Top fuel chassis failure

[e36jon]

I believe they also time the chassis out, or at least the front half. I've heard several crew chiefs say we 'front halved' the chassis after X number of runs.

- Found a quote here http://www.competitionplus.com/featured ... he-chassis: "Like the Funny Car teams, most Dragster teams will go about 60 to 80 runs and put a new front half on when it’s convenient to get to the chassis shop to keep the car fresh. Like the Funny Car, the Dragster takes a real beating in the shut down. The Dragster probably gets more abused than the Funny Car. It used to be common to have to fix an upright near the fuel tank in the front of the chassis after running at a rough track or a wheel stand."

I've also seen the teams welding chassis cracks at the track.

All this to say, like so many other parts of these cars, the chassis is pushed to the max.

I looked around online and found some interesting info.

- From https://www.thefabricator.com/tubepipej ... at-330-mph: The mediator in this debate is the chassis, and it’s made from lengths of 0.049-, 0.058-, and 0.095-in.-thick tubing.

- From http://www.bmeltd.com/Dragster/tubulartales.htm: Good read on tubing issues in the past related to heat treat variation...

[strad]

the NHRA sets the standards.
Which by the way is the F.I.A. I believe.

[J.A.W.]

the NHRA sets the standards.
Which by the way is the F.I.A. I believe.

NHRA/FIA?

On what basis do you believe that, Strad?

NHRA touts itself as 'World's largest auto racing organisation',
on its own site, but makes zero acknowledgement of FIM...

On the matter of flexi-tube space-frame horrors, I recall reading Frank Gardner's
memoir where he recalls testing the fast new,(with potent 12cyl engine) Porsche 917,
its flimsy space-frame design (inherited from its lesser brethren) being over-stressed
by the speed & power forces thereby induced, & duly folding up, catastrophically.

Frank insisted the German engineers sealed & inert gas-filled the space-frame
tubing complex, with a pressure gauge on view, so as to enable a stop to testing
immediately that a crack developed, as pressure/integrity was seen to be lost.

When the Porsche people demurred, ol' Frank, typically being fully frank, told them:
"Ok then, you get in, & bloody well drive the bastard!", following which, they did as asked...

[strad]

JAW on the site where I just checked they only list European drag racing. So I guess I am wrong. However in the past I have read where the FIA oversees the NHRA and even has their fingers in NASCAR.
I for one thank goodness that they don't.

[Tommy Cookers]

.... http://www.competitionplus.com/featured ... he-chassis:
.... the teams welding chassis cracks at the track.
- From https://www.thefabricator.com/tubepipej ... at-330-mph: The mediator in this debate is the chassis, and it’s made from lengths of 0.049-, 0.058-, and 0.095-in.-thick tubing.
- From http://www.bmeltd.com/Dragster/tubulartales.htm: Good read on tubing issues in the past related to heat treat variation...

interesting stuff .....

we saw on live TV from the 1960 French GP Colin Chapman lavishly accosting the starter so impeding/delaying the start
while the Lotus mechanics finished emergency welding of their car (Ireland's ?) - on the grid
OB TV footage wasn't recorded in those days - this was in eg Crombac's writing's (before Lotus used lawyers so much)
Lotus used (thinner) Reynolds 531 tubing on the works cars and (thicker) cheaper tubing on customer cars
531 famously isn't 'weldable' ('weldable' means only that there is no loss of strength when welded)
at the Belgian GP Taylor etc crashed due to weld failure ? - and he obtained compensation after litigation

iirc 4130 spec ignores weldability - as many aircraft 'space' frames weren't welded (doesn't mean a 4130 welds badly)

actual stronger tubing doesn't make a stronger spaceframe - though it might make it more durable
and Lotus-style choosing stronger material grade to allow thinner tubing reduces weight but also reduces stiffness

the spaceframe is (weight-for-weight) the strongest and stiffest structure - if space is available
(eg human-powered aircraft are this type of structure - in cfc not metal)

the so-called monocoque is superior eg stiffer where space is limited ie where the structure must be relatively dense

[nzjrs]

I believe they also time the chassis out, or at least the front half. I've heard several crew chiefs say we 'front halved' the chassis after X number of runs.

- Found a quote here http://www.competitionplus.com/featured ... he-chassis: "Like the Funny Car teams, most Dragster teams will go about 60 to 80 runs and put a new front half on when it’s convenient to get to the chassis shop to keep the car fresh. Like the Funny Car, the Dragster takes a real beating in the shut down. The Dragster probably gets more abused than the Funny Car. It used to be common to have to fix an upright near the fuel tank in the front of the chassis after running at a rough track or a wheel stand."

I've also seen the teams welding chassis cracks at the track.

All this to say, like so many other parts of these cars, the chassis is pushed to the max.

I looked around online and found some interesting info.

- From https://www.thefabricator.com/tubepipej ... at-330-mph: The mediator in this debate is the chassis, and it’s made from lengths of 0.049-, 0.058-, and 0.095-in.-thick tubing.

- From http://www.bmeltd.com/Dragster/tubulartales.htm: Good read on tubing issues in the past related to heat treat variation...

Amazing links and information here. Thanks a lot!

[strad]

Glad to see them mention the late Al Swindahl. He built my car in 1980 and at that time he was considered hands down the best in the business and an all round great guy.
RIP Al.

[Maritimer]

Looks to me like it came apart where they weld on the front end when they refurbish the frame. The "chassis" from a regs standpoint is the driver safety cell on those cars, the rest gets chopped off and rebuilt every few events. The chromoly can only handle being flexed like these cars do so many times.

[strad]

great picture. It shows something I mentioned in another post ages ago.

[Hoffman900]

Looks to me like it came apart where they weld on the front end when they refurbish the frame. The "chassis" from a regs standpoint is the driver safety cell on those cars, the rest gets chopped off and rebuilt every few events. The chromoly can only handle being flexed like these cars do so many times.https://i.imgur.com/vFRD2Kq.jpg

The flex is designed and they're suppose to cycle the chassis out. Doesn't mean in the age of Covid and cost cutting that teams pushed it or a defect made itself known.

[Maritimer]

The flex is designed and they're suppose to cycle the chassis out. Doesn't mean in the age of Covid and cost cutting that teams pushed it or a defect made itself known.

I know, nobody would design a frame that yields so easily at that level of competition. I feel like with the stress the frame sees it could be as simple as a weld that wasnt deep enough.