Technical Why Chrysler urged drag racers not to do a neutral drop

I'll bet that was one heck of a explosion! HRP

 

Now, that's some carnage!

 

It'll buff out!

 

Looks like that torque flight took flight.

 

Looks like they filled it with liquid nitrogen and dropped it.

 

No worries, it's just some spare parts that's not needed!

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It isn't just automatics, I saw a Mustang with a small block, explode about 25 ft from the starting line after beating all comers all afternoon. I was grateful that he had a scattershield or he would have been severely injured. There was shrapnel everywhere. I am guessing that he got things too hot after multiple runs without a lot of cool down time.
A friend of mine owned a transmission shop, and one occasion, a guy got a 727 so hot that it blew up just like the picture above. The converter had to be separated from the flex plate by cutting it apart.
Seeing just one explosion makes one want to take better care of the equipment.
Bob

 

Quick way of dropping the trans fluid.

Chris

 

''Looks like we found the weak link in the drivetrain''.
Wouldn't want to be the next car to stage in that lane!

 

When I was a lad I had a 318 & 727 push button auto in a Chrysler Royal, while coming down a hill I wanted to slow a bit, so I decided to punch the 2nd button- except I punched the Reverse instead. The car came to a screeching halt, engine stalled, car skidded off to side of the road. Being 17 years old, I first looked for a clean pair of undies, then I got out, looked under the car, to see the carnage. Nothing to see here-not even a drop of trans fluid. So I got back in, put it back in neutral, fired it up, and gingerly put it in drive. Hit the loud pedal, expecting noises or no movement, but it moved normally, as if nothing had happened. Trans was fine , never missed a beat. Them Mopar trans's sure are hard to break!

 

A couple more, OUCH!

 

Clean up in lane two please.

 

Back around 1970 when I was 12 years old I was standing next to my brothers car in the water box pouring bleach under his slicks. The Max Wedge that had just warmed his tires was doing neutral drops and the same thing happened to him. It sounded and looked like a bomb went off!

 

Honestly had never heard of a neutral drop so I looked it up, I honestly didnt think professionals would even dream of doing something like that, I used to get one goin backward in reverse then drop it in low and nail it but I thought that was ok (NOT)......It did some how seem safer than tacking one up dead still in neutral then dropping

 

The transmission and frontends were always a weak link for me back in my Dart and Duster days

 

I did something similar to 36roadster one time;, had a 68 Chevy, 327 powerglide. Going home from my GF's house, late night, had forgotten to buy gas before I went to her house, back then most stores closed up by 9PM, this was around 11PM. I knew of one automated station where you fed bills into the pump and it let you have that much gas, no more, no less. I was trying to make it to that station, I'd put it up in neutral and coast down the long hills then back in drive to the next one. Going down one long hill, bumped it up, but went too far, hit reverse instead of neutral. Those big L 60 15's let out a deadly scream , the big Chevy lurched like it was going to stop, then total quiet. I just knew I had blew it! Pulled it back down to neutral, hit the starter, she fired right up, pulled it into drive, and it pulled right away. Never seemed to have hurt the engine or transmission.

 

'63 Dart with a 170 & a pushbutton tranny. Punk ass high school kid. Hard rear tires. Neutral drops where fun, surprised a few back then with how quickly it could leave the line. They'd still walk away from me by the time I'd be punching up second gear. And yes, while no external carnage, I did destroy the guts of that poor slush box. Punk ass high school kid.
-Dave

 

I ain't cleaning that up!
I had a clutch blow once at somewhere between 8 and 10 grand depending upon how accurate the electric tach was. Luckily I had a scattershield on it because there wasn't much more than dust in the bellhousing when I pulled it.

 

On a TF they will do that if you do a burnout in low gear and let the tires hook up. If the rear end let's go while you are in low.... Same results.

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finally, someone who knows how Torqueflites work!

A neutral drop can rip the back of the case out, or at least damage the roller clutch. But it won't make the drum explode immediately...to do that requires you to rev the engine over 5000 rpm with a non functioning roller clutch.

 

Thanks for sharing your knowledge on the subject. HRP

 

That's why the clutch-flite.

 

Fortunately, the complete loss of tire traction save the day.

 

Most times you see a 727 explode like the pix show it's because the rear end broke. With the reverse valve body all the pressure on first gear would unseat the spag and push it into the high RPM planetary. Instant hand grenade. At least that's what Chrysler engineers said when it happen to us. Len Silvers was one of the first to find out at National Trails Raceway in 1965. Everyone thought it a fluke, then more guys saw it happen that year. Ray Daily broke one at Mt. Vernon in 1970 so bad the convertor sawed it's way across the brake pedal into the kick panel and was found on top the valve cover. Big fire. Guys on the starting line got Ray out and saved the car. Not a pretty site when it happens.

 

I did the same thing with my dads 62 Ford,I pushed my luck also. HRP

 

And folks still argue the need for a transmission shield or blanket

 

they should make adapters for turbo 400's so that stuff doesn't happen

 

I would think Big Daddy Don Garlits accident where he lost part of his foot would be reason enough for any sane person. HRP

 

They did (sorta), Clutchturbos and Clutchflites.

 

I was just reading an old magazine the other day talking about how the MOPAR small block racers needed help to get their cars off the line with out doing "neutral slams". Chrysler engineers came up with the Clutch-flite in the picture below. I had never seen that version, it's pretty clever. They shifted further development to one of the big race trans companies (B&M?).
My Austin was the victim of a trans explosion though not as bad as the OP, note the floor and the hole in the driver's door. That may be why it was retired many years ago.