G Body rear susp travel ?

[GregInAtl]

OK, I have an 86 Buick GN, I have it lowered a bunch, Moog coil 5385s w/ a coil removed, dropped it right at 3". I have KYB shocks, rear disc conversion, and 20x10s on 275-30s.
Here's the deal. It has no travel. Its all tire...and there aint much there!!
The rear driver caliper was hitting the frame, so I notched a vertical slice in it for clearance....test drove it, now its clear but now I have 1" travel.
Anyone w/ a G-body experienced this? I have seen many regal's lower than this, and something just doesnt add up. The shocks surely have more than 3" of travel...
Shed some light if you can...
btw pic of car below, it isnt all that low really.....

[GregInAtl]

here's the pic...

[BigBlockOlds]

I'm going through this currently on my build. I have 17x11's with 315/35's in the back which fit just fine. But when I set my ride height so that the fender lip is just about even with the top of the sidewall, I probably only have 2" of travel or so.
I notched my frame a good 1.5" or so and still have interference issues with the LS1 brake calipers back there that I'm trying to figure out. I'll probably do like you and notch the frame a bit for clearance.

Sorry I'm not much help. I'll be watching this thread too.

BTW, the 20's look perfect on your car. I've been contemplating going to a 20" rim front and back but only if I could get them to tuck in and look "right" like yours do. Do you have any more specs on the backspacing, tire size, etc?

Thanks,

[GregInAtl]

Heres the set up;
F- Boss 338- 20x8.5 w/ 5.25 BS and 7/16 wheel spacer, 245/35-20
R- Boss 338- 20x10 w/ 6.25 BS and 1" adapter, 275/30-20


F- Bell Tech spindles, and Moog 5658s w/ KYBs
R- Moog 5385s w/ a coil removed, KYBs, and rear disc conversion (thus the high BS wheels)

Front fender lips were cut to about 1/2 size, and pie cut the wheel well liners to keep the treads off them. Rear lips need minor grinding to get the room I need.

[T-CHRGD]

Greg, Your car looks Great !!

It doesnt look like 3" drop, with the space between the side body/frame and the ground. It must be the tall tire wheel package. So if you do have a 3" drop in the suspension, you must be Very close to bottoming out the pinion snubber on the rear axle. Or you could be at the end of the shock travel. Put jack stands under the frame, take the wheels off, unbolt the bottom of the shocks and jack the rear up and down to see the travel without shocks. See if the pinion snubber is hitting the rear center section. Good luck.

[T-CHRGD]

Upon further thought, try to measure axle to frame distance as it sits on the ground. Do as above, but also remove the springs to check full travel from where it currently sits. You could also be reaching the end of the trailing arm travel with a 3" drop.
Just my thoughts.:)

[Marcus SC&C]

Here`s the deal. Most G body cars in general only have about 2.5" of bump or compression travel. Out of 7" of total shock travel 4.5" or so is droop travel. Drop the car 3" and you`re on the snubbers and have basically no suspension in bump. A lousy ride and erratic handling result. You can remove the bumpstops like some folks do to get lower yet (probably what was done on the even lower cars you saw) and the ears that mount the UCAs will hit the trunk floor. The UCAs BTW will be at like a 40* down angle at this point and the pinion will be pointed toward the ground and likely cause nasty driveline vibes and u joint wear. You can correct that with adj. UCAs, then the spinning pinion will hit the tran tunnel. Doh. Your best option is to gain a little ride height so you have some usable travel, then throw the KYBs in the trash and put a set of good adj. shocks on the car so you can modulate that small amount of travel better. It does look wicked at that height, but short of chopping and fabbing it`s an anti performance modification. BTW I don`t normally care for 20s all around on G body but you pulled it off very nicely with your whele and tire choice. :) Mark SC&C

[nowukno]

do the calipers have an e brake?,is your rear end centered? also check your rear sway bar mounting bolt clearance

[GregInAtl]

do the calipers have an e brake?,is your rear end centered? also check your rear sway bar mounting bolt clearance
The WINNAH!!!
rear caliper BARELY hit the frame and stop the rear from traveling.
The 20" pkg is the same height as my old GNX clone pkg, so I knew that wasn't the issue. Once I have notched the frame, I'll be calling Marcus and looking into adj rear uppers to help w/ wear of important pieces. If all else fails, I have a welder and a bunch of cut off wheels and grinders. Not scared to cut......
BTW, thx guys for the compliments on the big wheels, I am stuck in between a Foose style and G-machine....I had to slam AND do big wheels...no one else would...20"s on a regal usually looks 4x4! Now I just have to work on functioning to a streetable level.

[nowukno]

cool,that ride does look good with that set up

[GregInAtl]

do the calipers have an e brake?,is your rear end centered? also check your rear sway bar mounting bolt clearance

Is there a tech way to center the rear end? I am 1/2 pass side from center.

[b-man]

Is there a tech way to center the rear end? I am 1/2 pass side from center. The only way I know would be to loosen up all of the body to frame mounts and shift the body over to center it over the frame better.

I just did this on my '64 Tempest (full-framed car) while I was in the process of replacing all of the old rubber body mounts with new urethane mounts. Did the same thing on my '64 GTO too, up front it was way off and now it's even from side to side.

I pried the body over using a piece of 1/2" X 1-1/2" flat stock about 2-1/2 feet long between the inner rockers and the frame rail, a good-sized tire iron could be used too. Body must be supported under the rockers using a long 4X4 piece of wood on a floor jack to take most of the body weight off the frame to allow you to shift it over.

[nowukno]

Is there a tech way to center the rear end? I am 1/2 pass side from center.
you need rear upper adjustable control arms

[GregInAtl]

you need rear upper adjustable control arms
Thats sound like the solution to most of my issues, that and a frame notch.
Thanks guys.

[nowukno]

Thats sound like the solution to most of my issues, that and a frame notch.
Thanks guys.
Talk to Marcus ae SC&C he should be able to help ya out!!!

[T-CHRGD]

Is there a tech way to center the rear end? I am 1/2 pass side from center.

Greg,
Are you measuring from the body or the frame ?? The answer (of both already offered) depends on whether the rear is off from the frame, or the body is off from the frame :)

[GregInAtl]

the rear tire is 1/2 closer to a lip than the other side, closer pass side....it scrubs, driver doesnt

[b-man]

the rear tire is 1/2 closer to a lip than the other side, closer pass side....it scrubs, driver doesntEither body is off to one side (shift body over on mounts to fix) or the rear end is off to one side in the chassis. Due to production tolerances on the assmebly line the body being off to one side by 1/2" is not the least bit unusual.

Shifting the body over is an easy fix, if there's an issue with the frame or suspension then that may not be as easy to deal with.