Bluebird and I were talking and decided to make this public for more input from you people. It may seem confusing but it'll get better Hello Niell Can you get me one more measurement? I need the distance from where the lower control arm would pivot to where the shock attaches and from the pivot to where the ball joint attaches in order to get the motion ratio. Thanks, Al. I will measure tonight. Do you also use half the weight of the control arms when calculating unsprung weight. 8.5" and15.5"
Thanks again, beers are on me this summer. Yes, It's the weight of the ball joint end with the pivot end supported. I used less than half of the numbers you gave me as the ball joint end has no bushings, but now that I think about it the balljoint will offset the Bushings. My measurement under the car was 10 and 16 inches to 8 and 13 inches. I couldn't quite get the proper pivot spot. Thanks for all the help.
Hey Al, how's it going? Do you remember the part number of the coil springs that you have used on your car? Thanks for any help. Neil lHi Neil, I don't know if I have the receipt still but I will search for it and get back to you. Al Hi Niell I found the number. MOOG 6312 Al Thank you. did you have to shorten them at all to get your ride height? with all your aluminum stuff I'd think that it would ride high. I asked because I'm looking at the moog 5370 but I think that they're the same as yours just 1/2 inch shorter. Neill When I bought my car I was surprised to see two pieces of 1X2 wood stuffed between the coils, especially after I paid for a PROFESSIONAL inspector to give me a report. I bought what was supposed to be a stock replacement set from Napa. Moog 5246. They were too high. I think they may have been for a convertible. I got a pair from JB Moog 6312, they were too high so I cut off a coil. They ended up too low. Then I noticed the part number on the spring was not the same as the number on the box. I returned them, and after the ensuing argument of returning damaged goods they replaced them with the 6312s. They don't like to see me walk into the store much. The ride height was good maybe a teeny bit low but that was before I re-did my engine. I like where it sits now but it most likely would look a bit high if I had 14 inch wheels instead of the 15 inch. I checked this morning the 6312s have a load rate of 1664 pounds and the 5246s have a load rate of 1872 pounds. I could not find the spring rate for either. My tires rub on the inner fender if I hit a bad dip in the road. The contact point is at the very top just inside of the outer fender. There is a slight bump in the inner fender, that is where I make contact. I don't know how people lower their cars two inches and still not rub. I've had four pairs of springs on mine and can't seem to avoid rubbing. Maybe with 14 inch wheels? Thats why I want the coil overs for the adjustability. But the dolt I'm communicating with at Chassisworks doesn't have a clue as to what springs I should use so I"m back in the same boat, trial and error to get the correct spring. I'd like to talk to the owner but keep getting people who know how to place and order but know nothing about the product.Humm, after all that I didn't answer your question, no I did not cut the 6312 springs I now have in the car. Al I stopped driving my convertible lastyear because I was getting scared of breaking a spring. Both front coils have spacers in them and the tires rubbed more each time I drove it..it needs a lot more than just coils but It was the only one that was roadworthy at the time. The 5370 coils are supposed to be the hd replacements for the 400 coupe with 10.25 installed height .64 diameter coil wire and 357 spring rate and 2022 load. 6312 has .64 wire, 337 rate 10.75 installed height and1800 load. Does this mean that your coils are identicle except for ride height to the 5370 ? If so then the 5370 would cause more tire rub than the 6312? Just trying to do this once and I don't really understand spring rate and load and how they affect things. If you don't know I'll post it to the forum. Thanks. Neill Neil Post it, I'm not a spring expert. I tried to find the specs for these springs but could not, Where did you get it? I couldn't even find them on the Moog site. The convertibles have an extra 150 pounds of cocktail shakers so need a heavier spring. No they aren't the same, load rate and spring rate are different. The load rate is how many pounds the spring will hold at a certain height. If you put a monster spring with no deflection 10.75 inches long it would hold the 1800 pounds at the 10.75" it wouldn't move up or down though. The load rate holds the said load at the said hieght, the spring rate is how much force it takes to compress the spring one inch. If the 5370 has a load rate of 2022 pounds and a spring rate of 357 it will compress 5.66" when 2022 pounds is applied. If the free legnth is 16.5 inches and the load is 2022 pounds it will give you the installed hieght. The 5370 will give a harsher ride than the 6312 due to the higher spring rate. If you got two springs with the same load rate and the same installed hieght you will get a softer ride with one that has a lower spring rate. Now you also have to think about shock travel. The shock should be compressed about 40% of it's total travel when everything is put together, the car is loaded and ready to drive. That gives you 60% bump travel for those not very smooth roads we have and 40% rebound. If a 5307 spring gets you in that range it may be the one to use. 50-50 is the next desirable but any lower and you will bottom out.
The only way to be sure is to weigh your car with you and the average load in and subtract the unsprung weight. That will give you the load rate. You then have to determine what the installed height should be to give you the ride height and shock travel you want, then get the spring that meets these paramaters. Now you know why there are vast number of springs listed for each car and why we keep reading about fellow FGF members that cannot get the spring-ride height they want.
After saying all that, we have bump stops on the control arms which are supposed to stop the travel before the tires rub on the fenders. Didn't work on mine. There may be factors other than springs that are contributing to the rubbing. Worn or damaged front end components, replaced non stock items or mods made buy us or someone in the past.
When I took the wooden spacers out of my front springs it rubbed more than ever. Then I noticed the control arm bushing were worn and they were completely missing on the right upper. $500 for an inspection well spent? I replaced the works but I still get rub once in a while with two or more people in the car and I hit a deep dip.
I wish luck with yours, after taking my front springs out four times I don't wish that job on anyone Al. .Hi Al, I was thinking of asking the admin. to make this thread public if its ok with you because you have some good info. The spring info I got is http://fme-cat.com/Application.aspx#passengercar Neill OK with me, if you don't mind. Al
If you want I can measure my springs which had a nice ride height on my 69 convertible 400 car. I have them out and decided to clean them up and reuse them instead of a new set which I could have the same problems?
I believe them to be originals OR very old replacements say from back in the 80's? There are no markings on them as far as I can tell.
I went ahead an measured exacting 17" from tip to tip.
I have a set of brand new Moog 5244 that I bought on accident and didnt realize they were for a 69 convertable. They are still in the box and they are 18 inches tip to tip. They look like someone put them on and took them out and returned them. There are no markings on them.
