Do as I say, not as I do. I suggested softer spring rates due to the W.A.F. (wife acceptance factor)
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Suspension (beating the dead horse)
- Thread starter s_firestone
- Start date
Cool Bob. I don't have that issue, as the wife generally does not drive the VR4. /ubbthreads/images/graemlins/grin.gif
joec
Well-known member
Quote:
4. AGX stocks are a "Best Value" as long as you stay UNDER 200 lb/inch front springs and 150-
200 lb/inch rears. Coil-over springs should be free length of 10" F & 10 or 12" R, if you have threaded coilover perches.
Bob, what do you suggest for coilover spring rates with AGX's? I was thinking of using 275lb/in 10" front and 200 lb/in 10" rears (similar to the custom gvr-4 gc setup that RiceKiller was selling). I guess this would overwhelm the front AGX's?
I don't have any desire to lower the car (at least not as far as looks are concerned) and want a suspension that can handle decently on potholed/bumpy roads.
4. AGX stocks are a "Best Value" as long as you stay UNDER 200 lb/inch front springs and 150-
200 lb/inch rears. Coil-over springs should be free length of 10" F & 10 or 12" R, if you have threaded coilover perches.
Bob, what do you suggest for coilover spring rates with AGX's? I was thinking of using 275lb/in 10" front and 200 lb/in 10" rears (similar to the custom gvr-4 gc setup that RiceKiller was selling). I guess this would overwhelm the front AGX's?
I don't have any desire to lower the car (at least not as far as looks are concerned) and want a suspension that can handle decently on potholed/bumpy roads.
The AGX's will be somewhat challenged but will work with those spring rates, at least for a while. I ran less-than-new AGXs with spring rates up to 425/375 f/r, and it was not long before they were pretty pathetic at damping those springs. I suspect that higher spring rates cause them to wear out more rapidly and am guessing the reason for that is that the accelerations are greater, causing the dynamic pressures against seals to be larger and fluid flow rates through orifices to be greater.
Mike R.
Mike R.
I agree with Mike R. What causes the worst problems is when you lower the car too much. The AGX's just can't keep control with the resulting short stroke. I've blow out a rear AGX because I slammed it too much this spring.
s_firestone
Well-known member
That brings up a question about the AGX. Is it possible that the AGX application was made for the low end of progressive springs? The reason I ask is that several people mention rebound dampening as being a problem past a certain point. Given that a progressive spring is an attempt to make a non-linear spring which is softer under compression up to the mid-point(lower rate) of its travel but ramps up quickly as the spring compresses beyond that(higher rate).
It would stand to reason that a lowered car on progressive springs would (in addition to the shortened travel and extreme arm angles) be at the higher point of the spring rates.
It would stand to reason that a lowered car on progressive springs would (in addition to the shortened travel and extreme arm angles) be at the higher point of the spring rates.
Sorry to piggyback onto this, but I have some bushing questions.
Is it worth it to go for the Noltec rear subframe bushings? They're expensive, and I've heard they don't fit too well. Would there be a noticable difference between these and the stock ones?
Also, what about Noltec vs. Whiteline? I have Whiteline front caster bushings not installed. If I get Noltec front control arm bushings, should I use a Noltec caster bushing too, or can I use the Whiteline?
To the OP, hopefully these are useful questions for you too.
Rob
Is it worth it to go for the Noltec rear subframe bushings? They're expensive, and I've heard they don't fit too well. Would there be a noticable difference between these and the stock ones?
Also, what about Noltec vs. Whiteline? I have Whiteline front caster bushings not installed. If I get Noltec front control arm bushings, should I use a Noltec caster bushing too, or can I use the Whiteline?
To the OP, hopefully these are useful questions for you too.
Rob
I'm not sure if I understand your question about progressive springs. If the progressive springs are lowered by cutting off their soft coils, then you have a much stiffer rate. But, if the car is lowered by lowering the bottom spring perch on a coil-over kit, then the progressive nature is retained. The car doesn't weigh any more when it's lowered.
Most of us with home-built or custom coil-over suspensions use linear-rate springs because they are cheap ($100-120/pair), readily available in 25 lb-inch increments and in 8", 10", 12" free lengths to suit our application.
As for Noltec rear bushings, I think they'll be much better than the original 14-15 year old rotting rubber ones, but maybe not cost-effective, if you have brand new OEM bushings. If I made all the effort to remove those bushings, I'd spend the extra $ over OEM for the better Noltecs.
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
Most of us with home-built or custom coil-over suspensions use linear-rate springs because they are cheap ($100-120/pair), readily available in 25 lb-inch increments and in 8", 10", 12" free lengths to suit our application.
As for Noltec rear bushings, I think they'll be much better than the original 14-15 year old rotting rubber ones, but maybe not cost-effective, if you have brand new OEM bushings. If I made all the effort to remove those bushings, I'd spend the extra $ over OEM for the better Noltecs.
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
Last edited by a moderator:
GVR-4
Well-known member
What size tires do you like, Bob? For a DD that is.
Last edited:
CP
Well-known member
Get ones that are VERY similar to the stock rolling diameter or you'll have speedo issues. I've used this calculator for years.
I'm currently rolling on 185/65/15 in the winter, and 235/40/17 in the summer.
I'm currently rolling on 185/65/15 in the winter, and 235/40/17 in the summer.
225/45/16 Dunlop SP9000 in summer (NLA). I'm afraid to run 40 series in this environment of potholes and stripped streets under going repaving.
Next DD set will be 225/50/16 for a greater choice of makes/models and for better fuel economy due to larger circumference. I'll need to re-calibrate my mental speedometer lower to avoid tickets.
Next DD set will be 225/50/16 for a greater choice of makes/models and for better fuel economy due to larger circumference. I'll need to re-calibrate my mental speedometer lower to avoid tickets.
atc250r
Staff member
Quote:
Get ones that are VERY similar to the stock rolling diameter or you'll have speedo issues.
Actually, if you want a larger diameter you can go with something close to the same OD as a DSM (205/55/16) and put a DSM speedo gear in /ubbthreads/images/graemlins/wink.gif. I'm 99.9% sure they have a different PN because of that.
John
Get ones that are VERY similar to the stock rolling diameter or you'll have speedo issues.
Actually, if you want a larger diameter you can go with something close to the same OD as a DSM (205/55/16) and put a DSM speedo gear in /ubbthreads/images/graemlins/wink.gif. I'm 99.9% sure they have a different PN because of that.
John
I'm going to do that.
E39: N=30, part number MD728827
D27: N=29, MD728826
I run 205/55/16 winter tires, and Eclipse wheels in summer so that will help me.
E39: N=30, part number MD728827
D27: N=29, MD728826
I run 205/55/16 winter tires, and Eclipse wheels in summer so that will help me.
s_firestone
Well-known member
Quote:
I'm not sure if I understand your question about progressive springs. If the progressive springs are lowered by cutting off their soft coils, then you have a much stiffer rate. But, if the car is lowered by lowering the bottom spring perch on a coil-over kit, then the progressive nature is retained. The car doesn't weigh any more when it's lowered.
Most of us with home-built or custom coil-over suspensions use linear-rate springs because they are cheap ($100-120/pair), readily available in 25 lb-inch increments and in 8", 10", 12" free lengths to suit our application.
As for Noltec rear bushings, I think they'll be much better than the original 14-15 year old rotting rubber ones, but maybe not cost-effective, if you have brand new OEM bushings. If I made all the effort to remove those bushings, I'd spend the extra $ over OEM for the better Noltecs.
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
But we are not talking about springs that were calculated for our vehicles weight. By progressive springs I meant Evo cut springs or 1G springs. The AGX has a strut collar for OE type springs. I know its not made specifically for coil-over sleeves.
Part of the lowering effect using 1G springs comes from the additional weight on the car. Putting the springs at a different point in the sprung weight curve would affect its overall rebound charateristics. Cutting a spring obviously would alter that parameter even further depending on which part of the spring(and how much) was cut.
I was only trying to constrain this question to progressive vs. linear rate springs in relation to the design of the AGX struts. That is afterall part of what this thread is trying to accomplish is finding a suitable steet suspension with the intention of not slamming the car to the ground.
As for coil-over sleeves and linear rate spring several people have chimed in about the advantages and disadvantages. I'm not trying to accomplish lowering or cutting if possible. Only cutting if the springs cause the height to increase above stock. I would consider it much more desirable to match a proper height close progressive spring with a shock that can dampen it at a reasonable frequency.
What I asked was in relation to the AGX rebound damping issues people have repeatedly posted and I wonder if its a characteristic being seen only with linear rate springs or manifests itself with progressive springs(or progressive cut springs with a curve closer to that of a linear spring)? If it is then I will take my spring choices into account if I choose AGX struts/shocks. If the rebound damping deficiency is due rather to insufficient travel from using only short or extremely high rate springs, then I can discard it as an issue since I plan to use neither high rate springs, nor extremely shortened springs (linear or progressive).
I'm not sure if I understand your question about progressive springs. If the progressive springs are lowered by cutting off their soft coils, then you have a much stiffer rate. But, if the car is lowered by lowering the bottom spring perch on a coil-over kit, then the progressive nature is retained. The car doesn't weigh any more when it's lowered.
Most of us with home-built or custom coil-over suspensions use linear-rate springs because they are cheap ($100-120/pair), readily available in 25 lb-inch increments and in 8", 10", 12" free lengths to suit our application.
As for Noltec rear bushings, I think they'll be much better than the original 14-15 year old rotting rubber ones, but maybe not cost-effective, if you have brand new OEM bushings. If I made all the effort to remove those bushings, I'd spend the extra $ over OEM for the better Noltecs.
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
But we are not talking about springs that were calculated for our vehicles weight. By progressive springs I meant Evo cut springs or 1G springs. The AGX has a strut collar for OE type springs. I know its not made specifically for coil-over sleeves.
Part of the lowering effect using 1G springs comes from the additional weight on the car. Putting the springs at a different point in the sprung weight curve would affect its overall rebound charateristics. Cutting a spring obviously would alter that parameter even further depending on which part of the spring(and how much) was cut.
I was only trying to constrain this question to progressive vs. linear rate springs in relation to the design of the AGX struts. That is afterall part of what this thread is trying to accomplish is finding a suitable steet suspension with the intention of not slamming the car to the ground.
As for coil-over sleeves and linear rate spring several people have chimed in about the advantages and disadvantages. I'm not trying to accomplish lowering or cutting if possible. Only cutting if the springs cause the height to increase above stock. I would consider it much more desirable to match a proper height close progressive spring with a shock that can dampen it at a reasonable frequency.
What I asked was in relation to the AGX rebound damping issues people have repeatedly posted and I wonder if its a characteristic being seen only with linear rate springs or manifests itself with progressive springs(or progressive cut springs with a curve closer to that of a linear spring)? If it is then I will take my spring choices into account if I choose AGX struts/shocks. If the rebound damping deficiency is due rather to insufficient travel from using only short or extremely high rate springs, then I can discard it as an issue since I plan to use neither high rate springs, nor extremely shortened springs (linear or progressive).
CP
Well-known member
Quote:
225/45/16 Dunlop SP9000 in summer (NLA). I'm afraid to run 40 series in this environment of potholes and stripped streets under going repaving.
They can't be any worse than here in Boston /ubbthreads/images/graemlins/frown.gif I've only had one bent tie rod in the last year...but my rims are fine.
225/45/16 Dunlop SP9000 in summer (NLA). I'm afraid to run 40 series in this environment of potholes and stripped streets under going repaving.
They can't be any worse than here in Boston /ubbthreads/images/graemlins/frown.gif I've only had one bent tie rod in the last year...but my rims are fine.
atc250r
Staff member
Ideally I would bet that stock Evo8 rear springs and 2.5" DSM front lowering springs would probably give you a nice stance. Not too low, and you won't have to cut anything.
John
John
skivittlerjimb
Well-known member
Quote:
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
I've got that set up in now, as I was the one that picked up the GC set that Rice Killer sold. Al Grabau's installed them in the car now, so once I pick it up and drive it back to VT I'll post on my DD impressions of those spring rates. When my AGXs (~3 years old now) wear out, I may go to another shock that works with this set up (I believe my choices are Koni or GAB, but I may be wrong there) and does a better job of controlling higher spring rates.
For tires, overall diameter is a lot higher, but 205/55R16 on a 16x7 wheel is a decent option that I ran last summer until I got a flat that couldn't be fixed. Wider contact patch but enough sidewall to dampen things a bit. I'll post a pic if anyone cares to see what that looked like.
-Jim B.
1432/2000
165k and waiting to play
Using "275lb/in 10" front and 200 lb/in 10" rears" would be just on the edge of too hard for the front, but I've had worse than that in my DD this last year (F 300 lb/in & R 250lb/in.) For my next set-up, I'll stay "too stiff" in the rear (250lb/in) and try softer in front (225-250 lb/in,) to make for a better DD on Chi-town roads. It's a gamble and may not be an improvement.
I've got that set up in now, as I was the one that picked up the GC set that Rice Killer sold. Al Grabau's installed them in the car now, so once I pick it up and drive it back to VT I'll post on my DD impressions of those spring rates. When my AGXs (~3 years old now) wear out, I may go to another shock that works with this set up (I believe my choices are Koni or GAB, but I may be wrong there) and does a better job of controlling higher spring rates.
For tires, overall diameter is a lot higher, but 205/55R16 on a 16x7 wheel is a decent option that I ran last summer until I got a flat that couldn't be fixed. Wider contact patch but enough sidewall to dampen things a bit. I'll post a pic if anyone cares to see what that looked like.
-Jim B.
1432/2000
165k and waiting to play
Steven, Someone can correct me if I am wrong, but none of the stock springs being discussed are progressive. The VR4, 1g and Evo springs are all considered linear. Of course, they do behave somewhat differently based on installation length. Mitsu rates the springs through the center range of their normal travel. At full extension or compression they may not exhibit their stated rate, but in normal installation height and range of travel they are considered linear.
The aftermarket 2.5" spring normally used with coilovers are very linear (usually, there are exceptions). You can see this in the construction.
The aftermarket 2.5" spring normally used with coilovers are very linear (usually, there are exceptions). You can see this in the construction.
I just bought a pair of QA1 progressive coilover springs from Summit for $100/pair. Cheaper than a set of linear AFCO springs, they are 10" free length & 2.5" ID. They are 225-475 lbs/inch. Part Number HAL-10-225-475. I've got my fingers crossed that they'll cure my overly stiff front end caused by the 300lbs/inchers.
skivittlerjimb
Well-known member
Quote:
I plan to use neither high rate springs, nor extremely shortened springs (linear or progressive).
You're basically desribing the stock springs. Other than a custom made spring, I don't know how many options you're really going to have on the spring rates and lengths unless you go with coilovers. I may be wrong, though.
In a nutshell, then, I think you should be fine with AGXs. After 2+ years running stock GVR4 springs with AGXs set on 2 front and rear, I don't perceive the ride quality (and or rebound control) to be a big issue, even on Vermont's crappy roads. If you keep them set on 1s, you should be fine.
My suspension stiffened up much more due to installation of WL poly bushings. Less compliance means harsher ride, even with reasonable spring rates and shock settings. If ride quality is the overriding concern, I'd stick with replacement OEM bushings, new OEM springs (springs certainly fatigue after 15 years), AGXs, a stiffer rear sway bar, and ditching the rear steer.
-Jim B.
I plan to use neither high rate springs, nor extremely shortened springs (linear or progressive).
You're basically desribing the stock springs. Other than a custom made spring, I don't know how many options you're really going to have on the spring rates and lengths unless you go with coilovers. I may be wrong, though.
In a nutshell, then, I think you should be fine with AGXs. After 2+ years running stock GVR4 springs with AGXs set on 2 front and rear, I don't perceive the ride quality (and or rebound control) to be a big issue, even on Vermont's crappy roads. If you keep them set on 1s, you should be fine.
My suspension stiffened up much more due to installation of WL poly bushings. Less compliance means harsher ride, even with reasonable spring rates and shock settings. If ride quality is the overriding concern, I'd stick with replacement OEM bushings, new OEM springs (springs certainly fatigue after 15 years), AGXs, a stiffer rear sway bar, and ditching the rear steer.
-Jim B.
