Strong vibrations on transmission or engine

[4yuckfous]

Hello

I have a big problem with the balance from the car.
The car has a new engine and new power train (balanced), with new assembled X-joints .
With 800 to 1300 RPM, the engine shakes normal, the way it is with a hot camshaft.

In the speed-up stage no bad vibrations, but if I drive on the same RPM over the sertain time,
the hole body shakes like mad.
It's the same if I drive or I stand with the car.
So it must be from the engine, flexplate or the torque converter.
Do you agree?

The flexplate what I build in is from B&M, part # 10236.
The flexplate disc has a one side cutout.
A friend told me, he believes that the vibrations are from that cutout.
That would explain a lot to me, then with a less balanced on one side frome the flexplate,
something has to get vibrations.

The car is not driveable, please let me know your experiance.

Thanks for feedbacks.
Andrea

[Moparal]

You said your engine is balanced. So you have an internal balanced engine and an external balance flex plate. You need to change the flex plate to neutral balance

[BIGSHCLUNK]

You said your engine is balanced. So you have an internal balanced engine and an external balance flex plate. You need to change the flex plate to neutral balance

   Thats the first thing that came to mind as I read your post..

[4yuckfous]

I just wrote a e-mail to the engine builder with the question if the
engine is internal balanced. I belive it is.
A phone call today gives me the same feedback with the balance.
I hope that's the problem.

If I have to change the torque converter, witch one do you recommend?

[4yuckfous]

It's interal balanced

Witch flexplate and torque converter do you recommend?

[BIGSHCLUNK]

If its internal you need a non-wieghted converter.  OR you could take a look at your maybe knock the weights off it? They are usually just tacked on...  you could probly do this while its still in the car . save a ton of labor. 

[4yuckfous]

The converter is the only old thing on the car.
Probably its to low with the hp and torque from the engine.

So I will change converter and flexplate together.