[HLJustin]

Installing Bilstein PSS10 B16 coilovers on 2017 340i sometime next week and just wanted to get some input on alignment specs. Won't be tracking but I do enjoy spirited driving in streets and quick cornering. Goal is to maintain high speed stability while reducing the understeer to be closer to neutral. Planning to drop car about .75" to 1.5".

With that being said, I'm thinking:
Front Camber: -1.5
Front Toe: .05

Rear Camber: -2.0
Rear Toe: .10

I also read that there's not much play in front camber without camber plates outside of dropping vehicle height, is this correct? Will this create the desired affect of slight understeer with less of that push feeling while cornering? Also will the reduced toe in front and back hurt high speed stability +100mph?

Did a lot of researching and deduced this spec. Any feedback or insight would be very helpful!

[kern417]

I'm at ~1.3 camber up front and close to tucking the front tire. Bilsteins won't go that low so I'm betting you'll be closer to -1 or possibly less. Your best bet is to reduce rear camber as much as possible to help the car rotate better.

Also you should be able to adjust dampening. Softer front/stiffer rear helps push more traction to the front tires. You'll have to play with the settings to find what's comfortable, safe, and fun.

[HLJustin]

What's your camber like in the rear? Maybe I'll do -1 Front with 0 toe, -1.5 Rear with .10 toe. Don't want to drop camber too low and end up with oversteer

[kern417]

My rear is -2.5. again since i'm so low, that's the least camber i could get. less than ideal, but i sacrificed performance for looks. now i'm looking for options to bring the front out closer to -1.5 or so. I think -1.5 is ideal to optimize tire wear and still have some fun. But until I find a way to bring the rears in I'll always have some push.

My tires are also staggered (245 front/275 rear) so more reason i need to dial in front camber. It might be easier for you if you have a square setup.

[B58 parts]

Rear camber is going to promote understeer.

You do what you want, but when I first aligned we put the rear at -2, fronts ended up at -0.8. No camber plates on a daily.. It understeered bad.

A few weeks later we changed the rear to as close to 0 as we could get it while keeping the toe even and in spec. I think -0.4 was as far as the stock eccentric was good for. You want the rear to break a little easier and have as much grip up front as you can.

Mine is pretty neutral with a touch of predictable throttle on oversteer. Still way too much body roll and slop .. but it does have a ton of grip.

Toe just go oem spec, i.e. square in the rear and 1/16th in upfront so it tracks straight.

[MacklinUSOB]

Originally Posted by YuminNuman

Rear camber is going to promote understeer.

You do what you want, but when I first aligned we put the rear at -2, fronts ended up at -0.8. No camber plates on a daily.. It understeered bad.

A few weeks later we changed the rear to as close to 0 as we could get it while keeping the toe even and in spec. I think -0.4 was as far as the stock eccentric was good for. You want the rear to break a little easier and have as much grip up front as you can.

Mine is pretty neutral with a touch of predictable throttle on oversteer. Still way too much body roll and slop .. but it does have a ton of grip.

Toe just go oem spec, i.e. square in the rear and 1/16th in upfront so it tracks straight.

Rear camber can promote understeer but be careful because less rear camber does not equal more front grip. -0.4 is well under OE spec (-1.0 minimum) and lower than what the maximum overall benefit would be by attacking the problem from the other axle. That little rear camber lowers ultimate grip a lot, increasing front camber increases ultimate grip a lot.

[B58 parts]

Yeah maybe some day I will drop the front subframe and install a stiffer roll bar. Until then this is as good as I can get it. It has plenty of grip and is very predictable. I can't have clunky camber plates up front.

[MacklinUSOB]

Originally Posted by YuminNuman

Yeah maybe some day I will drop the front subframe and install a stiffer roll bar. Until then this is as good as I can get it. It has plenty of grip and is very predictable. I can't have clunky camber plates up front.

There are other options to improve front end grip and camber, a stiffer front sway bar is definitely not one of them. I would strongly suggest increasing your rear camber if you want a better cornering car. That's all I have to say.

[HLJustin]

Okay, I'll probably just follow oe camber specs but go towards the lower end of range. With stock M Sport, -.20 camber up front and -1.5 in back and the steering just sucks.

[MacklinUSOB]

Originally Posted by HLJustin

Okay, I'll probably just follow oe camber specs but go towards the lower end of range. With stock M Sport, -.20 camber up front and -1.5 in back and the steering just sucks.

Sounds like a plan, just remember rear camber is even more important for you being RWD. The actual benefit to grip will be the amount added up front, not how much you remove from the back. Here's the spec sheet from my Bentley manual, just note this is for standard suspensions, your recommended minimums will be higher than these.

[kern417]

Just to piggyback, i def wouldn't run less than -1 in the rear. the looseness you feel is probably because you're rolling onto the sidewall. you still want to make sure the contact patch in the rear is sits square with the road when you turn. But my -2 or more is useless because street tires aren't pulling that many G's to use it all. Just my opinion/experience.