Possible track spring spring setup for use with Koni yellows

[stretch]

I'm curious if any folks here would be interested in springs designed specifically for Koni struts / shocks.

I always like to lead in with this quote: "Good shocks are probably the second most significant handling change you can make to a stock car," says autocross and road racing national champion Jeff Altenburg, "tires with an alignment being the most significant."

And I'll add to that, saying that shocks and springs must match each either. Shocks must be designed for a very specific spring rate or vice-versa.

The problem with most lowering springs, then, is that they're designed for the stock shocks. This severely limits what they can do, with only a few companies like Racing Beat having the discipline to actually run a drop appropriate for their spring rates on the stock struts and shocks. Many applications lower the car directly onto the jounce bumpers. This makes the car look great and sometimes it'll even maintain a modicum of ride quality, but it's by no means the best way to do things.

The problem here is that lowering springs are predominately a cosmetic upgrade rather than a performance one. The 10-20% stiffer "lowering" springs simply do make the impact that one would hope. Cobb recently demonstrated this on their Mazdaspeed3 suspension video- the springs had very little effect, with the upgraded sway bars making a very large improvement. This is because whereas the coil spring rates increased 10-20%, they had drawbacks of reduced travel and hitting the jounce bumpers. Meanwhile, the sway bar rates- which are far higher than the coil springs to begin with- went up 30-100%, which is more like doubling or tripling the stock spring rates in terms of roll stiffness.

Furthermore, Mazda does some strange things with spring frequencies to get good low-speed ride quality, and again, it's impossible to fix this if designing parts for the stock shocks because the required bump in rear spring rate would be too high. My measurements show Mazda doing with roughly 0.24hz lower frequency in the rear, whereas a more conventional approach is to go for 0.2hz higher in the rear. This is done to reduce pitching of the vehicle during highway driving. I have not dyno'd (nor found a dyno) of either the stock Mazda3 or Mazdaspeed3 dampers but my guess is they make up for this using uneven valving to play with what's known as the damped frequency, which isn't optimal for performance.

I'll cite these three articles:
Spring Rates | Build A Faster Car
Bump Stops, Bump Travel, and Lowering Springs | Build A Faster Car
Damper Valving for a Higher Spring Frequency in the Rear | Build A Faster Car

Anyway, all the theory aside, I think the only way to correct the suspension is to design springs that are meant to be used with high-quality aftermarket dampers. My first choice would've been Koni FSD's, since I haven't used them but am eager to try, but some users here report fast wear. So, I'll stick with tried-and-true Koni Yellows. Koni Yellows have never let me down, come with a lifetime warranty, and can handle nearly any spring rate I'll come up with. This allows us to pick good spring frequencies for a car that really behaves well. Since even some coilover companies do not always donate sufficient R&D to customizing their parts to the car, I think it's possible to make a spring/damper combo that easily outperforms many coilover sets while riding even better. I don't anticipate needing a custom Koni valving, but that's always an option too.

The key to this, as I've said, will be the excellent Koni dampers, which are used in some $2500 coilover sets (in other cars). We can take advantage of those dampers and design springs specifically for them, and users would only lose the ride height adjustment. When the springs and dampers are properly matched, magic should happen. Ride quality can be quite good when the dampers match the springs, even if those springs are much firmer than stock. However, the performance benefits can be quite large, and this would come from Koni dampers (~$730) and springs (~$300?) alone. For that money, these will blow cheap coilovers out of the water- it won't even be close, I can promise, unless the contest is for ride height adjustability.

The question is: is there a market for this type of thing? This would be sold under the Custom Performance Engineering brand as they are looking to start doing properly engineered suspensions. Believe me, there is a tremendous lack of suspension engineering (things are usually done with feel, which isn't always wrong, but isn't always right either) out there and I've been hounding CPE for YEARS to start! Before any announcements are made, though, I was personally curious what the community here thought about such a product.

[subparpunk03]

I've thought about upgrading my shocks to koni yellows, but since I have the cobb springs and they are designed for the stock shocks, I would probably go with a full coilover setup instead, mainly b/c the price of springs + top notch shocks is not much less than the coilovers, so I may as well just go balls to the wall and do that.

I think you'd have more interest in a coilover setup rather than a spring / shock combo. At least on the MS3

[prototype_x9]

I believe that many people dont want to go the full coilover route. A sensible adjustable dampening shock matched to fit a set of springs really would do our community some good. I know everyone says they want the 64-way adjustable height changing coilovers, but i guarantee you maybe only 10% of people who own them know how to properly adjust the dampening for better performance. I know a lot of people, frankly, are intimidated by that much customization. Most people dont know how to or just never will utilize the full abilities of a nice set of coils. People that do 90% street driving would just want somethin that would give them better performance that they will never have to think about. Then they would still be more sporty at the track. Offer the twist knob for dampening adjustment a track.

I think a nice performance shock that could be mated to a performance spring would sell very well. I believe that just about everyone who bought a cobb suspension kit or eibach or any of those spring kits would purchase a set. Combine it with whatever springs and hotchkis sway bars and give a small discount and people will buy the entire suspension at once.

Maybe you cant even get the dampening where you want them at all four corners. Offer up a simple twist knob for making the damper harder or softer. People love convenience in their cars, they dont want to have to go out with a wrench every day to change their dampening on their coil. Whihch explains why the EDFC is so popular. Did you know that if th EDFC gets wet it will fail. There is no weather protection for the actual step motor in the engine bay. so I wont take the chances of ruining my gorgeous coilovers by driving in the rain.

all this being said, if there was a good performance shock and spring combo on the market I know it would sell.

[AutoXRacer]

I'm looking for a suspension setup myself. I like the idea of coilovers, but I don't like all the adjustability. I loved my Miata setup which consisted of KYB AGX (4 settings) and my FM Springs. I set it on soft for daily driving and hard for autocrossing. And they performed awesome. I would love a setup like that for the MS3...

Koni Yellows and some firmer springs sound great... I just want to bolt-on and go.
I don't want a setup with 128 adjustments.

When would something like this be released to the market?

My ideal setup would eliminate the front to rear weight transfer and the floating feeling at high (+100) speeds.

Keep us posted on your idea!!!!

Even if this thing gets realized at a limited production, I would like in on it... PM me if you have to.

[numbnuts22715]

I love Koni Yellows.. I had them with Ground Control coilovers on my integra, and it made a world of difference. Someone NEEDS to make something like this for our cars!!

[stretch]

I'm glad the support is there, guys, believe me. I've helped design some coilovers and lowering springs in the past, and I'm very familiar with what makes a good suspension versus what is usually found on the market. I think the market focuses on cosmetics (lowering the car beyond its optimal handling or ride quality) or on feeling fast (usually lots of damping, which actually reduces grip) but very rarely on getting the damping right which results in a fast car that rides well. Normally I'd give specific examples and call out a bunch of brands as trash, but since I'm doing this for CP-E, I'll bite my tongue. I will say that the while folks claim their springs were designed for the stock shocks, the stock shocks were designed by a much larger group of engineers for the stock springs. That's why I'm looking into designing springs for Koni's.

That said, I am in talks determining whether I can make two sets of springs; one for the stock dampers and the other more aggressive for the Koni owners. I'll do the former only if by chance it'll work on the stock shocks, but my concern is in the rear- I'll know what the stock shocks can handle after seeing a shock dyno graph. I don't think most spring companies even get one, let alone design around a shock dyno graph, since I've never seen one posted here. (Hopefully I can post mine, not sure if I'll be bound by any restrictions.) If the stock shocks cannot handle anything too different from stock, then I'll just make the firmer set per the original plan. And when I say "firmer" set, it won't be anything that will rattle your kidneys, because- besides being unenjoyable- that generally means it's losing grip. Too stiff is slow. In the end this should feel like an OE suspension from Porsche or another high-end sports car manufacturer.

Today, I merely ripped apart a Mazdaspeed3's suspension for the first time and took a bunch of measurements. My hope is that something will come to market within three months. Sadly that'll be towards the end of autocross season, but this can't be a rush job just to push something to market. Most CPE products are worth waiting for. I'll do my best to publish my R&D data as I go along, although typically this data is not enjoyed by those who already have springs or coilovers! Hopefully we'll all learn a bunch of very specific details about the Mazdaspeed3 in the process.

Edit: does anyone run the existing Koni Yellow setup on Koni springs? I'm curious how aggressive they went with their setup. 40mm lowering front and rear sounds like something I wouldn't do, but that was off a standard Mazda3.

[prototype_x9]

Originally Posted by stretch Edit: does anyone run the existing Koni Yellow setup on Koni springs? I'm curious how aggressive they went with their setup. 40mm lowering front and rear sounds like something I wouldn't do, but that was off a standard Mazda3.

That is the inherent problem with the koni dampers. Nothing has been made for the speed3 by an aftermarkey shock company.

[AutoXRacer]

I'm fine with finishing the season on the stock setup...it handles very well as is; its just the squatting that sucks!!! And the understeer!!!

I'll wait!!!

[stretch]

I was under the impression that Koni's could mount into the Mazdaspeed3 dampers, is that not true? (I know Koni doesn't list that application, but what changed? Regular Mazda3 folks bolt up the Mazdaspeed3 parts just fine, it seems.) If not, I'll see if I can machine something to make it happen.

I'm sure these rates will help with the understeer. Getting proper spring frequencies will result in a raw coil rate roughly 70% stiffer in the rear than the front. This is due to the lower motion ratio in the rear, which has a profound effect on what the rate becomes at the wheel.

The example I gave on another forum was that 350lb/in front, 600lb/in rear results in spring frequencies of roughly 2hz front, 2.25hz rear. So, while the spring rates are 70% stiffer, the spring frequency is only 12% stiffer in the rear. These frequencies are "by the books" for an autocross or track vehicle on R-compounds (or very aggressive street tires). No spring manufacturer I can see goes that much stiffer in the rear, forcing owners to compensate for the lack of rear roll resistance with sway bars or other tools without fixing the spring rates first.

[subparpunk03]

Koni Yellows will bolt up to an MS3 just fine. There's several people on mazda3forums with them. The question is, how well will they work with the stock / MS / Cobb / H&R springs?

The more I think about it, the more I like the idea of a matched, high performance shock/spring combo. But what would the "real" difference be between that and say, a set of the H&R coilovers, which I think are minimally adjustable?

[stretch]

There needn't be any difference between a coilover kit and a matched spring/damper set except the ride height adjustability. Heck, as I mentioned earlier, there are some $2500 coilover sets that use the same off-the-shelf Koni dampers that are sold as inserts for your vehicle- they weld threaded sleeves to the body (and mark up the price). The key is to find a suspension builder who knows his stuff and actually spends the time to match parts together properly.

H&R, since you mentioned them, uses quality components but (in the application I sampled, which was not for the Speed3) they were pretty poorly matched. I could sell you a great brand name like Bilstein or Penske with the completely wrong valving, and it wouldn't be good because of the brand name. I talked with a racing team engineer who said he bought some Motons for five grand that were so stiff, his shock dyno couldn't measure them (that's very bad!). So, you want a good brand name so the quality control is reliable (stay away from Taiwan and Japan, example), but perhaps even more importantly you also want to make sure your builder has valved those dampers appropriately for the application. I'm not aware of any builder for the Mazda/speed3 that has released a suspension set with full disclosure of damping, so I have to wonder if the research was done.

In my experience, you want your dampers to be between 30% and 70% critically damped to the spring, and many coilover kits simply cannot do that even with an adjustment knob! Koni's off-the-shelf valving is usually pretty good compared to what the coilover manufacturers do, and that's why I think a Koni / spring set can and will outperform many coilover kits.

As far as whether Koni's will work with other springs, such as those from Cobb and Eibach, I don't have any measurements to know that yet. (I'm waiting on some phone calls to be returned before I head out to the shock dyno.) However, I will say that the incremental spring rate increases from those companies are not going to play a major role in increasing performance. If not for hitting the jounce bumpers more frequently, you'd barely feel a 10% or even 20% increase in spring rate. A 20% stiffer front spring only raises the spring frequency by 9%; it's not a linear scale. What most people "feel" from lowering springs is the car hitting its jounce bumpers, which can double a spring rate (and limit bump travel), and those are significant changes. So while Koni's (at or near full soft) would very likely work with those springs, I don't think those springs will take advantage of the Koni's.

[AutoXRacer]

Make it happen stretch!!!!

[melan47]

what a great thread...stretch you are awesome to have around for numerous reasons but your attention to the suspension is what i like. i am building a track only car from the b15 sentra platform and rest assure your methodology will spill over into my spring rate configuration...i am sensing around 500 in front and 600 in the rear and the eibach setup will be fitted by ground control on koni yellows. on the other hand, this thread timing couldn't have been better. I just recently spent some time on the track with the ms3 and here is my post and amongst other stories.

http://www.mazdaspeedforum.org/forum/foru...-one-week.html

[subparpunk03]

I'm curious what your thoughts on the different swaybars are as well. Should the swaybars be matched with the rest of the suspension, or is it more of a general rule the stiffer is better? As far as I know our only options are the 35% stiffer hotchkiss or cobb FSB, but the rear could be either cobb (50% / 90%) or hotchkiss (95% / 140%).

I'm thinking about picking up a set of the hotchkiss just to give me more options in adjustment for the rear sway bar.

[AutoXRacer]

Originally Posted by subparpunk03 I'm curious what your thoughts on the different swaybars are as well. Should the swaybars be matched with the rest of the suspension, or is it more of a general rule the stiffer is better? As far as I know our only options are the 35% stiffer hotchkiss or cobb FSB, but the rear could be either cobb (50% / 90%) or hotchkiss (95% / 140%). I'm thinking about picking up a set of the hotchkiss just to give me more options in adjustment for the rear sway bar.

I myself might be going with Racing Beat sway bars. My previous car, 99 Miata had all Racing Beat suspension components and it was the most neutral handling car ever...even all the instructors at the races loved driving my car.
Racing Beat has some pretty good parts...though they are just getting into the Mazdaspeed 3 stuff now...but in suspension, we can use the regular Mazda 3 stuff...

[stretch]

Thanks guys! I'm glad to hear there's interest in real suspension design.

Originally Posted by melan47 what a great thread...stretch you are awesome to have around for numerous reasons but your attention to the suspension is what i like. i am building a track only car from the b15 sentra platform and rest assure your methodology will spill over into my spring rate configuration...i am sensing around 500 in front and 600 in the rear and the eibach setup will be fitted by ground control on koni yellows.

Here's a spreadsheet I made a while back to help things like this. All the default values are for my Subaru STI, though:
Weight transfer, spring frequency, damper, body roll calculator... and more! - IWSTI.com: Subaru STI Forums

Originally Posted by subparpunk03 I'm curious what your thoughts on the different swaybars are as well. Should the swaybars be matched with the rest of the suspension, or is it more of a general rule the stiffer is better? As far as I know our only options are the 35% stiffer hotchkiss or cobb FSB, but the rear could be either cobb (50% / 90%) or hotchkiss (95% / 140%). I'm thinking about picking up a set of the hotchkiss just to give me more options in adjustment for the rear sway bar.

That'll be a new thread. I think Custom Performance Engineering is interested in making sway bars, too, and I'll be the one developing those. I'm an autocrosser so I do whatever I can to eliminate understeer.

The only thing I'll say about sway bars now is that they are profoundly stiff and have a dramatic affect on body roll. Sway bars absolutely do more than even very stiff springs to reduce body roll. Hotchkis claims their front sway bar has a rate of 560lb/in, but that rate doubles during body roll for each front wheel. So, you can see that the total rate of 1120lb/in is drastically higher than your front springs, which are only 188lb/in stock. This is why 30% stiffer sways make a drastically different change than 30% stiffer springs.

There is absolutely such a thing as too stiff of a sway bar, though. You don't want to completely lose your suspension's independence.

AutoXracer, aren't the RB bars the same diameters as the stock Speed3 parts? (I didn't double-check this, but I thought Mazda used RB's diameters on the Speed3.)

[MadOzodi]

Can't wait to see what you come up with stretch!

[stretch]

More on sway bars: Since the springs I'm doing for CP-E will be quite a bit firmer in the rear than stock (and other products), I was particularly curious what the rear sway bar stiffness looked like.

I have the stock sway bar at 835lb/in, but it's less than 130lb/in at the wheels for a one-wheel bump or 260lb/in during body roll, excluding flex from the soft rubber bushings. This isn't very stiff considering how soft the springs are back there already.

Suffice to our suspension kit will improve things quite a bit. I was worried about going too stiff and losing complacency over broken pavement, but after these measurements I don't think there will be an issue.

The stock dampers are off to the dyno, along with a set of Koni's, to see what spring rates will be comfortable and at what adjustment. Since CP-E doesn't yet have a dyno in-house (after all, this is their first suspension project), the turn-around for this might be a week. I'll have more information then.

It looks to me like even a rear spring to match the stock fronts should be well over 100lb/in stiffer. What I mean by this is that the rear spring frequency be made slightly higher than the front. Currently, the stock spring frequencies are roughly 1.5hz front, 1.3hz rear (rounding slightly). Ideally the rear would be more like 1.6 or 1.65hz to match the front, depending on the valving. If the rear shocks can handle this, which is very unlikely, I'm going to create a set of springs for the stock shocks that do just that.

Very likely the rear shocks will have to be replaced by Koni's, though, even for a rear spring that is designed only to match the OE front spring and shocks. (Yes, you can run stock front struts with Koni rear shocks; there's no inherent problem from parts of different manufacturers so long as the valving matches.) If we made springs designed the match the front shocks, the front spring rate increase would be minimal and so would the amount of lowering, probably to 5/8 of an inch. The advantage to this would be cost; it'd be the least expensive way to design a proper suspension for stock since we'd cut out the cost of front Koni's. Users would be free to run Koni's in all four corners if they wish, it just wouldn't be mandatory. The kit would also be very comfortable.

I know folks are happy on their brand X lowering springs on stock shocks, but those lowering springs- all of them, that I can tell- make compromises that I find unacceptable. I can't wait for folks to switch to CP-E springs to make a direct comparison.

But I don't know if we'll make a kit designed to reuse any OE part since it will be overshadowed by the full Koni / CPE spring kit. For that, we'll increase the front spring rate too, to somewhere just shy of where most coilovers kits run. Don't worry, I'm looking at 1.8hz as the max front frequency, so it'll still be pretty comfortable. I don't want to post any spring frequency targets because that'll depend on subjective testing, our damper dynos, and other yet-to-be-determined variables. I'm sure there will be tweaking.

I'm pretty excited about the project! Not to get too big of an ego here, but I always wished such a package was made for my Mazda6 when I had one. Now, I feel privileged to be designing what I think will be the ultimate Mazda3 suspension. Let me know if you guys have any questions, I can talk forever about suspension design.

[fjames]

Great thread.

I hate, loath and despise the stock ms3 setup. I think it's just plain dangerous. But I don't know what to do about it. The closest currently available product that makes sense to me is the mz3 coilover, just because the front rate is about what I think is should be (that's just me simply relating to previous cars and what worked with their weight.) But I don't like cheap 27 way adjustable coilovers, so there.

What I'm pretty sure I'm going to do is try and fix it with shocks. I'm trying to learn if revalving Koni yellows for the stock spring would make sense. I have this theory that the vague dissatisfaction with off the shelf yellows on the ms3 people are feeling is that they're turning the rebound up so much to get them to work that they're "out of balance." This is based on my presumption that a 50% difference in front spring rate (mzr->msr) would be enough that Koni would revalve the yellows if they decided to make one for us.

But I don't know shit, I'm just making this up. I don't even know if compression damping would be increased with a revalve. I understand that rebound controls body movement, but I kiss the bumpstops all the time in this thing, so with the stock springs, more compression damping is all I can think of to do. If it didn't go down so far, it wouldn't have to come up so far.

I'm going to try it first with the stock bars, then go to a Cobb rear if it needs it, but that would be more for overall roll control than balance - I'd rather do the rear than the front basically.

I don't want to lose any ride height, so your springs would have to have a very moderate drop for me to buy them. But if my shock experiment fails, I'll almost have to since there's nothing else out there. Good luck with your project, and try to make it happen, don't get lost in the art and forget it's a real product for sale and compromises will have to be made most likely

[stretch]

Originally Posted by fjames The closest currently available product that makes sense to me is the mz3 coilover, just because the front rate is about what I think is should be (that's just me simply relating to previous cars and what worked with their weight.) But I don't like cheap 27 way adjustable coilovers, so there.

I'm not impressed with many of the coilover spring rate choices, but I definately agree with you on cheap coilovers. The dampers simply aren't on par with a Koni product, and many aren't even close. I'm not saying they're all bad, but buyer definately beware: most are. I've got lots and lots of stories!

What I'm pretty sure I'm going to do is try and fix it with shocks. I'm trying to learn if revalving Koni yellows for the stock spring would make sense. I have this theory that the vague dissatisfaction with off the shelf yellows on the ms3 people are feeling is that they're turning the rebound up so much to get them to work that they're "out of balance."

In my experience, this is true. Koni's should usually be run at or very near full soft with most off-the-shelf lowering springs.

We've already looked into doing custom valving for Koni's. We'd have to order quite a large quantity for it to be practical, so I'm hoping it's not necessary. I don't want things to get expensive. Do you have a link to anything you think I should read regarding why folks were dissatisfied with Koni's?

Doing your own Koni revalve would be pretty expensive- $720 for the dampers, then probably another $500 for the revalve. However, how do you determine what specs the builder should valve to? I'd follow it with enthusiasm if you went that route, but it's not something I'd suggest unless you really know your stuff!

But I don't know shit, I'm just making this up. I don't even know if compression damping would be increased with a revalve. I understand that rebound controls body movement, but I kiss the bumpstops all the time in this thing, so with the stock springs, more compression damping is all I can think of to do. If it didn't go down so far, it wouldn't have to come up so far.

The Speed3 actually has quite a bit of travel before the bump stops compared to other cars I've looked at, like the Mini Cooper or Subaru STI. Those cars ride on their bump stops at full ride height! The bump stops are there, by design, to act as secondary springs- you shouldn't feel them engage. The Speed3's bump stops felt pretty soft in my hand, especially the rear which felt like a pillow.

Tell me to more depth what handling problems you'd like corrected, and I'll see if I can diagnose and fix things. This goes for everybody- I know what I like a car to feel like, but I'd like to hear others' opinions too.

I don't want to lose any ride height, so your springs would have to have a very moderate drop for me to buy them.

We certainly won't lower so much that it puts the car on its jounce bumpers (bump stops), so it will be less than what you typically see. Lowering causes roll center problems, too. My goals were going to be 5/8" if we did something for the stock dampers, and probably still less than an inch for our full Koni product.

I'd have to model the car and do the math, but I'd be willing to bet that lowering the Mazda3 an inch causes a larger-than-15% increase in roll couple. What this means is that a 15% increase in spring rate wouldn't be sufficient to break even and have stock amounts of body roll unless the bump stops add supplementary roll resistance (which they would, but that's bad too).

Anyway, point being that I am very adamantly against lowering a car too much. I hope people are disappointed when the car isn't totally slammed; it's going to be at a ride height that performs well.

Good luck with your project, and try to make it happen, don't get lost in the art and forget it's a real product for sale and compromises will have to be made most likely

Thanks!

Originally Posted by gofast i would be all for this!!! while i am in NO way knocking the drag racing guys here, i love handling. thats what makes me grin the most.

Yeah, I would always yell at CP-E, saying, "You're making HOW MUCH power?! ...on a FWD car, on a stock suspension?! Honestly, what's the point!"

So, they hired me. Ha!

They make simply incredible engine parts, probably better than most folks realize (I've seen many of the subtle details), and I'm so happy they are finally rounding out their offerings with suspension parts. I'm totally a suspension guy, just like you. Power is fun, but great handling is more fun! Besides: suspension, tires, and alignment, in addition to good driving, are what make for good lap times.

[Haltech]

You should contact H&R. They will have no problems making you custom ratio'd springs. You just need the right numbers from the Koni Yellow DA's and you will be good to go.

i ran KY DA's on my 1996 Cobra with some serious high spring rates from H&R. It served me well for a long time road racing. I eventually stepped up to Griggs Racing Full f/r coil over conversion for the mustang.

The Yellows are incredible shocks if you can get them properly matched to a quality set up springs. H&R is one of the only names that pops into my head.

[gofast]

i would be all for this!!! while i am in NO way knocking the drag racing guys here, i love handling. thats what makes me grin the most. this car has such a great platform to work with in terms of handling. so many car guys add so many braces to there cars to get a chassis as stiff as ours. however this car, like most fwd, has some wicked understeer. and stretch hit it right on the head. we need a matched set thats tuned for this car.

[AutoXRacer]

Patiently waiting...

[MadOzodi]

Holy crap I'm excited to see what happens with this! To me, not lowered is good! 245/40/18s here I come!!!

[gofast]

here are my major suspension beefs i have with this car...bump stops. very easy to engage and you feel when they do. (you, stretch, already mentioned this). second is wheel deflection. if you hit a hard bump you can tell the wheel actually shutters a but. third is suspension recovery. after a bump it takes too long to return to normal. suspension drop. wheel doesnt drop fast enough. higher spring rate should help this i think. fourth is the understeer. solving 4th should solve my fifth and that is lack of rear end rotation. 6th is body roll. some are very easy fixes but this is my complete list of complaints.

[fjames]

Note that I said mZ3 coilovers, which have about a 300lb front rate. I understand more or less the theory you're working with on rear rates, I drove a '00 Si before the ms3 and it was the hot setup with those and similar cars to go with a heavy rear spring for racing them (track.)

I have a pretty high comfort zone speed wise, due to road racing formula fords back in the day (I was very good), but all I want with the speed is a nice, well turned out ride that does what I tell it. My frame of reference is the Si, which was amazing with Mugen SS spring/shock units.

For me, understeer is a non-issue. I just take what a car gives me and adapt, within reason, and the ms3 is pretty decent for fwd to me. It's the "ride" then that's the problem. It's a catch-22 as far as I can tell. It doesn't have enough spring to control the front mass, so the front dips more than it should, but the spring is strong enough that instead of wallowing, it sproings back up. This on a single dip - go over ripples, hard on it, in a corner, while passing, with an 18-wheeler coming, and it gets exciting when you're used to a car that just ignores such things and suddenly find yourself balancing the various conflicting forces (I call it "dynamic pitch instability" just to call it something) when you should be reaching for a smoke.

The above is a commonly perceived problem, and that's why people try the yellows, to get some rebound control. But to me, the issue is the jounce. I know you're not "supposed" to use compression damping to make up for an inadequate spring, but I'm hoping the stock shocks are so bad that a properly valved Koni will make the springs happier. As to proper valving and others experiences, the two that come to mind both went to 3 half turns to get acceptable rebound. One was happy (he was wrong lol) and the other realized it didn't work, but neither did less. He was throwing a lot of variables into the mix (MS springs) but still, I got the idea that the off the shelf Konis just weren't going to make it. I assume you know the front rate of the ms3 is ~50% higher than the mz3.

Another issue, basically evidence that something's funny, is the sense of front mass I get just casually turning into a slow sharp corner. It's as if the front cg was 3 feet above the hood, or the roll axis (is that the right term? - the point about which the car rolls) was 3 feet underground. Very annoying, but it's more evidence of something weird in the front end. But again, with proper rebound damping, in a shock that doesn't need 3 turns to get it (i.e. where the compression and rebound were in tune with each other) this may be greatly reduced.

My concerns with lowering it are many. Camber gain with the front struts (I understand your springs would have enough rate to balance it but still ...); increased negative camber in the rear (it has enough already and I don't want to screw with adjusters); tire clearance (known issue with the ms3); day to day hassles of the real world (I drove a lowered car for 8 years and I'm tired of it lol.) If I do the custom Konis, and you come out with a spring for the stock shocks that's only a 5/8" drop I would probably try them.

Yeah, custom Konis, how do you know what to do? I've talked to one of their authorized places and didn't get anywhere really. I'm going to try another one when I get the car done with the stuff on the den floor (catch can, motor mount and pads - porterfield R4-S.) I don't even know what the numbers mean - 200/300 etc. - for the shims. Is it an arbitrary numbering system? Are they supposed to relate to the spring rate? I'm thinking that if I order some up, I should have them call me when they tear them down and tell me what the stock are using - get a better idea of where to go.

I didn't ever think I'd have to be getting this involved. I saw all the reports of "float" before I got the car, but I don't put much credence to how people describe their car's handling. Still it was widespread so it was obvious there was some kind of issue. I found it on my first test drive and wasn't looking for it at all. I was even on a familiar road, going through a corner my Si yawned at, and suddenly I was looking at sky. If the rest of the package wasn't so desirable, such a great value, I would have looked elsewhere. And of course I'm constantly frustrated by the lack of aftermarket support for our car. Coming from the Honda world, it's a bit of a shocker. On the other hand, having small custom shops like Cobb and CP-E is kind of cool, just a different approach than I'm used to.

Edit: Forgot to add that the stock bushings (not sure which are the culprit) are obviously going to be an issue for anyone that really wants to extend the car. Like gofast said, lots of shuddering. Thing is, what's so great about this car to me is how smooth and quiet it is overall. I'm trying really hard not to screw that up while still addressing the major issues.

[stretch]

Thanks guys, keep it coming.

Sounds like we'll be able to do custom dampers, just like I (and fjames) hoped. I'm pretty excited with where this project is heading. We're still doing a full evaluation of the existing Koni's as our baseline.

At this point I'm going to have to start curbing my candidness regarding the project as I want to maintain some secrets, but as one last morsel, you can see the Koni's do add suspension travel over stock so that ride quality can be maintained after lowering the ride height. That's about 3/4" more bump travel, meaning we can lower that much "for free" so long as our springs support it. The springs will be key here since this means having an extremely short solid length (or we'll get coil bind). The stock damper has a droop travel limiter (like a bump stop for droop) internally, so what you see isn't full droop.

The rear is pretty similar, with more travel than stock.

[MazdaSteve3]

Originally Posted by fjames As to proper valving and others experiences, the two that come to mind both went to 3 half turns to get acceptable rebound. One was happy (he was wrong lol) and the other realized it didn't work, but neither did less. He was throwing a lot of variables into the mix (MS springs) but still, I got the idea that the off the shelf Konis just weren't going to make it.

I think you may be talking about me. I tried many different settings with Konis, not just the setting that the other owner liked. I tried to find a sweet spot, but if there is one, it is very narrow. Going stiffer seemed to increase harshness and go out of range of the springs before taking care of the floatiness. Going softer just brought the floatiness back to stock specs. I tried the full range of settings on the front, since it was easy to adjust. On the rear, I tried 3 or 4 settings before getting fully frustrated. With each rear setting, I tried the full range of adjustment on the front.

Oh, another thing to be aware of, they raised the front ride height 3/16".

[fjames]

Yeah, you were one of them. I read everything you wrote in your thread over there, mostly because your frame of reference was exactly the same as mine - something about being sucked to the road.

For me that comes from 8 years with a '00 Si on Mugen SS suspension - hard to conceive of a better daily driver fwd setup. My ms3 on Konis isn't close, but it weighs 600 lbs more with a worse distribution so I don't expect to be able to duplicate the Honda (and of course I'm on stock springs.)

My experience with the Konis on 3/2 is they're not harsh at all. IIRC you had a bad tire which colored your view, and we could be driving on different types of surfaces. My roads are fairly smooth where they're good, but have a lot of sink holes and various whumps and whoops, all perfectly designed to launch you. The Konis have virtually eliminated that.

I don't preach about this stuff, but the simple fact is, if you're going to change one thing on a suspension, shocks is it for almost any car. For us, that pretty much means Konis, even if they're for the wrong model car. Coilovers are always a possibility, but I don't trust inexpensive ones, especially when they have 18 or 27 or 152 shock settings.

The last thing I looked at before buying them was the likelihood of something else coming out soon. It didn't look like Koni was going anywhere with ms3 specific shocks (and it still doesn't) and the CP-E solution seems like a long-term project. So I figured if I could get a couple years out of the Konis it would be money well spent, then I wouldn't feel bad about spending some more if a better option came along.

You do what you can do, and for me, Konis plus the Cobb RSB have transformed this car into something I can enjoy for more than it's acceleration. The truly amazing thing in all this is how many people think the stock suspension is fine. I don't know what's worse, that view, or people who judge handling by body roll, as if less means better handling by definition. There's so much misinformation out there you could drown in it.

[melan47]

+1 mazdasteve3 on the bilstein shocks..the bmw car club of america chose the h&r\blistein setup and it was by far the best setup for the price on a 3 series.

hey stretch - thanks for working with everyone and listening to what we all have to say. there is some really great feedback from these guys on driving characteristics. have you given any thought to tokico? they seem like a small company that may be looking for a new opportunity. I have used their hp series on a 350z and they transformed the cars overseer. never mind..looks like they have something in the works!

Tokico Gas Shocks - MAZDA

[AutoXRacer]

Stretch, can you give an estimate of when you foresee this project become finalized and available for purchase...?

[stretch]

I could only give you a very, very rough estimate- probably the second half of the summer. Where in that range will depend on how quickly we get parts. I'm told once we finalize the specs, which I hope to do within a month, we'll have to wait roughly 6-8 more weeks for parts. That puts us in the September timeframe.

[MadOzodi]

Hiya stretch, in light of Koni wanting someone to give them a car, how does this change your goals? Will you go with a different part#? Sorry, I'm not sure if I'm asking my question correctly cuz I'm a suspension n00b.

[stretch]

Koni doesn't know if they're going to change their part for the Speed3. They may use the same valving for both cars; nobody will know until they do their testing. We'll ask them what changes, if any, they make, then evaluate whether we want those too or something different altogether. Either way, I suspect our design will differ from the off-the-shelf part in stroke length.

[MadOzodi]

GIDDY-UP!

I'd be happy with only a 3/4" drop if that meant springs and dampers are in harmony. So this would also be tuned for the stock sways, right?

[stretch]

The big thing with sway bars is how profoundly they affect the balance of the car. To that extent, I don't want to tell people what sway bars to run since the ideal setup will vary so much according to driver skill and preference. I like my FWD cars to rotate as much as possible (re: huge rear bar), and I'm sure others would be uncomfortable with that. My Mazda6 would spin unless I kept the throttle down mid-turn... it was like mandatory corner exit speed, and I loved it.

While our springs will surely remove a lot of understeer, they won't be "tuned" for the stock sways. They'll be "tuned" for the car, for ride quality and response, and not for a specific handling bias. For that, it's the job of the sway bars. Sway bars do have an effect on one-wheel bumps and low-speed damping requirements, but I don't think this will have a significant enough impact to worry about.

I suspect some will love the balance on the stock sway bars, while nutjobs like me will still install a huge rear sway bar to get even more rotation.

[gofast]

lol yeah rotation is a good word. i over rotated mine this past weekend on the stock bars. im still thinking about a rear sway bar. if nothing else i am think of atleast upgrading the endlinks front and back

[AutoXRacer]

Originally Posted by gofast lol yeah rotation is a good word. i over rotated mine this past weekend on the stock bars. im still thinking about a rear sway bar. if nothing else i am think of atleast upgrading the endlinks front and back

Believe it or not, the upgraded endlinks gave me a little more stiffness regarding sway. I replaced mine due to breaking one of the rear stock ones autocrossing and Mazda denied me warranty due to my CBE.
The new ones are awesome!!!

[MadOzodi]

I'm not an autox guy, so more rotation isn't necessarily what I'm looking for. Good to know the setup will be tuned independantly of the sways (if I'm reading it right).

AutoXRacer...maybe I'll start just by upgrading my endlinks as well, instead of getting a whole new rear sway.

[gtlaw]

are the front struts going to need to be custom using the OEM strut housing? I already did that for my sentra, and don't feel like doing it for this car so if not I'm in for a set