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Author Topic:   Chevelle spring rates?
The Flash32
Dirt Maniac

Total posts: 120
posted October 11, 2004 09:33 PM  
Does anyone know what a stock 1972 Chevelle front spring weight is? I have been running them on my car but its time to replace with race springs. I don't want to have to buy a bunch of sets for trial & error. Chevrolet dealers here have no clue. Thanks!

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted October 11, 2004 11:49 PM  
Just find someone with a coil spring rater and have them checked.

WesternAuto17
Dirt Forum Champ
Total posts: 569
posted October 12, 2004 07:30 AM  
You really will want to find a rate checker for a few reasons. In 32 years, those springs have probably changed quite a bit, so whatever they were in '72 has probably changed. Also, old passenger car springs weren't held to same rating tolerances as racing springs, so they may or may not have been the rate that the factory said they were. On top of everything else, different Chevelles (big blocks, small blocks, six cylinders and wagons) came with different spring rates.

I understand why you don't want to mess with what's working and experiment with new spring rates, but the car will turn better with the correct spring rates in it as opposed to whatever the engineer thought would work in 1972. JMO.

The Flash32
Dirt Maniac

Total posts: 120
posted October 12, 2004 04:06 PM  
Ok, thanks alot. The old springs are going weak so I don't think checking them now will tell me much! Let me run this by you, my car weighs 3730 with me in it, I need to cut some weight out of the car, we are at a 3500# min., the cross LR to RF is 48.2%, front weight is 50.5%, rear is 49.5%, left side is 53.6% and right side is 46.4%. LF 1044#..RF 842#..LR 960#..RR 885#. Can someone give me a close estimate on what springs I need in the front? Thanks

o5racer
Dirt Freak

Total posts: 402
posted October 12, 2004 08:00 PM  
A 1200 RF and 1100LF should get you pretty close. 12 inch springs should work fine but you may need 5 inch diameter springs to fit.

The Flash32
Dirt Maniac

Total posts: 120
posted October 12, 2004 08:54 PM  
Thanks o5, I really wasnt sure because I have been running stock springs all the way around for about 6 yrs. now. But with the cost of the "collector" springs for old cars I need to change. I am gonna cut some front end weight just a little & get the car closer on rear percentages. Thanks again!

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted October 12, 2004 09:14 PM  
yeah 1200RF 1100LF 300LR 300RR should get you pretty close and you will need 5" diameter springs.

WesternAuto17
Dirt Forum Champ
Total posts: 569
posted October 13, 2004 07:12 AM  
I know it can be difficult with a street stock, but you've got to improove your rear percentage. It should be more like 52-53%. Getting the cross up a few points should help as well. If the rules allow it, moving the engine back will be worth all the work.

Speedway65
Dirt Freak

Total posts: 344
posted October 13, 2004 12:35 PM  

 
Must be nice to run 52 rear .Our track only allows max 47 rear on a coil car and 45 on leaf cars.We would really like to see how it runs with about 52 rear.With only running 47 rear it really a fine line on foward bite issues.Our metric car runs LF-800 RF 900 no sway bar and LR-200 RR-175
Our car is the 24a

The Flash32
Dirt Maniac

Total posts: 120
posted October 13, 2004 03:31 PM  
Yes I am going to shoot for getting it right at 52%. We finished 5th in the factory stock points at State Fair Speedway in OKC this year. Since I have never scaled a car, this is all new to me. I always put the weight where it feels it needs to be. My car handles great but need to cut weight & go to the race springs! Thanks for all the help!

HONDO
Dirt Full Roller

Total posts: 47
posted October 13, 2004 05:39 PM  
That 1200rf, 1100lf front is right on, but without a sway bar. With a sway bar go about 800rf and 700lf. I prefer no sway bar.

The Flash32
Dirt Maniac

Total posts: 120
posted October 13, 2004 08:27 PM  
I have a big sway bar on the front, car doesnt seem to work at all without it

HONDO
Dirt Full Roller

Total posts: 47
posted October 14, 2004 01:34 PM  
It would never work without it unless the whole setup is adjusted to compensate. You are radically changing your effective spring rate if you just unbolt it without increasing your front spring rate. That big sway bar was probably the only reason your car was working at all with the factory springs still in the car. It can be done either way, but the basis for which way you go is going to depend on how heavy of springs you buy. The springs are kind of like the foundation of a house, the rest of your setup is dependent on them.

The Flash32
Dirt Maniac

Total posts: 120
posted October 14, 2004 03:30 PM  
So what your saying is that if I leave the sway bar hooked up, the 800 & 700 springs will work. If I take it off the 1200 & 1100 will work the same? I have never scaled a car as I said before & since it has always handled pretty good, I want it just that much better! I appreciate the help.

HONDO
Dirt Full Roller

Total posts: 47
posted October 15, 2004 05:54 PM  
Like I said before, I prefer the no sway bar deal. Try it both ways. Springs are cheap. Or borrow some. Just be sure you know exactly what they rate at. Also watch your ride heights. Since it works pretty good now, measure what you have now before you start swapping things around so you have a good starting point. I would buy the 9 1/2" springs and run an adjustable spacer to set your ride height if rules allow.

The Flash32
Dirt Maniac

Total posts: 120
posted October 15, 2004 10:30 PM  
Thanks Hondo, I'll give it a try. I appreciate the help!

duff53
Dirt Roller

Total posts: 13
posted October 17, 2004 07:22 PM  
I run A 950rf & 850lf with swaybar on my 69 chevelle, 3/8 medium bank dirt track, works great

The Flash32
Dirt Maniac

Total posts: 120
posted October 17, 2004 09:00 PM  
Thanks Duff, that more of the rate I had in mind, wasn't sure thats why I thought I'd someone elses brain!!! Guess since we are through for the year, maybe Santa will bring me springs!! Just got home from running the Winternationals in Enid OK. Drove someone elses factory stock & running a strong 5th, had the carb. start sputtering. Anyway it was a fun season. Thanks again guys for the info......Flash

    

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