[Keith Seymore]

Originally Posted by JLMounce

Good information for sure. I have actually heard this about drag radials in general.

I can create my vibration sitting on the driveway in park, so it's definitely not the tires.

This is good. Divide and conquer is what it is all about.

If you can separate "RPM dependent" from "Vehicle speed dependent" from "Load dependent" then it creates a whole long list of things you don't have to worry about.

K

[JLMounce]

Originally Posted by Keith Seymore

This is good. Divide and conquer is what it is all about.

If you can separate "RPM dependent" from "Vehicle speed dependent" from "Load dependent" then it creates a whole long list of things you don't have to worry about.

K

It's definitely rpm dependent, but load effects the severity. In park you can feel the vibration grow between 2800-3000 rpm and it's at its worst from 3000-3500rpm. It is still there, but subsides after 3500 rpm.

While driving the car, the vibration is worse during moderate acceleration. At full throttle the vibration is present but not as severe.

Motor mounts perhaps? Those have been in the car since I purchased it in 98.

[johnta1]

I would say to check the converter to flexplate mounting.
If this is a new converter (to you?) it could be bolted up crooked.
Unbolt converter from flexplate and push converter away from flexplate.
Start engine and see if it still vibrates?

Check the flexplate while under there to see if there is any noticeable problems. (bent/crooked, holes wallowed out, etc)

When bolting back up, make sure the converter is pulled against flexplate evenly and tighten bolts without cocking the converter as it is rotated.

[JLMounce]

Originally Posted by johnta1

I would say to check the converter to flexplate mounting.
If this is a new converter (to you?) it could be bolted up crooked.
Unbolt converter from flexplate and push converter away from flexplate.
Start engine and see if it still vibrates?

Check the flexplate while under there to see if there is any noticeable problems. (bent/crooked, holes wallowed out, etc)

When bolting back up, make sure the converter is pulled against flexplate evenly and tighten bolts without cocking the converter as it is rotated.

This is definitely on my agenda to check. The flexplate was a new SFI unit that was installed about a year and a half ago. Doesn't necessarily mean anything however.

The converter is a new TSP unit. One of their billet faced triple clutch deals.

One thing I just realized is that the vibration range tends to be in the range where the converter starts to couple. It flashes to about 3100 rpm under load.