X Pursuit 1987 Mustang Drag and LSR Project

[milner351]

This car is a masterpiece, it has got to be one of the stiffest most rigid foxes on the planet when you're done.

[Deaf Bob]

WHAT???

Learn sign language!

[BBR]

One of the last items on the list for the cage are the Upper Control Arm pick up point reinforcements. This is how they'll work. We are adding some reinforcement plates to the sides of the bracket to thicken up the wall size of the factory mount as well.

This is a fantastic idea and will probably eliminate the crack that usually develops on the top of the rear transmission tunnel. (like my car has!)

[CDMBill]

This car is a masterpiece, it has got to be one of the stiffest most rigid foxes on the planet when you're done.

Thanks John, I'm hoping it won't be one of the heaviest as we have added a lot tube. This is my platform for the next ten years for better or worse so I want a good solid, safe foundation. Not the cheapest or easiest way to do this but at least I will know every nut, bolt, weld and part on the car.

[Deaf Bob]

I love maximum builds. Don't worry about weight just yet.. I am pretty sure you can build a plenty stout motor!
We built one Imperial that weigh 6700# run ready.. Could really feel it behind the truck..
Don't LSR guys like weight?

[squirrel]

lsr likes weight, drag racing doesn't. So this car is a compromise. But that's ok.

[Deaf Bob]

In derby, weight is nice, but there is a line (fine?) where the weight breaks yourself instead of them, or burys you in the dirt..

[CDMBill]

More and more, the LSR guys are moving away from weight for weight's sake. This is highly course dependent form what I see. Standing mile, 1/2 mile even El Mirage are long drag races with highly variable traction conditions.

For 1/4 mile drag racing weight is the enemy. The only offset is that the rules for safety apply to everyone who runs below each ET threshold so that aspect is equalized. That siad if I never threaten the bottom 8's it's been a watse of time from a Drag Race perspective.

[DanStokes]

I think in LSR the role of weight varies with speed/class and venue. At Ohio my little truck doesn't have enough power to worry about high speed traction but I have PLENTY of room to get to the speed where I'm just driving to the end of the track. Vic (Krusty) says that their rear engined roadster has enough power that they need to worry about weight to do a balancing act between rate of acceleration and traction - he is NOT just driving to the end of the track. On the other hand, I know a guy who adds almost 1K lbs. at Bonneville to try to stick it to the salt, so it depends.

Of course, aero enters in there, too. My class (and other gas-based classes, production classes, and others) are not allowed anything non-stock to generate downforce at the back of the car (wings, for example) so ballast is required where aero might otherwise provide downforce at speed.

Like I said, it depends but so far in my case there's no disadvantage to more beef in the truck.

Dan

[squirrel]

My views of LSR are skewed...since I've only seen it done on salt. Weight helps there, but not so much on other surfaces.

[Deaf Bob]

As for Bill, heaven forbid it happens, he will fare better in this car than some half way car that goes to pieces when it end over ends or something.. I hope he never finds out just how strong his car really is!
I do know there is a different feel to the ground when a half welded frame hits it's wheels versus a fully welded one.. You can stand on one corner of ANY stock frame and jump up and down and see the flexing.. Not so for a re-welded frame.. Just rewelding stock welds make a hell of a difference!

[CDMBill]

Thank you Bob, I want keep it rubber side too. This has been a real learning experience for me on the chassis fab front, especially a lot of little picky rules that have to right in order to get the faster cage certifications. We are trying to be by the book while adding or supplementing some parts to make it stiffer, safer, perform better and be easier to work on al at the same time.

[CDMBill]

The best laid plans… The 18" Kirkey passenger seat doesn't quite fit now that the door bar, funny car cage and rocker bar are in place. So we're bending in the 'wings' a bit as they hold it 5" off the floor in the back and cutting a bit off the lower inside corner as that hits the floor pan.

[CDMBill]

My Photobucket account isn't cooperating so these pictures are coming in huge. Sorry.

One of the other interesting requirements is the seat bottom attachment, a minimum of four bolts and the location of the anchor for the crotch belt which is supposed to be inline with the chest! This is our seat mount bracket which will reinforce the seat pan area add an additional cross member and very positively locate the crotch strap. The passenger side mounts will be simpler with pit pins so it can be easily removed for easier access to the electronics under that dash and for last ditch weight reduction.

[CDMBill]

The funny car cage doesn't have a natural place for the should belts to attach as the relationship of the horizontal bars and the verticals, a sort of 'tic-tac-toe' lattice would place the belts a little too high and either too far apart or almost on top of each other in the middle so we have added this small tube to locate the belts correctly in terms of the height behind my shoulders and the width necessary to line up with the HANS device I'll be wearing this year when racing. The first picture shows the small bar and the second how it sits just behind the seat and inside the seat's upper helmet containment supports. The belt width is 2" as that is what the HANS device uses and the experts are now saying that the waist belts shouls also be 2" because the 3" wide will fold over on themselves more in a high impact station providing less load spreading benefit than the 2" which runs against the conventional wisdom.