Many use the CalTrac traction bars & I'm using the Smith Racecraft bars. Anyway, has anyone made bar position/angle changes with their bars & what was the results?

I've had the below bars on for 10+ years. The only changes made since the original set-up, all delt with pre-load. The car has been hitting the tire pretty hard at the launch. I finally decided to change the bar position/angle after doing some research. I left the rear bar position the same & moved the front position down 2 holes. They were initially set-up in the upper most hole. I'm hoping to calm the hit down a little.

I have the same bars on my Truck. I started with the bar completly level. with me in the truck an all fluids filled up. Set up with a nickel gap on driverside and passengerside no gap or preload. Seems to work for me. I don't make anywhere the HP you do.

I think the bars level with driver installed, is what you want to start at.

I've been using CalTracs for 25 years, always in the upper front hole.

I notice that at least 80% of the CalTrac cars out there are using the bottom hole, but I've never felt a need to change the setup. I wonder if it may be that the Stockers are footbraking, where I am using a transbrake so the bar can still 'do it's thing' with less leverage on the pivot.

I set the driver's side bar with no gap or preload, and put a flat or two of preload in the passenger bar.

Install instruction

Install bar & adjust rocker with the drivers weight in the car so it makes contact with spring eye & lock jam nuts.
 For a basic starting point, set the bar in the bottom hole front and back.
 Basic tuning, for softer hit move the bar down a hole, for harder hit move the bar up a hole.
 Bar Angle, generally the more ideal adjustment would be to angle the bar higher in the back than the front, this
will keep the tire planted to the ground longer, angling the bar higher in the front will result in initially hitting
the tire hard but usually will result with the tire not staying planted to the ground.

quote:

Originally posted by 1leg:
Install instruction

Install bar & adjust rocker with the drivers weight in the car so it makes contact with spring eye & lock jam nuts.
 For a basic starting point, set the bar in the bottom hole front and back.
 Basic tuning, for softer hit move the bar down a hole, for harder hit move the bar up a hole.
 Bar Angle, generally the more ideal adjustment would be to angle the bar higher in the back than the front, this
will keep the tire planted to the ground longer, angling the bar higher in the front will result in initially hitting
the tire hard but usually will result with the tire not staying planted to the ground.

Thanks Jerry!

I found some of that in my research. My bars have been pretty close to level since installing them. The front might have been slightly higher, I never measured the angle.

I moved the front bar down to lessen the hit & keep the tire planted longer. The change does have the bar higher in the aft, but I need to measure.

Lenny,

I'm leaving off the transbrake also & fighting wheelies. Right now, I got it crutched with a launch retard. I would like to calm it down with more suspension work. Then hopefully add timing back in at the launch.

2BKING

TTT, to remind me to update!

2BKING

I think if you lower the front of the bar it will try to pick up front wheels MORE.

Lowering the front of the bar 2 holes took a bunch of hit out of the launch. The 60' went from low 1.30s to high 1.30s. While the results were not all bar related; we had record breaking heat & the DA was 2,000'+ higher than when we ran the low 1.30s.

As for the wheelies, they were very small. It would pick them up about 12" for about 20'.

I'm going to run it this way for a while. I only have 9 runs on the bar change & the 60's appear to have tightened up on the variance.

2BKING

quote:

Originally posted by B KING:
Lowering the front of the bar 2 holes took a bunch of hit out of the launch. The 60' went from low 1.30s to high 1.30s. While the results were not all bar related; we had record breaking heat & the DA was 2,000'+ higher than when we ran the low 1.30s.

As for the wheelies, they were very small. It would pick them up about 12" for about 20'.

I'm going to run it this way for a while. I only have 9 runs on the bar change & the 60's appear to have tightened up on the variance.

2BKING

Thank you for the update

I would like to know how it works, it seems to me that lowering the front of the bar would make it wheelie more. Seems simple enough if it is set up right and works.

Curly,

I'm only following the instructions to take away/soften the hit to the tire. It's the same for the Cal-Tracs, but they don't have the adjustment(s) as I have with my system.

This is the 1st time I've adjusted the bar position. It has always been as set up in the OP. The rear position in the middle & the front in the top position. With different shock settings, front-end travel & a launch retard. The car went 1.28 60's tripping with the back tires. The wheelies were just plain stupid how it was set-up. While we did get it calmed somewhat with tuning.

Moving the front of the bar down 2 holes was the best thing I could have done to calm the wheelies!

2BKING

^^^^^^^^ You have Holley ecu and if you have DA/ input channels available, a shock travel sensor on the RR could offer much in evaluating suspension changes.

M&M,

My Sniper ECU is not as robust as the bigger brother Holley ECU's. As far as I know I have no provisions to monitor shock sensors. I'm not so sure I would use it if I had it.

I'm an old school tuner trying to learn some new tricks with a basic TBI. It has been an eye opener with what I can do with this basic system. I'm pretty sure I would be overwhelmed with a full-fledged Holley ECU.

I appreciate you always trying to help us/me out with the EFI tuning!

2BKING