Rear trailing arms question

F1FTY · 04-04-2017, 01:45 PM

As we may know by now, the rear trailing arms on the Camaro SS are able to be bent relatively easily off the car which leads many to speculate on deflection existing under load.

The arms were created with light weight in mind and the design shows this. For the 1LE, the only difference is in the bushing being slightly stiffer.

My question is this: on old fox body mustangs, a popular and cost effective approach to strengthen the rear control arms was to box them. That was welding metal to close off the open side of the channel to increase rigidity. Has anyone looked at doing this with the factory Camaro arms?

glenB · 04-04-2017, 08:19 PM

I've thought about it, haven't done it. I did do it on a g-body, cheap effective mod over buying theirs.

If the ZL1 1LE can do what it does without it though.....

bybcous · 04-04-2017, 08:45 PM

I tried to bend my stockers with muscles as I read this too, but you aren't gonna bend them, but they are flimsy looking. I just upgraded to bmr this past Sunday. I notice no difference in ride quality. Going to track Friday to see if my 60ft have gotten any better.

F1FTY · 04-05-2017, 10:37 AM

Thanks guys!

I have the 1LE arms sitting around to go in with the rest of the 1LE suspension and am debating between them or just going full BMR out back instead. Kind of want to do it in stages or keep it OEM. Dilemma ��

bybcous · 04-05-2017, 01:05 PM

Quote:

Originally Posted by F1FTY

Thanks guys!

I have the 1LE arms sitting around to go in with the rest of the 1LE suspension and am debating between them or just going full BMR out back instead. Kind of want to do it in stages or keep it OEM. Dilemma ��

I thought they were the same wih different bushings? Bmr might benefit you if that's the case

drivingagain · 04-05-2017, 01:17 PM

I have been watching these threads because you can feel the rear end wiggle from time to time. Not the tires breaking loose but the suspension letting the body move from side to side it was it feels like. Is this what you guys notice as well?

F1FTY · 04-05-2017, 01:47 PM

Quote:

Originally Posted by drivingagain

I have been watching these threads because you can feel the rear end wiggle from time to time. Not the tires breaking loose but the suspension letting the body move from side to side it was it feels like. Is this what you guys notice as well?

Yes! A bobble to it too.

F1FTY · 04-05-2017, 01:48 PM

Quote:

Originally Posted by bybcous

I thought they were the same wih different bushings? Bmr might benefit you if that's the case

Yup, just different bushings. Wondering if that'll be enough for the 98th percentile or not.

F1FTY · 04-06-2017, 07:05 PM

Does anyone here know the torque specs on the trailing arm bolts?

jreagle56 · 04-06-2017, 07:41 PM

Noticed that bobble/wiggle too. it is unsettling, doesn't inspire confidence. Wondering if the axle/diff carrier frame (cradle) mount to the chassis is a little 'squishy' as well; pliable bushing mounted instead of hard mounted, contributing to it or actually the root cause of all of the movement?

Really don't know enough about how the rear is put together other than what is visible; seeing lots of moving parts where a few thousandths extra at each connection could add up to additional unwanted movement. maybe firmer bushings would tame it as was mentioned earlier?

my gut tells me it isn't just one thing but multiple points contributing to the whole.

BradfordCamaro · 04-06-2017, 07:43 PM

Quote:

Originally Posted by F1FTY

Does anyone here know the torque specs on the trailing arm bolts?

81ft/lbs is BMRs call out. Sounds right to me.
Shock bolt is 70...ish

F1FTY · 04-06-2017, 08:23 PM

Quote:

Originally Posted by jreagle56

Noticed that bobble/wiggle too. it is unsettling, doesn't inspire confidence. Wondering if the axle/diff carrier frame (cradle) mount to the chassis is a little 'squishy' as well; pliable bushing mounted instead of hard mounted, contributing to it or actually the root cause of all of the movement?

Really don't know enough about how the rear is put together other than what is visible; seeing lots of moving parts where a few thousandths extra at each connection could add up to additional unwanted movement. maybe firmer bushings would tame it as was mentioned earlier?

my gut tells me it isn't just one thing but multiple points contributing to the whole.

This would be a good question for BMR as they're the only ones I've seen that have released parts to deal with the rear suspension.

The Cradle lockout kit and differential lockout kit have my eye, but not sure which one addresses the movements. Wheelhop is listed the most on their site, but it's not what we're referring to here...

F1FTY · 04-06-2017, 08:24 PM

Quote:

Originally Posted by BradfordCamaro

81ft/lbs is BMRs call out. Sounds right to me.
Shock bolt is 70...ish

Perfect, thank you! I'm going to attempt this install myself.

JaxChris · 04-13-2017, 10:49 AM

I believe the cradle lockout adds a slight amount of NVH from freezing the cradle against the body. The differential lockout probably adds more.

For the wheel hop and wiggle, the upper & lower rear trailing arms will address this for most people.

GM builds in this flexing and calls it "compliance", which just means it will deflect for the sake of ride comfort.

The trailing arms are my favorite mod on the car so far.

04-04-2017, 01:45 PM	#1
F1FTY Drives: 2018 ZL1 Join Date: Oct 2016 Location: At the Dealership Posts: 1,019 View My Garage	Rear trailing arms question As we may know by now, the rear trailing arms on the Camaro SS are able to be bent relatively easily off the car which leads many to speculate on deflection existing under load. The arms were created with light weight in mind and the design shows this. For the 1LE, the only difference is in the bushing being slightly stiffer. My question is this: on old fox body mustangs, a popular and cost effective approach to strengthen the rear control arms was to box them. That was welding metal to close off the open side of the channel to increase rigidity. Has anyone looked at doing this with the factory Camaro arms? __________________ It's been fun, done with GM. 2018 Camaro ZL1 (SOLD) - Blown Airbags 2017 Camaro SS F1FTY Member Journal (SOLD) - Bad Motor

04-04-2017, 08:45 PM	#3
bybcous Drives: 2016 Hyper Blue 1SS Join Date: Jul 2015 Location: hampton roads Posts: 2,763	I tried to bend my stockers with muscles as I read this too, but you aren't gonna bend them, but they are flimsy looking. I just upgraded to bmr this past Sunday. I notice no difference in ride quality. Going to track Friday to see if my 60ft have gotten any better. __________________ 1ss/Auto-Hyper Blue acs carbon flash spoiler, bmr springs, gm clear tails. Texas speed cam, 223/227 .635/.635 116 LSA, Kooks Long Tube Headers with green cats, MSD Atomic Air Force Intake, CAI Cold Air Intake, QTP cutouts. 503 hp Best so far 11.5 at 123 with a 1.83 60ft. BMR lower and upper trailing arms and upper control arms,E85 DELIVERED 12/29/15 http://youtube.com/bybcous " no talking only racing on my youtube"

04-05-2017, 10:37 AM	#4
F1FTY Drives: 2018 ZL1 Join Date: Oct 2016 Location: At the Dealership Posts: 1,019 View My Garage	Thanks guys! I have the 1LE arms sitting around to go in with the rest of the 1LE suspension and am debating between them or just going full BMR out back instead. Kind of want to do it in stages or keep it OEM. Dilemma �� __________________ It's been fun, done with GM. 2018 Camaro ZL1 (SOLD) - Blown Airbags 2017 Camaro SS F1FTY Member Journal (SOLD) - Bad Motor

04-06-2017, 07:05 PM	#9
F1FTY Drives: 2018 ZL1 Join Date: Oct 2016 Location: At the Dealership Posts: 1,019 View My Garage	Does anyone here know the torque specs on the trailing arm bolts? __________________ It's been fun, done with GM. 2018 Camaro ZL1 (SOLD) - Blown Airbags 2017 Camaro SS F1FTY Member Journal (SOLD) - Bad Motor

04-06-2017, 07:41 PM	#10
jreagle56 Drives: 2022 2SS A10 NPP MRC Red Hot Join Date: Aug 2016 Location: CT Posts: 129	Noticed that bobble/wiggle too. it is unsettling, doesn't inspire confidence. Wondering if the axle/diff carrier frame (cradle) mount to the chassis is a little 'squishy' as well; pliable bushing mounted instead of hard mounted, contributing to it or actually the root cause of all of the movement? Really don't know enough about how the rear is put together other than what is visible; seeing lots of moving parts where a few thousandths extra at each connection could add up to additional unwanted movement. maybe firmer bushings would tame it as was mentioned earlier? my gut tells me it isn't just one thing but multiple points contributing to the whole. __________________ [SIGPIC][/SIGPIC]

04-04-2017, 08:19 PM	#2
glenB Drives: Chevrolet Camaro SS Join Date: Mar 2015 Location: Planet Earth Posts: 721	I've thought about it, haven't done it. I did do it on a g-body, cheap effective mod over buying theirs. If the ZL1 1LE can do what it does without it though.....

04-05-2017, 01:17 PM	#6
drivingagain Drives: 2015 Tiger XCX,2016 Camaro 1SS,LBZ! Join Date: Sep 2015 Location: Palm Coast, FL Posts: 1,311	I have been watching these threads because you can feel the rear end wiggle from time to time. Not the tires breaking loose but the suspension letting the body move from side to side it was it feels like. Is this what you guys notice as well?

04-13-2017, 10:49 AM	#14
JaxChris Drives: '16 2SS GD1 MX0 NPP F55 IO6 Join Date: Jun 2013 Location: Florida Posts: 1,298	I believe the cradle lockout adds a slight amount of NVH from freezing the cradle against the body. The differential lockout probably adds more. For the wheel hop and wiggle, the upper & lower rear trailing arms will address this for most people. GM builds in this flexing and calls it "compliance", which just means it will deflect for the sake of ride comfort. The trailing arms are my favorite mod on the car so far.

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