Spring Setup

[Serendipity]

I have a daily driver that needs some new springs, so why not upgrade? What do you recommend for improved street and possible XCross use? i do not intend to own a track car, so I still need the ride to be comfortable enough; no hemorrhoids please. I have also thought of buying lowering springs too. What are your thoughts?

Also, let me know if you have any for sale.

[Colbskee]

....what kind of car?

[Brian]

....what kind of car?

lol

+1. what car?

[Serendipity]

....what kind of car?

It's an 86 SR5. Just bought an Eibach Pro Kit, and KYB mounts. Thanks!

[Dugwillis]

How are your stock springs no good anymore?

Maybe look into an Eibach Pro Kit. They aren't great, but they are somewhat comfortable, with a small drop.

[Serendipity]

How are your stock springs no good anymore?

Maybe look into an Eibach Pro Kit. They aren't great, but they are somewhat comfortable, with a small drop.

My stock springs are wobbly and from the SR5 setup; thus a little looser than the GTS. I really feel it when taking corners .

[max attack]

My stock springs are wobbly and from the SR5 setup; thus a little looser than the GTS. I really feel it when taking corners .

Just for future reference don't call your springs wobbly unless your rolling them down the street.

Just call them soft,we'll all understand what you mean then.

[g penny]

buy an eibach kit and have the progressive rate shyte squished out of them.(at a spring shop) They made for a nice streetable setup on the woman's AE
a little view (tis the grey one)
http://www.youtube.com/watch?v=-vAuz...el_video_title

[Rokubes]

TRD springs 6kg/mm front & 4kg/mm rear. Streetable yet aggressive enough for auto-x and spirited driving.

[blackaspitch]

stupid question: squishing springs will soften them?

[Phunkshun]

stupid question: squishing springs will soften them?

makes the softer coils bind together, leaving the stiffer coils to do the work.

[blackaspitch]

gotcha!...hmm what if its not a progressive spring rate. what if its just a regular coil over spring? same thing?

[bertvorgon]

This is a post that I did on the 510 Realm, and while we were talking about a fellows particular 510, it does pertain to understanding your suspension. As a GTS is slightly heavier than a 510, the spring rates need to be slightly higher, at least in my opinion, depending on what you want out of the car, or to be more specific, what type of handling. I know you drift guys may take exception to my comment on oversteer, but you have to look at the context of the speeds involved, and safety issues, when driving on real road/hiway situations.

I post this only as a matter of interest, for those of you trying to really understand your supension...and to keep yourself safe.
The "BLUE" 510 I mention, was one of our Australian memebers, who had just finshed building his car, lots of power..but maybe did not figure out the handling thing, in a safe enviroment. Long story short...he came down a slight hill, likely had trailing throttle oversteer, and went into a tree...killing himslef. As we all jump in and buy this stuff, it is important to UNDERSTAND what we are doing.


I guess I pretty much agree with Okayfine. This is where it does get a bit tough, as to how do you quantify what it both "feels" like, and, how is the car actually handling.

The actual shock valving is the big key here, and that may be what you are feeling. I think it is in agreement here, that a 50/50 bump/rebound rate, for the most part, works very well. And that is the tough part, as most shocks do not specify that rate. I had my fronts custom valved by Bilstein, and my rears..., they are what I needed. Too slow a rate in the rear, will cause the car to jack down, which causes evil handling, as the shock does not let the suspension springs to actually work. And yes, the shock if too stiff will give you a tendancy to either over/understeer, depending on which end is too stiff. Koni shocks were really bad for this...I been there.

You don't want to use the shock to set the over/understeer characteristics.

Bumpy..jerky...that gets to be a ride preference thing, balanced with the reality of what is the car really doing...on a given road surface. Things are always a trade off somewhere No matter what, under whatever condition, things are kinda right, if the wheels are staying on the road, IE the car does not feel skippy on the surface. You need to feel that the tire..and of course the feed back to both your ass, and your hands on the steering wheel, is staying in intimate contact with the road surface, under all but the most severe conditions. Again, say under very hard braking on a short frequency bumpy surface, you may feel the tires almost locking, under the brakes.

Suspension "stiffness", should not be confused with lack of CONTROLLED suspension travel. As some of us use very high spring rates, that is still matched to a shock that can control the whole package so to speak, AND, the resultant weight transfer, both fore and aft, and, of course body roll during cornering.

The other thing to not forget, as we all throw money at all this trick suspension stuff, is how hard are you using the car?! If you are just farting around, you may find the ride is going to feel stiff, with all the stuff you have bought, from reading this site. But, really get the car up to speed, and I mean speed, and not straight, and that is when you really do find out how things are working. What feels stiff now, is sure going to start to feel a lot softer as both the g-load and speeds go seriously up. And that is said with the fact that the anti -roll bars will effect how things work, as much as anything else. As some of you know, a bunch of us run NO rear bar, as our rear spring/shock rate, plus our 1 1/8" front bar, gives us a slight terminal understeer condition at the limit, but..below that the car is totally drivable with the throttle. And never forget....WHAT IS YOUR DRIVING STYLE?

Personally, as the speed gets up there, I have never found a oversteering car very fun to drive. At the slalom, or other controlled area, fine. But, in our real world of canyon runs, scenic tours, bumps, gravel on corners, yada, yada., you kinda need that thing to not want to come around on you, should you have to get out of the throttle, on the brakes, in a corner, blah, blah. Again, get the car reasonably balanced, with the throttle to control the over/understeer tendancy, and you will have a fun package, that will keep you safe.

With todays adjustable shocks, not that the valving is perfect, you can at least run the thing at a reasonabale ride, and try to use the spring rates to control the handling aspects, plus tire pressure, plus wheel spacing, can all fine tune things.

All things considered, my car does not really ride that harsh, at least according to some of my passengers, but then I have lived with the things for 30 years in this mode. I actually have my GTS set up the same as the Datsun, and as it is a heavier car, could actually be a tad stiffer in the spring/ant-roll department. If you are the type of driver that really toss'es a car in, this requires that the aforementioned spring/anti-roll bars/camber, etc, become even more important, as the instantaneous g-load can really ramp up there. I measured my 510 once at almost 2 g's on a quick toss in.

I to cannot comment on the rear springs, as wheel rate needs to be figured. You are on the right track, for you, and, as you have already seen, there is no one magic setup for all conditions. It is all about comprimise, you just have to figure out which one you want to sacrifice, for the type of driving you want to do the most.

Hope that may help some.

[bertvorgon]

EDIT: as i thought about this some more, what we are talking about here is the spring frequency, which is what we feel in our seat of the pants. A soft spring has a low frequency, so we just wallow along. As the spring rate goes up, that frequency goes up, so we end up with a ride that feels "jerkier". That is the trade off, for both better roll control, and weight transfer under braking. When I thought back to my earlier days of experimenting with springs and shocks, ride quality became secondary to roll control. No brainer there, but, with our 510's, as most of us have found, we have needed to run quite STIFF, so as to minimze the rear toe change, which is the worst of the handling quirks. In using shocks built for heavier cars, we do have to be careful that it's bump /rebound rate and the speed with which it can react, is close to the stiffer spring rates we use. Other wise, it will just plain be too harsh for our needs, unless we are really pushing the cars suspension.

I know in the case of my GTS, I really went for the stiffest antiroll bar I could get, and just upped the spring/shock rate a reasonable amount. I went with 300# springs up front, and Tokico adjustables. I can soften the shocks up for rain and snow conditions. I live in this thing everyday, it needs to be compliant in rainy conditions ( and snow). The rear I left maybe a tad too soft, but, that solid axel and four link I neeed to be ok on some gravel roads that I go on. Again, a comprimise.

Any time a car "feels" like it is going to take off, makes me wonder if you bottomed the suspension?????..maybe just touched the shock bump rubber???? That is one thing to check for sure. You may not even hear it, or feel any THUNK, but, it just might have touched, which makes the car almost, specially the real feel like it is going to pitch UP quite dramatically.

I have lived this one! Just something to check at any rate. At 85 MPH, and in a good bump/dip, that gets the enertia going enough to eat up lots of travel, more than you might suspect.

There is a point, depending on spring rate, and some types of bumps, that you hit both under load, and in a corner, that may feel like the car is pitching back up. This is just one of the things that you have to live with....given the ability of the shock to be able to control things on REBOUND...specially on the rear. The stiffer spring that we put in, as it compresses down under a severe bump, and on the LOADED side of the car, has a lot of energy stored there, and it wants to "Spring" back very fast. Who knows what the Mustang shock's rebound rate is. If it is on the faster side, it may make the car feel like it is pitching up.

Yah, I think you have the "steering with the throttle concept"...it is all about being SMOOTH! Period. Sounds like that is exactly what is required....you can lift (in varying degrees), to get the rear to come out a tad, then feed power on again, without hardly putting any steering input in!

PREACHY, EH!...I thought I was just trying to keep you guys SAFE!

In the extreme, which is what I preach about, is that in our 510's, you want to be able to even snap right out of the throttle...in a corner...with a late apex in mind, that will get the weight transfer to the front,,,instantly..which gets the rear helping to rotate the car.....WITHOUT THE THING EVEN THINKING ABOUT TRAILING THROTTLE OVERSTEER! I do this quite a bit in my car, just at the speed you have been at. It gets the front to bite even harder, for turn in, then as soon as the rear gets the car rotated, your back on the power, transfering the weight to the back. Do this in a nice smooth fashion, and the twistys just become so much fun, and safe.


Sure, there is a point where stiffness would comprimise the handling of the car...if the suspension is NOT doing it;s thing, IE absorbing all the road irregularities..it just becomes a go cart at that point. Yes, if the shock is too stiff on rebound, that causes weight-jacking...the suspension will compress INTO the bump ok, but, upon EXIT, it will pick the whole rear end up, as the shock kept the spring from rebounding ok. It can be a subtle thing to, as the car may have hit small bumps progressively, thus jacking the rear down, then you hit the BIG one, and it feels like it may be pulling the wheel off the ground...which it is.

You are at the point now, of fine tuning how YOUR car feels to you, for your style, given that you have enough travel .

Not sure what to say about changing the spring yet. Play around with what shock settings you have, and again..bloddy make sure you are not hitting the bump rubbers!!!!!!!!!!!!!!! Preachy...yes on this one. Crashed my car because of this in 1978..ouch.

[bertvorgon]

it sounds like that may be the problem, worth ABSOLUTLEY eliminating any chance of that! Bottoming is one of the most dangerous conditions your suspension can throw at you, usually at the most dramatic times too.

I think I have told this story before....I was at Westwood race track, 1978, when I came up out of the hairpin, when, I was halfway through the s's, when I hit the BUMP. As it turned out, after forensic analysis, I had blown through the travel, and hit the stock bump rubber on the rear control arm. This sudden loss of compliance, coupled with the turning input, caused me to spin out, into the tire wall, all at 80+ MPH. I was lucky, as it took all the energy and dissapated it pretty good. It took us awhile to figure out what had happened of course.

I had tried a bunch of shocks, one of which was, at the time, to die for KONI'S. They were very bad for letting the car jack DOWN. They were one of the worst I ever tried, at least in the context of the time period, 70's and 80's.

When you have a shock out, try pulling it out fast. As the rebound rate goes up, of course this gets harder to do. So, imagine you hit a compression bump, which knocks the shock in 1", and then it only rebounds 1/2" before you hit the next bump(or transient toss) and you drive the shock in another 1", and again it only comes out another 1/2". the net effect, is that the travel is reduced each time, and at some point, on the next toss, the shock is so far in, that when the car is tossed in the next direction, it pulls the wheel off, or it just gets really light. so, yes you got it right. Just watch a 510 at the slalom with this probem, very evil handling car at that point.

what you are entertaining to do, is the best in my opinion, start with the softest setting, then, work up to the point that ...well....what does it feel like? that is exactly the best way, as you want it as soft (relativly speaking, as you can get away with, but, not have any wallowing or pitching ( which is a bit of a function of the front/rear spring frequency) but, you get the idea. I have actually tuned my mountain bike the same way, with those wonderful Fox fork and shock. The new fork I have, has a small bump sensitivity adjustment, which I have found quite amazing when you think of it. I could really drive myself crazy if I had this on my car.

I hope I have made sense of all of this for you all. The complete suspension package, on any of our 510's, is a sum of the parts we have chosen. There is no perfect setup, for all conditions. We must either strike a balance, depending on our total driving window, or, sacrifice something, ride qualty, whatever, to excell in one area. Due to my racing, I have chosen ultimate cornering and CONTROL, above all else. The steering is quite heavy (at low speed) due to the castor, but, at high speed, and in fast, tight corners, it is a dream of predicatability, same with the rear. Is that not what a good suspension is all about, predictabilty, in most, if not all situations, that also keeps our 510's nice and shiny. I still have that pictures of that poor young fellow in Australia, with his blue 510 wrapped around that tree. Not that that cannot happen to any of us when we drive hard out there, but, we sure want to balance the odds in our favour. I would bet my boots that he got bit by either trailing throttle oversteer, and/or lack of experience. Bad combo.

[TTC]

I'm going to sticky this. If you have the time, I would love a "how to" tune your suspension for track days. Great writeup thanks alot, this is one of the best contributions from a new person on the board I have seen in ages.

[max attack]

Considering the OP was after a set springs/dampers for a DD and bought Eibachs and KYB's thats a very long winded post regarding suspension set-up.

[Lu_e]

ya

This seems like a coilover/full custom suspension discussion. I for one am considering a custom setup rather than coilover kits for the replacement aspect, damper valving etc. Let alone the education

[DennyStrader]

Very good thing

[Calikid]

I'm a drift champion so suspension does matter.