbalance is the end that will loose grip first.  

So if  you have stock T-bars, a stock front sway bar and you put super stock springs with a sway bar on the back, you've created a gross percentage to the rear suspension and it will slide first and probably much more easily. The rebalance it will require either a step up in front rates to match, in percentage, to the rear rates, or you need to soften the rear rates (ie take off the sway bar).

So, with a classic mopar we have the situation where there are only a few t-bar and front sway bar rates available. By contrast a leaf spring pack can be built to almost any rate and this rate can be built to factor in the additional resistance of a rear sway bar. So simply slapping parts on and expecting refined improvements doesn't always happen, although sometimes guys get lucky with this. This is where the Cal-Trak can be an advantage because you can custom tune the leaf rate pretty easily. Alternatively, if you pick up the entire TVS system, it will be a matched set up that takes the guess work out of it for you. Plus their rear sway bars have adjustable points to fine tune the rate even further.

[Ghoste]

Like putting an 850 dp on your 318. 

[myk]

That TVS bundle is interesting, but I do have some questions.  First of all, what do the tubular control arms offer?  Something about affecting/correcting the stock suspension geometry?  Also, what's the improvement offered with their strut and steering rods?  What does Hotchkis mean with their "geometry" correcting leaf springs?  I understand buying the sway bars and possibly the leaf springs, but I don't understand the other stuff...

[HPP]

Tubular arms offer additional positive caster. OEM specs with manual steering and bias ply tires specified negative caster to make steering easy. Positive caster increases steering resistance because it also increase return to center characteristics and improves high speed stability. Many new cars have positive caster in the +5-10* range. On an old mopar, you might only get 2-4* of positive caster with the stock arms.

Hotchkis also modifies the anti-dive percentage built into the arms. The stock upper control arms are installed at a tilt to provide dive resistance under braking. This angle means that as the suspension moves through its motion, it creates increasingly obtuse angles that increase the angle the tread face is to the ground. The more you increase these angles, the less tire that touches the ground, the more grip is reduced. Reduce the tilt, you reduce the obtuse angles. This design is unique to Hotchkis.  There are varying opinions on the need for anti-dive and many track cars do not use it at all because they run such high spring rates, they don't need the geometric leverage. A street car can use some because they tend to run softer rates, but the trade off is compromised grip.

Strut rods that provide a more rigid front mount reduce the toe change experience under hard braking. Like the control arm scenario, this is a refinement to increase stability at the threshold of grip. If you only drive to cruise ins and parades, you may never notice the improvement. Additionally, the adjustability of many aftermarket strut rods allow you to dial in a bit more positive caster as well.

The steering rod change is to improve the bump steer. Stock mopars have awful bad bump steer. Ideally you want the tie rods to move in the same arc as the control arm to avoid unwanted toe changes as the suspension moves up and down. If the toe changes, it can significantly alter how stabile the car feels. Because the torsion bar is at the control arm pivot point, a mopar's tie rods cannot duplicate the same arc. However, you can put them in a similar range to minimize these changes. The Hotchkis steering rod change performs this update. As above, the ability to feel the difference depends on the levels you push the car to.

Geometry correction in the leaf springs is improvement in anti-squat and roll steer. As you turn into a corner, the outside spring flattens and move that tire towards the rear. Conversely, the inboard spring arcs up and pulls that tire forward. This introduces a steering action with the rear tires that can improve or decrease cornering ability. Taking the imaginary plane that the axle pivots on and changing the projected intersection of the spring eye, you can change these characteristics as well.