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Admiral Obvious
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Discussion Starter #1
Since there is only is the auto-x section I figure I post this here.
General track type suspension setups what do you run?
 

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I've never tracked a FF car (eventually I might... if it rains on my trackday...) so all my advice is based on theory, but the very first question is what kind of freedom are given with the car and what kind of budget? Common knowledge says to really stiffen up the rear end and try to keep the front end relatively soft. The nature of tracks would mean that this happens to a lesser degree than on an autocross though. A car that is well set up for autocross can be very hard to drive on track.
 

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Admiral Obvious
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Discussion Starter #3
Tracking an FWD is new to me, but not suspension setups. my last car, s2k, had 5 setups, street DD, street aggressive, Willow springs int, streets of willow and horse thief mile / auto-x. The budget is in the middle somewhere and want to keep it within time attack "enthusiasts class" Since I don't want to revalve coils again ( pain in the ass) the plan is kw v3's with corksport adjustable camber plates, rear sway bar of some brand, adjustable sway end links, rear camber kit, rear strut bar, and maybe some chassis bracing. I have an local hookup for alinements but 40 for each time they do an adjustment does add up, race shop charges 400 for an corner balance, so I try not swap springs a lot. I think I can deal with more oversteer than understeer, but again first fwd track car so it's a relearning process . Since I don't see 3's at track that often am going with the hit the track with what I got see how it reacts, plus I need an excuse to get rid of the crappy OEM dunlops.
 

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Celest Zoom-Zoom
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All I have ever owned is FF cars. I have driven Rear wheel drive but never owned. Some people hate the torque steer and the fact that the wheel tries to wrestle itself from you. I love it. It's engaging to me and makes it fun. Did you ever have a lot of problems with the rear end of your s2k washing out in the corners?
 

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Admiral Obvious
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Discussion Starter #5
All I have ever owned is FF cars. I have driven Rear wheel drive but never owned. Some people hate the torque steer and the fact that the wheel tries to wrestle itself from you. I love it. It's engaging to me and makes it fun. Did you ever have a lot of problems with the rear end of your s2k washing out in the corners?
Depends on the setup, the dd setup was for Max tire life, so ya the rear would get a little out there If you pushed, but not a real big deal to bring it back. The street aggressive added more camber a dash of rear toe in to combat vtec power surge due to poor traffic or road conditions. My 01 had no traction or electronic stability control so it was all about throttle control and being smooth on the wheel.
 

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Celest Zoom-Zoom
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A driver's car. That must have been a blast. Only bad part about a high hp front wheel drive is you can't stand on it a corner. It tend to not want to turn anymore. Gotta wait till your exiting the corner and nearly straight till you can really get on it.
 

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From what I have read, for FF you tend to want to stiffen up the rear, possibly more with a thicker anti-roll bar than a huge spring. That makes sense to me as having a much stiffer rear spring would mean the ride frequencies would be shot, which wouldn't be very fun on a daily. Structurally (not suspension), you actually want the front to be very stiff since that'll help keep deflection to a minimum up front. People say you want a relatively soft front suspension wise in roll, so that you get the requisite oversteer biased setup.

One thing I've always wondered about is whether it might actually work to set up the front to be very stiff. It's counter-intuitive, but for a strut car such as the 3, the camber gain is not very good meaning front roll might take you out of the tire's sweet spot. If that's the case, I'm curious whether having the front be stiff in roll would keep them planted better. This does go against conventional wisdom and I think the reason it might not work is you'll end up working the outside tire too hard. Front staggered tires anyone?
 

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^^^ I like the theory of stiffening up the front to help with front grip. It does make a big difference on a strut suspension. My experience with strut suspension in the past (MR2) is that stiffer springs give the stiffer end (stiffer than soft stock) more grip contrary to the popular theory that stiffer end gives more grip to the softer end. I believe this is the case because the stock setup has too much body roll for struts and tire contact patch is far from optimal.

From my experience, it is also beneficial to leave the sway bar as small as possible. Stiff springs with properly matched dampers give a lot more grip than stiff sway bars. It also makes the car handle more predictably on many road conditions including wet and dusty/slippery road surfaces because springs allow both sides' tires to do their job more independently. Sway bars overload the outside tire by lifting the weight off the inside tire.

The biggest factor I have found though, is still optimal tire contact patch. Even on soft-ish springs, my old strut based car with enough static camber dialed in can be easier to drive at the limit than a more stiffly setup car with not enough camber. There is something very vague about trying to drive on tires that are about to roll over onto the sidewalls.

I have a question, does anyone have experience with PSS9s on the gen3?
I've been trying to figure out if they can handle more spring rate than their standard 394lb/in and if their damping is digressive enough have good street driving comfort. I wish to make a no front sway bar setup that eliminates corner exit wheel spin and provides very quick steering response.
 

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Admiral Obvious
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Discussion Starter #9
drove it once with the front endlinks removed, that was, a experience for sure.
I run the oem front sway, with adjustable endlinks, 650 lb front springs 400 (for now, 500 is more likely with rear aero) rear and Tri-point .250 race RSB set to the mid setting
 

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The real question is, how many teeth do you want to have remaining in your head at the end of the year, and two, what tires do you want to run.

I'm at 450/700lbs setup right now with the hotchkis (heaviest RSB on the market), and it's not enough for me.
Next push since I'm on slicks and now have some aero that will receive updating I'll likely be pushing to 550/900lbs

Went back to stock FSB a few years ago, had a hotchkis front as well, just made the car want to push. It was balanced for sure, but kept lifting inner front and letting it slip until it was flat enough.
 

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My understanding was that good valving makes 500lb springs fairly smooth riding, no? I havent owned any really good dampers so I dont have first hand experience. I am surprised you are saying 500 is teeth shattering. What shocks do you have?
 

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Up front 500 isn't that bad, it has all of the weight of the front end so it's actually fine. The rough part is the rear, since... there is no weight there.
And honestly good valving doesn't stop rock hard suspension from being... rock hard, just makes it feel more normal.

Nothing more awful feeling than crappy or under valving on a stiff spring.
Believe it or not I'm still on my BCs from forever ago. I'll be moving up to a Koni 8211 setup up front and a bilstein shock setup rear, but the BCs have handling my awful setups extremely well.
 

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I hope the ride improves with the koni race shocks. I always thought the shocks and the sway bars dictated the ride more than springs but I haven't had the chance to ride in a really stiffly sprung car with really expensive shocks to know for myself.... still believe it from what I've heard though so not losing hope, yet, lol...

I'm looking for a 99% street 1% track setup. I will be going to the track once a year on my 280 treadwear street tires. It will have a lot less grip than race tires for sure. So, I can get away with much softer suspension. :laugh2: I'm mainly doing this to make my car into a much better handling street car. I don't mind running up to 2.5* of camber and don't mind it riding more like a sports car. With a family of 3, it's the best I can do with what is practical I guess.

Here's my take on how to improve the stock setup:
stock spring rates: (estimates from reading other threads)
front 150lb/in
rear 130lb/in
stock sway bars (estimates by reverse calculating the mazdaspeed accessories bars)
front 226lb/in
rear 234lb/in

motion ratios:
front spring ~.96
rear spring ~.7
front sway bar ~.96
rear sway bar ~.4

wheel rates:
front spring: 138lb/in
rear spring: 64lb/in
front sway bar: 208lb/in*2
rear sway bar: 37lb/in*2

total front wheel rate: 554
total rear wheel rate: 138

front roll couple: 80%
rear roll couple: 20%

ride frequency assuming 60/40 weight distribution of a 2900lb car and 50lbs of unsprung mass per corner:
front: 1.28hz
rear: 1.09hz

Do my numbers look reasonable? I'm kind of surprised the rear is so soft stock.
 

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Calculations with PSS9 dampers standard rates of 394lb/in front and rear:
wheel rates:
front spring: 363lb/in
rear spring: 193lb/in

total front wheel rate: 779
total rear wheel rate: 267

front roll couple: 74%
rear roll couple: 26%

ride frequency assuming 60/40 weight distribution of a 2900lb car and 50lbs of unsprung mass per corner:
front: 2.08hz
rear: 1.89hz

It looks like the PSS9 does change the handling balance by adding more stiffness to the rear.

If just for fun, if I disconnected the front sway bar with the PSS9s, which happens to almost equal the stock front roll rate with just its springs, the roll couple changes to 58% front, 42% rear. This sounds much more balanced than stock considering most of the weight is over the front, so the rear should be taking up more of the roll stiffness to give the front wheels more grip.
 

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From the reviews, it seems the PSS9s do ride quite smooth on other cars. Hopefully that carries over to the mazda 3. I would have expected over 2hz ride frequency to be a bit harsh but that's only because of my experience with koni sports on another car.

For the grip of something like the stock dunlop sp sport 5000s, I feel perhaps slightly stiffer than stock is adequate, which can be achieved with the standard pss9 spring rates with disconnected front sway bar. Note, even without a front bar, the car is stiffer than stock both front and especially rear. I do believe the stock sway bar bushings are soft and they flex quite a bit under load. that makes the front sway bar progressive as well. It means by relying on just springs, the actual roll resistance should be greater than stock springs + stock sway bar due to the progressive nature of stock sway bar bushings.

I haven't tried any of this so I'd appreciate any comments from you guys who have tried different setups.

The reason why I am so insistent on removing the stock front sway are two-fold. It's been my dream to drive a no sway bar at the drive wheels end of the car setup since I have experienced it in my previous car (MR2). But, due to lack of funds, I couldn't get a proper set of coilovers to make up for the roll stiffness to fully appreciate the truly independent suspension.

The second reason is I would like to eliminate as much wheel spin as possible on corner exit and no front sway bar seem to be the best sway short of installing a LSD.

As a 99% street car with moderate grip tires, I feel like I can afford to do so without destroying the ride quality of the car. Perhaps in 1.5 years when the warranty expires on the stock suspension, I can convince the wife that I need coilovers. :)
 

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The rear spring setup is extremely soft everywhere you look.
Stock coilovers are typically 350/225 lbs, at least most places you'll look. 6/4k

It's because like I mentioned earlier, the rear is the lightest part of the car, so any jouncing and it makes the ride much less pleasant.

Even for 280 tires you can go WAY stiffer in springs, what are those rates, Prokit? With 280 tires you'll have plenty of body roll to not make use of those tires.


But as a 2c, there's a reason why I have 7 sets of springs for my car, and yes, it's daily 99.99% street driven, every day.


Even if you do stay with that soft of a spring in the rear, the next solution is the biggest sway bar you can find. As far as gen3 goes, I'm not sure what all is being offered, but [not that I've looked], I don't think I've seen anything massive yet.
The typical response is, two directions, soft springs, fat sway bars
hard springs, soft..ish? sway bars.


Your calculations I suppose are fine and all, but something worth considering is that while numbers can be great on paper, doesn't mean it will be just right on track. You have to think about tires, tirewear, tire temperatures thus camber, weather, track conditions, etc. and none of that has much to do about suspension Hz. All that has to do with is how "comfortable" the ride is, and is just a statistical number. Hunting down a perfect 2 or 3Hz ride by numbers, will not mean it's good on track.
Besides, everyone drives differently. I like oversteer because it's easy to control in a FWD and allows me to have faster turn ins because I like to trailbrake. But of course not everyone likes that.
 

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Even for 280 tires you can go WAY stiffer in springs, what are those rates, Prokit? With 280 tires you'll have plenty of body roll to not make use of those tires.
Those are PSS9 wheel rates using the motion ratios I got elsewhere. The spring rates are 394/394. Do you feel that is still too soft in the rear?

I get what you are saying about paper vs real world. I guess the interesting part starts in about 18 months. Now is just saving for it, lol...
 

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I'm 400f/550f with JBR 32MM rear sway on the middle setting with 245 RE-71R's. Yes this car rotates by throttle and will rotate well with trail braking. It feels good where it is now. Will probably need to up to 450/625 with 225 slicks to get the same feel.

Am I right?
 

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I just did a quick calculation, XCNuse's 550/700 with stock front bar and hotchkis rear bar on full stiff has total wheel rate of 923 front and 992 rear.

Rherold9, your setup has total wheel rates (assuming stock front bar) of 785 front and 499 rear.

So it seems like the roll couple of neutral setups that rotate are between 48%/52% (XCNuse) and 61%/39%(Rherold9).

if I ran 394/394 with no front bar and stock rear bar, my roll couple would be 58%/42%, somewhere between you guys. :nerd:
 
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