Shorten the Control Arms? - Lateral-g Forums

Mrfixit · #1 05-08-2011, 08:33 AM

Hey guys,

I just received my wheels and tires for my 68 and am concerned that I didn't specify enough back spacing for the front wheels. I've been pondering my options and was wondering if anyone knows what the results would be if I shortened my upper and lower control arms by 3/8" to 1/2"? Has anyone tried this? Results?

Thanks in advance,

Blake Foster · #2 05-08-2011, 06:25 PM

what size and back space wheels did you order/receive?
are you using stock control arms?

dhutton · #3 05-08-2011, 06:37 PM

How much camber do you have in your alignment?

Mrfixit · #4 05-09-2011, 07:25 AM

Hey guys. Thanks for the reply. I bought 18x7 wheels with 4.5" BS. I'm using stock spindles with drum hubs and 13" C5 hat rotors. The tires are 225/45. I am concerned that I'll either have to run really stiff springs (uncomfortable) to prevent rubbing or compromise the stance. I've done the Gouldstrad conversion. I can't give any alignment numbers because the car is in the final stages of paint prep and not on the street.

My other option that I'm looking at is to have the tires dismounted and taking the rims to a machinist and have 3/8" cut off of the mounting pad. Very risky and expensive. Since I have an extra set of control arms, shortening them would cost me virtually nothing except a few hours of labor but I don't want to waste my time if it could create sever issues with the handling.

dhutton · #5 05-09-2011, 07:48 AM

Sometimes adding a scooch more camber is all that is needed to tuck the tire in. Post a pic.

Don

Blake Foster · #6 05-09-2011, 10:20 AM

Quote:

Originally Posted by Mrfixit

Hey guys. Thanks for the reply. I bought 18x7 wheels with 4.5" BS. I'm using stock spindles with drum hubs and 13" C5 hat rotors. The tires are 225/45. I am concerned that I'll either have to run really stiff springs (uncomfortable) to prevent rubbing or compromise the stance. I've done the Gouldstrad conversion. I can't give any alignment numbers because the car is in the final stages of paint prep and not on the street.

My other option that I'm looking at is to have the tires dismounted and taking the rims to a machinist and have 3/8" cut off of the mounting pad. Very risky and expensive. Since I have an extra set of control arms, shortening them would cost me virtually nothing except a few hours of labor but I don't want to waste my time if it could create sever issues with the handling.

you should have no issues,DO NOT CUT TEH BACK OF THE WHEEL, there is not enough material under the lug nut taper.
like Dhutton said once you get it all together and get a propper alignment done then you can evaluate your clearance, normally an 8 with 5" back space will fit fine

Mrfixit · #7 05-09-2011, 04:31 PM

Thanks guys. I'm hoping it's just a case of jitters. When you pay that much for wheels and tires, you certainly want them to fit. By the way Killer69, I bought your Speed Tech caliper adapters... great piece of machine work. I bow to your superior experience.

Blake Foster · #8 05-09-2011, 10:29 PM

Quote:

Originally Posted by Mrfixit

Thanks guys. I'm hoping it's just a case of jitters. When you pay that much for wheels and tires, you certainly want them to fit. By the way Killer69, I bought your Speed Tech caliper adapters... great piece of machine work. I bow to your superior experience.

lol

Hotchkis · #9 05-12-2011, 09:35 PM

Quote:

Originally Posted by Mrfixit

Hey guys,

I just received my wheels and tires for my 68 and am concerned that I didn't specify enough back spacing for the front wheels. I've been pondering my options and was wondering if anyone knows what the results would be if I shortened my upper and lower control arms by 3/8" to 1/2"? Has anyone tried this? Results?

Thanks in advance,

Mrfixit - Solving your fitment problems with shorter control arms isn’t a great fix. Changing the length of the control arm will adversely affect your handling by changing camber curve geometry and shorter arms will change the leverage of the suspension causing the spring rates to increase exponentially as the arms get shorter. Another problem with the shorter control arms is possible interference between the wheel and the control arm due to steeper angles of the tubing to compensate for the shorter arms and decreased turning radius due to interference.

Mrfixit · #10 05-25-2011, 04:44 PM

Quote:

Originally Posted by Hotchkis

Mrfixit - Solving your fitment problems with shorter control arms isn’t a great fix. Changing the length of the control arm will adversely affect your handling by changing camber curve geometry and shorter arms will change the leverage of the suspension causing the spring rates to increase exponentially as the arms get shorter. Another problem with the shorter control arms is possible interference between the wheel and the control arm due to steeper angles of the tubing to compensate for the shorter arms and decreased turning radius due to interference.

Thank you for the info. I'm hoping that it will be a non-issue once I get it on the ground. To help the camber curve along and gain clearance, I'm installing taller upper ball joints. If that doesn't work, my next-to-last resort is to modify the arms. The last resort is to buy new wheels. I'm hoping that I have to do neither.

Thanks again for your comments.