Hot Take: OEM vs lowered OEM
01-20-2020, 10:34 PM
#1
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Hot Take: OEM vs lowered OEM
So I've noticed a lot of S2000 owners say that lowering springs will not hurt performance versus stock and disagree with that heavily and I will attempt to explain why, feel free to disagree. On my 2002 AP1 I fixed a wrong and replaced the old Megan Street coilovers with some 2003 AP2 springs on Tein STech springs. According to forums and my real world experience, the AP2 suspension did indeed understeer a little more than AP1 and that is expected but I noticed over time the limits of the Tein springs.
Tein is a fantastic brand and the spring itself is at least a quality part but over bumps on the highway, it would undulate 2 or 3 times while my parents' BMW only undulated once. Something seemed off, the spring rates were higher than stock but the ride is springier. After a track day, I mistakenly thought I blew a shock (I didn't, I just loosened an endlink, ugh) so I went back to full OEM AP1 for a change and the shift was astonishing! The car rode noticeably better than before and that same bump in the highway only took one undulation. But what got me was the behavior approaching the limit, while the old AP2 setup would just understeer and I would need to turn the wheel more to rotate, the AP1 suspension rotated on a dime the moment I lifted off the throttle. This probably is why AP1s have that infamous snap oversteer but it really does make the whole car come alive.
My next step (ironically) is most likely to add Swift Spec R springs. I've been told by many members on the forums and FB groups that Spec R springs are actually matched properly for our cars so that will be interesting to try, I still miss being a little lowered after all.
What are your guys' thoughts on 100% OEM suspension vs lowering springs?
Tein is a fantastic brand and the spring itself is at least a quality part but over bumps on the highway, it would undulate 2 or 3 times while my parents' BMW only undulated once. Something seemed off, the spring rates were higher than stock but the ride is springier. After a track day, I mistakenly thought I blew a shock (I didn't, I just loosened an endlink, ugh) so I went back to full OEM AP1 for a change and the shift was astonishing! The car rode noticeably better than before and that same bump in the highway only took one undulation. But what got me was the behavior approaching the limit, while the old AP2 setup would just understeer and I would need to turn the wheel more to rotate, the AP1 suspension rotated on a dime the moment I lifted off the throttle. This probably is why AP1s have that infamous snap oversteer but it really does make the whole car come alive.
My next step (ironically) is most likely to add Swift Spec R springs. I've been told by many members on the forums and FB groups that Spec R springs are actually matched properly for our cars so that will be interesting to try, I still miss being a little lowered after all.
What are your guys' thoughts on 100% OEM suspension vs lowering springs?
Last edited by InjunS2K; 01-22-2020 at 09:46 PM. Reason: Mislabeled car as 2003 when it's a 2002
01-21-2020, 03:41 AM
#2
I think what you're experiencing is that AP1 shocks (dampers) are valved more agressively than AP2.
Lowering springs will all cause the bumpstop to engage more...since the shocks don't have much room to travel even at stock height.
Tein's springs are quite soft, and the (1.25"?) drop is pretty agressive. The Swifts are stiffer with the same drop. I assume the swifts would allow a lot less body roll, but they'll also demand more from the shocks.
I would also assume that the Swifts actually give the car potential to lap a track faster as compared to stock.
The stock shocks aren't bad at all. They can handle quite a bit more rate than stock.
The stock springs are (IMO) too soft for track use. There's a lot of wasted movement, and the car gets too tossed up when you're trying to make a side to side transition.
So your swift/stock shock combo will probably be an improvement over stock.
Lowering springs will all cause the bumpstop to engage more...since the shocks don't have much room to travel even at stock height.
Tein's springs are quite soft, and the (1.25"?) drop is pretty agressive. The Swifts are stiffer with the same drop. I assume the swifts would allow a lot less body roll, but they'll also demand more from the shocks.
I would also assume that the Swifts actually give the car potential to lap a track faster as compared to stock.
The stock shocks aren't bad at all. They can handle quite a bit more rate than stock.
The stock springs are (IMO) too soft for track use. There's a lot of wasted movement, and the car gets too tossed up when you're trying to make a side to side transition.
So your swift/stock shock combo will probably be an improvement over stock.
01-21-2020, 06:37 AM
#3
You have to consider the shock/spring combo.
Some people don't like the body roll at stock height and/or spring rates and are willingly to accept some of the deficiencies with just lowering springs. On AP1s, lowering the car actually diminishes the rear suspension's "bump steer" or oversteer tendencies since it reduces the range of motion the suspension can work through. Stiffer spring rates also helps in this regard.
Honda spent A LOT of time fine tuning the suspension. The spring rates (and sway bars) were tinkered with throughout the S2000's run with significant variations and its a fair guess that the shocks were tuned to accommodate. So the fact that lower/stiffer springs are probably not as good a match with the stock shocks as the factory springs is unsurprising.
Having said that, the stock shocks are a fantastic design and are probably better suited for moderate lowering springs as opposed to most aftermarket shocks. The rear shocks are restricted in how much travel it has due to space constraints which is why the OEM units have an external reservoir - it gives the shock a bit more travel space internally. Most aftermarket replacement shocks do not have this external reservoir, so aftermarket shocks tend to have even less travel than the stock setup. Put lowering springs on and there is an even greater chance of bottoming the suspension out despite the stiffer suspension.
If given a choice between a new Koni or new OEM shock with lowering springs, I'd take the OEM shock. If given the choice between lowering springs or OEM springs on OEM shocks, I'd go with lowering springs since I have an AP1. Only ~1" drop though. My knees are old now, lol.
Some people don't like the body roll at stock height and/or spring rates and are willingly to accept some of the deficiencies with just lowering springs. On AP1s, lowering the car actually diminishes the rear suspension's "bump steer" or oversteer tendencies since it reduces the range of motion the suspension can work through. Stiffer spring rates also helps in this regard.
Honda spent A LOT of time fine tuning the suspension. The spring rates (and sway bars) were tinkered with throughout the S2000's run with significant variations and its a fair guess that the shocks were tuned to accommodate. So the fact that lower/stiffer springs are probably not as good a match with the stock shocks as the factory springs is unsurprising.
Having said that, the stock shocks are a fantastic design and are probably better suited for moderate lowering springs as opposed to most aftermarket shocks. The rear shocks are restricted in how much travel it has due to space constraints which is why the OEM units have an external reservoir - it gives the shock a bit more travel space internally. Most aftermarket replacement shocks do not have this external reservoir, so aftermarket shocks tend to have even less travel than the stock setup. Put lowering springs on and there is an even greater chance of bottoming the suspension out despite the stiffer suspension.
If given a choice between a new Koni or new OEM shock with lowering springs, I'd take the OEM shock. If given the choice between lowering springs or OEM springs on OEM shocks, I'd go with lowering springs since I have an AP1. Only ~1" drop though. My knees are old now, lol.
01-21-2020, 07:15 AM
#4
The spec R springs are heavily forward biased, toward undeersteer, compared to ap1spring rates. Even more forward biased than the CR springs.
In each suspension iteration of this car, things were progressively tuned to more and more forward (understeer) bias. Too many cars were spinning off the road from drivers with limited rwd experience. Plus forward bias is more stable in high speed sweepers, better for track duty.
ap1 suspension with its more eagerand lively rear end can be more fun on the street. CR suspension with its planted rear yields faster lap times on the track.
Point is if you liked the way stock ap1 suspension rotated on throttle lift, the spec R springs are moving you even farther away from that direction.
Most lowering springs were created when the car first came out, and so were based off the ap1 more rearward biased rates. They tended to take the rates Honda used, and amplify them to compensate for less travel. So most lowering springs can be considered to have 'ap1+' rates. The spec R were built for CR, and as such have more like 'CR+' rates.
As pointed out by others, a big issue with lowering springs on this car is setups that end up riding on bump stops. Typically its the rear that suffers from this, hence causing excessive higher rear spring rates.
Suspension is art and science. Its far more complex than making simple statements like lowering is worse than stock.
In each suspension iteration of this car, things were progressively tuned to more and more forward (understeer) bias. Too many cars were spinning off the road from drivers with limited rwd experience. Plus forward bias is more stable in high speed sweepers, better for track duty.
ap1 suspension with its more eagerand lively rear end can be more fun on the street. CR suspension with its planted rear yields faster lap times on the track.
Point is if you liked the way stock ap1 suspension rotated on throttle lift, the spec R springs are moving you even farther away from that direction.
Most lowering springs were created when the car first came out, and so were based off the ap1 more rearward biased rates. They tended to take the rates Honda used, and amplify them to compensate for less travel. So most lowering springs can be considered to have 'ap1+' rates. The spec R were built for CR, and as such have more like 'CR+' rates.
As pointed out by others, a big issue with lowering springs on this car is setups that end up riding on bump stops. Typically its the rear that suffers from this, hence causing excessive higher rear spring rates.
Suspension is art and science. Its far more complex than making simple statements like lowering is worse than stock.
01-21-2020, 05:15 PM
#5
Want to chime in that you alter suspension geometry when you lower the car, and also change the toe curve. The stock ride height is actually pretty dang low. Thinking otherwise is an illusion caused by the truck like fender gap.
Lowering the car directly lowers the value of your car as well because most people do it wrong. For one they don't clock their bushings, but that's amateur hour. I wouldn't lower this car without getting spherical upper control arm bushings and a toe correction kit. Using OEM bushings will just wear them out if lowered, even if you clocked the bushings properly.
Lowering the car directly lowers the value of your car as well because most people do it wrong. For one they don't clock their bushings, but that's amateur hour. I wouldn't lower this car without getting spherical upper control arm bushings and a toe correction kit. Using OEM bushings will just wear them out if lowered, even if you clocked the bushings properly.
01-21-2020, 10:33 PM
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I see, I'll be taking my AP1 to autocross this weekend so I'll report back on what I think after then to be sure. I'll do some more research on suspension because while I did like the rotation on the street I can see how that would pose problems above 7/10's. Swift Spec R seems to be the best for our cars but I guess I might as well save more for coilovers for a few more months after I get more HPDE/autoX experience
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01-22-2020, 06:52 AM
#8
Because you introduce more lateral movement across the bushings when you lower. So even if they're not twisting more than necessary, they're bending, particularly the rear most bushing. This is because of the altered suspension geometry. This isn't as big an issue on AP2's and partly why Honda increased the thickness of the rear upper bushings. Spherical/rose joint bushings don't allow any of that lateral movement.
Think about what happens when you space the arm mounting further apart? As AP2 subframe VS AP1. The lateral force on the upper arm is less because it's spread out over a wider angle, on AP1 the lateral force is greater. The AP1 toe curve was calculated by not just suspension geometry but bushing compliance as well. By introducing more lateral movement on the bushing via lowering you change the original compliance characteristics.
Using rose joints and toe curve correction kit you can get close to factory toe curve, which is why I wouldn't lower the car without them. Then again listening to me should come with a disclaimer.
Think about what happens when you space the arm mounting further apart? As AP2 subframe VS AP1. The lateral force on the upper arm is less because it's spread out over a wider angle, on AP1 the lateral force is greater. The AP1 toe curve was calculated by not just suspension geometry but bushing compliance as well. By introducing more lateral movement on the bushing via lowering you change the original compliance characteristics.
Using rose joints and toe curve correction kit you can get close to factory toe curve, which is why I wouldn't lower the car without them. Then again listening to me should come with a disclaimer.
01-22-2020, 09:57 AM
#9
Interesting. This adds another layer to my theories about perceived 'snap oversteer'. I've long thought that this myth has been strongly influenced by poorly done lowering. It seems ap1 suffers from this in more ways than I previously realized.
Lower your car using stock shocks and lowering springs that go down low, without any supporting changes, is a recipe for poor handling. Failing to shorten bump stops, failure to address additional toe change due to lateral bushing flex. Failure to include any driver mods when inexperienced with rwd... You can see where the urban legend of snap oversteer was born.
Lower your car using stock shocks and lowering springs that go down low, without any supporting changes, is a recipe for poor handling. Failing to shorten bump stops, failure to address additional toe change due to lateral bushing flex. Failure to include any driver mods when inexperienced with rwd... You can see where the urban legend of snap oversteer was born.
01-22-2020, 02:03 PM
#10
An older performance test showed a totally stock CR S2000 was faster than a host of heavily modified S2000's from some of the best tuners out there when tested on a racetrack. That was a very impressive test, sorry I don't have a link to it, but it is out there somewhere.
Dumping springs on stock shocks can easily make things worse. Having springs and shocks engineered together is the way to go, so either stock or a high quality set of coilovers with a mild drop setting. I ran Bilstein PSS coilovers and they were fantastic, perfect in every way, no complaints and no compromises. I ran a drop of about .75" or less. I went with the PSS over PSS9's as the PSS are non-adjustable in terms of shock settings, I wanted the shock engineers to match the shocks to the springs as they are most qualified to do that, rather than some bloke like me turning a shock knob that no one knows what is being changed. I personally feel any drop beyond .75 or 1 inch can result in worse handling unless you have a shortened shock and matched spring combo. .75 was perfect on my Bilsteins. Shock tuning is a black art kind of thing, very few people know what they are getting from aftermarket suppliers and quite often adjustable shock settings are non-intuitive or inconsistent at best. Easier to screw up the handling than make it better, not many people have access to shock dynos so leave it to the expert engineers.
Dumping springs on stock shocks can easily make things worse. Having springs and shocks engineered together is the way to go, so either stock or a high quality set of coilovers with a mild drop setting. I ran Bilstein PSS coilovers and they were fantastic, perfect in every way, no complaints and no compromises. I ran a drop of about .75" or less. I went with the PSS over PSS9's as the PSS are non-adjustable in terms of shock settings, I wanted the shock engineers to match the shocks to the springs as they are most qualified to do that, rather than some bloke like me turning a shock knob that no one knows what is being changed. I personally feel any drop beyond .75 or 1 inch can result in worse handling unless you have a shortened shock and matched spring combo. .75 was perfect on my Bilsteins. Shock tuning is a black art kind of thing, very few people know what they are getting from aftermarket suppliers and quite often adjustable shock settings are non-intuitive or inconsistent at best. Easier to screw up the handling than make it better, not many people have access to shock dynos so leave it to the expert engineers.
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