Bumpsteer issue SOLVED

[thomsonmatthew]

I recently got an alignment done and the only thing that was off since my last alignment was the toe. I believe this was because of the top nut on my bumpsteer kit on passenger side was not tightened properly. The car is lowered and cambered on bc coilovers with a j&m bumpsteer kit. running 285 tire all around. while driving after the alignment was done i noticed heavy bumpsteer going over any uneven part of the road almost as if my car was in a death wobble. i will upload photos of the alignment sheet and of the setup underneath.

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[kz]

You have insanely high rear camber. Front alignment looks fine though (I prefer zero toe but it is fine). Rear has way too much camber.

 

[petronix]

It looks like your tie rods are installed in a high position of the bump steer kit. Looks like it's about the same as stock position. If car is lowered more than an inch, then the tie rods should be mounted lower for the bump steer kit to be effective.

Agree that rear camber is too much, probably negatively effecting acceleration and braking.

 

[thomsonmatthew]

the camber all around was originally set up for autocross. what would be a good degree for all 4 wheels while daily/street driving on 285’s?

 

[kz]

the camber all around was originally set up for autocross. what would be a good degree for all 4 wheels while daily/street driving on 285’s?

Still doesn't make sense - -2.2 - -2.5 degrees rear is probably most I'd do for autocross.
For daily and street driving I'd just use OEM specs in the manual, whatever they are (pretty low numbers). Added bonus, any shop has access to them.

 

[Dallas J]

Sounds like you're guessing on bumpsteer, you should really pull the spring and install the shock, then look up how to measure bumpsteer through a sweep. A good general starting point on macstrut is to make the lower control arm and steering arm parallel at static ride height.

Also, that style of rod end is cheap and crap. Theyre the cheapest style to make but also have the most slop with little wear. A 3piece carbon steel ptfe rod end would be a dramatically better cheap-ish alternative.

I use these for steering components. Just make sure you order the "T" version. For instance, if its a 3/4 rod end, youd order the "JM12T" and not just the "JM12"

https://www.fkrodends.com/products/rod-ends/precision-series/jm-jf/

 

[Grintch]

Still doesn't make sense - -2.2 - -2.5 degrees rear is probably most I'd do for autocross.
For daily and street driving I'd just use OEM specs in the manual, whatever they are (pretty low numbers). Added bonus, any shop has access to them.

Yeah -3.5 front and -2.5 rear sounds about right to me for hard use. Maybe max of -3 in the rear. I am wondering what hardware you are using that will even get you to -3.8.

I wouldn't take it all back to stock settings for street use unless you never plan to drive it hard. I mean you have already paid for the camber aids, might as well use them at least some. Maybe -2.0 F and -1.5 R?

 

[kz]

Yeah -3.5 front and -2.5 rear sounds about right to me for hard use. Maybe max of -3 in the rear. I am wondering what hardware you are using that will even get you to -3.8.

Don't think you really need anything - slot in the camber arm mount has so much adjustment that it may allow for that much camber. Someone probably pushed it all the way in and called it a day (+ maybe lowering spring added some extra).

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