Weighted alignment question

[DreamTime]

I’m installing my camber plates tomorrow so I set up an appointment at my alignment shop for Monday. I was given a few options for how to distribute the weights in the car for the alignment. Can someone please help me decide what the best option is? Thank you.

1. Standard weights, per a friend who works at BMW this is 150lbs each in driver seat, passenger seat, and rear seat, then 60ish lbs in trunk.

2. Weights based on how my car will be at the track (this was a suggestion by the shop owner) - for me that would be 2 adults in front and an average of half a tank of gas.

3. No weights at all… the shop owner said that he has done a ton of testing and that cars with altered (lowered, camber plates, etc) suspensions requesting custom, non-factory spec alignments have almost no movement in the alignment when weights are added/removed. This is just based on his experience, so I can't speak for him on this.

Any insight is appreciated!

[sgreer78]

When I aligned my car I did it with no ballast at all. I got in the car before we disconnected the sensors and NOTHING changed. YMMV

[DreamTime]

Yeah, that's pretty much what I was told by my alignment guy. I was just under the impression that BMWs in general needed to be weighed down in a specific way in order to get the right alignment. Since I was leaning towards that line of reasoning from the get-go, he gave me the option of putting weights in specifically placed with track time in mind, which some of his customers request. Then he told me that it was up to me and I just needed to let him know what I wanted when I dropped the car off on Monday. Just trying to figure out what's best, but I could be over thinking it. Thanks for your input!

[1MOREMOD]

Didnt think it mattered unless can do corner balance then its track alignment and weight goes in drivers only.

[DreamTime]

Awesome, well that's helpful to know. Maybe it doesn't matter? I'll ask him about corner balancing just for the sake of understanding his process more, so that's kinda cool to know about. Thanks!

[s14_kev]

Originally Posted by 1MOREMOD

Didnt think it mattered unless can do corner balance then its track alignment and weight goes in drivers only.

This.

Alignment only I would not worry about adding a ballast, but if you're corner balancing that's a different story. If you're worried about it I would add weight for how the car will most often be driven. When I corner balanced my car, I only added weight to the driver seat. How much weight should be based on your "actual" weight.

[CSBM5]

You will definitely see changes in camber, especially in the rear, between an empty car and one that is weighted per spec. The factory alignment spec also says a full tank of fuel. This is the reason BMW specifies it as they do since cars with no weighting and and empty tank that have rear camber set to spec will immediately be running too much rear camber once loaded up.

Try it on the rack. Set the whole car up, set the front and rear toe and camber. Now sit in the driver's seat and weight the passenger seat, rear seat and trunk without changing anything. Promise you'll see movement in both toe and camber readings, esp in the rear. However, on a car with 700/1000 lb/in springs...not so much, so if you have those types of spring rates on coilovers, it isn't as much of a concern. On a street car with typical spring rates, the suspension compression does result in camber change (by design) with some minor associated change in toe.

[EricSMG]

^^Agreed - you will for sure see rear camber changes once weighted. You would need to roll the vehicle back and forth a bit after the weight was added in order for the suspension to settle - simply getting into the car once it's already settled on the rack won't do it, necessarily, as the track needs to widen as camber increases.

I always go in with a full tank of fuel, minimum. Sometimes I'll add my weight just behind the driver's seat for maximum accuracy.

Full tank, though, is essential as rear camber changes a LOT with very small changes in ride height. You want your rear camber to be set at your normal loaded ride height.

[1MOREMOD]

Does it accelerate so hard you usually end up in the back seat

[DreamTime]

Sorry, been really busy. On Friday I helped a friend drop the rear subframe on his 540i on jackstands, which made me VERY thankful for lift access for the work I needed to do on my car yesterday lol.

Anyways, thank you everyone for your responses. I finally had a chance to go over everything and think about it for a minute. I feel way more informed now. I'm going to talk to my alignment guy about corner balancing. And, I think I'm going to end up going with a weighted driver's seat and a full tank of gas. Still thinking it over. I appreciate all of you!

[DreamTime]

Originally Posted by 1MOREMOD

Does it accelerate so hard you usually end up in the back seat

Many inappropriate jokes came to mind when I read this... but I will refrain from sharing them with all of you lmao

[1MOREMOD]

I dont use full tank of gas for corner balance. It's only full for a minute when on track half tank is more likely to be close to what is in there more of the time, sometimes more, sometimes less but closer to actuality.

[DreamTime]

I just found out he does not do corner balancing at his shop. So, just the standard alignment I guess. That will work for now. That being said, there is a place in town that offers corner balancing... so this thread has given me something to think about for the future.

Thank you again, everyone!

[1MOREMOD]

Car has to have height adjustment at each corner, ie coilovers

[DreamTime]

Okay, got it. So, even if he did offer that service, it would not apply to me. No coilovers... yet. Once I get my B8s (heard from friend at Bilstein, sadly they have not even started production on them yet), my suspension setup will be H&R sport springs, and the B8s + GC street camber plates I already mentioned. I might be happy with that setup for a while tbh. But, I'm sure I will be looking at coilovers sometime in the next year or so.