dmp

At first I thought it was just because my Miata handled pretty well that I was never impressed with the RX8's handling...now, I'm not so sure.

Anyone else experience this:

Sharp corner, pretty fast speed...back end starts swinging out a little or a lot, the body rolls over (what feels like a foot or so) and BAM! All of a sudden I'm into MOUNTAINS of understeer - so much so it makes it even difficult to correct. It's like the front tires are just letting go, or the steering stops working. VERY un-nerving. It's not easy to explain, except for it's as if the inside two wheels come off the ground, and the car is just kinda stuck plowing and rolling for a minute...

Anyone local have an otherwise stock RX8 with a good rear sway bar I could check out? I'm hoping and praying a rear sway bar + decent tires fixes most of the problem...

How some of y'all rant and rave about this car's handling is beyond me...I 'will' concede after driving my wife's 95 Altima for about 5 minutes, I appreciate the 'handling' of the 8...still...

ZoomZoomH

iTrader: (1)

need video of what the heck you were trying to do....

khtm

yeah you crazy ****!

Hunter

That sure sounds like either tire pressure, alignment or tire wear. Or, all three.

What sound are the front tires making before they let go? Are they "singing" or are they screaming in pain?

When you say the "back end starts to swing out a bit," are you saying you're going from moderate oversteer to snap understeer? Is there enough oversteer or is it going on long enough that you're correcting?

How fast is fast?

One of the things I've read about these tires is that while they have tons of grip, when they let go they let go in a big way. So, maybe you're just going a lot fast than you think you should? :D

Hunter

dmp

I'll look into getting a 'good', race/street alignment done asap...I honestly have no idea of where the car is now. Good call.

No or little sound.

I guess I'm not sure...I suppose it's 'snap understeer'. The car simply starts body-rolling to the outside, and applying throttle doesn't help move to oversteer...in fact, I'm convinced it's impossible to accelerate in a sharp turn with this car. I HATE the throttle by wire. but I digress...

It's as if, once the body starts rolling, I lose the ability to adjust the attitude of the car w/ the throttle or steering. I've had the car turn sharply (10mph corner) at 25mph-30 or so, and the car makes the corner, but wants to continue to turn...I have to muscle the car back into a straight line...as if turning the steering wheel has a reduced effect on turning the wheels. I think that's understeer.

Wow. That is VERY vague I know..and hard to follow...sorry.

Banked 10mph corner at 20-25mph - corners I'd take 5-10?mph faster with 'zero' drama.


I suppose it could be how the miata 'felt' faster...even when It wasnt. Low, open, loud...as opposed to how isolated drivers are, from the road while in the rx8.

Dark8

Just a theory, but could this be what is happening: The body rolls and you hit the bump stop on the outside front corner which send the spring rate through the roof and overloads the front outside tire causing it to have sudden understeer.

If that is happening, a good set of anti-sway bars should help.

dmp

Makes sense...should I go on a diet? lol :D

Dark8

I meant the body in the trunk....

Hunter

well, I had a nice long detailed answer all typed out and as I went to preview it, Internet Explorer crashed on me

so, here's the short version

If you're not hearing the front tires scream for their lives, you're not going all that fast -- or it's raining really hard. So, I think that contradicts the bump stop theory.

If you don't want the dealership to look at it, try a local race shop you like. Also, see if there's any way you can find out if there's anything wrong with the limited slip differential. If it's locking up in the middle of a corner -- it sounds like you're going quick through a sharp corner as opposed to a long high speed sweeper -- that could cause problems at the front end with understeer.

Also, with your comment about it not wanting to straighten out, I think you need to have somebody look at it. It should be wanting to do the opposite of that.

Icemastr

What is your racing experience?

kristopher_d

This car handles beautifully when working properly and daftly handled. I'm not trying to be an ***, either. You definately need to make sure your linkages are intact. Your car should not be behaving that way.

red_rx8_red_int

Well I have never experienced a "snap understeer" in my stock mt 8, I have experienced a sudden stopping of oversteer that sent me in the wrong direction! Last year at a test'N'tune autox session there was one long sweeper of decreasing radius that I never learned how to handle. I kept trying to maintain as much speed as I could, in other words entry speed and turning speed were more important than exit speed, but that may have been wrong for that portion. Anyway, I would enter and the tires would squeel with over steer, I would compensate with turning the wheel more (which is why oversteer is built into most cars, its safer and the more intuitive reaction) and slow down. All of a sudden, the car was neutral and would dart where the front tires were pointed! Not where I wanted to go! Never did master that part of the course after 17 or so runs.

dmp

'handles beautifully' is subjective. Handling is 75% "Feel" anyway...As-is the car feels like a pig. body-roll...gobs of understeer. Kristopher - what car are you coming from, prior to the 8?

I have no 'racing' experience...but I do have 'track-day' experience in my Miata.

The more I think about it, the more I think something in the suspension might be off.

Icemastr

I was questioning you on your racing experience to maybe get a gauge for how much experience and knowledge you actually had with handling and suspension. In my opinion handling on the street and handling on a race course is quite a bit different. I have never experienced the problem you describe however I cannot imagine hitting the bump stops like someone else suggested with stock suspension on a race track, much less driving on the street. After having driving an RX-8 on a track and at a few autocross I find the handling to be excellent, the structural rigidity is excellent, and the geometry is really well engineered. The RX-8 is definitely setup to handle quite a bit better than the 3rd gen RX-7s except for the fact it is setup to be a lot more comfortable drive so it does have a good bit more body roll. I rode with a SCCA nationally competitive driver in an RX-8 who races a 93 RX-7 in SM2 and he loved the handling of the RX-8, his only complaint was the huge lack of power, but he was coming from a 400rwhp RX-7 that has pretty much zero turbo lag with sequential twin turbos. In my opinion there might be something suspect with your suspension, maybe something got bent, I do not know try having an expert check it out. If everything checks out fine there I personally would try upgrading your shocks and springs to adjustables and some well designed sway bars and the RX-8 would handle amazingly well, with just reducing the body roll and tightening up the front end turn in with a shock tower brace it would be a very sweet time on the autocross. If you plan to compete though all you could do would be adjustable shocks though if you want to stay in BS otherwise you will get put into a street prepared class where it would be pretty tough to compete.

dmp

Thanks Ice - I'm not into Autocross in the least, so I'd just buy what I thought could help...but first things first...A suspension check up, I think.

Nemesis8

iTrader: (3)

Well, not so stock now - but you really do need to drive my car.

MazdaManiac

iTrader: (3)

Most cars are daftly handled around here. :p

The front shocks on the RX-8 are practically shot right from the factory in N/A. Our compression rates are extremely low.

dmp

...an offer I'd gladly take you up on - I'd like to see just how well the MS Suspension 'fixes' things.

Nemesis8

iTrader: (3)

The shock tower braces will have you grinning ear to ear

Icemastr

Any of you guys going to ABF? I would be willing to check out your car from a racers perspective and you could get a chance to have an RX-8 driver see if there is anything amiss with your car. I could also get under your car and see if I can spot any bent or messedup bushing. Im a Miata driver as well even though I race an SM2 93 RX-7 I also have a CS Miata that I will be taking to ABF that will be in SM2.

Yes shock tower braces do make a considerable different on a lot of cars. It will give you better turn in and your car will corner flatter I know it is an easily noticed difference on both Miatas and RX-8s.

Sway bars will decrease chassis roll in cornering and increase the sensitivity of steering inputs to really help your cornering.

Adjustable shocks and heavier springs will allow you to adjust the compression and rebound to achieve the optimal level of handling vs. streetability.

If you do find nothing is wrong with your car I would recommend these upgrade paths and see how you like it then proceed to the next if you want to get further in but not necessarily a path you want to follow if you plan on being competitive in a class for racing: Shock tower brace, sway bar, springs, adjustable shocks, tires. I put tires last although they should usually be first because I am not sure how satisfied you are with the stock tires. I would probably recommend the Racing Beat RX-8 suspension package for $516 that includes the sway bars and springs if you do not plan on going with adjustable shocks, or are not going all out and don't mind just running the racingbeat springs with adjustable shocks (there are some better springs that give up streetability out there than racingbeats which compromise more towards daily driving). I have little experience with the RX-8s suspension however so look towards people who have tried this stuff on RX-8s as all my advice comes from experience on other cars.

dmp

I can't make it to Apple Blossom...

Also, I couldn't tell that a front shock-tower brace on my Miata made 'ANY' difference in handling...I left it on because it looked cool. :D The car had RB front/rear sways (Should have left the front bar stock), RB Springs, and factory Billsteins.

For this car, after the alignment, I'll likely just save for coil-overs and a rear sway bar...next time I get a couple thousand to spend, that's where I'll focus....Oh...and yeah...I'm of the opinion the factory dunlops are nearly worthless.

Nemesis8

iTrader: (3)

The stock OEM front shock tower brace pales in comparison to the Mazdaspeed brace...

I'm going to the ABF on Saturday from about 10AM till 5PM

HeelnToe

Hmmm, my car is stock, yet it does exactly what I'd want: generally neutral in a corner if left alone, understeer increases slightly with gentle throttle application, oversteer increases when lifting off throttle... or even more when over-feeding in throttle.

For me, that's great fun. But I'm coming from FWD cars (the throttle OVERsteer thing is new to me), so I'm no expert

I also agree that the stock 040s give llittle warning. They either stick or they don't. I actually miss my Pirelli SnowSports.

Nemesis8

iTrader: (3)

I took my off ramp exit this morning at 45 MPH. This is a very tight right hand turn of about 45 degrees on Highway 12 at the Brady Exit. DSC did not ativate, which I have made it do here when it is raining. The car held it's line, did not roll at all, the tires were singing a little, and I accelerated out of the turn. I left my buddy in his '04 Eclipse in the dust

This car needs the FULL MS suspension and bracing to make you happy. I'm even thinking of adding the tunnel cross braces -

Blue87Sport

I like the handling of my 8 but I could do with less body roll too. My first instinct would be beefier sway bars, e.g., Racing Beat ones. Would a better shock tower brace be a better way to control body roll than sway bars?

I don't want to do springs/shocks as I don't want the ride to be more harsh. I had enough harshness in my second gen RX-7.