midyear handling...

[Bill W.]

Hello all,

Once again I need advice, can't think of a better place to start than here. I would like to improve the handling of my '66-350hp coupe without degrading the ride. Car has 95000 miles on the original suspension, I plan on changing lower ball joints/tie rod ends, idler and any other parts showing any wear.

Car currently has 7/8" bb front sway bar and '69 rear strut rod bracket. I am considering adding carbon fiber rear spg.(330 lbs./inch), new front springs (550 lbs/inch), gas shocks and poly bushings at front suspension pivit points. I don't want race car ride, just better handling. Car is used only on public hiways and for attending ncrs events. Car is never judged. Any members have experiance with what I am trying to do? Give me specific info about the springs and shocks and poly bushings, if possible. Thanks in advance. Bill

[Bill Clupper]

Re: midyear handling...

Bill, in my experience (limited though it is) the single best change you can make is to move to a modern tire. you don't specify what type of tire you are carrying, but it would make sense to start with a good Radial tire and then tune the suspension for that tire. Quite a few posts have appeared in the past with regard to a specific brand/size option, somewhat determined by the tire size, suspension mods, chassis ride height. Remember that if you go to a lower-profile tire (70 series or less) that GM changed the lower pivot bracket ( in '68 I think) to relocate the strut arm pivot points to be more compatible with the lower profile tires. Other wise the direction you're headed in is a good start, although the suspension design is not with out it's limitations, being very early sixties technology.

[Bill Clupper]

Re: midyear handling...

Bill, in my experience (limited though it is) the single best change you can make is to move to a modern tire. you don't specify what type of tire you are carrying, but it would make sense to start with a good Radial tire and then tune the suspension for that tire. Quite a few posts have appeared in the past with regard to a specific brand/size option, somewhat determined by the tire size, suspension mods, chassis ride height. Remember that if you go to a lower-profile tire (70 series or less) that GM changed the lower pivot bracket ( in '68 I think) to relocate the strut arm pivot points to be more compatible with the lower profile tires. Other wise the direction you're headed in is a good start, although the suspension design is not with out it's limitations, being very early sixties technology.

[John H.]

Re: midyear handling...

I'd recommend that you NOT do the poly bushing routine - the marketing hype is great, but in truth they're only suitable for a race car. Aside from major harshness transmission to the structure, they squeak and howl, and there's no effective way to lubricate them. Just replace your aged/worn/deteriorated bushings with new stock rubber parts. Been there, done that.

[John H.]

Re: midyear handling...

I'd recommend that you NOT do the poly bushing routine - the marketing hype is great, but in truth they're only suitable for a race car. Aside from major harshness transmission to the structure, they squeak and howl, and there's no effective way to lubricate them. Just replace your aged/worn/deteriorated bushings with new stock rubber parts. Been there, done that.

[Jimmy G.]

Re: midyear handling...

I had a 64 that I completely rebuilt. I mean every rubber piece in the suspension. I added a good set of Delco gas shocks and drove to the convention in Lake Placid. It was as good as I could ask for for a 30+ year old car. P.S. I put in new springs also.

[Jimmy G.]

Re: midyear handling...

I had a 64 that I completely rebuilt. I mean every rubber piece in the suspension. I added a good set of Delco gas shocks and drove to the convention in Lake Placid. It was as good as I could ask for for a 30+ year old car. P.S. I put in new springs also.

[Bill Baird]

Re: midyear handling...

Bill,

I've got a '75 coupe, and I've done much of what you are asking about on it. Here's what I've done:

550 lb. front springs

360 lb. fiberglass rear spring

1-1/8" front anti-sway bar

3/4" rear anti-sway bar

Carrera gas shocks

poly shock bushings

poly strut rod bushings

poly upper A-arm bushings

poly lower A-arm bushings

poly sway bar bushings

poly sway bar link bushings

I've loved the results. I do autocross my car some, but it's primarily a street car. The poly A-arm bushings do occasionally squawk, but not annoyingly so. If I hit a solid bump (such as a speed bump), I know that the car is more stiffly spung than stock, but most of the time the ride is just fine (though I'll admit to preferring a firm-ish ride). Body lean in a hard corner is definitely reduced. The cornering is more neutral than stock - there's less of a tendency to understeer in a corner, and a little oversteer becomes evident under a hard braking corner.

None of this would helps the car during Flight Judging, or be considered proper "restoration", but it sure makes the car a hoot to drive.

Bill Baird

[Bill Baird]

Re: midyear handling...

Bill,

I've got a '75 coupe, and I've done much of what you are asking about on it. Here's what I've done:

550 lb. front springs

360 lb. fiberglass rear spring

1-1/8" front anti-sway bar

3/4" rear anti-sway bar

Carrera gas shocks

poly shock bushings

poly strut rod bushings

poly upper A-arm bushings

poly lower A-arm bushings

poly sway bar bushings

poly sway bar link bushings

I've loved the results. I do autocross my car some, but it's primarily a street car. The poly A-arm bushings do occasionally squawk, but not annoyingly so. If I hit a solid bump (such as a speed bump), I know that the car is more stiffly spung than stock, but most of the time the ride is just fine (though I'll admit to preferring a firm-ish ride). Body lean in a hard corner is definitely reduced. The cornering is more neutral than stock - there's less of a tendency to understeer in a corner, and a little oversteer becomes evident under a hard braking corner.

None of this would helps the car during Flight Judging, or be considered proper "restoration", but it sure makes the car a hoot to drive.

Bill Baird

[Bill W.]

Re: midyear handling...

Thanks for the advice, this is a long term project, I'll keep you informed of results as I progress. Bill

[Bill W.]

Re: midyear handling...

Thanks for the advice, this is a long term project, I'll keep you informed of results as I progress. Bill