Has anyone made their own Caltracs?

ron67fb · Sep 25, 2009

The down side to TMs and under-riders is while they can prevent axle wrap-up under acceleration, the rigid connection means they will also bind the suspension under hard braking. Caltracs work like a de-coupled torque arm and are basically disengaged under braking.

I don't see how the Caltrac prevents rearward movement of the rod, though, the bracket rests on top of the spring, which would allow the spring to wrap when braking.

That's correct, however limiting axle rotation to zero is not a correct way to control axle wrap-up under braking. That's usually done with staggered shocks, horizontal shocks (e.g. Fox quad shocks), or torque-arm dampers such as:

or:

http://www.cobraautomotive.com/

Neither Caltrac-style and welded under-riders are optimal for braking anyway as they're drag-oriented pieces. Caltrac just makes it more tolerable for dual-purpose cars since they're near invisible when not needed.

2+2GT · Sep 26, 2009

ron67fb said:
Neither Caltrac-style and welded under-riders are optimal for braking anyway as they're drag-oriented pieces. Caltrac just makes it more tolerable for dual-purpose cars since they're near invisible when not needed.

You make a compelling case. Certainly much better than "CTs are better". I wanted to see someone explain why. You have. Now people can look at the function of each and judge whether the difference is useful for their own situation. After all, this is a technical forum, and discussions should be, well, technical.

BTW, I like the idea of the CobraAutomotive "torque absorbers", I suspect they would work more smoothly, with less clunking, than the Caltracs.

65ShelbyClone · Sep 26, 2009

ron67fb said:
however limiting axle rotation to zero is not a correct way to control axle wrap-up under braking. That's usually done with staggered shocks, horizontal shocks (e.g. Fox quad shocks), or torque-arm dampers....

A fun fact I thought I would mention is that early Fox3s, or at least SVOs built before Dec 1983(like mine), had "slapper" traction bars under the rear LCAs instead of quads.

IMO, they work better too.

10secgoal · Sep 26, 2009

Anyone show me how to adjust the instant center on a set of under riders ?

stonecoldtx · Sep 27, 2009

I am switching over to an 8.8 out of a '94 Mustang, and adding new springs.

I started researching the best traction control devices out there, and came up with two--Cal-Trac's and Slide-A-Links.

I considered the Traction Masters until someone told me they blew out the bushings after taking it to the track and making one run with their high HP stroker engine.

That was enough to eliminate Traction Masters from my choices . . .

While Traction Masters might work just fine on a 289HP that might be pushing 400HP at the flywheel in the upper RPM ranges, I would imagine that on a 351-based stroker that produces lots more torque throughout the entire RPM range, something like the Cal-Trac's or Slide-A-Links appear to be a better choice.

Also, lots of folks were indicating a good set of slapper bars are good enough for 10's on some cars, if they're set up right . . .

Just my two cent's worth . . .

10secgoal · Sep 28, 2009

ron67fb said:
Neither Caltrac-style and welded under-riders are optimal for braking anyway as they're drag-oriented pieces. Caltrac just makes it more tolerable for dual-purpose cars since they're near invisible when not needed.

Missed this part in your post. I had thought about put in another bar across the bottom side of the leaf on the caltracs to to help with any problems,....but haven't had anyone with brake hop problems using these bars yet. But heaver hitters on the road race don't generally lean that way anyways.

10secgoal said:
Anyone show me how to adjust the instant center on a set of under riders ?

Anyone figure this out ?

ron67fb · Sep 28, 2009

10secgoal said:
Anyone show me how to adjust the instant center on a set of under riders ?

There is no adjustment as it's all welded. Their length and position is specific to move with the axle's swing as defined by the leafs. If you go into adjustments as to the height of the front and/or rear pivots you might run into binding problems or severe stress on the leafs and mounting points since the arcs of the under riders would be different from the leafs'.

Wicked65 · Sep 28, 2009

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Example 2- If you know what tires those are, you know why it matters to show this pic-

Discussion over~

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10secgoal · Sep 28, 2009

ron67fb said:
There is no adjustment as it's all welded. Their length and position is specific to move with the axle's swing as defined by the leafs. If you go into adjustments as to the height of the front and/or rear pivots you might run into binding problems or severe stress on the leafs and mounting points since the arcs of the under riders would be different from the leafs'.

Yeah I know, sorry lol. Was a rhetorical even though I asked again. Was making point.

rebel65 · Sep 28, 2009

blown65 said:
Those traction master bars are nothing to compare to caltracs. No offense.

As for making them, if you have the time go for it. I sure don't for the 150 bucks you will save at best.

Funny how ppl feel fine stealing someone elses design, yet there is someone on here that made his brake handle and that's somehow different.

traction masters aren't a copy of caltracs, and if that isn't what you meant, i don't think the OP is going to start marketing his own Caltracs... so what does that have to do with a e-brake handle. which i agree makes no sense to whine about.

66Runt · Sep 28, 2009

The reduction in brake-hop is a function of the solid front bushings. It is effective.
Most road-racers do not like solid bushings, as spring twist is is affected by too many variables to remain constant, and is in effect a type of "bind".

2+2GT · Sep 29, 2009

rebel65 said:
traction masters aren't a copy of Caltracs…

That's for sure, the Traction Master dates back to the 50's. BTW, that price is equivalent to over $300 today, so the price has actually gone down by more than half.

ron67fb · Sep 29, 2009

Nice ad.

Nobody said TMs are copies of Caltracs. The comment was referring to someone making their own Caltracs from online plans. He got his answers but, well, you know how this place goes.

rebel65 · Sep 29, 2009

rebel65 said:
and if that isn't what you meant, i don't think the OP is going to start marketing his own Caltracs... so what does that have to do with a e-brake handle. which i agree makes no sense to whine about.

hence the reason i put ^

2+2GT · Sep 29, 2009

10secgoal said:
Anyone show me how to adjust the instant center on a set of under riders ?

Yeah I know, sorry lol. Was a rhetorical even though I asked again. Was making point.

Actually, it IS adjustable. You mount the bar, put full normal weight on the axle to adjust the exact position of the Traction Master, and weld the front bracket on. That IS the adjustment. After that, no adjustment is required. I would prefer that to something I had to constantly screw around with to get it right.

Wicked65 · Sep 29, 2009

2+2GT said:
Actually, it IS adjustable. You mount the bar, put full normal weight on the axle to adjust the exact position of the Traction Master, and weld the front bracket on. That IS the adjustment. After that, no adjustment is required. I would prefer that to something I had to constantly screw around with to get it right.

So you setup your car. weld this thing on.. then you change something completly on your car, and have no adjustment without cutting parts off your car?? and your worried about adjustable suspension?? Its not like cal-tracs are rocket science? Well, for some people... Its leaf spring not four link for god sake

2+2GT · Sep 29, 2009

wickedcobra96 said:
So you setup your car. weld this thing on.. then you change something completly on your car, and have no adjustment without cutting parts off your car?? and your worried about adjustable suspension?? Its not like cal-tracs are rocket science? Well, for some people... Its leaf spring not four link for god sake

Change "something"? like what, the wheelbase? Because that's the only thing that would effect the Traction Master setup. Other than changing the length of the leaf spring between the eye and axle there no change that would effect the Traction Master. When you change the engine or transmission on a Fox-body Mustang, do you change the length of the lower suspension arm?

10secgoal · Sep 29, 2009

2+2GT said:
Actually, it IS adjustable. You mount the bar, put full normal weight on the axle to adjust the exact position of the Traction Master, and weld the front bracket on. That IS the adjustment. After that, no adjustment is required. I would prefer that to something I had to constantly screw around with to get it right.

Than you prefer an inferior product, and that's ok, but they are far from equal.More adjustment would be required, but I think you mean you can't adjust it. The way you describe the "adjustment", is standard install. There is no adjustment in these. You don't have to constantly change anything in Caltracs. You mess with it until you find what the car likes, because each is different. You can't do that with under riders. You can't change preload, you can't change the instant center ( BIG deal with cars the vary in ride height), and the the end are rubber. So there is deflection, AND binding. Jut because you may not notice it, it's there. You have made a 4 link without rod ends. It's a bing fest. The caltracs on the suspensions limited travel invisible as far as binding goes...unless preload is installed.

If you change the engine and transmission on a fox, and the power is different, yes, you would make a change. You would change the instant center, seeing as that is a different requirement for each car, and power level. This is were wheel hop and traction are different.

I personally don't think they are even safe. The thick brackets that are welded to the frame are severely stressed when they are bent at 90% always leaving a crease. And it a tiny area welded to the frame, begging to be torn away every hit.I just removed a set about 3 month ago where a small tap of the hammer was all it took to break the bracket with at the bend. When the car was up in the air we saw it cracked almost all the way through, so that's why we removed it. Could you imagine it the car was at speed and it broke ? Catapult ?

Wicked65 · Sep 29, 2009

2+2GT said:
Change "something"? like what, the wheelbase? Because that's the only thing that would effect the Traction Master setup. Other than changing the length of the leaf spring between the eye and axle there no change that would effect the Traction Master. When you change the engine or transmission on a Fox-body Mustang, do you change the length of the lower suspension arm?

www.baselinesuspensions.com

Might want to read the drag racing portion. Not leaf spring, but might help you understand suspesion better.

Argue about it all you want. The atari was the greatest thing on the planet, in 1980.

Just because you dont like the facts doesnt make it wrong.

2+2GT · Sep 29, 2009

10secgoal said:
Than you prefer an inferior product, and that's ok, but they are far from equal.

I personally don't think they are even safe. The thick brackets that are welded to the frame are severely stressed when they are bent at 90% always leaving a crease. And it a tiny area welded to the frame, begging to be torn away every hit.

You are more fun than a barrel of monkeys.

I have over 200,000 miles on a set of Traction Masters, which by the way have urethane, not rubber bushings, as you claim. No cracks. No binding. No changes in height, since it's not a hopper. Zero problems of any kind. The only TM bracket I ever saw fail was a high school kid who drove over a curb. Fast. Even your Caltracs would probably fail that test.

Mind you, I have nothing against Caltracs, might even use them some time. But Caltracs are great and everything else is crap sounds a bit sophomoric.

Has anyone made their own Caltracs?

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