Installing adjustable rear lower control arms: best track+street setting?

iPhoneEngineer · 08-26-2012, 08:00 PM

Hey all,

I drive my car daily, but also hit the track a couple times a year, and am putting down 500BHP. I'm looking for some alignment settings that are appropriate for those conditions (obviously a bit of a compromise).

Tires are the widest that can fit on stock rims: 245 front, 275 rear. I've been happy with a -2.5º camber up front (I have had ground control camber plates), but have no idea what the rear should be given the tire size, or if there are any other adjustable parameters on this car.

Thanks for input! The adjustable RLCA are going on the car tomorrow, so I have to tell the shop what settings to use in the morning.

mfanatic325 · 08-26-2012, 08:41 PM

Dang, I don't know about control arm adjustments Scott...
But my rears are -2.2* camber, with slight toe-in (I believe it was 3/16" total). Fronts are 0" total toe.

Not sure what you can get with the adjustable control arms. Maybe have the shop recommend settings for your? Good luck!

Finnegan · 08-26-2012, 08:54 PM

Just my 2 cents but I don't see a reason to go more than -2.0 rear (front is another story).

Personally I'm happy with -1.8 rear and don't see any extra outside wear from track days.

There may be an argument to be made for moderate rear camber to keep a more even contact patch with that much power. Certainly straight line it's better, and with good weight transfer out of corner, maybe there as well.

Lon's rear toe recommendation sounds fine.

The HACK · 08-27-2012, 12:17 AM

TOO MUCH rear camber on a car with more power than grip actually decreases straight line speed. At this point you'll either have to find more rear grip, or learn to compromise between cornering grip and straight line speed.

Most race cars that run adjustable rear lower control arms run it to dial camber into the rift range, because when the car's lowered the rear camber increases.

VMZ432 · 01-08-2013, 09:11 PM

Hey iPhone, what type of RLCAs did you go with, and what did you think of them? Would be great if you could post into this thread:

http://www.zpost.com/forums/showthre...9#post13276729

08-26-2012, 08:00 PM	#1
iPhoneEngineer Lieutenant 43 Rep 476 Posts Drives: 2007 BMW Z4 M Coupe Join Date: Jun 2010 Location: La Honda, CA iTrader: (2)	Installing adjustable rear lower control arms: best track+street setting? Hey all, I drive my car daily, but also hit the track a couple times a year, and am putting down 500BHP. I'm looking for some alignment settings that are appropriate for those conditions (obviously a bit of a compromise). Tires are the widest that can fit on stock rims: 245 front, 275 rear. I've been happy with a -2.5º camber up front (I have had ground control camber plates), but have no idea what the rear should be given the tire size, or if there are any other adjustable parameters on this car. Thanks for input! The adjustable RLCA are going on the car tomorrow, so I have to tell the shop what settings to use in the morning.
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08-26-2012, 08:41 PM	#2
mfanatic325 ///M-fanatic 193 Rep 3,885 Posts Drives: '01 911 Turbo Join Date: Oct 2007 Location: Cupertino, CA. iTrader: (23)	Dang, I don't know about control arm adjustments Scott... But my rears are -2.2* camber, with slight toe-in (I believe it was 3/16" total). Fronts are 0" total toe. Not sure what you can get with the adjustable control arms. Maybe have the shop recommend settings for your? Good luck!
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08-26-2012, 08:54 PM	#3
Finnegan Dog Listener 703 Rep 7,850 Posts Drives: Z4M/. Z3M, E36/46 M3 Join Date: Oct 2008 Location: Teaching the dog to slalom iTrader: (22)	Just my 2 cents but I don't see a reason to go more than -2.0 rear (front is another story). Personally I'm happy with -1.8 rear and don't see any extra outside wear from track days. There may be an argument to be made for moderate rear camber to keep a more even contact patch with that much power. Certainly straight line it's better, and with good weight transfer out of corner, maybe there as well. Lon's rear toe recommendation sounds fine.
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08-27-2012, 12:17 AM	#4
The HACK Midlife Crises Racing Silent but Deadly Class 1821 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	TOO MUCH rear camber on a car with more power than grip actually decreases straight line speed. At this point you'll either have to find more rear grip, or learn to compromise between cornering grip and straight line speed. Most race cars that run adjustable rear lower control arms run it to dial camber into the rift range, because when the car's lowered the rear camber increases. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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01-08-2013, 09:11 PM	#5
VMZ432 Fast Everything 10 Rep 98 Posts Drives: Z4MC Join Date: Sep 2010 Location: Australia iTrader: (0)	Hey iPhone, what type of RLCAs did you go with, and what did you think of them? Would be great if you could post into this thread: http://www.zpost.com/forums/showthre...9#post13276729 __________________ 2006 IBlue BMW Z4 MC - ESS VT2-525 Supercharged, JRZ RS1 suspension (500#F, 600#R) with Vorshlag plates, ST Trophy BBK with CL R6E pads, KKS gated exhaust, TMS sway bars, RE rear camber arms, VT engine mounts, Recaro Pole Position (driver), APR GT wing, Street: Volk G2s and Potenza, Track: Volk TE37SLs and BFG R1s.
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