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I was talking to Griggs Racing today, John Griggs, about their GR40 suspension. I specifically wanted to know if their rear-end GR40 suspension system can work with a 1-piece drive shaft. He said at one time they were concerned that it wouldn't but they have installed their GR40 system with the torque arm using a 1-piece 3.5" alum. drive shaft on their S197 GT test mule and it works w/o issues..

John then said that they changed back to the stock 2-piece driveshaft because of vibration problems with the 1-piece driveshaft, especially over 100mph.

Now a little background is needed here, I have run two (2) 1-piece drive shafts in my GT500; the first one was a 4" alum. DS from Powerhouse and the second a 3.5" alum. DS from the Driveshaft Shop. Why two DS's? Because the 4" one was hitting a low section of the tunnel after I lowered the car, the 3.5" doesn't hit anything but with both of them I too experience a lot of vibration over 100 that increases as the speed increases, the vibration stabilizes at around 140 mph and doesn't increase but it doesn't go away...

So here's my question, has anyone broken the stock 2-piece DS yet? I can see it happening with a drag set-up with some sticky tires, but does anyone know of a 2-piece failure yet and if you do, what were the parameters of the failure? What were they/you doing when it failed?

I'm thinking of going back to the 2-piece DS to get rid of the vibration, my GT500 is set-up for track/road racing, that straight line stuff doesn't interest me much, so the stock DS will probably never be subjected to the stress that a drag set-up can put on the powertrain.

Anyway, just thought I'd throw this one out there to gather some thoughts and experiences.

Thanks for reading the above,

Jay
 

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I was talking to Griggs Racing today, John Griggs, about their GR40 suspension. I specifically wanted to know if their rear-end GR40 suspension system can work with a 1-piece drive shaft. He said at one time they were concerned that it wouldn't but they have installed their GR40 system with the torque arm using a 1-piece 3.5" alum. drive shaft on their S197 GT test mule and it works w/o issues..

John then said that they changed back to the stock 2-piece driveshaft because of vibration problems with the 1-piece driveshaft, especially over 100mph.

Now a little background is needed here, I have run two (2) 1-piece drive shafts in my GT500; the first one was a 4" alum. DS from Powerhouse and the second a 3.5" alum. DS from the Driveshaft Shop. Why two DS's? Because the 4" one was hitting a low section of the tunnel after I lowered the car, the 3.5" doesn't hit anything but with both of them I too experience a lot of vibration over 100 that increases as the speed increases, the vibration stabilizes at around 140 mph and doesn't increase but it doesn't go away...

So here's my question, has anyone broken the stock 2-piece DS yet? I can see it happening with a drag set-up with some sticky tires, but does anyone know of a 2-piece failure yet and if you do, what were the parameters of the failure? What were they/you doing when it failed?

I'm thinking of going back to the 2-piece DS to get rid of the vibration, my GT500 is set-up for track/road racing, that straight line stuff doesn't interest me much, so the stock DS will probably never be subjected to the stress that a drag set-up can put on the powertrain.

Anyway, just thought I'd throw this one out there to gather some thoughts and experiences.

Thanks for reading the above,

Jay
Jay , it is interesting that you bring this up because I have been experiencing a great deal of vibration in the drive train ,that starts above 90 mph and gets worse over 120mph ,which is transmitted into the transmission tunnel .
I am not sure if it is the 1pc DS or not but I have been thinking of reinstalling my 2 pc DS just to see if it is the DS that is causing the vibration.
I currently have the Dynotec 3.5 aluminum 1pc DS.

I do know that they don't recomend driving over 155mph with the OEM 2pc unit.
If I do determine that it is the DS then I will have the balance checked on the 1pc unit.
If the balance is correct then I will assume that it might be a design problem.

George.......
 
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