Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - View Single Post - RUCAs for camber better for toe curve? (or, why noone using trailing arms?)

prj3ctm4yh3m · 08-02-2016, 12:06 PM

too long to post in the Q&A thread....

i came over from s2000's which had both the burden and blessing of a double a-arm in the rear-the car was a handful anyway, so maybe the multilink here affords more opportunity for fine-tuning camber and toe curves.

my questions:

1) it seems like shortening the LCA to correct camber, and adjusting the toe arm accordingly, puts unnecessary off-axis tension on the trailing arm pivot at the knuckle [see pic below - use your mental travel simulator]. it SEEMS like lengthening the UPPER control arm in lieu of the LOWER to correct camber would have less effect on the trailing arm curve. i.e. its not rotating as much around the vertical axis. is this accurate? what am i missing?

2) i see a ton of trailing arms for sale lol. Why does noone use them here? (i know the standard explanation for them - they just adjust caster/thrust bblabla) it SEEMS like NOT shortening them can drastically affect the toe curve, which is a REALLY important thing in a car with no weight over the rear end. is there a general consensus on any beneficial affect it has on the toe curve at say 25mm drop (adjusting either the LCA and/or UCA)?

http://www.edmunds.com/car-reviews/t...alkaround.html

Please learn me.

08-02-2016, 12:06 PM	#1
prj3ctm4yh3m Senior Member Join Date: Jul 2016 Drives: CRV AWD 5MT Location: San Francisco, CA Posts: 183 Thanks: 84 Thanked 69 Times in 43 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	RUCAs for camber better for toe curve? (or, why noone using trailing arms?) too long to post in the Q&A thread.... i came over from s2000's which had both the burden and blessing of a double a-arm in the rear-the car was a handful anyway, so maybe the multilink here affords more opportunity for fine-tuning camber and toe curves. my questions: 1) it seems like shortening the LCA to correct camber, and adjusting the toe arm accordingly, puts unnecessary off-axis tension on the trailing arm pivot at the knuckle [see pic below - use your mental travel simulator]. it SEEMS like lengthening the UPPER control arm in lieu of the LOWER to correct camber would have less effect on the trailing arm curve. i.e. its not rotating as much around the vertical axis. is this accurate? what am i missing? 2) i see a ton of trailing arms for sale lol. Why does noone use them here? (i know the standard explanation for them - they just adjust caster/thrust bblabla) it SEEMS like NOT shortening them can drastically affect the toe curve, which is a REALLY important thing in a car with no weight over the rear end. is there a general consensus on any beneficial affect it has on the toe curve at say 25mm drop (adjusting either the LCA and/or UCA)? http://www.edmunds.com/car-reviews/t...alkaround.html Please learn me.