Thread: 1932 glass 3 window rear coilover spring rate help

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I rode in my son-in-law's fiberglass 32 with coilover rear suspension this Thanksgiving weekend. Man, what a rough ride! The TCI All American progressive coilover is what he is usingT because they were FREE. I can understand this, but I think he can get a better ride with just a spring change. Can someone give him a spring rate that they think would be a good ballpark figure. The car has been scaled and has a rear corner weight of approximately 650 pounds with him in it. I think the progressive spring that is on it is rated at 250# on the high end. This broken down old man isn't getting back in it until he does something different. Any suggestions would be greatly appreciated. Thanks

I don't have the info handy right now but I remember using the chart from Speedway and found them all to harsh. The original rating and the next one "lighter".. all to hard for my taste. I ended up working with AFCO and have been pretty happy with it. But I don't remember the ratings off the top of my head! We nailed the fronts perfect and the backs are just a tad tougher than I'd like, but not bad... After I got that part done, AFCO was bought by Speedway and they came out with a line of Hot Rod shocks, double adjustable too.

Unless you are pulling a trailer I don't think you should need progressive springs. I fought a rough ride for 20K miles, most of the problem was I did not know how to adjust the coilover shocks properly. I thought the adjustment screw on the shock was for the down bounce, I found out it only affects the return rate of the shock.

I was never happy with the progressive springs, always too harsh and wouldn't let the shock work! With a 650 pound wheel weight, the 250# springs is way too harsh IMO. As for the Speedway chart I too found it very inaccurate and Seth's comment on the shocks is worth looking into also. If you can make it through the salesmen on the phones at Speedway and actually talk to one of the AFCO shock and spring techs you should get an accurate answer to the correct spring rating. I have a leftover pair of 200# springs that I took off a guys '34 coupe and went to a 150" AFCO spring, he hasn't been back so I guess they were ok! LOL, of course, your results may vary! Again, just my opinion but I believe the double adjustable shocks are worth the extra $$$$ just for the ability to tune them!

I just looked, I have 250 lb on the back of my 53 pickup. It has an aluminum luggage box in the back, receiver hitch and fuel tank mounted in the rear as well. When I measured spring compression as I lowered the pickup, 250s were about perfect for it ( 2 inch drop if I remember right, I could be wrong though ). I'm guessing they are way too heavy for your application.

Guys, thanks for the replies. My son in law found where Ridetech recommended a 130# or 150# rating for a 32 that scaled close to his car weight. We are trying to get by with springs only right now so that he can purchase a Speedway swaybar kit. I found a 175# set locally to replace the progressive springs that are on it. Dave's comments, along with Ridetech, make me think we may still be a little too stiff. I will let everyone know how these springs ride. The limited shock travel may make it difficult to run a soft spring rate. We will see. Thanks again.

For the limited suspension travel, look into a tapered bump stop. Energy Suspension sells them, for one. The tapered stop will not be as harsh when you do hit it. Unfortunately, short travel has its problems. I lived with the same issue on my T bucket. I ran air bags instead of springs. Ride was good, but found the bump stops regularly on rough roads.

Originally Posted by Deuce4dad

Guys, thanks for the replies. My son in law found where Ridetech recommended a 130# or 150# rating for a 32 that scaled close to his car weight. We are trying to get by with springs only right now so that he can purchase a Speedway swaybar kit. I found a 175# set locally to replace the progressive springs that are on it. Dave's comments, along with Ridetech, make me think we may still be a little too stiff. I will let everyone know how these springs ride. The limited shock travel may make it difficult to run a soft spring rate. We will see. Thanks again.

We don't know if the chassis was setup for it but if you must run the 175 rating springs, and, if the chassis was configured for it, lean the shocks as much as possible and it'll make them less effective. A bit of a cheat but it may get you by for a while.

Just an update. The 175# springs were not enough with the limited shock travel. We then went with 130#-220# progressive springs with a 12 inch length. These were just a spare set that he had. The coilover shocks on the car used 11" springs so we preloaded this spring 1 inch to install them, then preloaded them further to get the correct ride height. There was no coil bind at ride height. The car rode much better but did bottom out. Next thing to do is to install bump stops as mentioned above. Don't think we will leave these springs on the car. I'm sure the progressive spring is using up too much shock travel. We will most likely go with 200# or 225# springs later on. He's hoping to buy Ride Tech coilovers as soon as he recovers from paying taxes of one kind or the other. I know his pain! Will update later.

well sounds like you're getting closer!