Designing road race truck chassis, could use help.....

[TC]

TC there is no reason to have the bar go all the way to the back of a non leaf spring frame. There is no weight to carry and the load would be unsupported for to long a distance. It looks much better, the "Back" bars should land on top of the spring/shock mount to help with the load from them. With limited supports I would use a cross bar comming down from the left top to the door X bar at the right top at the main hoop. I also would add a X in the top of the door bar to the rear rails at the hump for the axle.

You should cage the whole thing not just half of it........Caging to the rear of the car/truck will make the rear a lot more stable, right now there is nothing going to be there but lateral braces, what's going to prevent the frame from twisting under hard cornering..........

Also aren't there some rule books that he could be looking at..........No need to build a cage and then go to the track and them tell you you didn't do it right.........Size of tubing, thickness of tubing and tubing placement all are major factors and if the rules require tubes to be place a certain way or in a certain design, it's best to know before hand than have to redo it later.........

[TC]

I would take some ques from this pic......... This is a Nascar COT design..........

[JeffMcKC]

TC, we will see how this goes, "I dont See you"

[TC]

TC, we will see how this goes, "I dont See you"

Just my opinion Buddy, just my opinion........Take it as you will.......

[Deaf Bob]

Looks good to me... I like the light blue removeable one!
Jeff has it on the nail head! Go to the top of the spring mounts if coil sprung
On our derby cars we are not allowed to do that so we do it like the drawing shows but not attached to frame (a rule thing), then we run chain from the tops of the humps to the axle tubes... Same principle
The COT impractical for street driven cars... And they are made to be bumped and bump.. Apples/oranges...

[CDMBill]

I may well have missed it, but I didn't see any particular class or rules requirements so for a DD I'd look at ease of entry/exit and the ongoing ability to work in the vehicle over time. More bars equals more pain and suffering, good thing he's young. The removable door bars are a good idea IMHO. The big question is how it ties through the cab structure to the frame itself. I'd be tempted to follow either NHRA or SCCA/NSRA or SCTA/ECTA rules for roll bars/cages as what starts as a fun vehicle often morphs into something that has to pass a tech inpsection or get a certification.

[Deaf Bob]

CDMBill, 2 nd post, "auto cross, time trials". Doesn't seem to be a governing body... SCCA?


Looking at the COT. Frame, I see where the top of the humps are tied in... Prolly for your application, one to the middle MAY be sufficent? Like Bill says...rules/governing body build would be best...
We all have ideas... Bill is in drags (right?) I am in demolition derby... Need a road racer's imput...

[mike343sharpstick]

I'm restoring my old IMSA Gremlin and I have been doing some research, My plan is to run both vintage events, and some SCCA solo stuff.
The SCCA solo rules are more strict than the vintage rules, so I'm basically building my car to the SCCA solo rule book.
I would recomend you do the same, then you covered for just about anything you would want to do with it.

Remember the NASCAR stuff is built to run 200 mph next to brick walls, a bit much for most 'street/autoX cars. Still a good basis for reviewing the latest design in cages.

[Cyclone03]

PER Qadrabind: I can't speak of a "normal" panther chassie but the 03 Marauder had parralle bars and a watts link. IMHO except for overall width a pretty good set up for a fun driver/track car. Like the 4 valve MOD motor it carries, way to wide for all but a full size Ford,think 64 up Galaxy.

[OHC230]

So, as it stands; I have read through pages and pages of rule books that apply to roll cage construction for NASA, FIA and the SCCA and pored’ over hundreds of pages of banter concerning roll cage construction.

I can now say with some certainty, that no pure consensus exists, when it comes to chassis construction. There is a fine line between structures that absorb and those that do not absorb high impact loads and cases made for either side of building a highly rigid structure over one with ample crush zones...CONTINUED ON PAGE 4