Stock R3 suspension setup versus upgrades (any direct comparison / input?)
 

Hi -

So I'm driving an R3, and the car feels really well balanced as it is. I know that the factory had some modifications to make the R3 handle better than the other sub-models, but I'm wondering if anyone has a direct comparison between the stock R3 setup and any aftermarket suspension setups as it relates to HPDE / driving (not necessarily ride height).

I've been eyeballing suspension mods (I figure at some point the stock bilsteins will wear out), but I'm concerned that anything that I get could disrupt the balance of the car - that and I have no idea what I'm doing as far as utilizing the adjustability of adjustable shocks and/or coilovers (I suppose if I got them, I could play around and learn via trial/error).

Just wanted to see if any other R3 owners had played around with the suspension and what the end results were in terms of driveability / handling. How good is the factory setup on the R3 versus the aftermarket setup? If you had to do it again, would you? What is the weak point of the factory setup on the R3?

I'd like to maximize the capability of the stock setup before upgrading, but am looking to start doing some research and didn't see much in terms of suspension upgrades / results on the R3...

thanks in advance!

PCS

I drive around 12-14 track days per year and see quite a few R3s out there. With a good driver, they more than hold their own with the stock suspension. In fact, I had a very good driver edge me out on my home track with his bone stock R3. If I had an R3, I would spend all my money on seat time and not change a thing with the suspension. If you want to improve it, you need to spend north of $2500 on premium coilovers and then start thinking about matching sways. And, doing that will make little to no difference if you haven't shelled out for premium track tires, which brings up the next and most important point: if you are not skilled enough as a driver, nothing you do will make any difference in improving your lap times.

Spend your money on seat time and enjoy your R3. I wish I had started out with one. If you really want to upgrade something, start with good extreme performance summer tires.

That's what I've figured over the years with the R3 - better to spend the $$ to upgrade the nut behind the wheel. I have had plenty of seat time, but definitely feel like I could improve substantially... Most of my track days have been on good tires, but not track tires (NT-05s and PSS). R-comps are in the garage and will be on next... but then... i worry about how the brakes will hold up with better tires, hah.

which brings the next question... if/when the shocks go out... is it possible to get factory replacements or have the bilstiens rebuilt?

I guess the point I was trying to make is that the stock R3 is more capable than most drivers, and it can take years of seat time to outgrow the car. Performance is made up of 80% driver, 15% grip, and 5% everything else. It makes the most sense to focus on driver and grip. Although, adding R-comps to the equation could change things in terms of how the R3 suspension performs.

Many people think the R3 Bilsteins are the same thing as the HD series, but I would have to see the spring perch measurements to confirm that. I found that the Sport shocks did not work in my GT, because the rear spring perch locations were different than OEM. (This is a change Mazda made between S1 and S2 cars). You can buy the OEM part number Bilsteins for the R3 from a variety of online dealer sources. Prices are pretty reasonable. Here is an example:

2010 Mazda RX-8 Parts - Front Suspension

2010 Mazda RX-8 Parts - Rear Suspension

Stvnscott - thanks for doing the research for me :).

If you ever make it out to a track day in CA (road trip to Laguna?) let me know - I'd love to join you and pick your brain / get a ridealong!

I found that going to a good set of coilovers really helped my cornering speed. My suspension was at 65-70k miles. I tend to think that a driver should equip himself with the best tools he can and grow comfortable with those. I don't personally think your growth would be hindered by changing your setup and the experience of learning what makes your car handle the way it does is well worth the cost, but I am a learn by doing kind of guy, so take it with a grain of salt.

I do agree that tires are more often than not more important than changing the suspension. Seat time is very important as well, but if you are at a point where it is convenient to spend money on upgrading the suspension, you should probably just do it.

I tracked my car one weekend with stock suspension and tires (much more aggressive alignment though), then went to KW V3's set to the factory recommended specs, Hotchkis sways set to the middle holes on both ends, 17x9, 48mm TRM C3 wheels and 255/40/17 Nitto NT01's and was very happy with both setups. The main reason for the switch to the suspension was to get more stiffness to be better able to take advantage of the tires. The car rides quite well, but is obviously stiffer, the handling balance is about the same and I'd definitely recommend it for a dual purpose street/track setup.

As for brakes, I use Hawk DTC-60's at both ends, Wilwood EXP600 plus fluid, RacingBrake SS lines and I've removed the front rotor dust shields to get more cooling air to the brakes and it's worked very well so far.

I used to always want to mod my car to make it faster, but as I've gotten older and wiser, I'm really coming around to the school of thought that if you can't get the most out of the car now, then what's the point of making it any faster?

Laguna is on my bucket list to be sure!

Black2010 - that must be what Stvnscott was talking about with the $2500 upgrade to the suspension to get anything worthwhile, hahaha. Will have to look into those as the car starts to accumulate more miles and wear.

Yes, they are expensive, but also high quality and double adjustable. I got mine for less though, since they were lightly used.

Cheaper coilovers may be double adjustable and may have similar spring rates, but there's more to it than that. Things like damping curves, consistency from damper to damper, long term durability, ability to be rebuilt and re-valved are all also quite important.

I saw one shock dyno where the maximum adjustment on one side was LESS than the minimum on the other, which makes tuning the handling impossible, as you'd need to run them that way to have even a hope of getting reasonably consistent handling turning in either direction, but without the dyno, how are you supposed to know this?

It's said that shocks are the second most important element in making a car handle/perform well second only to tires, so it's best not to cheap out. If you're looking for a cheaper option, perhaps revavled stock shocks (if possible) and coilover sleeves will be the way to go, since most people don't actually adjust their shocks, so it's not really a big loss to not have the knobs.

Yeah, the infinite adjustability is a blessing and a curse. More the latter for me since I'd have no idea what I'm doing. That was my biggest concern at modifying the suspension - trying to find that small window where I'd set something up better than the factory on what everyone says is a very well set up suspension...

Looks like something to consider when things start wearing out - until then, I'll be running what I have and tightening the nut behind the wheel.

I've done just 1 HPDE day with my R3. Only mod at the time was the BHR ignition kit and carbotech pads. I have had a hotchkis front sway bar I bought off of my cousin really cheap in the basement for about a year. I will put it on tomorrow and let you know my thoughts once I've had a chance to compare to the stock suspension set up.

As you said, the R3 is very balanced from the factory as is. However, It still feels a little on the soft side in regards to body roll as RX8s do (I used to have an 04 base model years ago, so comparing it from memory to that one). I know everybody says do sway bars in pairs, but I have the front and until I can get a rear, I will be interested to see how it feels. Honestly, I believe that stiffening up the front grip may actually help the car rotate the rear a little better. To me, the car felt so balanced before, but still had a tendency towards mild understeer. Maybe at the absolute limit, the stiffer front bar may cause more understeer, but I have a feeling that the limit will be harder to reach now, and within the scope of that limit, the increased grip up front should help the rear rotate easier.

I'll be sure to let you know how it works out though. Hope this helps some!

That's not how it works really. The stiffer front bar will cause more understeer for sure.

Not entirely...it sort of depends. Here's why. The front outside tire is the one moving towards positive camber during cornering. A bigger front bar can tame some of that body roll and allow for the tire to do more of the work, which would decrease understeer. Basically, the bigger front bar allows for the tire to have a better camber pattern, and therefore more grip. However, it also will diagonally transfer weight to the rear wheels, and will increase understeer at the same time. But the way I look at it is this will only occur at the absolute limit.

I will be installing a rear bar in the not so distant future once I can snag one at a good price, but for enjoying back roads and street driving, I am interested to see how the new bar up front feels. Plus, if you compete in SCCA stock class, I'm pretty sure you can only change the front bar...unless the rules have changed since I last read that.

According to the suspension engineering I have read and my own personal experience...

In general, a stiffer front bar will increase understeer / decrease oversteer. A stiffer rear bar will decrease understeer / increase oversteer.

There are a lot of variables involved that contribute to the handling characteristics of any given car, but the above rules are true for many, if not most, suspension setups. And, they hold true for an RX-8 that does not have its suspension bastardized too much.

A stock 8 is designed to tend toward understeer, as are most cars. It's a government thing. An R3 is designed to tend toward mild understeer; that is to say it is more neutral. It will rotate, given the right circumstances and/or driver inputs.

The easiest way to dial out understeer in an R3 without changing the springs is to stiffen the rear bar or soften the front bar. Stiffening the rear bar will decrease body roll slightly, and softening the front bar will increase body roll slightly as well.

Another approach is to lower the car (lower roll center) and/or stiffen the springs. My GT arrived with a good deal of understeer, and as I progressed as a driver, it obviously began to limit me. My approach was to lower the car 1" and stiffen the springs to a medium stiffness by installing Bilstein PSS9s. Those modifications allowed me to drive faster, but I induced a little too much oversteer in the process. The car was fairly neutral, but biased toward oversteer. Very occasionally, that oversteer would snap on me if conditions were just right. An unexpected bump or patch of dust or film of some kind on the track would cause the rear to step out unexpectedly. To solve the problem, I slightly increased the stiffness of the front bar by installing a Progress Miata bar on its softest setting. That made the car even more neutral and further reduced body roll in the front.

Camber is an important factor, but slip angle, roll center, center of gravity, and other factors are equally as important.

Another example is the way in which one of my track friends has set up his 8. He went to very stiff springs and a very low center of gravity. Those changes introduced a lot of oversteer. He compensated by installing heavy end links in the front and removing the rear bar altogether. Actually, this is a very common setup for track-oriented 8s.

For my purposes, I am a proponent of using as little bar as possible. I also do not subscribe to the idea that both bars should be changed together. Only change the one that needs adjustment if you can get away with it.

Miata forums are great resources for researching this stuff since they share a similar layout with the 8. Miata guys have been tuning suspensions for how long now? And, there are tons of knowledgeable Miata autoXers and racers out there.

Here are some good resources for understanding how sway bars work (and suspensions in general).

https://en.wikipedia.org/wiki/Anti-roll_bar

Autocross to Win (DGs Autocross Secrets) - Weight Transfer

One of the best and least expensive things you can do is to take the car into a competent shop for a performance alignment. That will set enough negative camber to help counteract the tendency of the front outside tire to lose grip as it moves into positive camber. I am running a modest -1.8 in the front and -2.0 in the rear.

I set my alignment a little more aggressive than that, I shot for 2.5 front, 2.0 rear and the shop was able to get it, with pretty much zero toe all around for less drag.

That's one area that you can change on a stock car that can change the handling balance of the car quite significantly, especially if you're going from near zero camber now.

Got the sway bar on the car today and from a quick drive in it around some twisties, it definitely feels more flat. I have not experienced any more understeer at all. What I have felt is more grip, and the car feels much more planted, especially on quick change of direction turns. There is a quick chicane I take in 2nd WOT near my house. The difference from taking that same corner on the stock bar vs taking it with the new bar is night and day.

pcs: I think you are taking the correct approach in maximizing the capability of the stock setup first. It is very capable. One thing you should do if you have not already is to get a track oriented alignment (Basically max out the front camber, and set the rear to be about 0.5 less than that. Set the front toe to be zero, and the rear to be slightly in.)

After that, and before considering any upgrades, I would drive it and take tire temp measurements to see how well you are using the full contact patch. I have a tire temp probe you are welcome to borrow if we manage to get to a track at the same time...

If you want to adjust the balance to remove a little understeer, you can switch to a slightly stiffer rear bar. I would actually look for an aftermarket miata bar with adjustable end links or holes for this.

Bilsteins can be re-built and also re-valved if you want to do that at some point.



OfficerFarva: Good that you are enjoying the car, and the quicker transitions from the stiffer bar, but as Black2010R3 and stvnscott have mentioned above - stiffer front = more understeer. Stiffer rear = more oversteer. stvnscott gave a very good write and provided some excellent links that explain this. To add to that, if you are experiencing understeer, then you are beyond the limit of the front tires, so your thinking that it will decrease understeer when you are not at the absolute limit does not make sense. So, it may well be more fun on the street, but if you are going for a track setup to drive at the limit then stiffening the front bar alone on any stock suspension does not make sense.

Actually, a lot of track set up cars go with a stiffer bar in the front. Reason being is with the smaller bar in the rear, you can throttle steer better. The ass end will a little more tame, so if and when you experience understeer you can lift and let the body roll over. Smaller rear bars are very common among Miatas too. Pro MX5s run stock bars.

My point being about how it feels with the stock bar vs the new bar is that I can definitely feel an improvement with regards to camber. And of course, if you can decrease the positive camber gain of the front outside tire during cornering with a stiffer sway bar, then you can maintain better traction, and understeer less. That does not mean that it still wont transfe weight diagonally to the rear and cause understeer at the same time. Like everything there is always give and take.

I am not arguing that a stiffer front = more understeer and a stiffer rear = more oversteer. It is just not always simply black and white. There are always a lot of variables with anything to do with a suspension.

Yes, it's not 100% black and white, like you said, but that mainly applies to camber challenged suspensions like struts, but the RX8 suspension is much better than that. Also, in some cases like with FWD cars, once you lift the outside rear tire, going stiffer won't change a thing. Also true that many race cars run stock or even sometimes no rear bars, BUT that's when used with spring rates that allow that sort of sway bar setup, NOT stock springs.

In your case it seems that you're simply feeling increased roll stiffness without getting to the limit, so you really can't comment on the overall balance of the car.

All I can really comment on is what I've experienced, which is stock suspension with an aggressive alignment and my KW/Hotchkis setup and both have slight tendency towards understeer that can be overcome with proper driving technique (on track, I never get that close to the limit on the street).

I guarantee you 100% that at the limit, your car will understeer.

I should add that if you're looking to go with coilovers and don't want to spend a ton, then maybe look at the Tein Flex. I had those on my old FC RX7 and they were pretty good for track use. Build quality was good, damping seemed pretty good and I never had an issue with them. The spring rates are close to what I'm running, but a little softer in the front, so they'll likely work better with a big front bar, stock rear bar type situation like what you've got.

I still think that looking into getting the stock Bilstien shocks re-valved for use with coilover sleeves would make a good, less expensive option as well, certainly better than any sub $1000 coilovers.

Can any shop that does alignments do camber adjustments? Or do I need to find a specialist of some sort in my area?

I imagine a specialist will be best, but I don't have an understanding of how complicated an adjustment this is. If it's relatively simple (with the right equipment), then I'd opt to just go to the local shop for alignment. If it's more complicated than that, then I'll search and go elsewhere.

Any alignment shop can do it. It is an integral part of performing any alignment.

In theory, but a shop that does race alignments is much more likely to do a good job. The typical shop for general aligments are more often than not clueless about doing anything outside the standard alignment specifications.

The only reason to have driver weight is is for corner weighing. Alignment change is so minimal it's not sorth the hassle.

Also, any stock RX8 can be made to oversteer like a mofo at the limit with a simple alignment adjustment.

As the above 2 posts. Anywhere should be able to make the adjustments. Whether they understand that you want maximum camber and how to achieve that is a different story. Explain that you want custom and not factory specs. Make sure you check what it is set to before leaving. Expect to pay more too. If you are on the factory alignment it might take a couple of passes front to rear to get everything set.

For a track setup, I would aim for maximum (negative) front camber, max front caster without taking any camber away, 0.00mm front toe, rear camber 0.25 to 0.5 less than front camber, rear toe-in to 0.08 to 0.12mm total (0.04 to 0.06mm in each side).

With the low toe settings, tire wear on the street should be reasonable, but do make sure to keep the tire pressures up, as you will wear an inner band pretty quickly due to the camber if you let them drop.

The process should be something like:

Empty out everything that you would not have in the car when on track. Make sure tire pressures are even all around.

Roughly set front camber to max, caster to min. Get toe somewhere close to zero (does not have to be exact as it is not the final setting).
Rock/roll the car

Set rear camber to around 0.5 less than front. Get toe-in close to 0.04mm on each side (0.08mm total). Re-adjust camber if needed once the toe is set.
Rock/roll the car

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If you don't have reasonable camber at this point (let's say -1.5 on each side front, and -1.0 on each side rear for the stock ride height), then stop and figure out what is wrong. You might have a bent suspension arm, or some damaged/worn adjustment bolts, but the 1st thing to try would be loosening and re-tightening all the bolts that go through a suspension bushing with the suspension compressed to make sure they are all seated correctly.
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Ideally, sit in the car at this point.

Go back to the front and more accurately set camber to max, caster to min, toe to 0.00mm (no toe-in or out). Then add caster back until it just starts to affect camber (then you have max caster and camber at the front). Re-adjust toe as needed to get it to 0.00mm
Rock/roll the car

Check & re-adjust the rear if needed.

Sounds like it should be simple, but it never seems to work without a few passes for me.

Managed to get -1.42/-1.44 (left/right) in the front (they said this is about as close to even as they could get), and -1.20/-1.25 in the rear.

went to the track on Sunday, and... unfortunately, it's been too long since I've driven the 8 on the track to recall a different feel due to the suspension. I also have been doing it just for fun in the past, so I don't have any times to compare things to, hah!

Car felt great though - short of a 3rd gear issue...

That alignment sounds good.

You should now have a bit more grip, a bit less understeer, and better tread wear on track, but honestly for alignment it is pretty hard to tell without tire temp data or looking at tread wear over multiple events.

you don't want front caster maxed either, but whatever ...

edited: mistakenly wrote camber, but had intended to write caster
.

I'm still trying to read through the other sticky on alignment settings in the racing section... my eyes are going a little cross, hahaha

I'm curious on why not?

I'd like to know the theory on this as well. A high end alignment shop, West End, maxed out my front to -1.9 front at their recommendation for ideal handling.

Wondering if you got anywhere with this been thinking of doing some wheels and tires daily driving and was wondering what sort of suspension to pick up or what good options are as the wheels would be going down to 18s so didn't want a huge gap in the wheel wells so was thinuking coilovers but at the same time I know the stock blister on the R3 are awsome so how would a lowering spring be on the stock blisten?? Anyone know ??

Going down to an 18" rim will not change the fender gap if you buy the right size tires (225/45/18). If I had an R3 as a daily driver, I would not change a thing in the suspension. It is one of the most perfect setups from the factory ever made IMHO. Anything you do to it will degrade it. Those of us not fortunate enough to have an R3 have spent a ton of money trying to make the suspension as good as what comes in an R3 from the factory.

Also, you will want to do a lot of research on lowering springs installed in Series 2 cars. Mazda changed [at least] the rear spring perch locations, which makes things very unpredictable since pretty much all aftermarket springs were designed for the Series 1 car.

If you really must lower your car, your best bet is coilovers: either the Bilstein PSS for around $1000 or the Bilstein PSS9 for around $1500 if you must have adjustability. Installing these and lowering the car will change the balance of the car from mild understeer to oversteer, which means you will need to experiment with new sway bars to make it neutral again. You will also need to replace your sway bar end links with adjustable units to relieve the bind that lowering the car puts on them and the sway bars. Finally, you will need to have the car aligned.

The adjustable sway bar end links are really more of a nice to have than a need to have. They take out pre-load if the car's a little high on one side or something like that. They can be used to shorten the links when lowering to maintain the same bar end position (otherwise lowering points the ends up), but that's not really too important.

Going back to this, I'm looking at replacing the front and rear Bilsteins, or getting ready to do so. In going through the links above, the struts (item #1) have an option with a side spoiler in the front and a large spoiler in the rear...

Anyone know what the spoilers are referring to, and whether they are needed or not if the strut is the only piece that is being replaced?

If I'm replacing the strut, is there anything else I should be replacing as well?

I figure replacing the struts will last me another good amount of time, and if eventually I want to go with say a fatcat setup, I can send the old set to get revalved / built to spec while driving on the other set...

Thanks in advance!

I'm ok with the gap from the factory, doesn't bother me.

At this point, I'm sticking with the stock setup (likely for the forseeable future), even when the stock stuff wears out.