S2000 Suspension Theory

[Clone]

I felt we needed a discussion thread for suspension mods... what works, what doesn't, and for what driving situation... Discussion starts now. Post any experience you have with certain mods, and how your S2000 has handled it. Any autocrossers, I'd love to hear your opinions and setups (as I'm planning on AutoXing mine here this winter)

Here's a small, beginnner's write up found on S.2.K.I.

Originally Posted by Originally Written by Drew Gross

Another modification commonly considered by S2000 owners is modifying the suspension for looks and/or handling purposes. There are a number of options available, ranging from a $200 set of lowering springs to $8000 full custom coilover sets.



There are many reasons to modify the stock setup. Some folks are just looking for a lower more aggressive look. Some think the stock ride is too stiff, while some think it’s not stiff enough. Some drivers want to maximize their handling, while some just want a little extra grip. The stock suspension on the S2000 is an extremely well designed system for our car, and many modifications will actually cause the car’s performance to decrease. If you know exactly what you want before you spend your hard earned money, you’re much more likely to chose the right setup for your kind of driving, or decide that the stock is good enough after all. We thought we’d give you a little primer about various suspension modifications, their uses, and the good and bad of each.

Springs:



Springs are the lowest cost suspension mod you can do, and can significantly alter the look and handling of your S2k. If what you’re looking for is to have your car sit lower to the ground for the “bling” effect, springs are the most cost-effective way to do it. There’s a trade-off here. The stock suspension was engineered specifically for the stock spring height. When you put in shorter springs, you mess up the geometric design of the system. Frankly, the car will not handle as well. (No matter what self professed “experts” might say.) Lowering springs alone are for looks only. Not only will they not improve the handling of your S2000, but they will actually diminish it.



Some replace the stock springs with same height aftermarket choices to either stiffen or soften up their ride. As long as the height is the same, the geometry will be fine. Keep in mind that the stock shocks were valved to match the stock spring rate. While stiffer of softer springs will have a similar effect on your ride, they will not give you the optimal symentry with the factory shock absorbers. There are a number of excellent spring manufacturers to consider here including Eibach, HKS, Espelier, Takata, and Tanabe.



Springs with shocks:



This is a better option if you want to lower your car but don’t want to screw up the handling or if you want to change the spring rate and have a shock that’s set up to match. There are a number of options here, but the most important thing to consider is the importance of matching the spring height/rate to the design/setup of the shock. An improperly matched set will actually make things worse than the stock shocks with aftermarket springs. Some popular choices here are Koni yellows, Ohlins, Penskes, Jic, and Bilstein PSS . While a good matched set will allow you to lower your car without messing with the handling, most don’t provide a significant performance benefit over stock. (Although they are often adjustable and might allow for a more comfortable ride)



Coliovers:



The only way to significantly improve the handling of an S2000 is with a full coilover setup. Most coilovers have multiple adjustments available for compression and rebound and some even include separate adjustments for high and low speed compression. There are a huge range of coilovers starting with relatively inexpensive offerings (under $1500) from Tein and Buddy Club (that often provide little or no benefit over stock) to mid-priced systems ($1500-$3000) from Tein and KW, (At under $2k discounted, the Variant 3 setup is quite possibly the most bang for the buck suspension available for the S2000) up to megabuck ($4-8k+) double and triple adjustable setups from JRZ, Penske, Ohlins, and Moton. A good set of coilovers makes a huge difference keeping the car planted in hard cornering, and is almost a necessity when driving hard using r-compound tires. While the stock suspension is capable of taking the car right up to its limits on street tires, a set of r-comps will definitely allow you to push the stock suspension well past its limitations.



Before you start to spend money on suspension modifications, first decide what exactly you want to achieve. Is your goal looks, performance, or comfort??? Before you spend any money, make sure you know what you want or you might make a very expensive mistake.

[5gencivic]

I know that I'm a few days late to this party but I'll bite.
I think that the people who claim that the only way to improve the S2k's handling is by changing the stock suspension out with a set of high priced coilovers are simply nuts.
Of course I have no grounds for this claim but I would imagine that a stock S2k (any MY) against an S2k (same MY) with eibach prokit springs, koni yellows and some track time to adjust the setup, would get owned.
I think that most people who buy s2000's think that because they have a sports car that is relatively hard to find parts for that they have to spend the most that they can to get the best parts they can find to get any kind of improvement.
Ok. That's all I have to say.

[Boski]

Originally Posted by 5gencivic

I think that most people who buy s2000's think that because they have a sports car that is relatively hard to find parts for that they have to spend the most that they can to get the best parts they can find to get any kind of improvement.

i don't think that finding parts for the s2k is hard, there is a huge aftermarket support for it, however the reason why most of the s2k aftermarket parts are expensive is because the car was designed so well out of the factory that to improve it requires great engineering and quality materials which in turn means higher priced.

[RED MX5]

Originally Posted by 5gencivic

I know that I'm a few days late to this party but I'll bite.
I think that the people who claim that the only way to improve the S2k's handling is by changing the stock suspension out with a set of high priced coilovers are simply nuts.
Of course I have no grounds for this claim but I would imagine that a stock S2k (any MY) against an S2k (same MY) with eibach prokit springs, koni yellows and some track time to adjust the setup, would get owned.
I think that most people who buy s2000's think that because they have a sports car that is relatively hard to find parts for that they have to spend the most that they can to get the best parts they can find to get any kind of improvement.
Ok. That's all I have to say.

Well, the OP asked for first hand experiences, so even though I'm late to the party too, it's a good topic, so I'll jump right in.

We lowered the S2000 because I wanted to make sure I could live with a 1" drop on a day-to-day basis. It is a given that when you lower this car you create some undesirable changes in the dynamic suspension geometry, and I wanted to make sure that I could live with the drop before investing in an expensive coil-over kit and all the suspension reengineering it takes to sort out the mess that lowering with coil-overs (or springs) makes. To get things back to as good as stock you have to correct bump and roll steer at BOTH ends of the car, and that requires major suspension work that very few people ever do. It seems that many of those who buy expensive coil-over systems seem to think they are bypassing these problems when in fact they're not, and I just didn't want to open the can of worms until I knew I could live with the reduced ground clearance.

Now, keep in mind as you read the rest of this that we only put the springs on the car as a test. Still, lowering springs can be problimatical, so I did quite a bit of research before selecting the springs. I decided on an Eibach Pro Kit because it offered the 1" drop I was looking for, and because after discussing their design decisions with them I was convinced that their springs would minimize the negative effects of lowering an otherwise stock car. I'm not going to go into the details of their design decisions here, because that's not my area of expertese and I might get some of it wrong; If you want details, do what I did, and contact Eibach directly. They're very nice people.

I expected to have more oversteer because the rear spring rates are higher. I expected to have a harsher ride, because the suspension travel is reduced and the rear spring rates are higher. I expected to have a bump steer issue becasue lowering the early cars (pre MY04) produces unfavorable changes in the dynamic suspension geometry at BOTH ENDS OF THE CAR. (And no matter how much you pay for your lowering solution, you still have this problem.)

After we installed the springs we alighed the car to the UK specs, and I drove it on the street for a while. The ride quality was a pleasant surprise. The engineer at Eibach had told me that the ride would be almost the same as stock, but I had to experience it to believe it. Obviously the car has less suspension travel after it is lowered, but I have yet to bottom out the suspension, so at least on the roads I drive on, and the places where I compete, it's not a problem. Your mileage may vary, depending on the road and track conditions you have to deal with.

I was also favorably impressed with the handling, at least on the street, so I decided to leave them on the car for a while and try a few autocrosses. To my amazement, the handling at the limit was amost unaffected by the springs. Lowering the car lowers the CG, but it also lowers the roll axis, so the moment is longer and the weight transfer goes up rather than down, but with the Pro Kit (at least, I cannot comment about other spring kits), the handling is as close to stock as is the ride quality. So close that it's hard to tell the difference. However, high speed stability (130+ MPH) was a little scary.

After discussing the high speed stability problem with my friends on S.2.k.I I finally noticed that we'd set the rear toe wrong (near zero), and after we corrected our mistake the cars handling was as good as it was the day the car rolled off the assembly line. Now I compete on surfaces that have small dips and inclines, but no sharp dips or bumps, so bump steer may be more of an issue for others, but it has NOT been an issue for me.

Next we installed the Comptech SC/AC. I expected the extra power to make it easier to slide the tail out when I wanted to, and I expected the extra weight in front of the front axle line to produce a little more understeer, and for my driving style, and the MY00-01 suspension tuning, that's a good thing. The SC/AC did as expected, but the change in cornering bias didn't move as much as I'd expected. Autocross times improved, but I still felt the car needed just a tiny bit more push coming off corners.

The next mod that affected the handling was the installation of the new differential; Competch reinforced, 4.30:1 gears, KAAZ 1.5 LSD. As most of you probably know, a Torsen LSD is usually preferred for autocrossing, because clutch type diffs lock up more quickly, and behave like a solid axle whenever torque is being applied, so they tend to increase understeer. In most cars the battle is alwasy to get less understeer, so normally replacing a clutch type with a Torsen would be an improvement. However, if you want to be able to push a little on corner exit without changing the other handling characteristics of the car, a clutch type LSD will do the trick. With the S2000 the car was TRANSFORMED. I can now drift up to the point where I run out of steering angle, and it's easy to maintain control. On the autocross courses the car turns in as well as it did when it was bone stock (and wasn't carrying the weight of the supercharger), and I can push the front end right out to the edge of the track on every corner, every time (or I can gas it a little harder and get the tail out as far as I like, depending on what the course and my mood dictates).

I'm still running OEM S02's, stock wheels, and stock shocks, and on our skid pad I'm now able to hold a steady state 0.94G, which is a little *higher* than I could do before the springs, diff, and alignment tweaking. I'm hoping to pick up some more grip through weight reduction, and while we'll probably never make it, I've got my eye on getting a full G out of the OEM tires.

IF you are running stock tires, and don't race on an unusually bumpy surface, the Pro Kit minimizes the downsides of lowering to the point where they don't matter. Upgrading the shocks never hurts, but it is not necessary. Koni yellows have less compression damping than the stock shocks, and with the stock springs this makes the car easier to drive (at least for some drivers), but because of the reduced compression damping, the car is going to be more likely to bottom out over large bumps. Probably a bad idea on a car that is lowered, but I can't say for sure because I haven't actually tried it.

We will eventually put a set of full coil overs on the car, and then fix the geometry problems that the lowering causes, but given the way the car is handling right now we're not going to change anything else until we are ready to go to R compound (or larger) tires.

Note that there are most certainly cheaper ways to get the car to handle better than stock than a Pro Kit and KAAZ LSD, but the two together make for an almost magical synergy. The downside is that a clutch type LSD wears out and has to be rebuilt periodically (a Torsen doesn't), and the clutches chatter and create nasty vibrations when the diff is cold and torque is applied while turning at low speed. The KAAZ is a hard-core mod that you'll hate if you don't know what you're getting into, so I'd advise seroius though before getting rid of the stock Torsen LSD. It is silent, trouble free, and is likely to last the life of the car. With a clutch type diff you have to change the differential oil every 3000 miles (same interval as my oil changes), so the advantages don't come without a price. For me, the price wasn't important, because my S now handles exactly the way I want, and at the local autocrosses I beat everyone else on street tires and most of the guys on R compound tires and/or racing rubber (there are two, sometimes three, exceptions, but all three are national champions running R compound, and I'm still on my OEM tires, so they'd better be beating my times .

As an aside, R compound and racing tires tend to break things on the S2000, so making a big upgrade in the traction department brings lots of problems. The inside rear wheel will lift too, and without a diff that actually locks, the inside rear will spins uncontrollably. Whether you lower or upgrade traction, you create other issues that need to be addressed. With lowering, at least with the Pro Kit, the issues are so minimal that they can be ignored (unless you drive or race on roads that are much bumpier than the ones I have encountered to date).

Boski is absolutely correct. The problem isn't finding aftermarket parts for the car. The problem is finding aftermarket parts that actually make a real improvement. Springs alone are NOT an improvement, but the idea that they spoil the handlilng (and the idea that any handling problems cause by lowering will be lessened by using a more expensive coil over kit) is incorrect. Using a poorly designed product will cause problems, period, no matter how much they cost. The Eibach springs are extremely well thought out, and work amazingly well on the car. The Espler (SP?) springs are also quite popular, but they drop the car more than an inch, and I couldn't live with more drop than I already have. Driveways and speed bumps are already a problem, and my strakes are constantly taking a beating.

OK, that's my experience guys, and it's contrary to a lot of the BS you'll hear from people who are convinced that lowering with springs alone will spoil the cars handling. They haven't tried it, because they know it won't work. I tried it because it was a test and I didn't care how well it worked, and to my surprise, they work wonderfully. Let those who've never tried things talk you out of them if you like ... that'll be your loss.

Who's next? The OP asked for first hand experience.

[5gencivic]

See now that was a good post. My head hurts but it was a good post. Rep for joo.

[Clone]

yeah, good stuff... keep it coming!

[RED MX5]

Originally Posted by Clone

yeah, good stuff... keep it coming!

I did my part. Now somebody else has to step up to the plate.

As unlikely as it seems, I just found out that I won first place in my class at the NOPI Nationals Supershow in Atlanta last weekend, and the three Miata's we took won first, second, and third place in the street Miata class. LOL, I know there were cars there that had bookoo more mods, and none of our cars were even show ready, but we won anyway. Go figure.
(Yea, that's off topic, but I think it's funny that I keep winning national shows with my autocross car. )

[RED MX5]

Originally Posted by Clone

Any autocrossers, I'd love to hear your opinions and setups (as I'm planning on AutoXing mine here this winter)

You probably already know this, but the biggest improvements you can make will be in your driving skills rather than the car. An Evolution School will take severl seconds off your times and only cost a few hundred bucks. You will learn more, faster, if you go to the schools with a completely stock car, and the S2000 is the perfect vehicle.

I don't care how good you are, the Evloution Schools will make you better. I go to at least one school every two years, and some years (like this one) I do two or more schools in the same year. The instructors are all multi-time national and pro SOLO champions, and you get individualized instruction that focuses on the things that you personally need the most to go faster.

http://autocross.server269.com/evolu....php?storyid=1

[Clone]

know of any around atlanta?

[RED MX5]

Originally Posted by Clone

know of any around atlanta?

As a matter of fact, the schools I go to are put on by the Atlanta Region SCCA and are held at Turner Field.

There won't be another Evolution School in the area this year, but there will be a least one, and possibly two, next year. The Atlanta Region usually has an Evolution Phase 1 School in on the same weekend they have their regional autocross school, and this year they had a Phase 2 School in parallel with their test-and-tune day. Once you start autocrossing with the club and going to the meetings (you are going to go to the SCCA meetings, aren't you? ) they'll keep you up to speed on the schools and schedules.

Why don't you come down to Macon this weekend and join us at the PCA autocross? In Atlanta you'll only get three runs at an autocross, but down here we usually get in at least six runs, and things are a lot more casual. Come on down and join in on all the fun.

[Clone]

I just might take you up on that... although I can't do it this weekend... if I had like, two weeks notices I can get out there... so keep me posted.

[RED MX5]

Originally Posted by Clone

I just might take you up on that... although I can't do it this weekend... if I had like, two weeks notices I can get out there... so keep me posted.

Unfortunately, the event this weekend is the last PCA autocross until next year.

The SCCA is having an autocross at Watermelon Capitol Speedway in Cordele, on October first, but I don't usually go to the events in Cordele. I'm sure the SCCA would be happy to have you join them though. I could probably arrange for Tripper or one of the other guys to give you a few pointers. Think you might want to try to make that event?

[Clone]

depends on when it is... I'd love to be there, but as I'm sure you can understand, scheduling conflicts and such... I'm a busy person.