studio camber roll center adjusters (RCA)
08-06-13, 07:42 PM
#1
studio camber roll center adjusters (RCA)
this thread documents my experience with studio's camber roll center adjusters aka RCAs. i will not go into much detail on what RCAs do in general, let alone camber RCAs. the following will show my results during installation, driving impressions, etc.
unfortunately studio only made camber RCAs for 95-00 LS models. these are the studio RCA kit version 2.1. from what ian, the owner of studio, told me, the previous versions had more offset by about 0.25in which meant more camber. they were also left in a raw state rather than deburred as shown below.
i decided to replace my lower ball joints with OEM while i was already there. my old ones had no play but i took precaution.
the RCA kit came with hardware:
- 4 bolts (12x50mm 1.25 pitch 8.8 grade hex head) to bolt the RCA to the ball joints
- 4 flat washers
- 4 bolts (12x50mm 1.25 pitch 12.9 grade allen head) to bolt the knuckle to the RCA
- 4 flat washers
with all the recent failures of bolts breaking and shearing off on other memeber's RCAs (also from studio) i took more precaution and replaced the 8.8 grade hex bolts with 12.9 grade allen bolts.
this was taken from another thread regarding my going with 12.9 grade. for now i have not changed my choice but am open for further discussion. this is very relevant information and worth the reiteration.
here is the RCA half way bolted up to the ball joint using the replaced hardware.
you can see the amount of offset the holes are in, which repositions the knuckle outward for more negative camber.
all bolted down, the RCA is 35mm tall. i torqued everything to 83ft-lbs evenly which is the factory spec.
IMPORTANT: from the above picture note by the RED arrow the bolt coming from the RCA then through the knuckle protruding upwards. on the other side of the knuckle, there is no exit hole for the bolt to protrude. the 50mm long bolt is probably 5mm too long so i will either need to cut the tip off the bolt or buy a shorter one. ian warned me that this may happen as some knuckles are threaded deeper than others. i have yet to fix this!
with the wheels on, the RCAs not only added camber, they pushed my wheels out by probably 10mm or so!
it's hard to see but from the height shown the camber is almost the same as the rear now. i want to get it all to tuck, but the tires are stopping me.
time to get smaller tires (currently 225/35/19), and/or do some fender pulling.
for comparison this is w/o the RCAs.
i have yet to do a test drive. the fact that the bolt is too long and probably did not tightened properly is currently stopping me from driving. when i was repositioning the car on the driveway, i got a few metallic creaks and squeaks
! more to come soon.
unfortunately studio only made camber RCAs for 95-00 LS models. these are the studio RCA kit version 2.1. from what ian, the owner of studio, told me, the previous versions had more offset by about 0.25in which meant more camber. they were also left in a raw state rather than deburred as shown below.
i decided to replace my lower ball joints with OEM while i was already there. my old ones had no play but i took precaution.
the RCA kit came with hardware:
- 4 bolts (12x50mm 1.25 pitch 8.8 grade hex head) to bolt the RCA to the ball joints
- 4 flat washers
- 4 bolts (12x50mm 1.25 pitch 12.9 grade allen head) to bolt the knuckle to the RCA
- 4 flat washers
with all the recent failures of bolts breaking and shearing off on other memeber's RCAs (also from studio) i took more precaution and replaced the 8.8 grade hex bolts with 12.9 grade allen bolts.
this was taken from another thread regarding my going with 12.9 grade. for now i have not changed my choice but am open for further discussion. this is very relevant information and worth the reiteration.
Everyone having trouble with the RCAs should read this thread.
https://www.clublexus.com/forums/sho...d.php?t=406600
There's a lot of stress on those bolts especially when they're offset and cambered. Although a high grade bolt like a 12.9 is strong, it is brittle as well. OEM suspension uses grade 8.8 or 10.9 because it is relatively flexible but strong at the same time.
I would only torque it maybe 10 ft/lbs past the stock torque spec max. They are just like your wheel studs. Too much torque and they will snap. Use some medium thread lock and retorque after 50 miles or so. Hope this doesn't happen to anyone else.
https://www.clublexus.com/forums/sho...d.php?t=406600
There's a lot of stress on those bolts especially when they're offset and cambered. Although a high grade bolt like a 12.9 is strong, it is brittle as well. OEM suspension uses grade 8.8 or 10.9 because it is relatively flexible but strong at the same time.
I would only torque it maybe 10 ft/lbs past the stock torque spec max. They are just like your wheel studs. Too much torque and they will snap. Use some medium thread lock and retorque after 50 miles or so. Hope this doesn't happen to anyone else.
you can see the amount of offset the holes are in, which repositions the knuckle outward for more negative camber.
all bolted down, the RCA is 35mm tall. i torqued everything to 83ft-lbs evenly which is the factory spec.
IMPORTANT: from the above picture note by the RED arrow the bolt coming from the RCA then through the knuckle protruding upwards. on the other side of the knuckle, there is no exit hole for the bolt to protrude. the 50mm long bolt is probably 5mm too long so i will either need to cut the tip off the bolt or buy a shorter one. ian warned me that this may happen as some knuckles are threaded deeper than others. i have yet to fix this!
with the wheels on, the RCAs not only added camber, they pushed my wheels out by probably 10mm or so!
it's hard to see but from the height shown the camber is almost the same as the rear now. i want to get it all to tuck, but the tires are stopping me.
time to get smaller tires (currently 225/35/19), and/or do some fender pulling.
for comparison this is w/o the RCAs.
i have yet to do a test drive. the fact that the bolt is too long and probably did not tightened properly is currently stopping me from driving. when i was repositioning the car on the driveway, i got a few metallic creaks and squeaks
! more to come soon.
Last edited by timmy0tool; 08-07-13 at 11:09 AM.
08-08-13, 02:38 AM
#3
specs may differ between manufacturers, but based on the bolts used you should be torquing them down higher than stock since they are longer.
I know on my Fig's Engineering Roll Center Adjusters (RCAs) (non camber-adding) the spec is ~90 something ft*lbs. (something something, stock +10%, i forget.)
For those hunting for bolts that mount the LBJ to the spindle (UCF2x confirmed):
(I recommend grade 12.9 or better)
M12x1.25 socket cap bolts. The factory bolts are ~34-35mm long
For my 17mm RCAs I run 60mm bolts and ~5mm washers.
for ~34mm RCAs (straight through, not offset) I used 70mm bolts with ~5mm washers.
I got replacement bolts from my local fastenal/mcmastercarr for cheap.
I know on my Fig's Engineering Roll Center Adjusters (RCAs) (non camber-adding) the spec is ~90 something ft*lbs. (something something, stock +10%, i forget.)
For those hunting for bolts that mount the LBJ to the spindle (UCF2x confirmed):
(I recommend grade 12.9 or better)
M12x1.25 socket cap bolts. The factory bolts are ~34-35mm long
For my 17mm RCAs I run 60mm bolts and ~5mm washers.
for ~34mm RCAs (straight through, not offset) I used 70mm bolts with ~5mm washers.
I got replacement bolts from my local fastenal/mcmastercarr for cheap.
08-09-13, 05:52 PM
#6
i was PMd stating that 95-105 ft-lb is a good torque for the studio parts. from what i gathered so far, i will be torquing at 95 ft-lbs.
i found this pic from elvis' build thread. the RCAs look to be the older version but it is stamped "version 2.1" as well. notice the raw finish! the offset does look bigger than what i have as i mentioned before.
my fav pic from his build shows the front negative camber setting!
i found this pic from elvis' build thread. the RCAs look to be the older version but it is stamped "version 2.1" as well. notice the raw finish! the offset does look bigger than what i have as i mentioned before.
my fav pic from his build shows the front negative camber setting!
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08-19-13, 08:43 AM
#11
was thinking of picking up a set but not sure about it after all the people having issues with them. Don't they have 2 versions? one which cambers and add 10-15mm and 1 which just help it lower the car a little?
08-19-13, 02:11 PM
#12
regular RCAs add more suspension travel. camber RCAs do that and give more negative camber allowing for more clearance of the tire. it's all dependent on your setup.
there are issues but they all have been covered so you can minimize it. i think they are wonderful and lots of other guys have had success with them (me included). this thread shows some roadblocks but nothing too overbearing.
it sounds like they are more than 2 versions which leads me to believe they can custom made. i know i have the standard set. any RCA will lower the car a little depending on the thickness of it.
it sounds like they are more than 2 versions which leads me to believe they can custom made. i know i have the standard set. any RCA will lower the car a little depending on the thickness of it.
08-19-13, 02:39 PM
#13
small update.
instead of shortening one of the 50mm bolts, i was able to get a 40mm long bolt. to reiterate, the 50mm bolt was too long and did not thread in all the way into the knuckle.
as i was tightening it all, one of them suddenly stripped. i did NOT use air tools on it!
my guess is that debris fell into the threads and stripped even the nut.
i set my torque wrench to 95ft-lbs. good thing the RCAs have removable nuts.
and here is a quick shot from the nisei show this past weekend showing the final results. i had to run a different set of wheels since i had no time to play with my SSR Vienna Kreis. my buddy gladly loaned me his Weds SA-55M in a custom grey steel matte finish. sizing is 19x9.5 +24 225/35 and 10.5 +24 235/35.
with the RCA, the front fender perfectly splits the tire and wheel never touching anything! tsuraichi! and keep in mind i do NOT have my towers cut for the upper ball joint. this is with the upper a-arm resting on the tower. rears are tucked.
i drove on this setup (aired up of course) for over 200 miles this weekend with no adverse affects at full speed on the fwy! next is to get an alignment to correct the toe but overall i am very happy with the outcome.
instead of shortening one of the 50mm bolts, i was able to get a 40mm long bolt. to reiterate, the 50mm bolt was too long and did not thread in all the way into the knuckle.
as i was tightening it all, one of them suddenly stripped. i did NOT use air tools on it!
my guess is that debris fell into the threads and stripped even the nut.
i set my torque wrench to 95ft-lbs. good thing the RCAs have removable nuts.
and here is a quick shot from the nisei show this past weekend showing the final results. i had to run a different set of wheels since i had no time to play with my SSR Vienna Kreis. my buddy gladly loaned me his Weds SA-55M in a custom grey steel matte finish. sizing is 19x9.5 +24 225/35 and 10.5 +24 235/35.
with the RCA, the front fender perfectly splits the tire and wheel never touching anything! tsuraichi! and keep in mind i do NOT have my towers cut for the upper ball joint. this is with the upper a-arm resting on the tower. rears are tucked.
i drove on this setup (aired up of course) for over 200 miles this weekend with no adverse affects at full speed on the fwy! next is to get an alignment to correct the toe but overall i am very happy with the outcome.