Spring rates for street car.

['96_Talon_TSi]

Ok, heres the deal. I'm not looking for a SLAMMED look. I want a nice simple drop to reduce the wheel gap. However, THe main thing i'm looking for is handling. I'd love to have some great handling characteristics, without having to get into sway-bars and stuff (at least not yet).

WHat sort of spring rates should i be looking for? I'm wiling to sacrafice a litle driveability for the handling, but it needs to be bearable still. maybe somewhere in the 300-400 range (not too soft, but not like riding w/ no shocks/springs)?

I know with an adjustable coiover system, i would be able to fool around and dial in what feels best to me. I'm looking at either the Tien SS or Tien Basic, leaning towards the SS. For those of you guys who know your suspension stuff, is the SS damper a good street damper, or would i be better off with a shock/spring combo?

 

[kiakarimi]

I run Ground control coilovers which are obviously height adjustable for your "nice simple drop." My rates are 500 front and 450 rear with Konis. It rides a little stiff, but thats the way i like it and its definately bareable. It handles amazing and with my rear rates closer to my front ones, it has tendency to oversteer rather than understeer.

Also, sway bars aren't really something that you have to "get into." They're cheap, rediculously easy to install (the rear one, which is all you need), and will probabely make greatest diffence in the handling characteristics of your car for the least amount of money.

 

[jtmcinder]

The only thing that I would add or subtract to the above is the bit about not needing a new front swaybar. If you upgrade the rear (only) with something around 24mm and couple this with 500/450 springs, the car would be so loose as to be almost dangerous. You have to plan these things a bit more carefully. If you are only upgrading the rear bar, then I'd be thinking 500/375 or so, not 500/450.

As to the ride quality, the key is the high-speed compression damping. If you combine 400+ rear springs with something like AGXs, it will be pretty rough. I've never seen shock maps for Teins, and I've only ridden on Teins in a ScoobyDoo, so I can't help there, but agree that it works fine with Koni Sports. In my daughter's words: "daddy car fast, daddy car loud, daddy car bumpy" (she's three) ... but we both enjoy it.

- Jtoby

 

['96_Talon_TSi]

Cinder- you suggest something like the GC coilovers, Koni sports, and sway bars. I'd rather have a little oversteer than understeer. What size sway bars would you suggest for front/back?

 

[jtmcinder]

We (as in 2G drivers) don't have a lot of options for swaybars. I'd start a setup by assuming RM sways front and rear (24mm), and then play with the front vs. back weight transfer with springs. If you haven't driven a loose 2G AWD, then I'd move slowly in this direction, to give yourself a chance to get used to it. I'd start with 500/400 or so and, then, if you really want it looser, up the rears. ERSprings are not that expensive. They're a whole lot less expensive than a trip to the body shop.

If you're thinking of drifting the car, then you can always disconnect the front sway bar (and put it back for the drive home).

Most of all: don't be cheap when it comes to the shocks. They are so much more important than the springs.

And put some time into how the front upper mounts work. The GC plates are good for extra travel, but they are not pillowballs and the hat is not coaxial. These turn out to be a big deal. Right now I'm right on the fence about what to run this summer. Either spend some time getting a pillowball top for my GC/Koni setup or go out on a limb and switch to Tein Flex (which come with these OTS), even though I worry that the Flex damper isn't as good as a Koni and I don't like adjusters that do compression and rebound at the same time.

- Jtoby

 

[kiakarimi]

jtoby, do you think if i'm not running any sort of front upper mount that its gonna mess up my front suspension (rebuilding shocks and what not). Or is that only if you do get the GC plate for more travel, it hits at a bad angel, messing up your shocks?

 

[jtmcinder]

My current understanding is that the damaging package is GC upper front plates combined with either GC or ES upper shock bushings on a lowered 2G. If you stick with stock rubber upper bushings, you should be alright, since these have a lot more give than the GC or ES bushings.

The bad angle is not caused by the plate, itself. It is caused by lowering the car and then using large steering angles (which cause the twin, offset lower balljoints to do lots of weird things). This is why I think this problem only shows up on autoXed cars and not on road-racing cars. You don't use anything close to an autoXing steering angle on a road course. Or, at least, if you do, you are going to be blacked for driving too slow.

- Jtoby

 

[ACM]

The only thing I would add to Jtoby's comments are to have the rear Konis revalved before installing them - once installed it's a major pita to go the revalve route.

Have the rears revalved to increase the rebound dramatically, that way you don't end up in the last 1/2 turn of adjustment, which is where the compression starts rocketing skyward.

Rear Konis are good for about a 350lb spring, above that puts the adjuster into the last turn to get the rebound, and that delivers way too much compression.

Charles

 

[kiakarimi]

Originally posted by ACM
The only thing I would add to Jtoby's comments are to have the rear Konis revalved before installing them - once installed it's a major pita to go the revalve route.

My setup was already installed a long time ago so i guess its too late for that... My rear rates are 450 and i keep the rebound on the back about 3/4 turned up. Is that bad...?

 

[jtmcinder]

This is actually one of the few topics where Charles (ACM) and I really disagree. I do not believe that compression goes up in the last part of the range of adjustment on a Koni (and I've got some shock-dyno maps to back me up). Instead, what I believe causes what feels like a sharp increase in compression damping is the very high rate of rebound.

Here's how this works: when rebound is very high, transitions and mere bumps cause the car to jack down. In a nutshell, the car compresses a lot easier than it rebounds, so all those small compressions get stored up (and the car drops down). Once jacked down, it takes more and more of a bump to actually lift the wheel any more, so the wheel stops moving up on a bump and, instead, just bangs the car upwards.

I know that I didn't explain that very well and it is mostly second-hand from Joe Cheng, but I understand the idea and it does fit with the fact that the compression trace on a shock-dyno map doesn't change as you adjust rebound on a Koni Sport.

- Jtoby

 

[MNGSX]

Originally posted by jtmcinder
My current understanding is that the damaging package is GC upper front plates combined with either GC or ES upper shock bushings on a lowered 2G. If you stick with stock rubber upper bushings, you should be alright, since these have a lot more give than the GC or ES bushings.

- Jtoby

I dont think the ES bushings are any harder than OE.

I just installed them and it is alot softer poly than their arm bushings.

I think it is the prothane and the GC bushings which are made from hockey puck hard material.. The ES shock bushings were about as soft as the OE ones... Probably slightly harder but not much at all.



Another thing to look into is progressive rate springs...

Meaning the more they compress the higher the rate is... The initial 1/4" or so of a 600lb progresive may be as soft as a 450lb linear...

Progressive

 

[jtmcinder]

Originally posted by jtmcinder
This is actually one of the few topics where Charles (ACM) and I really disagree. I do not believe that compression goes up in the last part of the range of adjustment on a Koni (and I've got some shock-dyno maps to back me up). Instead, what I believe causes what feels like a sharp increase in compression damping is the very high rate of rebound.

For archive-completeness sake:

I am wrong and Charles is right. When a Koni Sport is adjusted, there is a change in compression and it does occur in the last 1/2 turn or so. It just doesn't show up in football-shaped (force-displacement) shock maps ... it only shows up in force-velocity maps.

edit - May 2006 - turns out that I was correct all along ... the adjuster on a Koni Sport only changes rebound and the apparent change in compression is due to packing down

- Jtoby

 

[ACM]

And this goes back to my incessant whining about shock plots only telling half the story at best. Shock dynos are why Japanese market dampers look so good, yet put them on the road and they're horrible.

Shock dynos don't get even close to measuring the sort of shaft velocities a road car sees daily, they're measuring low-speed damping, even when set on the highest speed. Being Scotch Yoke designs everything is smooth, there's none of that smack-a-frost-heave or hit-a-pot-hole velocity stuff. To do that you'd have to whack the bottom of the shock with a bloody great mallet - but those are the shaft velocities we care about on the road.

Charles

 

[14.5 drift]

Originally posted by MNGSX
I dont think the ES bushings are any harder than OE.

I just installed them and it is alot softer poly than their arm bushings.

I think it is the prothane and the GC bushings which are made from hockey puck hard material.. The ES shock bushings were about as soft as the OE ones... Probably slightly harder but not much at all.



Another thing to look into is progressive rate springs...

Meaning the more they compress the higher the rate is... The initial 1/4" or so of a 600lb progresive may be as soft as a 450lb linear...

Progressive

any one selling these springs for my dsm, but adjustable like ground control

 

['96_Talon_TSi]

MNGSX- I haven't really heard too much about these progressive spring rates. I read that link you supplied, and it seems like a good thing. So basically they provide a softer spring when the car isn't loaded down, but as the spring gets loaded, it gets stiffer, in order to prevent the wheel from hopping up and smacking into the wheel well?.. sounds interesting.

Who makes those progressive springs? I didn;t look aorund the site much, but can you get them there? If not, where can you get em.. for AWD? how about a price?

Cinder,ACM - what do you guys think about these progressive springs? To me they seem like good springs for a daily driver that will see a little track action, what are your opinions on these? compared to say.. the GC coilovers?


P.S. reiterating.. i'm looking for a reasonable ride for a daily driver.. and we have some pretty crappy roads up here... so i dont want super hard suspension.. but i dont want a crappy bouncing/bumpstop hitting suspension... ANd i'll probably go with either Koni or Tokico shocks..

 

[ACM]

The biggest piece of ride quality comes from dampers, not springs.
Spring choice is determined by factors such as ride height, available travel, desired roll angles, stuff like that.

If one is willing to spend the money on good dampers, poor ride quality is more likely to be a result of too soft a rate rather than too stiff.

Any time the setup allows regular contact with the bumpstops, the ride will suffer horribly.

Dampers are engineered with a certain spring rate range in mind, and as such the ratio (compression/rebound) is chosen accordingly, and the absolute rates as well. If the fitted spring rate falls outside the expected range, the ride will usually go to hell. The best ride will invariably result from fitting the same springs the damper engineers used when they developed the damping rates.

Soft spring rates require more travel - thus a higher ride height - than stiffer springs to bring the car under control before hitting the bumpstops.

I run 700 front 550 rear springs in my 98 - the ride is great, better than a fresh stock setup, but I've revalved my Shockteks several times to optimise the rates and ratio. My autocross car runs 800f/650r - the rears are a shade too stiff for the street, other than that they're great. That's because the dampers and springs were engineered as a package.

I've used Koni, AGX, Illumina, Shocktek and Penske dampers on DSMs. Illuminas are valved for stock springs - anything stiffer and they can't cope and ride goes to hell. AGXs are nasty dampers, not worth the boxes they're shipped in. Konis are a good budget shock, they have a shorter body, they can be revalved, and they can be upgraded - the rates and ratios are off as delivered, in my opinon from using them with several different sets of springs. Shockteks are great, shame the company didn't survive; for what you got they were a bargain. Penskes are, well, Penskes - superb.

Charles

 

[14.5 drift]

penske is a pretty track oriented shock, any thing more geared for street use out there?

 

['96_Talon_TSi]

Originally posted by ACM
The biggest piece of ride quality comes from dampers, not springs.
Spring choice is determined by factors such as ride height, available travel, desired roll angles, stuff like that.

If one is willing to spend the money on good dampers, poor ride quality is more likely to be a result of too soft a rate rather than too stiff.

Any time the setup allows regular contact with the bumpstops, the ride will suffer horribly.

Dampers are engineered with a certain spring rate range in mind, and as such the ratio (compression/rebound) is chosen accordingly, and the absolute rates as well. If the fitted spring rate falls outside the expected range, the ride will usually go to hell. The best ride will invariably result from fitting the same springs the damper engineers used when they developed the damping rates.

Soft spring rates require more travel - thus a higher ride height - than stiffer springs to bring the car under control before hitting the bumpstops.

Charles

Yea, i understand how the damper effects ride quality more than the spring does. But, would the Koni shocks or Tokico shocks work well with these progressive rated springs, or would i just be better off with some set springs (H&R or GC coilovers)?

DO you know what spring rates the adjustable Koni shocks are fit best with? how about the Tokico Illumina adjustables?

 

[14.5 drift]

Can any one tell me what the stock spring rates are? (gsx 96)

 

[jtmcinder]

Stock 2G AWD springs are 260/170.

OTS Koni Sports are good for up to about 450/350, maybe a little more. After than, you should seriously consider a revalve. This makes them very good partners for H&R Sports, which are 430/260.

- Jtoby

 

[MNGSX]

Originally posted by '96_Talon_TSi
MNGSX- I haven't really heard too much about these progressive spring rates. I read that link you supplied, and it seems like a good thing. So basically they provide a softer spring when the car isn't loaded down, but as the spring gets loaded, it gets stiffer, in order to prevent the wheel from hopping up and smacking into the wheel well?.. sounds interesting.

Who makes those progressive springs? I didn;t look aorund the site much, but can you get them there? If not, where can you get em.. for AWD? how about a price?

Cinder,ACM - what do you guys think about these progressive springs? To me they seem like good springs for a daily driver that will see a little track action, what are your opinions on these? compared to say.. the GC coilovers?

The Eibachs that come with GC's are a 2.5" x 7" spring... FWD, AWD anything that GC sells the kits for... Homodas etc...

I am running these springs on GC coil overs I just sh&t canned the eibach springs because they had settled unevenly and I did'nt like the rates.

They did'nt have anything progressive in a 7"... They said there was'nt as much demand for it in a short spring... I still think its a good idea... A spring that increases rate as it is compressed makes sense for the street... Expansion joints or rumble strips it would give more that first little bit of compression than a linear rate spring with the same max rating... Oh well... I got 450# fronts and 350# rears..

I'm not a cornering junkie like some people here so I wont be running 600-700# springs and penskes... The quality of the springs is very good and alot less money than hypercoils... They list at $42 but some mail order places sell them for $36 or $39 or so.... I just picked them up from the ppl that made them...

 

[Knoob]

you want Eibach Pro Kit.....

i have Eibach Sportlines... i love them. people complain about them... i have no complaints. but it is the SLAM look you dont want....

 

[jtmcinder]

Originally posted by MNGSX
The Eibachs that come with GC's are a 2.5" x 7" spring... FWD, AWD anything that GC sells the kits for... Homodas etc

While you are correct that the default spring length from GC for our cars is 7" and while I agree that HyperCoils, for example, are to be preferred over ERS springs, I think it's worth pointing out that GC will let you select your own rates and your own spring length for no extra costs (at least, they didn't change extra when I bought mine). And it is strongly suggested that you ask for 8" front springs, not 7".

- Jtoby

 

['96_Talon_TSi]

Originally posted by jtmcinder
Stock 2G AWD springs are 260/170.

OTS Koni Sports are good for up to about 450/350, maybe a little more. After than, you should seriously consider a revalve. This makes them very good partners for H&R Sports, which are 430/260.

- Jtoby

When paired with the OTS koni sports, how could these feel(any experience?), how would they handle when paired with some swaybars?

I dont think i'll be going much stiffer than 450/350 so i won't need a revavle on the dampers.
I think witht he slightly softer spring rate (compared to the GC) the H&R will provide the support i'm looking for.. but also a fairly smooth ride. I'm pretty sold on the Koni shocks, just deciding on springs now.

 

[MNGSX]

Originally posted by jtmcinder
While you are correct that the default spring length from GC for our cars is 7" and while I agree that HyperCoils, for example, are to be preferred over ERS springs, I think it's worth pointing out that GC will let you select your own rates and your own spring length for no extra costs (at least, they didn't change extra when I bought mine). And it is strongly suggested that you ask for 8" front springs, not 7".

- Jtoby

For the front on a lowered car 7" is plenty...

Free length is dependant on the length of suspension travel... Measure the travel available on a car dropped 2" or so and look at a spring mfg's guidelines... Hypercoil... Who ever.. 7" is just fine..
Maybe at 1" drop or so 8" becomes the recomendation..

Where I got them from has them in 7" and 9" no 8"

They are QA1 springs... May not have quite the same ring to its name in sport comp circles but in serious racing circles well known.