RX8Maine

The slight aignment change more than compensated for the extra 200lb? Wow. Sensitive alignment!!

Matt RX8

Anyone have some street/track alignment for people running on the stock suspension and street tires? I'm running zaneis (245/40R18s) on stock sized rims and stock suspension.

4D-Sport

Our experience is pretty consistent with others:

http://www.4d-sport.com/images/432_S..._Alignment.jpg

The current wheel and tire combo is, likely, different than most (couldn't pass up a deal on 710 take offs from an ASP RX-7):

http://www.4d-sport.com/projectcars/rx8resources.html

Thanks to many of the RX8Club peeps, we're quite pleased with the results.

Barry

PS. Anyone getting a 285 to fit their 8" wheels?

Matt RX8

Is that an autocross or track alignment in your specs?

4D-Sport

Autocross, track and street.

Thought I'd need some additional rear toe in for stability on the track but it behaved quite well. The tire temperatures looked near perfect on left front and right rear but not the cross We attributed the disparity to the track and the way I was driving it. Will have to take some tire temps at an autocross too (scheduled 13-SEP-2006).

Barry

takahashi

Do you find understeer with the front camber less than the rear.

I still wear out the shoulder of my R spec tyres (and they are just 245s). I am on Tein Flex on the firmest damper setting...

I have -2.15 front and -1.75 rear, but I need more I guess. I max them out but thinking that I will have massive understeer on braking if I max the rear more than front. Currently I have slightly oversteer on trail braking and helping with my turn in. ... well I will try again. Maybe I should be sitting down the car while aligning it?

4D-Sport

The used 285/30x18 V710s I bought off a SCCA Championship A-Street Prepared RX-7 (http://www.sfrscca.org/solo2/Results...nship/asp.html) were worn on the outside shoulder too. I flipped them to even the wear and maximize their life... so far, so good.

Yes, you'd think the greater rear camber would contribute to understeer but that's not been my experience, even with the Tokico D-Spec dampers equally set all around. Perhaps it's the front toe out that keeps the car in balance, perhaps my driving style. I've driven front wheel drive cars in competition successfully in the past, so perhaps understeer is something I've learned to overlook.

takahashi

Yes, I am relieved. I thought my spring is not strong enough.

I am using Bridgestone's RE55S. Unfortunately they are directional tyres, so I wonder the outside and inside can be use successfully . Anyhow, the set of tyre last me 4 track days plus and about 150 hot laps.

Will adjust and report back.

rotorpr

4D-Sport

This is my first year in road racing and back in May I bought four Enkei RP-02 with Azenis 615 225-45-18. I drop my lap by 2.5 seconds (before I have the stock wheels with Dunlops). I race like once a month and I am stock in 1.37 min since that time. I have not touch the cambers. The only modification I have in the suspension is the racing beat sway bars. Do you think your camber settings would work for me?. Attach the layout of the track. Any help would be appreciated.

4D-Sport

My 8 is multi-purpose and, therefore, it's performance somewhat compromised; hopefully oriented to be reasonably competitive in an autocross setting, stable on the variety of race courses we run (Buttonwillow, Laguna Seca and Thunderhill) and acceptable on the street (commuter). I also use RP-02s and RT-615s (245/40x18) on the street and the setup, while it tracks uneven pavement (ruts in the highway), is acceptable.

Your track looks like a lot of fun and, more technical than Thunderhill (where we tested the new alignment).

http://www.4d-sport.com/images/CDS_THccw.pdf (26 page Thunderhill track analysis)

Here's a 10 meg video of a couple laps before the recent alignment, shock and tire changes (following a reasonably conservative driver): http://www.4d-sport.com/images/thunder_Mark.wmv I was on OEM wheels and Dunlop Sport 8000 Race tires (235/40/18) with a factory miss-alignment .

I'll be adding video of chasing the Z06 as soon as I resolve a software issue. I don't have a lap timer but I'm guessing I was significantly faster chasing the Z06 than the 997. That's, in part, because the better grip of the tires but primarily because the Vette driver is much more aggressive than the Porsche's. Reviewing the video, we knocked off 3/4 of a second each successive lap (according to the video player's clock).

Good luck RotorPR!

Barry - http://www.4d-sport.com/images/06_Ro...Event_v1.7.pdf

Speedtoys

Cant wait to see it.

To whup a stock C5/Z06 around the full Thill using the lower bypass to T5, you'll need to find about a 1:58-1:59 when everything's clicking just perfectly, even on OEM Supercar T1 rubber.. Up to about a 2:03 with traffic or old stock tires. Those are the best times ive ever gotten out of mine.

Id expect a C6/Z06 to find another 2-3 seconds top, in OEM form.

Speedtoys

The video you did post looks ok.

If I had to say one thing..its find the edges of your car and the edges of the track.


You're giving up what WILL turn into many many many seconds of lap time in not using all of the track. Youre just not going fast enough in that video to notice that its a problem. But in another 5mph or so, it will be a huge problem for you, and you probly have another 10mph of speed available to you at most areas of the track that you could have used in catching that porsche [easier] than it already was.

"But I wasnt going that fast, so I didnt use all the track..."

No excuse, every lap needs to be a perfect lap..gotta train the subconscious mind to drive the -line- without even thinking about it. Yellow, pace, race, cooldown laps should be conscious efforts to be more perfect than the last lap unless youre doing those kinda days, where you buy 2-3 sets of shot tires, and burn them up learning off-line bad things to perfect alternate corner lines and passes one corner at a time. Its a great way to burn up 3-5 sets of tires in a weekend..but its all useful.

mwood

So...I've just read 6 pages of a sticky on alignment settings...and have really found zero agreement or even a general consensus (front vs. rear camber differential, in particular) for an autocross application? I guess I'm not reading carefully enough...

Speedtoys

At this point..ask yourself if YOU can be any better at autox.

Find someone who's a real hotshoe to take your car out, if he does better, alignment only gets the car better, not you.

mwood

good advice...but, do YOU know anything about my autocross experience?

Also, I would suggest that, without a proper alignment, all that can be learned will be compensatory bad habits.

BTW, what is YOUR experience with autocross? I'm in NorCal and don't believe we've met...

Sparky

Abolutely correct, no agreement on setups yet. It's only been 2 years after all.

Max out the front camber and add some front toe, but after that you'll find many different setups running similar times. Of course, Jason's way out in front but we'll never know if it's just Jason, or the car, since no one else to my knowledge has ever driven it.

Fundementally, the car is traction limited in front, so you have excess in the rear and can choose what you want to do with that to suit your driving style and the courses you run.

Approach #1, max camber on the rear, maximum (or as near as you can stand it) rebound in the rear shocks. This setup maximizes responsiveness in the car and can be very fast on higher speed courses if you're a very good driver and can keep from getting the rear upset on turn-in. It's what Jason runs (or atleast used to run) which obviously is a good setup. Biggest problem I had with this was wheelspin on turn exit in lower speed corners.

Approach #2, minimum camber on the rear and a much lower rear shock rebound setting. Makes for a car that is ulta-forgiving to late or agressive inputs and virtually eliminates wheelspin on exit.

Approach #3, somewhere in the middle.

One limiting factor that you might not have with the car is that most of us run off-the-shelf koni sports which you can't adjust in the rear between runs. Have to remove the rear shocks from the car for rebound adjustment. So we set up the car so that we can adjust other things besides the rear shocks. We can adjust the front shocks, so I try to set up the car with plenty of adjustment both ways there. Secondly is rear toe. The car is relatively insensitive to rear toe settings but you can make changes with relatively large adjustments. I've been as far as +-1/4 per side in rear in order to cure a missed setup on some courses.

Finally, front swaybars. This cars strength is sweepers, a big swaybar kills that so most people either run the stock swaybar or a Mazdaspeed which is about 15% stiffer than stock. The car does lack some stability in slaloms with these bars, but I've found that the rear suspension really does a good job of holding on at high slip angles and won't go around on you like on other cars.

That's about it. It's great the you and Jim and Carter are coming over and can hopefully try some new things to continue to advance the developement of the car.

ULLLOSE

iTrader: (1)

Actually Gary Thomason, Jason Munchhof and Brian Coulson have all driven it. While Jason's RX8 is set up a lot like mine, I installed his shocks, I don't think Brian rushed out to change his setup after driving it. My setup is a little on the tight side on entry and will one leg on exit if the surface has a lot of grip, the other draw back is slow 60' times at Prosolos but I like how it feels everywhere else.

mwood

Thanks for the feedback Sparky, that's a lot of good information.
But, please don't put me in the same category as Jim and Carter, either in terms of set up or driving skills!! I'm working on it, though

Jason, what did GT think of the RX8? Did you kick his axx?

ULLLOSE

iTrader: (1)

It was like a year ago, I can't remember his comment about how the car felt but I seem to recall him thinking the 968 was still a better car. He only took two runs and one was with me in the car, so even though I did beat him I would not consider that an @ss kicking.

ULLLOSE

iTrader: (1)

Something for everyone to keep in mind comparing alignment numbers is like comparing dyno numbers, not all racks are the same. If the tech has dropped a head, or the rack has not been calibrated recently the numbers can be way off. Also hand held do it your self camber units are going to read different than a full rack. Unless you go to the same shop and use the same rack as the next guy you need to take those numbers with a grain of salt. There are also some clowns out there that only know how to read the screen and do what it tells them, a good tech is the most important part of the alignment.

mwood

Good point(s).

But, regardless as to the actual numbers, the proportional relationship between front and rear measures should be a constant, for a given handling expectation...I would think.

Sparky

Buy a good camber gage and learn how to do it yourself. Then do it the same way everytime. I'm very reluctant to talk absolute numbers because truthfully I don't know what they are, or care. But I can get consistent repeatable results and that's all that counts.

mwood

Agreed. And, marking the eccentrics for your baseline set up makes sense.

I got off on this tangent when I started "polling" various friends who have autocrossed the RX8 with success at a National level and discovered a pretty wide variance in alignment. If you did the same thing with the Z06 guys, you'd find that the only thing that really varies much is the ride height/rake (within a pretty small range)...camber and toe are pretty much the same on all the top cars.

Sparky

Agreed, when you compare the upper/lower control arm ratio's front to rear it tells you that you get more camber gain in the rear than the front. However, the roll center is also much higher in the rear so you need more to get the same contact patch. For me, I get neutral skidpad handling with an even camber stagger front to rear, telling me that Mazda knew what they were doing when they designed the car.

One thing that is different from car to car is the max front camber that is attainable. We get reports of every thing from -0.9 to -1.6, but the car should be neutral if you match the rear to whatever you get in front. Now that's not necessarily what you want for autox as steady state push is often desirable, but utilizing a known front/rear camber stagger should yield consistent results across cars.

ULLLOSE

iTrader: (1)

One might think it is that easy but shocks, swaybar and tires will also have an effect on how the car works. You got to put the whole package together.