View Full Version : Spring rates, whatcha running?
High Plains Mopars
12-27-2008, 02:14 PM
For you guys already out there running your cars, what springs rates are you running front and rear, and what size sway bars front and rear?
How do you like the ride, feel, handling?
Have you ever tested on a skid pad or run the car competitively?
Would you like to step up or down in rate and why?
79T/Aman
12-27-2008, 03:08 PM
what car? will the geometry be altered?
High Plains Mopars
12-28-2008, 07:44 AM
I suppose a note of the car and alterations may also be interesting as well, though I'm more interested in empirical data and perception/feel from those cars already in use.
May be a brief description of the road condition you use the car in would be nice to know too.
SDMAN
12-28-2008, 08:09 AM
A big part of what springs/sway bars you pick is based on weight distribution as well as total weight. Without knowing the weight, and if possible the front/rear weight distribution, knowing what the spring rates and bar diameters are doesnt provide much useful information.
My project is still being completed. But we have a very good idea of what both the total and distributed weight will be. Should be 3400# total with a 52/48 front/rear distribution. The front coil overs have 500# springs and the rear coil overs have 200# springs. Front bar is a .875" and the rear is .750". While the bars might appear to be small in diameter to some, the arms on these bars (and its the arms that apply the twist) are quite short. The target is a well handling street car, and Im damn sure I dont want something that rides so stiff I have to get the kidney belt out.
After some initial street driving, we will re-evaluate these specs to see if 'adjustments' need to be made to either spring rates or bar diameters.
Derek69SS
12-28-2008, 10:37 AM
All steel smallblock chevelle w/ stock spring locations & motion ratios.
925/200 is way too firm... rides like a 3/4-ton
700/175 worked much better. It was firm without being harsh. :)
79T/Aman
12-28-2008, 03:04 PM
there is the problem, I assume you need Mopar info but you got 2 different GM guys reply, how does that help? unless you know wights, suspension geometry, wheel size and offset, the problem is that a 600# front spring on one car does not translate to the same wheel rate on another and even on the same car the wheel rate can change due to IC location
slowcamaro
12-28-2008, 03:18 PM
Yes at the very least the vehicle and application you plan to use is needed. Even then you'll get a variety of responses.
In my case third generation F-body. Folks are running anywhere from a 600/100lb spring rate up to 1000+/250lb springs. And that is in classes where suspension pickup geometry remains stock. Once you cross the line of being able to run drop spindles, alternate height ball joints, adjust track bar height you get into even more useless numbers...
So what is your application?
High Plains Mopars
12-28-2008, 03:39 PM
A big part of what springs/sway bars you pick is based on weight distribution as well as total weight. Without knowing the weight, and if possible the front/rear weight distribution, knowing what the spring rates and bar diameters are doesnt provide much useful information.
If I was looking for specific information on a specific car, then yes, this would be absolutely critical. However, that is not the case here. I'm simply asking for "feel" and how you like that feel on the roads you drive on.
High Plains Mopars
12-28-2008, 04:00 PM
there is the problem, I assume you need Mopar info but you got 2 different GM guys reply, how does that help? unless you know wights, suspension geometry, wheel size and offset, the problem is that a 600# front spring on one car does not translate to the same wheel rate on another and even on the same car the wheel rate can change due to IC location
Your assumption is incorrect. I know what options are available for mopars. I also know of options for GM and Ford offerings. I also can calculate motion ratios to find out what spring rates will translate into what wheel rate.
You guys are reading too much into the request. A simple seat of the pants, how does it feel is all that's being asked here.
79T/Aman
12-28-2008, 04:14 PM
this is like debating with a wife!
79T/Aman
12-28-2008, 04:21 PM
I need to ad that this type of imbegious question does not help anyone, I understand that the poster expects his question answered but it needs to be remembered that thousands of poeple read these boards for info and just throwing numbers out there without reasons as to why or what is of no help no anyone.
High Plains Mopars
12-28-2008, 05:23 PM
...because posts like "help me name my project" or "isn't XYZ car the baddest on the planet" or "does my car look better with Fiske or Budnicks" are so much more enlightening.
Sheesh. I'm not trying to educate people. I'm asking for opinions. But if we want to be educational then perhaps this will help; empirical-The word empirical denotes information gained by means of observation, experience, or experiment. It is a central concept in science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses. Empirical data points are data that are produced by experiment or observation.
I'm asking an empirical question here. What do your senses tell you about how your car rides? What have you observed about the ride and handling while using your car?
Maybe I should just post it as a poll; do you like the way your pro-touring car rides, yes or no? Would you change your spring rates up or down based on the previous answer?
Lets be honest here; most pro-touring cars are not going to get a complete suspension make overs from scratch to optimize everything with unique pick up points and custom fabricated parts. Most are being built with off the shelf parts, bolting them on and then the owners are either satisfied or dis-satisfied with the result.
I didn't know that I needed to provide a "why I'm asking this question" to my posting. I've never seen this as an expectation of pro-touring.com unless someone was really looking for some specific results to some specific questions. But, since that seems to be the case here, the only reason why is for my own twisted interest.
Derek69SS, than you for the simple answer to what I thought was a simple question.
1969CamaroRS
12-28-2008, 06:41 PM
550lbs/in front coilovers and 220lbs/in rear coil overs. Its a big block but going for streetable cornering. Not on the road yet so can't speak to how it rides.
David Pozzi
12-28-2008, 07:38 PM
If I tell you what spring rate I like on a first gen Camaro, that would help a first gen Camaro owner. It wouldn't help a Mopar or even a Chevelle guy because his suspension geometry is different, - different spring and bar motion ratios.
But if I told you my F/R spring frequencies at the wheels, and anti-roll bar rates at the wheels, then you could use that info on any car, but it would be most useful on a car with similar CGH and F/R weight bias.
I think the questions asked were trying to address these important issues about providing specific spring rates and bar sizes used.
Your other questions below are more relevant in my opinion.
How do you like the ride, feel, handling?
Have you ever tested on a skid pad or run the car competitively?
Would you like to step up or down in rate and why?
chicane67
12-29-2008, 03:48 PM
With a 16" wheel and tire package... 720/320, 0.750" front bar/no rear was the sweet spot for my 67. The suspension bushings and damper valving made it comfortable considering the spring rates... although, the car was set-up to run sustained high speeds (150+).
I loved the way it felt, the way it rode... it was my daily driver for years. It handled within my liking, meaning... BMW's, Corvette's, Porsche's were daily prey.
Testing... well, at the time I was working for Guldstrand so it was a daily thing... but it pulled in the high .8's to low .9's on the pad and I did some autoX and open road race events in the early 90's. Not to forget to mention... being a daily driver, it was a constant test of ability.
Would I change the rates ?? Well... I personally would like to play around with a slightly lighter front rate, but with a Penske Triple or Moton Triple adjust... as the rate can be tweaked with the gas pressure and valving settings. Other than that... I would also step up the front bar at the same time... probably a solid 1.000".
Randy67
12-30-2008, 04:20 AM
I have 1000 lb front/350 lb rear spring on a 67 El Camino with a 3/4" front bar and no rear, with Pro-shocks stock car shocks (extra heavy valving). Street manners are good, the 115" wheelbase is probably helping out some. Car weights 3350 lbs. I will be upgrading the sway bar in the front, either 1" or 1-1/8" with the SC&C adjustable rear bar before the autox season starts. While it corners nice and flat on the street, there is a bit too much body roll when autoxing, thus the sway bar upgrade.
Norm Peterson
12-31-2008, 07:00 AM
Springs 640f/167r (claimed), 32mm front bar poly chassis bracket and endlink bushings, 22 mm LCA-mounted rear bar, rear LCAs modified poly (stiffens the rear bar somewhat). Bilsteins, S10 fronts to work with S10 spring rate, A/G-body rears.
Daily-driveable just about anywhere that's paved, fairly good pitch control but heaves a little on certain stretches of highway, lateral grip is good even with rather narrow tires (225/60-15), handling is "benign" in sweepers, but it is clumsy in slaloms. Roll is too much for auto-X, and enough to be noticeable but not particularly objectionable in street driving.
I could live with that car's ride on a daily basis with somewhat stiffer springs and possibly bars. Ideally with less weight as well. But the geometries need to be fixed first and re-tuning then done to suit that effort.
https://www.pro-touring.com/forum/attachment.php?attachmentid=25749&d=1220475235
Norm
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