Push Bar Question

[DKrause615]

This year we plan to push off the start line.

I know this seems simple, but I am looking to draw upon other peoples experience, (both good and bad) when building one.

Some ideas I have are:  It should double as a mount for the parachute.
                                 It could be used to hold ballast and aid traction.
                                 Could it be designed to improve air flow?
                                 What is a good length??
                                 

[Bville701]

Your ideas that you have are good. On our car we have our push bar as the mount for our parachute and it also is able to hold ballast. As far as using a push bar to improve air flow, I believe that is illegal in most classes according to the rules. What kind of car are you building again?

[DKrause615]

It's a 2000 mustang.  We run C/FALT.

[Dr Goggles]

This year we plan to push off the start line.

I know this seems simple, but I am looking to draw upon other peoples experience, (both good and bad) when building one.

Some ideas I have are:  It should double as a mount for the parachute.
                                 It could be used to hold ballast and aid traction.
                                 Could it be designed to improve air flow?
                                 What is a good length??
                                  

Adding ballast behind the rear axle will unload the front of the car , it'll add to your available thrust but it will move the CoG rearward thus increasing your cars wish to make a waiters entry*


*Going through the back door azz first.....

[55chevr]

Check out the Cajun Kid's Stude ... photos are on here ... his works ...

[fastman614]

We have ALWAYS pushed our cars off the line.....it saves on clutches and spinning rear tires- BIG TIME!
Mounting ballast way back there may not be a good idea.... Don't try to use it to streamline..... I and a lot of others will protest you..... and yes..... you can tether your 'chute to it and/or mount your pack to it .... pretty much any way you want.

As far as design ideas.... about 12 to 16 inches (300 to 400mm) behind your car.... We use a straight, heavy wall tube that is mounted into a 3 point (pyramidic shaped) support from the rear crossmember to the frame rails- with a wheel mounted in a "forkshaped" pair of plates. The push plate on the truck is 12" X 36" and rides against the wheel. That way, as the racecar/push car each steers independant of each other and will waver sideways when in contact, the wheel allows the two vehicles to "float" without one or the other transferring steering forces to the opposite vehicle.

[DKrause615]

OK, Thanks for the help.  I have modified my transmission for a push start.  Now being a lazy engineer I am lookinf for any one willing to send a photo of their push bar, preferably incorporating a parachute mount.

[Joe Timney]

Hope this helps,
joe

[Bootleggerjim]

Here's mine

[Joe Timney]

Another angle

[SPARKY]

While at it practice aligning it at home. More and more teams are putting some kind of "sight" for the push truck driver.
Can be as simple as a plastic spoon taped to the hood to a permanent mark on windshield or hood.  just something that lets the PT driver line up the centers from his normal driving position. Saves the embarrassment and damage of the bar slide off the side of the push plate and the pusher and the pushee getting Hung Up   BTDT 

[maguromic]

Saves the embarrassment and damage of the bar slide off the side of the push plate and the pusher and the pushee getting Hung Up   BTDT 

Like some have gone to, I prefer a push bumper instead to avoid this situation and be able to push from any angle.  Tony

[Bootleggerjim]

Hope this helps,
joe

That's a cool deal Joe !!!!!

[Joe Timney]

One other thing...parachutes need to be mounted at a 45 degree angle with the top of the bag near the top of the trunk or wing so the pop chute can catch the air flow. As the chief timer at Maxton, I see too many just come out and bounce and drag on the ground for a while before opening.

As a dealer for Stroud Chutes, I LOVE IT...looks like money to ME!!! LOL

[dw230]

2.I   PUSH BARS:
All cars incapable of starting under their own power shall be equipped with bumpers or push bars. Push bars shall not offer any aerodynamic advantage. No horizontal paneling is allowed between the rear of the body and the bumper/push bar. No towed starts are permitted from the starting line without special approval. All cars shall be equipped with a push bar or a readily available tow attachment.

Sentence 2 & 3 kinda say it all. Ballast behind the rear axle is not a good idea.

DW