Proof the Opel torque tubes aren't that strong!

[RallyBob]

Originally Posted by wrench459 I'm stuck on picture number one. Mighty big exhaust tubing and I like the flange.

Bigger is not always better! Generally you don't need 3" exhaust tubing until you're at/above 200 hp.

By chance is this a turbo car?

Nope. Twin carb'd 2.2 as I recall.

Did it wheel hop on the dyno?

4th gear pull, probably not!

It's more common than you think actually, they just fail at high rpms and higher speeds. More than one of my top speed runs was aborted because of the tell-tale vibration in the torque tube. The whole car starts to vibrate. Lift off the gas or it gets ugly quick...

[wrench459]

Originally Posted by RallyBob It's more common than you think actually, they just fail at high rpms and higher speeds. More than one of my top speed runs was aborted because of the tell-tale vibration in the torque tube. The whole car starts to vibrate. Lift off the gas or it gets ugly quick...

I've jumped off the dyno more times than I care to admit with FWD vehicles.
99.9 percent of the time it was due to bent rim/loose suspension pieces traveling at at awesome rate of 25 mph. What ever you do when a pull goes bad don't hit the brakes
Question keep the torque tube or dump it for torque arm with the differential change? ie toyo rearend

[bello]

To Bob Legere; Bob- y'in't gonna believe this- the pictures are on the way! Ernie Bello

[RallyBob]

Originally Posted by bello To Bob Legere; Bob- y'in't gonna believe this- the pictures are on the way! Ernie Bello

Gracias Ernesto. Now hopefully you're not in any of the pictures....

[heimue]

Here's the original thread from the German Hecktriebler-Forum, and here's a shortcut to a video showing the Kadett C with a 2.2 with Weber carb and around 160 HP when it happened.

Dieter

[opelgtworld]

This explanation is interesting:

In erster Linie biegt sich eine Kegelrad Verlängerungswelle wegen zu hoher Drehzahl und nicht wegen zu hoher Motorleistung oder Drehmoment. Ich habe noch nie gehört, daß es jemanden die Welle im ersten oder zweiten Gang verbogen hätte. Der Serienmäßige Kadett C Coupe 2,0E Rallye z.B. hat eine zulässige Höchstdrehzahl von 6150 Umdrehungen. Mit dem Serienmäßigen 4 Gang Getriebe ( im 4. Gang 1:1 Übersetzt ) dreht somit die Kegelradwelle ebenfalls 6150 Umdrehungen und nicht mehr. Wird jetzt ein Sportmotor, der im letzten Gang vieleicht 7500 Umdrehungen schafft und dann noch dazu ein 5 Gang Getriebe, z.B. 0,87er ZF, in den Kadett eingebaut und die Serienmäßige Kegelradwelle beibehalten, ist über kurz oder lang das Unglück vorprogrammiert. Die Serienmäßige Kegelradwelle muß dann plötzlich im 5. Gang nicht mehr nur die Serienmäßigen 6150 Umdrehungen sondern unter Umständen über 8000 Umdrehungen aushalten. Die Welle schwingt sich auf und macht eine Banane. Selbst die Kegelradwelle vom 1000er GT/E wurde gegenüber dem Kadett C Rallye 2,0E um einen Millimeter im Durchmesser verstärkt, da durch das 0,87er ZF im 5. Gang andere Drehzahlen der Kegelradwelle erreicht werden. Das Drehmoment und die Zulässige Höchstdrehzahl beider Fahrzeug ist aber identisch.

[heimue]

Originally Posted by opelgtworld This explanation is interesting: ....

Let me try it this way:

"A drive shaft bends because of high rpms, and not because of high power or torque. I've never heard about a shaft bent in first or second gear (under high torque). The original Kadett C 2.0E Rallye has an allowable maximum rpm of 6,150. With the original 4-speed gear box (1:1 ratio), the max speed of the drive shaft is the same 6,150 rpm. If you put in a high-powered engine that might make 7,500 rpm, and even add a 5-speed gear box with around 0.8 ratio, the drive shaft will suddenly make 8,000 or more rpm, and the failure can be expected sooner or later. The shaft gets into resonance, and bends like a banana. Even the drive shaft of the Kadett C 1000-Series was already beefed up 1mm over the 2.0E shaft, because this car was available with a 0.87-ratio ZF 5-speed. Interesting to know, that the torque and the maximum engine rpm was identical in both cars!"

Dieter

[wrench459]

OH My.. thanks for the info guys.
Ya'll have saved sandspur from planting my hard headed body in the ground.

[opelgtworld]

Dieter:
Perfekt Translation ! Vielen Dank.

[blancojp]

Originally Posted by heimue Let me try it this way: "A drive shaft bends because of high rpms, and not because of high power or torque. I've never heard about a shaft bent in first or second gear (under high torque). The original Kadett C 2.0E Rallye has an allowable maximum rpm of 6,150. With the original 4-speed gear box (1:1 ratio), the max speed of the drive shaft is the same 6,150 rpm. If you put in a high-powered engine that might make 7,500 rpm, and even add a 5-speed gear box with around 0.8 ratio, the drive shaft will suddenly make 8,000 or more rpm, and the failure can be expected sooner or later. The shaft gets into resonance, and bends like a banana. Even the drive shaft of the Kadett C 1000-Series was already beefed up 1mm over the 2.0E shaft, because this car was available with a 0.87-ratio ZF 5-speed. Interesting to know, that the torque and the maximum engine rpm was identical in both cars!" Dieter

That is why I never had any problems with the drivetrain on my V-6 GT. I had a limiter which did not allow the engine to go over 5K Rpms. It had massive torque but after 10 years of use, rear end was solid.

[namba209]

Originally Posted by blancojp That is why I never had any problems with the drivetrain on my V-6 GT. I had a limiter which did not allow the engine to go over 5K Rpms. It had massive torque but after 10 years of use, rear end was solid.

In the same vein JB, I've got a 6250+/- limiter in Willit?'s computer and running about 2500 RPM at 75 MPH, I don't think I'll ever get to a critical resonating rpm to the rear driveshaft, even with the .87 overdrive in 5th gear. I do get a vibe around 90 MPH, but I attribute that to a non-balanced, super short, front drive shaft. And I sure don't intend to be driving that speed too often.

[wrench459]

Topend run using a GPS unit.
I've got three gallons of AV fuel in the tank.
So what the hey 120mph is not out of the question.