looking for help figuring out what went wrong with front coil spring replacement (Page 2/2)
Signupacct MAR 19, 11:24 PM


help me to understand your calculations and conclusion that the 6730 is too stiff

I am not asking for any other reason than to learn something regarding this

the SMS6730 or I may have referenced in previous posts as RC6730 but the same spring the prefix letters I think are unique to the vendor

thank you in advance
Rick Vanderpool MAR 20, 12:09 PM
Your indicated you bought RC6730 from Husky, so I looked up that item. Here is the page listing the specs for that spring.
https://www.huskyspring.com/Home/ProductDetail
The spring rate for that spring is 1501 pounds per inch, which means it takes 1501 pounds to compress the spring 1 inch. your calculations put each front corner at 705 lbs., which would result in a compression of less than 1/2 in. There are other factors which affect spring rate calculations but they would all reduce the required rate.
Having said all that, the evidence that this is the issue is the fact that the car sits way to high and doesn't move down when you sit on it.
Rick

The link doesn't go directly to the spring in question. Put RC6730 in the search box and select the item that is listed. them click on the specifications tab.

[This message has been edited by Rick Vanderpool (edited 03-20-2023).]

Signupacct MAR 21, 02:16 PM
well

the selection of the RC6730 was not a casual process and was led to believe that was going to meet the specifications for the car

as I double check the process I can see that somehow the process broke down

the 6730 spring according to Husky is the lightest for a chevy chevette with no a/c as the 6556 and 6558 are rated even heavier


the 1987 Pontiac Fiero GT with a V6 and a/c was pretty common

so how would you recommend determining the proper spring specs and also specs for what was oem (such as spring coil wire diameter, inside diameter, number of coil winds, uninstalled height, spring rate per inch)

I did find the following number 10034101FJF but I am unable to convert that to any specifications or to currently available spring part number.

obviously I thought I did but maybe not








[This message has been edited by Signupacct (edited 03-21-2023).]

PhatMax MAR 21, 03:52 PM
Read this….

https://www.fiero.nl/forum/Forum2/HTML/139002.html
Signupacct MAR 21, 10:38 PM
great read

unfortunately it references a car way lighter than mine and no specific mention of oem spring part numbers for a 1987 pontiac fiero gt v6 with a/c

appreciate the mention

still hoping someone has an idea what the oem part number is for the front coil springs and the specs for those springs such as

diameter of the coil wire, the inside diameter, the uninstalled height, the rate per inch, how many winds


the best I have for oem part number is the 10034101FJF but have no more information than that

oem specifications would help identify other aftermarket springs that might work

[This message has been edited by Signupacct (edited 03-21-2023).]

PhatMax MAR 22, 05:24 AM
Perhaps this company has the spring rates on file. I know they can make whatever you need.

Kevin Crane
Coil Springs Specialties
PBX "G"
632 W. Bertrand Avenue
Saint Mary's, KS 66536
785-437-2025
fieroguru MAR 22, 05:46 AM

quote
Originally posted by Signupacct:
still hoping someone has an idea what the oem part number is for the front coil springs and the specs for those springs such as

diameter of the coil wire, the inside diameter, the uninstalled height, the rate per inch, how many winds



Looks like you have the original springs out, so all you need to do is measure them to get the needed information to calculate the spring rate. It will be about 200 lb/in +/- 10%.
https://www.thespringstore....rate-calculator.html

You can do the same with your new springs to verify the rate.
Signupacct MAR 22, 12:04 PM
great suggestions both

unfortunately as for measuring the springs that came out the previous owner that I purchased it from lowered it

and cut some off

also it appears that the husky catalogue and the numbers appear suspiciously wrong

someone in previous post suggested that by the specs in the husky catalogue and the phone rep that the springs inch rate was twice what it needed to be but i asked husky to double check their numbers becuase they dont agree with the 6730 springs they shipped

I will reach out to the suggested spring sources and see what they have


stay tuned

[This message has been edited by Signupacct (edited 03-22-2023).]