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Old 05-30-2018, 05:24 PM   #1
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Join Date: Sep 2017
Location: Minneapolis
Posts: 21
My Ride: 2001 330i
Downshift shudder and vibration

Had the #799 2001 330i out to Heartland Park for the NASA weekend round for a shakedown weekend and HPDE. All went well mostly.

Winter build included:
MSC Coilover kit + springs
Hotchkis swaybars
Bimmerworld spece46 exhaust
Vanos rebuild
Solid trans, diff and motor mounts
Bimmerworld solid shifter
Adjustable trailing arms
LSD 3.46 3 clutch

Super fun and lots more exit power due to the diff and solid handling all the way around.

On maybe 6 of the overall50+ laps I ran, an extreme shudder/vibration thru the whole driveline would happen upon a 4th to 3rd downshift when entering certain corners. Rotational but no loss of power. It would last for 5-10sec thru the next turn or upshift perhaps. It was hard to nail down exactly but it would go away. And not even reappear the next lap. More towards the last 1-2 laps of my sessions but that didn't make sense either.

Thinking something with a motor or trans mount perhaps. Over/under torque maybe?
Any other ideas or places to look are welcome.
trackaddict799 is offline   Reply With Quote

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