Couple random questions about shimmys and knocks

[Joebednar4]

My 2020 is lowered on Silver's NeoMax coils. Apex SM10 19x9.5/11 with oem 255/275 tires. They've been balanced multiple times, and the alignment done multiple times. When I accelerate quickly to get on the highway, or to just accelerate quickly, it feels like there's a light shake up front, but only while accelerating. Not while cruising, at all. Front pads/rotors have been replaced as well with Zimmerman rotors and oem pads. I checked the whole front end over, and everything is tight. It does have an aftermarket front sway on it, with oem links, though. Could that be a cause of a slight shake while accelerating?

Secondly, I got this car used. When I come to a stop, and then go to take off again, there's a knock in the back end. Almost feels like the diff spins and then grabs, if that makes sense? It only happens at stops, though. Never while moving or accelerating. I've searched and searched, but nobody seems to have these issues.

Thanks!

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[FLtrackdays]

Definitely look for a good independent BMW mechanic. Ask around, word of mouth and go get her checked out

 

[Joebednar4]

Definitely look for a good independent BMW mechanic. Ask around, word of mouth and go get her checked out

Funny enough, I run a high end repair facility. My BMW Tech's have looked it over multiple times, and there doesn't seem to be anything awry. It's why I asked on here. Sometimes there are gremlins that techs can't find, that other people have had the same experience with.

 

[FLtrackdays]

Funny enough, I run a high end repair facility. My BMW Tech's have looked it over multiple times, and there doesn't seem to be anything awry. It's why I asked on here. Sometimes there are gremlins that techs can't find, that other people have had the same experience with.

Gotcha

My 2020 is lowered on Silver's NeoMax coils. Apex SM10 19x9.5/11 with oem 255/275 tires. They've been balanced multiple times, and the alignment done multiple times. When I accelerate quickly to get on the highway, or to just accelerate quickly, it feels like there's a light shake up front, but only while accelerating. Not while cruising, at all. Front pads/rotors have been replaced as well with Zimmerman rotors and oem pads. I checked the whole front end over, and everything is tight. It does have an aftermarket front sway on it, with oem links, though. Could that be a cause of a slight shake while accelerating?

Secondly, I got this car used. When I come to a stop, and then go to take off again, there's a knock in the back end. Almost feels like the diff spins and then grabs, if that makes sense? It only happens at stops, though. Never while moving or accelerating. I've searched and searched, but nobody seems to have these issues.

Thanks!

Well the 1st thing, stating the obvious, the brakes shouldn’t matter while accelerating. Since you didn’t do the swaybars yourself, I’d find out which swaybar company and look at their installation guide to see if it was done right or if any parts are missing. Also, by being lowered, you know the geometry is altered. I personally went with SPL adjustable swaybar endlinks.

For your 2nd thing, rear traction links would be a great place to start.

https://www.splparts.com/supra-g29-2020/

To me the SPL parts are worth it. I went lower for tracking. Unfortunately too low but my SPL parts were able to handle it. I’m now on Ohlins and linear springs and that fixed a few other track issues I was having. So I’d start with those two SPL things 1st and checking the swaybar installation.

Those are just some things I did. I’m by no means a mechanic. I just love tracking this Supra. Good luck amigo!

 

[bushido]

i wonder if problem #1 is related to problem #2? sounds frustrating..

 

[Joebednar4]

i wonder if problem #1 is related to problem #2? sounds frustrating..

Haha knowing it's BMW, I wouldn't even be a little surprised if it was

 

[Joebednar4]

Gotcha


Well the 1st thing, stating the obvious, the brakes shouldn’t matter while accelerating. Since you didn’t do the swaybars yourself, I’d find out which swaybar company and look at their installation guide to see if it was done right or if any parts are missing. Also, by being lowered, you know the geometry is altered. I personally went with SPL adjustable swaybar endlinks.

For your 2nd thing, rear traction links would be a great place to start.

https://www.splparts.com/supra-g29-2020/

To me the SPL parts are worth it. I went lower for tracking. Unfortunately too low but my SPL parts were able to handle it. I’m now on Ohlins and linear springs and that fixed a few other track issues I was having. So I’d start with those two SPL things 1st and checking the swaybar installation.

Those are just some things I did. I’m by no means a mechanic. I just love tracking this Supra. Good luck amigo!

Good stuff man!! I really appreciate it. I guess I have some testing out to do this weekend

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