VividRacing.com

As our American Touge 2 battle approaches December 19th we are gearing the car up for its showing. We just finished the alignment on the car and wanted to share our results for those with similar track needs and setups.

First off, we are running the Agency Power Sway Bar Competition Package with JIC strut bars, and JIC FLTA2 coilovers. Our rear control arms have all remained the stock. To get the most handling out of the car for track compeition, this is how we set it up on our car.

The front has -2.3degrees of camber, 7.0degrees of caster, and .09degrees of toe.

The rear has -2.9degrees of camber and .15degrees of toe.

These are on our 19x8 and 19x10 inch wheels.

Red Devil

Very cool car, if you guys would answer a few questions. What width tires are you guys running front to rear?

And how, if at all, has the staggered width affected the car's balance and how the sway bars were adjusted?

I'm really just interested in the finer aspects of suspension tuning and would like to hear your rationale for how you upgraded the vehicle.

thanks

VividRacing.com

Thanks!

We run BFG KDW GForce 2 tires front and rear. We have run these on our EVO VIII and some other cars with great results. Now on the track we might drop to 18" and run R compound, but we might leave it as is.

The front is a 235/35/19 and the rear is a 275/30/19. Staggard is the best for RWD cars. Gives the car more foot on the ground in the rear to help with traction. Sway bars were adjusted according to our driving style. We like a bit more oversteer so we stiffened the rear up alot. The front is set on the mid setting.

EZZY

would you recommend that setup for everyday driving?
with that sort of samber, how long do you think the tyres will last?

thats probably as good as you will get to the factory spec overall diameter.
had the same setup for my 19"

VividRacing.com

Run -1 degree in the front and -.5 degree in the rear. Make sure the Toe is set accordingly as well.

mazdaexe

Thanx vivid, I assume the front toe is out? and the rear toe is in?
I never know much what caster does... a little lecture would be nice. :]

BlueRenesis82

does the car have that much power that you need 2" wider wheels in the back?

TeamRX8

iTrader: (25)

sounds like that came from Van Diesel hisself

florent75

I could yo be more "precise" for the modification on standart rx8 (with 18' wheel)

we should put on the front :
xx degrees of camber
xx degrees of caster
xx degrees of toe

we should put on the front :
xx degrees of camber
xx degrees of caster
xx degrees of toe


thanks a lot

alnielsen

iTrader: (4)

Vivid Racing,
I'm confused. You say"We like a bit more oversteer so we stiffened the rear up alot". And yet you put bigger tires on the rear. Running a staggard configuration would give you more rear traction and make oversteer more difficult. Could you explain?

Red Devil

^^^
Al, I was actually thinking the same thing as far as tire width. Personally, I've never liked the idea of staggered tires, but to each his own and their respected driving style.

tuj

Caster is the angle of the wheel ahead/behind the mounting point. Think of a shopping cart wheel; that's negative caster. If it was flipped around, and the wheel is ahead of the pivot point, thats positive caster.

More positive caster makes the steering heavier, but more responsive. Less caster makes the steering lighter and less twitchy. For performance applications, you generally want the most amount of caster possible, after setting camber.

Caster only applies to wheels that are steered, usually just the front.

ULLLOSE

iTrader: (1)

:D You guys are funny.... Staggard might be the ticket if your car had some power and needed a bigger rear tire.. All you have done is short changed the front end. You should be on 275 all around. Our stock class race cars are on 245s all around, you are smaller front and wider rear on a car that is prone to understeer. I guess when you guys are done with the bling bling show car stuff and hit the track you might find that out.

At 7stock one of the drift teams was telling us that could not get thier car to turn... They ran the same dumb @ss tire stagger you guys are on, no wonder it would not turn.

Maybe one day Mazda will be smart and put a staggered setup on the 8 from the factory... No they wont, they want the car to have some level of performance.

mazdaexe

thanx tuj for the caster explaination. :]
I agree w/ the others about staggered, I personally run 245s all around. and dont like the idea of wider rear. Prefer to keep the car neutral. If you look at bestmotoring videos, hot options etc, most their tuned cars are running the same tire width all around.

Red Devil

What is it that we can run up front - 265 with the fenders rolled and 255 without?

I've been thinking I'd like to upgrade to either at the point when I go with a supercharger, but I want to leave the car neutral like it was from the factory. Until FI arrives, 225's is plenty for me.

tuj

Well, I'm not sure I totally agree with the people who are against staggered setups. The Corvette's and S2000's use it quite effectively. But those cars are set up like that from the factory. Still, the hot combo in 04 for the S2000 was 245F/275R.

But generally speaking, the staggered does promote understeer. There is nothing inherent about a staggered setup that makes it any better or worse than an even setup. Its still all about tuning.

mazdaexe

^^^ I agree w/ tuj on this part. I know many stock FR nowadays run staggered.

In some bestmotoring/hot option episodes, if you look at the amuse S2000, they actually run 255s all around instead of the stock staggered set up. There was another episode of NAs vs turbos. I think all the GTRs were running same all around, not staggered.

Red Devil

My thoughts are simply that if the 8 came with a non-staggered set-up than Mazda tuned the car to be as such. Though perhaps they did so also for ease of rotating tires/tire wear and to make it more owner friendly...in any case, I guess with adjustable sway bars and such a staggered 8 could be made neutral like it was from the factory.

ULLLOSE

iTrader: (1)

I have 265s all around. I have seen 275 front and rear on lowered cars with stock fenders.

mazdaexe

what rims you running ULLLOSE? not stock rite?

BOOSTD 7

How about this, you're right ... I know it, you know it, guys with track experience know it. Instead of bashing them, how about get in touch with them. Let them pay you as a consultant to do their suspension setup. That way the 8 does better at the competition, and everybody is happy

Stagger is just a for looks thing 99% of the time. About the only time you 'need' it is if you're putting down something like 400hp at the wheels. And even then it's just for the street. The only cars running stagger in real racing are 911's, because they're so incredible tail happy and have all the weight back there.

mazdaexe

Based on tuj's explaination on caster, wouldnt that be like changing the wheelbase of the car?

ULLLOSE

iTrader: (1)

Our street tires are Kumho V700 Ecstas, 265-35-18 on stock wheels. For racing we use the Kumho V710, 245-35-18 on 18X8 SSR comps.

ULLLOSE

iTrader: (1)

I can understand where you are coming from. On the other hand as a "vendor" here people are going to listen to them and assume they know what they are talking about. Unfortunately there is no requirement when you start selling parts that you have a clue what they do. .
These guys have a terrible rep all over the Internet, I am starting to see why.
When you make blanket statements like "staggered is best for rwd" without any data points, testing or anything to back it up you open yourself up to ridicule.

tuj

Not if the center of the wheel doesn't change, which it doesn't. The upper ball joint location is moved in relation to the lower join, thus changing the angle of the axis that the wheel pivots on.

Look at this picture here:
http://www.i-club.com/reviews/showpr...hp/product/386

The pair of slots in the center allow the top of the shock to move in towards the engine, increasing negative camber. Once this is set, a pin put into one of the series of holes determines caster. Thus caster should generally be set after camber, as what camber you have affects the max caster value, and camber is more important.

By rotating the wheel around an axis that is not perfectly vertical, we gain negative camber on the outside front wheel when we turn in, which is very nice. BTW: OEM adjustment is usually via eccentric bushings, not sweet plates like the one in that pic.