SB Chevelle spring rates?

[protour_chevelle]

Anyone know what the spring rate is on say a 70-72 Small Block Chevelle? I just need to know so I can kind of figure out if I want 650 or 750 rate springs in the front. Will a 750lb spring be tiresome on a 800km drive? Anymore so then 650 lb springs?



-Matt

[dennis68]

Matt, my 750/175 combo rides great. I am even thinking of stepping up the fronts to 850.

[protour_chevelle]

Thanks Dennis

You think 750/250 would work nice in my Chevelle?

-Matt

[dennis68]

Ohhhh, 250 is going to be too much in the rear.

[zbugger]

Yeah, with the 750 front, that 250 may be a bit much in the rear. Remember though Dennis, his CAR has a little more weight in the back than your.... Ummm..... Thing? What is that anyway?

[dennis68]

Actually bugg, there is only a 100lbs or weight difference. That empty bed thing is very deceiving.......how much more does a velle' have in the space from behind the front seat to the trunk that an Elco doesn't?

Thanks for your input though.......

[USAZR1]

Actually,El Caminos have a little better weight bias than a Chevelle,all things being equal.
I agree that a 250lb rear spring would be very harsh.

[protour_chevelle]

Dennis, Jeeze. :rtfm: You even said to me 250 would be ok. Sooooooooooooo What should I go? 150, 175, or?

Thanks guys!

-Matt

[dennis68]

250...me. Must have been half asleep or something. I'm running 175lbs. I haven't donea frequency analysis yet as the set of scales I was due to have access to several months ago are still "lost" ( in somebody elses garage I'm sure).

I would go with the 175's.

[Conekiller13]

I've been running a 625lbs/250lbs combo for a few years now. Hasn't been rough at all. 625 is too weak though for My use. Going up to 850 in front. I run -3 degrees camber in front and still scrub the outside of the tire on the track. I'm starting with 275lbs springs in the rear for My new coil over set up...........We'll see what happens.

[dennis68]

Daniel...coil-over rates are VERY different than conventional spring rates, that 250lbs coil-over is probably around the same as a 140lbs pigtail spring.

[protour_chevelle]

I've been running a 625lbs/250lbs combo for a few years now. Hasn't been rough at all. 625 is too weak though for My use. Going up to 850 in front. I run -3 degrees camber in front and still scrub the outside of the tire on the track. I'm starting with 275lbs springs in the rear for My new coil over set up...........We'll see what happens.

Daniel,

You and me have the same last name. How do you pronounce yours?

Off topic for a sec.

-Matt

[Norm Peterson]

Anyone know what the spring rate is on say a 70-72 Small Block Chevelle? I just need to know so I can kind of figure out if I want 650 or 750 rate springs in the front. Will a 750lb spring be tiresome on a 800km drive? Anymore so then 650 lb springs?

-Matt

I've got 639/167 in my '79, along with 32/22 mm (approximately 1.25"/0.88") bars, and I'll drive it almost anywhere (for reference, it's around 3625# with me in it and the rear bar bolts to the LCA's). IOW, it's fine for daily use but still a little too soft for auto-x. Even my wife's complaints about that car are not concerned with the ride quality. YMMV, depending on how firm you individually feel is too firm, though if your car's as-driven weight is slightly higher than mine it will ride marginally better with similar-rate springs. All else equal, as the disclaimer goes . . .

Like Conekiller, I am looking at stiffer springs, and I don't think that even 850-ish/225-ish is going to be a deal-breaker in terms of ride (for me, anyway).

With 750's up front, 175# rears should work fine with a weight distribution that looks like 56% or 57% up front. If you're down around 52% front weight, I'd look at 200's instead.

Conekiller - With rear springs up around 250 lb/in and only 625 fronts, I'm guessing that you're not running any rear bar at all. But what's your front tire/wheel combination?

Edited for clarity

Norm

[USAZR1]

I think the spring rate on my rear coilovers is around 200-225lbs and it's kinda harsh.

[protour_chevelle]

Oh man, Soooo many mixed opinions. 750-850/ 175-250.

Dennis, Does your car 3 wheel going up curbs? What about your El Clint?

-Matt

[dennis68]

Nope, rides very smooth in fact. When I redo the front suspension I will most likely put in 850's.

[protour_chevelle]

hmmm, For comparison....like the title, do you have an idea of what the factor SB spring rate is? Also, factory ride height? I'm thinking a 2 inch drop is all I want.

-Matt

[dennis68]

I beleive the OE spring rate for a small block is like 340lbs in the front and 110lbs in the rear. Factory ride is very difficult to gauge, I have the factory service manual in front of me and I couldn't even begin to explain what is involved in measuring OE height. Maybe somebody from one of the resto site will measure wheelwells for you. I don't think anybody on this site has a complete running A body that has not been altered......if so WHY?

[protour_chevelle]

I beleive the OE spring rate for a small block is like 340lbs in the front and 110lbs in the rear. Factory ride is very difficult to gauge, I have the factory service manual in front of me and I couldn't even begin to explain what is involved in measuring OE height. Maybe somebody from one of the resto site will measure wheelwells for you. I don't think anybody on this site has a complete running A body that has not been altered......if so WHY?

Heres just a quick pic of where my car sits right now. This is where I want it to sit with the new springs. Right now if I take a corner hard my tires rub really bad. Way to soft. I'm guessing my cars at about and 1 1/2 drop from sagged springs? I could just order springs that are 11 inches unsprung with that adjustable spacer which will take to within half inch from a 17inch factory spring.

As for the rear though... 2 inches is where I'm thinkin.

-Matt

[dennis68]

I'd look into some different backspacing....Here is mine and it never rubs, quite a bit lower than you it looks. The crossmember height is 4.5".