'71 springs on an '80

[amawds]

So I'm building up an '80 that just got out of paint. On my '76, I have the iap lowering springs and have hated them since I got them. The fronts brought the car down to where I wanted it but the rears actually lifted the car, and I had to cut a coil and a half to get them close to the front. Even now the car still sits a half inch higher on the rear.

I'm looking for a streetable ride. I tend to veer more towards overly stiff. This car will have yellow koni's and poly front bushings. The '76 has cheap kyb's and cheap rubber.

I have a '71 parts car. My understanding is that these cars were lower than any other model and had a higher spring rate. Should I powdercoat these and toss them on the '80? Or is the spring rate actually really soft? Any recommendations would be great. This is my daily driver but I definitely like a firm, non floaty ride. I'll likely be running the koni's a bit harder than most people would.

[perthling]

As I understand it the 75-on springs were longer to allow for the heavier bumpers and also to raise the ride height to satisfy the US regulations.

I had no problem with the ride quality with my '74 on standard springs.

[amawds]

Does your car feel decently stiff? Or does it feel like you're driving on a marshmallow

[perthling]

It certainly wasn't pillow-soft, but I have now (approx 18 months ago) put in some slightly shorter springs (my '74 used to sit up a bit at the front for some reason) so the ride is a little more firm now. But it was certainly not wallowy with the original springs, I changed them for aesthetics only, not because there was any problem with the ride.

[amawds]

Perfect, that's exactly what I was looking for. Ride height can be fixed by cutting, although I use it as a last resort. I'll pull the springs from my parts car, have them media blasted, and paint them black.

Anybody happen to know the spring rates of early springs?

[perthling]

Ride height can be fixed by cutting

Yep, and don't forget that with a few of these cars in your fleet you've probably (as I have) acquired a collection of spring spacer rings and cups which can be mixed and matched to adjust your stance.

[amawds]

Don't actually have spring spacers laying around. Never needed em. I don't fiddle with suspension very often but with this build I'm going all out. Tubular control arms and all.

[perthling]

I was referring to the ones which are fitted in the Spider standard suspension - the plastic rings of varying thicknesses. I seem to have a large collection after pulling apart a bunch of Spiders and Coupes over time.

[azruss]

I have 71 springs on my 80 FI. originally had KYB gas-adjust and the car was stiff to the point of a very harsh ride. I installed kyb low pressure gas shocks and the improvement in ride quality and the ability of the car to stay connected to the ground is dramatic. I am running 195-55 tires which is so much stiffer than stock tires it makes the car a completely different ride. I do not find the springs to be soft and make the car float. I also added a rear sway bar and a front spoiler that works very good at keeping the car hunkered to the road at speed. I removed the crash bumpers and installed early style. the cars ride height is like the early models. Even with the heavier engine, my nose is slightly higher than the tail.

[amawds]

azruss do you have any pictures you could post from the side of the car? I'd love to see exactly how low it is. This sounds very promising though. Exactly what I'm looking for. I'm running 205/50r15's so I have quite a stiff sidewall as well.

[azruss]

check out the following previous posts.
Jury is in: posted 10/17. this has actual height measurements and shock information.
Bullet turn signals: 7/28. pictures of car
off the deep end: 5/26. pics of car from a lower point. this is before shocks and added weight of trunk and interior.

[amawds]

Actually looks really tall. My ideal ride height is about a quarter inch from fender on the front, half inch on the rear. I'll likely settle for a more conservative half inch in the front, 3/4 in the rear. I am using the same panasport style wheels and early honeycomb grill you're using though! When pushing down on the parts car, the springs definitely feel much stiffer on the front at least so I think I'm good there. I'll measure out the springs and run them through a calculator to see what the spring rate should be, and what they would be if I cut a coil out of the front, then go from there.

[azruss]

I dont know of anyone that makes a street spring that short. Of course, when you cut, you automatically make the spring stiffer. If I cut mine that low, i would have to crawl thru every intersection as there are no storm sewers and they just dip the road for drainage. Driving like that is just an open invitation for a jacked up truck to come and sit in the back seat.

[azruss]

do your due dilligence before you cut. I measured 2 3/8" from top of tire to the high point of the fender flair arch. I also measured the low point on the car was the lead pipe to the cat at 4" off the ground. the bottom of the side rail seam measures 7". If you want to drop down to as little as a 1/2", that is a 1 3/4" plus change. that would put my exhaust 2 1/4" off the ground and the chassis 5 1/4" off the ground. Didnt even measure the pan to see where that would end up.

[perthling]

If you lower the car so much that the bottom wishbone exceeds the horizontal (i.e. the arms point 'up' from crossmember to the wheel) then prepare for some pretty unruly handling.