larkin

iTrader: (1)

Seems stiffer sway bars (PT/agency) are a top upgrade for an otherwise stock rx8. The stiff sway + soft stock shocks = decent handling improvement (reduced body roll). I'm not happy with how the car's nose lifts up a bit when I accelerate. So, a stiffer shock seems in order. One problem with going with a stiffer sway to begin with is that you've cornered your self into softer shocks to upgrade to, right?

I'm considering MS springs/shocks but I'll bet the PT sways even on soft settings don't get as soft as the MS sways which means that combo wouldn't be an ideal handling pairing, even if better than stock. So, what's the right combo that keeps the sway/shock synergy?

Considering:
1) MS sways/MS springs
2) MS sways/MS springs/MS shocks
3) MS sways/RB springs/Koni Yellow shocks
4) PT sways/RB springs/D-spec shocks
5) PT sways/MS springs/D-spec shocks
6) PT sways/MS springs/Koni Yellow shocks
7) PT sways/RB springs/Bilstein HD shocks
8) suggest?

most interested in 3 vs. 6.

Thoughts?

Driving style: ripping around town, autoX and miata club cruise once a year, never gonna track. Preference for ride adjustability. Street car, so preference against substantial lowering.

Car: 2007 Sport 6spd, RB flash, AFE SS, beatrush front strut (rear strut on order)

Gratsi, rx8c.

Arca_ex

iTrader: (10)

So you think that having stiff sways and springs and dampers would impair handling? What's your logic behind this lol...

shr3da

First of all, you need to realise that the coilovers are the centerpiece of your suspension set up, think of sway bars as a fine tuning tool.

Get some descent coilovers first, adjust them, see what are like on different settings. If you want to fine tune even further then look into sways.

Another great mod is under chassis bracing, get on it, less body roll and faster corner speeds!

You said the car pulls back under acceleration, under hard braking you will notice a lot less nose dive with coilovers which means less braking distance!

comebackqid

iTrader: (13)

Well don't know if you guys heard of fortune auto but they have swift and good prices, also made here in the good ol' US of A.

http://www.fortune-auto.net/

get a good set coilovers first then worry about sways and endlinks later, if you do get sways I recommend progress tech they have 3 settings for the front and 2 for the rear, dont forget about tires and alignment as well if you are trying to get maximum traction/handling

JCrane82

iTrader: (3)

I usually look at anti-sway bars as bandaids, used only for street cars since you want them liveable day to day. If performance was the ultimate end goal, then you would be running stiff springs with little or no bar. Stiff bars are good for street cars though, since it is hard to live with super stiff springs day to day. There is such a thing as too much roll stiffness though, and this will result in lifting inside wheels. The general rule of thumb is that you don't want more than 30% of your roll stiffness to come from the anti-sway bars, since this will cause a lifting inside wheel. If you get to this point, you either need to reduce anti-sway bar stiffness or increase spring stiffness. Four tires will always grip better than three....

This is of course a very general rule, and suspension tuning is never black and white. There is plenty of grey area that is dependant on many different variables. Based on what you say will be your focus (ripping around town, autoX and miata club cruise once a year, never gonna track), it really comes down to what you are willing to accept in terms of ride quality. I think the Progress Tech, Tanabe, Whiteline, etc. adjustable bars will all work fine with even stock springs due to the adjustability they provide. Just remember you want to keep the roll stiffness to spring stiffness ratio similar, meaning that if you go with a stiffer anti-sway bar you want a stiffer spring.

larkin

iTrader: (1)

In most cases I see people getting non adjustable sways with stock end links. In this case your thicker sways are either on or not on. To fine tune with sways do you do so through adjustable end links or are progress sways with fixed end links like AP links sufficient to fine tune?
Ideally I'd like coilovers but unless I manage to get some MS on the cheap I'll go with stiff sways. This won't address the car pulling back while accelerating. Would springs alone help this or are springs and shocks needed? If so, any of the 7 options look especially suited for this application to you?

Thanks guys

JCrane82

iTrader: (3)

The adjustable end links only allow you to adjust the position of the anti-sway bar in its zero energy state. They also allow you to cross load the bar, but that is for another discussion. Adjustable anti-sway bars are what you want for tuning the oversteer/understeer of the car. You do not need adjustable end links to accomplish this.

I am a little confused by your first line there. Are you saying you want Mazdaspeed springs, but are only willing to get them if they are cheap? I am also confused on your comment about coilovers. (maybe it is too late in the day and I just need to go home...)

As for reducing the pitch motion of the car during acceleration or braking, this can only be accomplished by a change in spring rate; anti-sway bars only control roll motion, not pitch. The difference between springs and shocks is that springs set the steady state motion and shocks set the transient motion. In other words.....springs will determine how much pitch you will get during braking and shocks will determine how quickly you reach that position.

There are many people here who will suggest that you get shocks at the same time as springs. Usually this is a good idea, but not due to damping values. The stock shocks are gas pressurized and are designed at a given ride height. Once you lower the height, you over stress the seals in the shocks and cause premature rupture. It is hard to say how long stock shocks will last on aftermarket springs, but it is also dependant on many things (ride height, application, spring rate, temperature, etc.). I personally have been using my stock shocks on Progress Sport springs for 10k miles, and no issues yet. My stock shocks only have a total 32k miles on them though.

When you consider the cost of springs plus shocks, you are near the price of some well made coilovers. The Powertrix coilovers come to mind (probably what I will step up to when my stock shocks go out).

larkin

iTrader: (1)

Reasonable that you would be confused. I was just addressing other people who replied about coilovers there and I meant the MS coilovers. There's someone selling them for $1,300 in the for sale section but he seems to be MIA.

I'm now leaning towards coilovers instead of just sport springs and stock shocks. I see powertrix has a group buy right now. They seem like a decent value but what do you think of their adjustability. They don't appear to have separate compression and rebound adjustments. Just ride height and pre-load adjustments. If I got these, I would still go with sways bars, since I don't think coilovers will get me the same steering response as sways (might be wrong).

dannobre

iTrader: (3)

You have to decide how much money you have to spend...and figure out where to go from there.

The dampers are more important than you think...and sometimes "cheap" coilovers don't work as well as a set of shocks and springs that are matched properly.

There are as many opinions about suspension setup as there are racers/drivers...and it depends on many things....the driver being one of the most important ones.

If you can try and drive a few cars with different setups and see what feels best to you

HiFlite999

iTrader: (2)

You realize the spring rates are about 3-4 times stiffer than stock?

Also, many adjustable dampers require removing the strut from the car to adjust.


See this thread: https://www.rx8club.com/showthread.p...70#post3773570

larkin

iTrader: (1)

I wish I had access to a community of rx8 drivers that were willing to give me a ride but I'm somewhat on my own here.

I'm sure in general cheap coilovers can be worse than good springs / shocks but I have to make a decision. Do you have any reason to believe powertrix coilovers are an inferior selection to the options I posted in the original post?

I think they get pretty close to stock at their softest dampening. Also, I was told they can be adjusted by popping the hood and yeah, maybe having to remove the strut which isn't a big deal. The rears can be adjusted from inside the trunk. I'm thinking sways and decent springs will probably satisfy me but I'm up for trying something new. Haven't heard anything bad about these.

HiFlite999

iTrader: (2)

*Spring* rates, not damping (though that will have to increase too). Stock is about 150 lb/inch, most coilovers start at 500 lb/in.

"Driving style: ripping around town, autoX and miata club cruise once a year, never gonna track."

If you don't mind getting beaten up and skittering around on rough streets, go for coilovers. Some don't mind, I do. The Powertrix shocks are adjustable in compression only and probably the rears require removal to adjust. Double adjustable coilovers are around $1800 and up.