szigler

I would have to agree the difference between both cars was HUGE!
Mine was tail happy (needs more rear toe), on stock tires and no shocks (yet).
The difference in our driving styles is also very different.
Not sure when/if I will be doing anything to the car, but my first order of business would definately be to get good shocks and do a minor modification to the alignment.
The only similarity between the two cars was the amount of cones we hit and the dents we ended up with on the rt front under the door.

Shelbi

Dark8

Cone dents?

Banannie

Yup

Brand new cones + 40 degree weather = DENTS

Both of us hit far more cones on the passenger side. Both cars ended up with dents on the lower panel - Shelbi's is more under the leading edge of the door, mine is on the bottom part of the fender.

SUCKY!



Shelbi, let me know if you figure out if your dent can be pulled out. I've got one name of a guy down closer to me, I may see if he's available to look at it over the long weekend.

Dark8

Whew! There for a minute I had the image of you running over course workers!!

AlexCisneros

yeah, running over the course workers give you 4 sec penalties and dents


...Luckily Miami doesn't see 40 degree weather. Our cones are soft and gooey

FM, might want to try 0 toe in the front :o

fastmike

Zero is basically what we ended up with front and rear.
I did not like car's rear under full power while turning.
I need to add some rear toe.
I can do that without going back on the rack and setting everything up.
8 makes it easy to adjust rear toe.
I am going to add about an 1/8 inch in a side for a 1/4" total rear in.
FM

Pololo_RX8

I am indeed bringing this topic from the "death"

I have searched but nothing is quite clear with this topic. At least I am not getting what I am looking for.

Now with ALL the experience some of the forum members have with alignment settings, what is a good compromise street/track wise?

I just installed my MS suspension that lowered the car by ~1" and I looking into getting this setting spot on. I am aware camber and toe perhaps changed due to lowering the car. Coming from a Miata with similar characterisitics, I am having a hard time finding these settings.

I am aware that there are definite setting for track, AX and street. However one that can be a good compromise is what I am looking for.

After installing the suspension, the car "hunts" the road and it easily follows any imperfections I encounter, making it very nervous. Needless to say, it's a bit harder to drive and I assume this is due to the Toe settings.

The car had the "factory specs" before.

Anyways thanks for your help.

Carlos

tuj

Max negative front camber, max caster after camber. Front toe zero. Rear camber -0.5 more negative than front camber. Rear toe either zero, or 1/8 in.

TeamRX8

iTrader: (25)

FWIW max front camber occurs at the minimum caster setting and I would do just the opposite on the rear camber, especially on a lowered stiffer suspension

tuj

What? My car started at -0.1 front camber and 5.6 degrees of caster. After alignment it got -1.1 degrees of camber (max possible on my car) and 6.2 degrees of caster. My car had about 0.2 degrees of toe out from the factory, on both sides, front and rear. Now the toe is zero front and rear.

With a lowered suspension, I would be concerned about loosing the rear end over bumps. That is the biggest problem on my Miata that is lowered about 1.75". So I would think that going with -1 (or -1.5 if you can get it) front camber, and -1.5 or -2 rear camber would be a good idea. If the springs are really really stiff, you could maybe deal with less rear camber. If its primarily an autox car, I would say set the rear camber equal to the front.

TeamRX8

iTrader: (25)

First, it's an RX-8, not a Miata, completely different car, suspension, and geometry.

Second, you're not hearing what I'm telling you. Maximum camber occurs at minimum caster. That doesn't mean there aren't inbetween settings. You only have 1.1 deg, I had 1.7 on the left and 2.2 on the right in a Stock class car i.e. no lowering which increases camber capability. So to simply tell someone "max camber" is like saying "somewhere wy over there" when giving directions. You're setting them up to end someplace different than you may have intended. If I had 2 deg in the front you're telling me to run 2.5 deg in the rear, which IMO is seriously f'd up.

ps: and why do you want the settings to be equal? Do you want to have slower cornering speed in both directions???

Pololo_RX8

I usually set the front camber 0.5 degrees less than the rears with the maximum caster.. So it should be about -1 F/ -1.5 R and around >5 caster...

This will give me a good compromise between Street and Track...

However what I am having a hard time is TOE settings since this needs to be adjusted so the car is less nervous in the road. As I said it picks up every imperfection and it follows it...

What should my Toe setting be? In? Out? F? R?

TIA<
Carlos

tuj

Toe is more important in the rear than the front. Rear toe-in will increase straight-line stability. Police crusiers are often set up with a significant amount of rear toe-in to make them more stable at high-speeds. Rear toe-out will make the car rotate easier. Front toe-in will increase understeer at corner entry, but it will make the car's steering more stable, as will increasing caster. Front toe-out will increase steering response, but will tend to follow ruts and such in the road at speed.

Remember that your alignment can change over time, and any shop should tell you the before and after specs so you can see how your car is wearing. They should also weight the car to your typical load (probably just your weight on the driver's side) before aligning it. I would suggest checking your toe on an alignment rack first, as it is probably toed out. If so, try zero front and rear. If its already zero, try adding a little rear toe-in first, then try adding front toe-in. The rear toe generally has more of an effect on the car's handling than the front.

tuj

Fair enough, but since we're talking about instability in lowered, rwd, a-arm front, independent rear suspension, coil-over-shock cars, its still relevant.

I said max because every car is different. Mine can ONLY get 1.1 degrees of negative camber in front. There is no more to be had. Which is why I don't understand why you say that the max camber occurs at minimum caster. Anyway, I think we can agree that the RX-8 wants as much front camber as possible to get and still keep the left and right sides the same. That's -1.1 in my case, but other cars like yours can get more.

The typical RWD alignment has more negative camber in the rear to keep the back end in check. Giving up camber on one end is usually to change the handling of a car by giving up grip on the end that's not slipping to balance the car. More negative camber equals better cornering. Too much negative camber is bad for putting power down and for braking. The rear suspension is designed to get much more negative camber than the front: the engineers did that for a reason.

I was giving advice for a STREET car that is also autox/tracked. I think the rule for these cars of max front, 0.5 more negative in rear is a good, fairly aggressive alignment. Unless you are using very stiff springs or the car is lowed a lot, the front end of the car is camber-challenged and can use all the negative camber it can get.

If you are talking about setting the left and right sides equal to each other on an end, well again, we're talking about a street car. Setting each side to a different value will upset the straight-line stability of the suspension. For autox-only, I would agree that maxing out the front camber on each side is a good idea, since stability is usually a moot point in autox.

Getting rid of camber in the rear to make it break loose at the same time as the front doesn't fix the fact that the front is still breaking loose. But maybe I don't understand what you're trying to say. What alignment would you suggest for this guy?

TeamRX8

iTrader: (25)

ok, believe whatver you want

tuj

TeamRX8: You still never said what alignment specs you would go with.

Pololo_RX8

Thanks this is indeed very helpful for getting a bit of understanding on this. The lates Miata and RX8 share teh same chassis and even some suspension if I am not mistaken.

In the Miata.net site, for the new car MX5, they even suggest going with the same setup as others have for Street/Track cars with a good compromise. This is well documented and proven.

I am going with -1F/-1.5R, Max Caster ~ 5, and Toe In. This will be a decent compromise w/o destroying my tires during commute.

Of course I am still waiting for what TeamRX8 will recommend...

Carlos

John V

iTrader: (1)

I'm still curious how you guys plan to get max caster AND max camber on the RX-8.

As long as you keep the toe at zero you can run a lot of camber without destroying your tires.

olddragger

iTrader: (3)

Ok guys here are my secret settings for my suspenion--what do yall think? These are track settings not autocross
1- camber -1.4 F and -1.9R
2- cross camber 0
3- caster 6.6
4- cross caster 0.2
5- toe(front) 0.05 r&l--total toe 0.10
6-rear toe 0.09 r&l --total toe 0.18
8- thrust angle 0.01
Car drives tight--a little squirrley on the street--drive with 2 hands on the wheel. turn in is great --middle turn is solid and the tail is planted. Still has a little power understeer but I figue my R compunds will help some with that. with a 35 offset wheel i also have an increase in my wheel track of about 3/4 of an inch. every little bit helps. the rear toe in really makes for high speed stability(in the esses you really feel it) I had very even tire wear at Roebling.
what do yall think?
Olddragger

takahashi

Carlos,

I don't think the MX-5 can compare with the RX-8 since they are different in weight. From an exp MX-5 driver, they don't need a lot of negative camber but just a nice toe

Tell you what I have. Don't have much tyre wear so far

Front camber L) -2"08' R) - 1"54' (NOTE: 60' = 1")
Front Toe L) 0.00m R) -0.10m (ie. Zero front toe).

Rear camber L) -1"35' R) -1"36'
Rear Toe L) +2.40m R) +2.30m (ie Rear toe in).

so I tell people as, "2 degree camber front and 1 and a half rear. Zero toe @ the front and toe in @ the rear."

BTW = do not get too much camber at the back - it is pointless, wear out the inside and get understeer. For me (it is personal choice), is to have a slight oversteer when turn in and use my right foot to control (*either brake or accelerator). Zero toe front is good for track with long striaght but twisty track and auto-x (with cones and stuff) better to have the front toe out.

I can show you this video . Note the video is in DivX format. (www.divX.com). Adrian in Melbourne, Australia done car from nanny to Porsche Carrera cup racer.

I turn my DSC off when tracking. I actually try toe zero and toe out (but only on the front). I never thought of trying toe zero at the rear. Judging the tyre wear and photo taken my photographers. I do need more camber than 1.5 at the rear. But perheps just slightly more (say 1"45' and definitely not near 2). I have been loving the toe out since it is so progressive underpower. I am a slow in fast out driver and I power out sometimes before mid corner. I trailed break when I push my car and I fear if I zero the rear toe I would have less directional grip.

But that is something to keep in mind and speak to Adrian about it next time I go.

takahashi

OD I concur with what your experienced.

Trust me Power Understeer will not cured by R Compound tyre - been there, done that. When you are too fast into a corner. You are always too fast

1.9 at the rear is very nice. I think I need around 1.6 or 1.7. Toe zero will make the car wonder on the road but it is ok on the track??

Last time I had power understeer, which is just 2 weeks ago on the track, I took advice from everywhere but I event found something works for me:

1. Lower the tyre pressure (I end up having 34psi front and 36psi rear when the tyres are hot).
2. Stiffen the damper in the front of my Tein Flex (I have setting of front 1 and rear 4. NB - 0 is the hardest).
3. The zero camber front does not work well when the car understeers.

4. The last thing I need is to slow down and power early

I think there must be a setting for the radials (like the Michellin PS2) and the R Compound tyres -... the grip is SOOOOO different and it is justified to have a seperate settings.

When you are comfortable with one setting and it works for your driving style. It does not matter what other people think. Experiment all options and find one that you feel comfortable with.

I will get slightly more camber at the rear.

Winning 8

more camber on the rear is a safty issue, not the fastest way going around the track. most alignment shop will give you more camber or toe in so you will not oversteer or crash your ride and give them a bad name.

takahashi

I increased the rear camber from -1.5 degree to -1.75 degree.

It is much nice under turn and certainly much safer on the wet track. The tyre wear is bang on target for the track too.

I found -2.25 maybe a bit too much. I will be happier with -2 in the front.

Keep searching the best combo for my new fav track :p

DaveRX8

So I am having some problems with my alignment. After I put on my new wheels the handling has been worse. The back wheels rub and they shouldnt. 18x9.5 +40 with tein coilovers. I took it to firestone today and told them I wanted 1.4 camber on front and 1.8-2.0 on the back. They told me that the most they could get it was .8-1.0 in the front and in the back they got it to -1.4 on left rear and -.9 on right rear. He said I need to buy something so that I can achieve that. I dont know what it was, i didnt pay attention because I know I dont need to. Everyone else with the same wheel size isnt having problems so it is the alignment that is wrong. Any advice would be very helpful asap, thanks, Dave

TrackAddict

Best advice is take it somewhere else. Find out where racers or autocrossers go and take it there. Make sure your alignment is done with you in the drivers seat.

My alignment specs are here.