[Luftwaffe1O1]

After I had my Dinan springs installed, car has developed a vibration from about 50mph- 70mph, but only at about 50%-100% throttle, light throttle, and coasting its not there.

And at higher speeds it isn't there either, or even when flooring it from a stop. I thought maybe something was rubbing? But that would be noticeable even at lower speeds because the rear sits more.

I had the tires/wheels balanced once, that didn't fix it, had them road force balance it, it seemed to have gotten a bit better? But its marginal. I also notice it gets a bit worse when I am making a left turn vs right. (So swooping higher speed left turn vs right turn such as freeway interchange).

I am going to have the alignment double checked, but I suppose it could have been there before the springs went on but not nearly as noticeable? I have VMR wheels 19x8.5et35 (225/35/19) fronts and 19x9.5et45(255/30/19) rears tires are about 8 months old, still pretty good life. The shop never mentioned any difficulty road force balancing the tires/wheels, so not sure if it was an issue with a bent wheel or something?

But the tricky part is that it only happens under acceleration?

[HP Autosport]

Vibration while accelerating is usually related to the driveline, trans, driveshaft, diff and axles. Wheels and tires usually cause high-speed vibrations.

You definitely got an odd one on your hands.

[Luftwaffe1O1]

Yeah i am aware that these symptoms are usually driveline/axles etc related. But usually it would be felt at other speeds also, especially under heavier load.

But it also only occurs at a specific speed, and is less pronounced when turning in one direction vs other. It's definitely strange.

[dradernh]

Originally Posted by Luftwaffe1O1

...less pronounced when turning in one direction vs other

Wheel bearing?

[overcoil]

could it be the springs, vibrations and their frequency can be very specific, the right versus left effect could be spring load.

wonder if making drastic change in the tire pressure just for testing purposes would have an effect, or even heavy weight in the trunk.

[Luftwaffe1O1]

Originally Posted by ScottSinger

could it be the springs, vibrations and their frequency can be very specific, the right versus left effect could be spring load.

wonder if making drastic change in the tire pressure just for testing purposes would have an effect, or even heavy weight in the trunk.

So its worse when there are people in the rear. From the testing i have done, vibrations come when the rear is loaded. If i have lets say 2 heavier passengers in the rear, it is significantly more pronounced.

[Nexus313]

If you have VMR rims, and vibrations.. Your rims are bent. Get them checked! Absolutely horrible quality wheels.

I had VMR V710 that bent all 4 from normal driving in just 2 weeks! Didn't even hit any potholes. Not even visible bends, just slight bends that cause vibrations in the higher speeds, during take off, etc. Our cars are really sensitive even to slight bends. If you have a road force balance done, make sure you tell them to ensure that each wheel is under 9LB of PLimit, otherwise you will feel it.

The best way to test it, is use a friends set of wheels that have no vibrations their car on yours.

[Luftwaffe1O1]

It was the rear half axles, bmw replaced both of them, car is fine now. I had gotten the wheels/tires road force balanced, they would have picked up on it.

I honestly havent had a problem with my VMR wheels and ive hit potholes, even slight bend on the lip of one of the fronts. Are the 710s flowformed or just plan cast?

[Strike_Zero]

I took mine into the dealership a few months ago and "they couldn't reproduce it".

I'm taking it back after new years and take the tech out to reproduce it for them.

[Luftwaffe1O1]

Originally Posted by Strike_Zero

I took mine into the dealership a few months ago and "they couldn't reproduce it".

I'm taking it back after new years and take the tech out to reproduce it for them.

Thats what i had to do, sat with them in the car, and had the tech drive it. I can feel it even from passenger side. So in my case, they supposedly fixed it, gave it back, but atill did it, turned out rear halfshafts were bad.