[PONTIAC DUDE]

Has anyone run Caltrac's on the street for street racing & the adjustability difference from street to track conditions. Are they that adjustable? My Southside bars are too stiff for high HP street racing & pulls hard in one direction cause I can't load the tire hard enough on the street, but set well on the track. I have to set the bars for the hook & am looking for a more broader traction devise that is quicker to tune for both conditions. I want my cake & eat it to. Later.

[PONTIAC DUDE]

Has anyone run Caltrac's on the street for street racing & the adjustability difference from street to track conditions. Are they that adjustable? My Southside bars are too stiff for high HP street racing & pulls hard in one direction cause I can't load the tire hard enough on the street, but set well on the track. I have to set the bars for the hook & am looking for a more broader traction devise that is quicker to tune for both conditions. I want my cake & eat it to. Later.

[David Holmberg]

PD, Cecil has them on his 69 T/A.

[Steve C.]

PD, My T/A has them....They work ok on the street... however my car sees very limited street use and it is primarly set up for the track. Check out the Jan. '00 issue of Car Craft magazine, there is a piece about installing them on a '68 Firebird. Yes, there adjustable and will help your situation. Also, Comp Eng has a new product out that is very similar.
SC

[This message has been edited by Steve Coombes (edited 01-03-2000).]

[Vascar]

Steve, Do you mean the cal-tracs arn't good for the street? Do they bind? What are the characteristics of them? I'm interested in getting a set.

[Doug]

These units can be adjusted off to where they don't do anything on a street setup. Your suspension will travel normal. If they are not adjusted all the way off they will start working and, when your suspension travels up and down much they become a solid link (bind). This would also happen when you you accelerate hard and the springs wrap up. If you were running weak leafs with the adjustment backed off you would run the risk of changing your pinion angle (driveshaft alignment )under hard acceleration and you could damage u-joints, push yokes into transmission,etc. When the Caltracs do their thing the suspension in effect becomes solid link.

Awhile ago I read an article on a 68 Mustang wheelstander super stock that uses them. He preloads each side differently for traction tuning. I think I saw an article on these units in the Mopar Performance magazine a year or so ago.

I've talked to guys at the drag strip about them. They like them because they can preload each side differently. They said snubber-block type traction bars didn't give the precise adjustment like Caltracs.

I looked into the basic geometry of the Caltrac setup. The axle end "pivot point" of the unit is several inches or so below axle centerline and the front link lower bolt hole is usually less inches from the spring hanger hole. As a result when the axle assembly rotates (wraps up) on hard acceleration, the travel distance of the Caltrac front bracket is "magnified"( An inch of travel at the front bracket equates to far less travel at the axle,) As far as binding up, a little travel in the rear amounts to a quick lockup at the front. This action is further enhanced by "shortening" of the front half of the spring leak when it wraps up on heavy acceleration.

I diagrammed all this out in full size scale drawings for a 1957 Pontiac leaf spring type setup. You would be surprised to see how little travel distances in the rear axle housing( up and down or rotating) affects things like driveshaft alignment, pinion angle, etc. I'm making myself a setup similar to the Caltracs for installation of the 57 rear end under a big block 63 Lemans.

[Vascar]

Cal tracs sounds like what I want. I'm going to get a set and give them a try.

[Steve C.]

At this site there is additional information about Cal-Tracs used on the street: www.jersey.net/~firebird68/birdpage.htm
(Classic Firebird Page)
Although not necessary, a heaver rated spring is recommended inconjunction with its use. Landrum Spring Company has done alot of R&D work with John Calvert, consider giving them a call to discuss your needs. Some consideration might be made for a street type car in reguards to the stiff ride caused by heaver springs. You see alot of super stock guys using them and they seem to work well for heaver type cars. The only difficulity in the installation is putting in the solid bushing thats required in the spring eyelet.

[Ron]

I own a set of Cal Tracs for my '72 Firebird. I have not installed them yet. Before I bought them I checked with a number of NHRA Stock racers. With one exception they all said it did not make them any faster, but it did make them very consistant.

Good Luck,

Ron
pontiacdragdays.com

[Brian Baker]

Doug,
The '68 S/S Mustang you mentioned is in fact owned and raced by John Calvert himself. He invented these Cal-Trac bars to use on his super stocker and in essence, the Mustang was the "mule" for testing them. When I ordered mine, they asked if it was a street/strip car or strip only. I was told the reason they ask is the street/strip model has the ability to adjust them "back" so as not to cause any binding under normal highway driving. Apparently, their strip only models don't have this much flexibility. They have a fulcrum at the front spring eye mount that causes a bolt to "slap" the top of the spring under hard acceleration. What you do is adjust them so that this bolt touches the top of the spring while the car is at rest and on level ground. You then "baseline" them by preloading the bolt against the spring with a 1/2 turn of the lower bars. This is for strip driving only, you obviously can't run them like this all the time on the street. When adjusted properly, they work similar to a 4-link (with the Cal-Trac bars being the lower links and the springs being the upper).

[Vascar]

My cal tracs came in the mail and now I need some help putting them in. They look great. I'll be out there having some fun this year.

[Steve C.]

Vascar. Let us know how they work in your application.