Vintage Mustang Forums banner
  • Hey everyone! Enter your ride HERE to be a part JUNE's Ride of the Month Challenge!
  • May's Ride of the Month contest ended with a tie! Go to this thread to vote on the winner! VOTE HERE
1 - 12 of 12 Posts

·
Registered
Joined
·
9,844 Posts
Discussion Starter · #1 ·
Here's the situation on my 67 GT350. Completely rebuilt front suspension that is stock except for roller spring perches. No Shelby drop. 215/65 tires on 15x7 Shelby ten spoke wheels. The rear has new 5-leaf "stock ride height" springs.

The factory front springs on these cars are pretty stout. IIRC they are stiffer than 1967 GT springs and if you look at period photographs from the 60s you see most 1967 Shelbys have a "nose up" attitude.

The 347/T5 combo is lighter than the stock drive train so the nose got even higher when I put it in. Then I had to shim the rear axle to change the pinion angle and that dropped the rear lower. As a result the front end was 1.5" higher than the rear and it looked pretty goofy.

So I bought a set of 1065-66 contour coil 1" lowering springs from NPD. I bought the 65-66 because they are not as stiff as the 67-70 (480 vs. 520).

When I removed the original springs I found that they were 3 full inches longer than the lowering springs. I installed the lowering springs anyway and sure enough the front end dropped 3". Now the front tires drag on the fenderwells in a full lock turn - even at 5 mph. The top of the wheel cutout is only 23.75" off the ground.

I'm looking for suggestions. I am not going to change the tires or wheels. Is it possible that dropping the front end that far gave me a lot of negative camber and that a realignment will help? Has anyone ever tried the 1/2" thick insulators? Are the 65-66 springs shorter than the 67-70 and are part of the problem?
 

·
Registered
Joined
·
7,294 Posts
68RCodeConv said:
Are the 65-66 springs shorter than the 67-70 and are part of the problem?
I think you nailed it, because a cheap and dirty trick for us 65-66 owners is to get a set of stock 67-68 springs and cut quite a bit off, volia!, 65-66 performance springs. Maybe a set of 1" insulators would work, or you could sell the 65-66 springs and cut a set of big block springs to whatever ride height you'd like, which ought to get you in the 480# range, according to my SWAG-o-meter :lol:
 

·
Gone but never forgetten
Joined
·
25,239 Posts
Is it possible that dropping the front end that far gave me a lot of negative camber and that a realignment will help? Has anyone ever tried the 1/2" thick insulators?
I doubt that changing the spring has made any change at all to the camber, or any other aligngment settings for that matter. You could try to dial back the camber to a more positive one to avoid the valance (IME, fitment problems in the front are almost always with the valance, not the fender), but the car won't handle as well if you do.

They also make a 1" polly-eurothane coil insulator if you wanted to raise it back up a full inch and keep the current springs. I haven't personally used either the 1/2" or the 1" insulators, but I don't see where they would cause any issues at all.

FWIW, on my '69, I have 225/60's in the front on 15x8 wheels. I do have an interference problem with the wheels at either full lock. I don't want to change anything, though, especially how the car corners. My solution ... never turn the wheels to full lock ;)
 

·
Registered
Joined
·
992 Posts
John,

Lowering the front will affect the camber angle.

I don't think to the point it would do what you are describing.

I think you are going to have to change springs.

We can measure it out for you to be sure if you like.

You have my number right?

Sluggo
 

·
Registered
Joined
·
12,306 Posts
gotstang said:
68RCodeConv said:
Are the 65-66 springs shorter than the 67-70 and are part of the problem?
Maybe a set of 1" insulators would work, or you could sell the 65-66 springs and cut a set of big block springs to whatever ride height you'd like, which ought to get you in the 480# range, according to my SWAG-o-meter :lol:
I'm thinking cutting the springs would increase the spring rate.. If I recall.
 

·
Registered
Joined
·
9,844 Posts
Discussion Starter · #8 ·
Opentracker said:
Send me an email. I might be able to trade you a set of our 67-73 560 1" drop coils for those.

The only right way to fix it is to get new springs.

[email protected]
Assuming everything else is the same - raising it 1" from where it is now would be perfect. I think I will take you up on this offer.

I'll shoot you an email.
 

·
Gone but never forgetten
Joined
·
25,239 Posts
sluggo said:
John,

Lowering the front will affect the camber angle.
How would it affect the camber angle? By changing nothing but the springs, you haven't changed where either the upper or lower arms attach to the car. You've only changed how far the fenders are away from the upper arm. I just can't see how you're effecting camber angle, which is basically the forward/aft relationship of the upper arm to the lower.
 

·
Registered
Joined
·
992 Posts
johnpro said:
sluggo said:
John,

Lowering the front will affect the camber angle.
How would it affect the camber angle? By changing nothing but the springs, you haven't changed where either the upper or lower arms attach to the car. You've only changed how far the fenders are away from the upper arm. I just can't see how you're effecting camber angle, which is basically the forward/aft relationship of the upper arm to the lower.
Because you changed the center point of the axle.

As the control arms move through their arcs the camber fluctuates, negative as they go up and positive as they go down.

Anyway, when John gets it the way he wants it and if he has me realign it the proof will be in th pudding. I'm sure he has the previous print out and we can compare them.

If it does not change the camber I will buy you a doughnut and some coffe :)
 

·
Registered
Joined
·
992 Posts
johnpro said:
sluggo said:
John,

Lowering the front will affect the camber angle.
I just can't see how you're effecting camber angle, which is basically the forward/aft relationship of the upper arm to the lower.
I re-read your post and figured out where I think there may be some confusion.

The forward/aft relationship between the upper and lower arms (ie a line drawn from the upper arm to the lower arm through the ball joint) is the caster angle.
If the upper control arm is trailing the lower you get positive caster. The more positive the better straight line driveability and steering wheel return and
increases steering effort.
If the upper control arm is leading the lower it's negative caster.
I agree that caster would not change significantly.

The side/side relationship between the upper and lower arms (ie a line drawn from the upper arm to the lower arm through the ball joint) is the camber angle.
 

·
Gone but never forgetten
Joined
·
25,239 Posts
The side/side relationship between the upper and lower arms (ie a line drawn from the upper arm to the lower arm through the ball joint) is the camber angle.
DOH! I knew that *LOL*. I must have been asleep at the wheel, while typing that. I was thinking camber, even when typing caster. :shrug:
 
1 - 12 of 12 Posts
Top