truck arm suspension

[revolutionary]

I'm considering a truck arm / panhard / coil spring setup for my car - 4th gen firebird.  Anyone have good/bad experience with these in lsr?  Suggestions?

[hitz]

Revolutionary,

  What's a truck arm ?

  Harvey

[doug odom]

I use a modified nascar truck arm under our Corvette. I had a floater housing from a cup car and it fit perfect so why not use it. I use air bags instead of coil springs to remove the vibrations and give a smooth  ride. I only want about 3/8" travel so I set ride height with shims under the air bags. I monitor the pressure in the bags to see how much down force I have.

[Jerry O]

I think the truck arms will work just fine. Just  pay close attention to the placement of the panhard bar. Placing the bar in the wrong position can give you a undesirable roll center height and off set. You will also want to make the panhard bar as long as possible. You want to minimize the lateral movement in the chassis when the car goes through compression and rebound movement. A short bar will make it near impossible to control the movement.  I would draw everything out or mock it up in you car and run it through the motions just to make sure you have it right. JMO

[SPARKY]

doesnt your gen 4 already have a panhard bar that reaches completely across the car?

[interested bystander]

Just saw this topic and being in a sarcastic mood  thought I'd add -You don't know what a truck am is ?-it gets millionaire NASCAR drivers hooked up at race tracks all over.

Or helps your (maybe not current- haven't looked under one lately) GMC or Chevy pickup down to Home Depot and back.

[Dynoroom]

I think the truck arms will work just fine. Just  pay close attention to the placement of the panhard bar. Placing the bar in the wrong position can give you a undesirable roll center height and off set. You will also want to make the panhard bar as long as possible. You want to minimize the lateral movement in the chassis when the car goes through compression and rebound movement. A short bar will make it near impossible to control the movement.  I would draw everything out or mock it up in you car and run it through the motions just to make sure you have it right. JMO

Jerry. If you have a panhard rod thats say 24" long. but only have 2 or 3" of suspension travel what does that mean to you?

[7800ebs]

Mike,

   If your panard is parallel to the ground... and 24" long.... and moves up OR down 1", it will try to move the rearend "sideways" ... .020"    if it moves 1 1/2" it will be moving .050" sideways ... If you go to a 48" long bar.. it will cut that sideways movement if in half..  Any of this can cause a theoretical bind ..... So Just Mount with rubber rod ends... 
       The center point between the two ends will be where the car rolls..  Cars that turn Left and Right .. normally would have that close to center ..   Our dirt car that turns Left.. currently has the roll center shifted left ... Also.. the higher you mount the panard bar .. the higher your roll center will be ... so the less roll at the rear of the car.. since your are not trying to corner... that is good as the outside tire will have less load on it when you get sideways and spin .. so it will not flip..   although a case could be made for a real low roll center... loading the outside tire quickly so as to not spin.. but that would require soft springs and driving it could get out of hand .. quickly...  but may be not.. I would be afraid of an oscillation starting..

   Bonneville speed secret....  Tape Egg to throttle pedal...   squeeze... slowly with foot.. if it breaks .. clean up mess on floor and in seat..

bob

[Racerboy]

This all sounds to much like a left turn supermodified tuning secret LOL
How are the Daltons doing with their car

Will you be on the salt this year?

Ken Pike

[Sumner]

.........The center point between the two ends will be where the car rolls..  Cars that turn Left and Right .. normally would have that close to center ..   Our dirt car that turns Left.. currently has the roll center shifted left ... Also.. the higher you mount the panard bar .. the higher your roll center will be ... so the less roll at the rear of the car.. since your are not trying to corner... that is good as the outside tire will have less load on it when you get sideways and spin .. so it will not flip..   although a case could be made for a real low roll center... loading the outside tire quickly so as to not spin.. but that would require soft springs and driving it could get out of hand .. quickly...  but may be not.. I would be afraid of an oscillation starting.........

That is the best I've heard all of that explained.  Now I have a little better idea of what is going on when they raise and lower the track bar during Kent's skittle races  .

Thanks,

Sum

[7800ebs]

Ken,

  Money is super tight... although we have all the parts to go fast.... the super engine would be fun... time is hard to justify right now... there is a time to play and a time to work...    Biblical you know..    Manufacturing in America is difficult right now..   

check out this pic from concord, nc    look at the spill plates.. on the wing.  think we have some load?

we have a new website also ...   www.quickturnparts.com


bob

[Dynoroom]

Wow! do you think that quick change will fit in a 'liner?      

[7800ebs]

Yeah..... Soon as I cut my car in half..... install rear... build frame section AROUND it....... lol  ....that is why it is on the jig....

where the hell did I leave my cutting torch ...lol

bob

[Racerboy]

Bob that QC looks cool you should market them. I have to get a QC and mount it for my car and then it is off to have the sheet metal done. I hope to have it done for next year. I am starting with a c fuel (my 360 from the super). It had 750 HP on the dyno when I had it freshened and changed the cam. Let me know if you need anything. I still have my parts business Specialty Cars. Good luck with the super this year.
KP