'66 Biscayne- chassis adjustment for better traction-

66cayne · 05-25-2019, 06:36 PM

I have a '66 Biscayne, 496BBC, 4 speed, 12 bolt, M/T 10.5/29/15 slicks. I am trying to improve traction when I launch this thing. She is running 11.60s s with a 1.70 60 ft.. I have fiddled with slick air pressure, an airbag in the passenger side rear spring and different spring and shock combinations. I am now trying to adjust the instant center( where the 2 upper and 2 lower control arms would theoretically intersect if they ran through the entire car) more towards the center of the car instead of slightly in front of it (by my calculation, hard to do with the body on the frame). I understand this change in I/C will benefit planting of the rear tires and hopefully improve my launch/60 ft times. My plan is to change the angle of the two upper control arms so they will intersect with the projected line of the lower control arms more towards the center of the car. I believe by adjusting the angle downward on the two upper bars by about two inches it will get me there. I suppose this could also be done by lowering the rear mounting point of the lower control arms to achieve the same effect. Just want to hear from those with more chassis experience if I'm on the right track for attempting this change. Thanks

impstocker · 05-25-2019, 09:46 PM

I ran a 1968 Impala with a 396/325HP I/S 2003-2005 Jerico 4 speed, McCloed Sof-Lok clutch, 14 lb flywheel, (you make enough HP to run a Aluminum flywheel too) 4:88 w spool. Rear suspension was a set of Southside Machine lower control arms, they are no longer around, but the bars lowered the mounting point of the back of the bar changing the IC I have them on my 65 Impala stocker now, but with automatic. I also run adjustable upper control arm with Heim joints. The crossmember they bolt too was also braced and I run a X frame off my roll bar to it, these tend too pull out without any bracing. I ran 11.70's , 115 MPH with it. I never really sorted out the clutch, but I remember running only like 600 lb clutch base pressure. My best 60 ft times i believe were high 1.50's , this was at 4095 lb
Will Lamprecht
I/SA 65 Impala 396/325

Dan Fahey · 05-25-2019, 10:31 PM

Have a 1969 Impala that ran in M/SA.
Used airbags and glued on a piece of 2by4 on axle housing.
On launch this would hit the Pinion Snubber.

Doing a full restoration on the car.
The new chassis set up will have the Southside Machine lower control arm.
Chassis was restored and reinforced by Steve Yeagle.
Including the Crossmember that the Upper Control arm attaches to.
Every year hope to finish the car.

Years ago designed a bracket raising Upper Control Arm at the Axle 2.5 inches.
Made it and never installed it.
That is when we started having kids.

All said and done.
Gluing the piece of wood on the top of the Axle worked well.
At rest was 1.5 inches from the Snubber.
Car squatted smoothly, launched hard pulled left front tire.

Lee Valentine · 05-27-2019, 09:05 AM

Have a friend with 66 Biscayne running low 10's with reinforced crossmember and an air bag

Mark Yacavone · 05-27-2019, 11:55 AM

That type suspension is one of the easiest to raise the rear of the uppers on .
You need some flat stock , a few extra short bolts, and a welder..and. oh yes , the ability to use it properly.
I don't think I'd go up 2, 1/2 inches though.
Solid lower bushings help those cars immensely . There is very little binding, with the uppers running straight ahead.

66cayne · 05-27-2019, 01:38 PM

thanks for responses and ideas. Yes, unfortunately Southside Machine does not make the lower bars for our 65-70 b-body cars anymore. Thats why I started looking at lengthening the upper control arm rear mounts help make the needed change to the I/C. Dan Fahey- if you still have the bracket or a drawing you designed I would love to see it. 2" -2.5" is about right for setting that upper control arm at parallel. Also, I have do have brackets welded in support the upper control arm mounting frame cross-brace.

05-25-2019, 06:36 PM	#1
66cayne Junior Member Join Date: Mar 2019 Posts: 7 Likes: 0 Liked 2 Times in 2 Posts	'66 Biscayne- chassis adjustment for better traction- I have a '66 Biscayne, 496BBC, 4 speed, 12 bolt, M/T 10.5/29/15 slicks. I am trying to improve traction when I launch this thing. She is running 11.60s s with a 1.70 60 ft.. I have fiddled with slick air pressure, an airbag in the passenger side rear spring and different spring and shock combinations. I am now trying to adjust the instant center( where the 2 upper and 2 lower control arms would theoretically intersect if they ran through the entire car) more towards the center of the car instead of slightly in front of it (by my calculation, hard to do with the body on the frame). I understand this change in I/C will benefit planting of the rear tires and hopefully improve my launch/60 ft times. My plan is to change the angle of the two upper control arms so they will intersect with the projected line of the lower control arms more towards the center of the car. I believe by adjusting the angle downward on the two upper bars by about two inches it will get me there. I suppose this could also be done by lowering the rear mounting point of the lower control arms to achieve the same effect. Just want to hear from those with more chassis experience if I'm on the right track for attempting this change. Thanks

05-25-2019, 09:46 PM	#2
impstocker Member Join Date: Dec 2008 Location: Wingdale, NY Posts: 302 Likes: 27 Liked 53 Times in 16 Posts	Re: '66 Biscayne- chassis adjustment for better traction- I ran a 1968 Impala with a 396/325HP I/S 2003-2005 Jerico 4 speed, McCloed Sof-Lok clutch, 14 lb flywheel, (you make enough HP to run a Aluminum flywheel too) 4:88 w spool. Rear suspension was a set of Southside Machine lower control arms, they are no longer around, but the bars lowered the mounting point of the back of the bar changing the IC I have them on my 65 Impala stocker now, but with automatic. I also run adjustable upper control arm with Heim joints. The crossmember they bolt too was also braced and I run a X frame off my roll bar to it, these tend too pull out without any bracing. I ran 11.70's , 115 MPH with it. I never really sorted out the clutch, but I remember running only like 600 lb clutch base pressure. My best 60 ft times i believe were high 1.50's , this was at 4095 lb Will Lamprecht I/SA 65 Impala 396/325

05-25-2019, 10:31 PM	#3
Dan Fahey VIP Member Join Date: Oct 2008 Posts: 2,128 Likes: 1,084 Liked 184 Times in 113 Posts	Re: '66 Biscayne- chassis adjustment for better traction- Have a 1969 Impala that ran in M/SA. Used airbags and glued on a piece of 2by4 on axle housing. On launch this would hit the Pinion Snubber. Doing a full restoration on the car. The new chassis set up will have the Southside Machine lower control arm. Chassis was restored and reinforced by Steve Yeagle. Including the Crossmember that the Upper Control arm attaches to. Every year hope to finish the car. Years ago designed a bracket raising Upper Control Arm at the Axle 2.5 inches. Made it and never installed it. That is when we started having kids. All said and done. Gluing the piece of wood on the top of the Axle worked well. At rest was 1.5 inches from the Snubber. Car squatted smoothly, launched hard pulled left front tire.

05-27-2019, 09:05 AM	#4
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: '66 Biscayne- chassis adjustment for better traction- Have a friend with 66 Biscayne running low 10's with reinforced crossmember and an air bag __________________ Lee Valentine 1661 STK

05-27-2019, 11:55 AM	#5
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,815 Likes: 2,904 Liked 5,121 Times in 1,952 Posts	Re: '66 Biscayne- chassis adjustment for better traction- That type suspension is one of the easiest to raise the rear of the uppers on . You need some flat stock , a few extra short bolts, and a welder..and. oh yes , the ability to use it properly. I don't think I'd go up 2, 1/2 inches though. Solid lower bushings help those cars immensely . There is very little binding, with the uppers running straight ahead. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

05-27-2019, 01:38 PM	#6
66cayne Junior Member Join Date: Mar 2019 Posts: 7 Likes: 0 Liked 2 Times in 2 Posts	Re: '66 Biscayne- chassis adjustment for better traction- thanks for responses and ideas. Yes, unfortunately Southside Machine does not make the lower bars for our 65-70 b-body cars anymore. Thats why I started looking at lengthening the upper control arm rear mounts help make the needed change to the I/C. Dan Fahey- if you still have the bracket or a drawing you designed I would love to see it. 2" -2.5" is about right for setting that upper control arm at parallel. Also, I have do have brackets welded in support the upper control arm mounting frame cross-brace.