Mustang ll coil over spring rate

[Hampshire]

What do you have for a spring rate? I have iron head SBC with springs rated at 500#. The shocks are Viking A201 (similar to the A203).

Without going into a long winded explanation, we're doing a little readjustment this coming spring & I'm re-evaluating what I have. Ride is firm but very nice. Hitting a bump on the highway at 70mph is tolerable, but it wouldn't hurt to be a little better. Anyway, I have the opportunity to first change things up front: longer travel on the shocks & maybe swap in a lighter (375#) spring.

[mr48chev]

I'd think this is where you start studying various coil over manufactures spring weight vs vehicle weight (load per wheel) charts and work on a viable solution.

It isn't all springs or weight of the vehicle though. My 2000 Cad DTS daily driver with it's 17 inch rims and 245 tires is one of the roughest riding vehicles I have ever owned and according to my wife our 77 Chevy flatbed dualie rides smoother most of the time. Those low profile tires relay every road surface change and let you know where every expansion strip on the concrete surface freeway is while the dualie just rolls over the road and the 10 ply tires don't relay the differences as much. So much for riding like a truck.

[Rude Dude]

Sounds as if you have V8 springs good for TF Trucks with A/C or if you are running a Big Block . You might consider the V6 springs the are rated at 350lbs better suited for AD Trucks. If you want even a lighter springs the 4 cylinder springs I think are rated at 250 or 275 it escapes me know. Usually found on fat fender rides like 40 Chevy or 41 Ford.

[Hampshire]

start studying various coil over manufactures spring weight vs vehicle weight (load per wheel) charts and work on a viable solution.

...good way to start - planning do do some figuring on load per wheel next month with a guy I work with.

RudeDude - a couple others have been telling me to also look at lighter springs. The recommended Viking Coil over for a 67-69 Camaro/Firebird w/V8 is 375#. Mine can be setup for the same ride height/travel spec.

[mobileortho]

Is the ride that much better with coilovers?

[yoshi]

My 49 weighs 3218lb with an sbc350 fitted, i've fitted 375lb springs & it seems to ride just fine

[jweb]

I'm really confused about this myself. I plan on upgrading soon and I can't seem to get a good answer for spring rate. I currently have Mustang V6 springs and monroe shocks. It rides pretty rough with the low profile tires. I plan to switch to QA1 double adjustable coilovers.

QA-1 recommends a #700 spring which seems like it will be way too stiff. Here's a link to their chart and they list an average weight of a 47-54 truck.

https://www.qa1.net/tech/documents/S...le-Weights.pdf

[solidaxel]

We have QA1 on the 46 pick up with a LS and a Scotts suspension
He said we needed 500# springs but when the truck was all together we could not compress the front end! Changed the springs to 400# and adjusted through all the settings (10) still rattled your teeth! Changed to 300# adjusted and the ride is very good, I have not hit any big dips at hiway speeds(75+) so I am not sure I will like them!
I am thinking maybe 350 or 375# may do the trick and run through the adjustments again to fine tune.

[jweb]

Originally Posted by solidaxel

We have QA1 on the 46 pick up with a LS and a Scotts suspension
He said we needed 500# springs but when the truck was all together we could not compress the front end! Changed the springs to 400# and adjusted through all the settings (10) still rattled your teeth! Changed to 300# adjusted and the ride is very good, I have not hit any big dips at hiway speeds(75+) so I am not sure I will like them!
I am thinking maybe 350 or 375# may do the trick and run through the adjustments again to fine tune.

I plan on using the QA-1 coilover conversion kit. It uses an 8" tall spring, so I wonder if that makes a difference? It seems like the 375# would be the best since I have an LS1 and no A/C.

[yoshi]

https://www.eatondetroitspring.com/o...-coil-springs/

[jweb]

I just called QA-1 and talked with one of their techs. He said since their coilover kit uses an 8" spring they recommend a 700# spring. He told me the front of these trucks weigh around 1900# even with an LS motor.

[solidaxel]

Originally Posted by jweb

I just called QA-1 and talked with one of their techs. He said since their coilover kit uses an 8" spring they recommend a 700# spring. He told me the front of these trucks weigh around 1900# even with an LS motor.

They must have a very steep angle to use 800#, we could get the 500# to compress standing on the bumper
WE must be doing something wrong

[jweb]

Originally Posted by solidaxel

They must have a very steep angle to use 800#, we could get the 500# to compress standing on the bumper
WE must be doing something wrong

I doubt you are doing anything wrong. The conversion springs taper from 2.5" at the bottom to 3.5" at the top so they will fit in a stock spring hat, that may be another reason for the 700# spring. There are so many factors when figuring this out, I guess I will end up with a few sets of springs sitting in the corner by the time I'm finished. Seems like I've bought every part at least twice.

[solidaxel]

Well we are talking two different angles Mll and Aldan coil overs so 700# as stated for Mll is most likely true.
Although on my 55 GMC with a true Mll I used the lightest springs I could find and Bilstine shocks and it very comfortable at all speeds