alnielsen

iTrader: (4)

Alignments for the track will change depending on what tires you put on. Grip level and sidewall flex, even different tracks will change the requirements for camber. This is best found by taking temperature readings across the face of the tread surface.

dannobre

iTrader: (3)

I only see 1 opinion in this post

Highway8

iTrader: (11)

I have finaly bought a DIY alignemnt kit and a real tire pyrometer, now I need to start playing with my alignment settings.

BTW, if anyone is looking for a IR pyrometer with tire probe, Joes Racing makes a very affordable dual unit. http://www.soloperformance.com/Joes-...it_p_2038.html $149 minus $25 through dec 31st 2010 if you use coupon code "nopistons" and you wont find better service then SPS.

REDRX3RX8

Well, yeah, I checked temps when I was running Kumho SPT's with about -.5 camber up front, 40psi, and the temps were 139 inside, 149 middle, and 144 outside. After I aligned to -1.6 up front, I got 149 inside, 144 middle, and 139 outside. I think that means that the alignment works better, and can even use a stickier tire like the Hankook V12's that I'm running now.

I've improved my handling with only an alignment, new tires, and shortened sway bar endlinks. I don't think I'll need any stiffer springs or sway bars for a while.

The best air gauge I found is a dial type for $4 at a grocery store, and it's very consistant, and accurate. Even if it wasn't accurate, it would be consistent for me to find the pressures I like if I only use it.

Nitrogen for tires is theoretical nonsense. You might save 1 psi over normal air over a 6 month storage. You can't fill and check that accurately.

Spin9k

How stuff works......and I quote...

"Many race car teams use nitrogen instead of air in their tires because nitrogen has a much more consistent rate of expansion and contraction compared to the usual air. Often, a half pound of pressure will radically affect traction and handling. With track and tire temperatures varying over the duration of a race, the consistency of nitrogen is needed.

Nitrogen pressure is more consistent than normal air pressure, because air typically contains varying amounts of moisture due to changes in the relative humidity on race day. Water causes air to be inconsistent in its rate of expansion and contraction. So, a humid race in the southeast United States or a dry race in the desert western United States could make for unpredictable tire pressures if "dry" nitrogen were not used. "

...storage reasons is what they tell Joe motorist at BJs.

Spin9k

Interesting....my race alignment shop uses a muti-$1000 alignment machine with gismos mounted on all 4 wheels at once...wirelessly feed into a computer, with a guy under the car while on a lift, carefully adjusting the various suspension bits that all interplay as adjustments are done to get just what I request.

Good to see it can be done DIY style with a string and a thermometer while sitting in my driveway...

Highway8

iTrader: (11)

HAHA not exactly. The thermometer is just for checking temps at the track. The kit I have includes a camber/caster gauge and tire plates to check toe. http://www.soloperformance.com/Quick...it_p_1172.html If you have 18" wheels (most of us do) be sure to get the magnetic adaptor. The dunlop adaptor only fits up to 17" wheels.

For anyone checking tire temps, be sure to use a tire prob and not just a IR pyrometer. I added a discount code ($25 off) for the dual unit I mentioned above.

Spin9k

^ cool... but yea my old back is just to tired to get down and dirty with cranking on my alignment...besides it's low enough I can barely get a jack under it, no less me.

Highway8

iTrader: (11)

I use blocks to drive up on when I adjust the alignement. I have a 1" drop and MS Body kit, so it sits about 4" off the ground.

Doing your own alignment isn't for everyone, but if you want to find every last bit of grip, you will need to make adjustments based on the track, track conditions and tires. Using the tire pyrometer is another great tool to help confirm the alignment is dialed in.

REDRX3RX8

Yeah, my bad. Nitrogen is OVERKILL for me. Nothing is overkill for racing, but even some types of racing send tires out underinflated, and depend on scrubing to raise pressure unless maybe F1 where they heat the tires. Many teams have stacks of tires with different air pressure readings to go on the next pit stop.

Once I run at the track, I have to compare traction and psi with hot temps that seem consistent to me. Does anyone here top off with nitrogen at the track?

The only decent air compressor I can find is the one that came with my 8, and I know what psi I'm running with.

Highway8

iTrader: (11)

My local tire shop charges $10 per tire for nitrogen but you only pay once. They will top it off or purge and refill if needed. On my last set of tires I went with nitrogen and I had them topped off before every track day. I hardly ever need to add air as the day goes on, if I do it's only a little.

I'm no longer running nitrogen, I will casualy compare the difference.

fastlaneracing

Yes, its correct.

If I where to post my alignments I have tested you guys will propably think im crazy. =)

04Green

iTrader: (1)

Post, Post, Post..

Really, as people move through fixing stuff, you get to alignments. anything that worked is a good starting point. Please share. I will have something to post next week. This weekend will determine if it is in the "try this" category or in the "never again" category.

fastlaneracing

Im testing new setups almost every race as I am only in my second season with the RX-8, really I dont remeber exactly my last... I need to look if I can find it writen down somewhere. if not its in my little black racebook in the car.

About race book, its a great thing to have in the car to write down stuff on your mind during racing, observations, settings, tire temps & pressure etc etc... great thing thats recommended.

EDIT: Found it but its in swedish. see if its possible to understand otherwise I need to translate it.

Setupen för helgen var:
Ca 1cm lägre runt om (mot innan).
FL: 357kg FR: 355kg RL: 329,5kg RR: 326kg
Left 50,2% Right 49,8% Rear 47,9% cross 50,1%
Caster fram 9 grader, Camber fram ~2,5 grader, Camber bak ~3,5 grader, Toe out fram 1,5mm Toe in bak 1,5mm
Dämparna är satta i läge 6 fram och läge 16 bak.
Krängningshämmare satta på mjukaste läget både bak och fram.

Loggs:
Logg 1:

Blandad förbrukning ??L/100km Råkade radera det i denna logg =(
Blandad förbrukning 27,5l/h
ECT Min: 63grader medel: 92,86grader max: 98grader
IAT min: 16grader medel: 16,90grader max: 20grader
fart min: 54km/h medel: 105km/h max: 165km/h
rpm min: 1173rpm medel: 5819rpm max: 8643rpm
MAF g/s min: 6,21 medel: 92,88 max: 224,95
Acceleration G Max 0,92g
Deacceleration G Max -1,86g

Logg 2:

Blandad förbrukning 17,3L/100km
Blandad förbrukning 26,8l/h
ECT Min: 79grader medel: 95,9grader max: 101grader
IAT min: 15grader medel: 16,11grader max: 28grader
fart min: 50km/h medel: 110,9km/h max: 165km/h
rpm min: 1254rpm medel: 6194rpm max: 8741rpm
MAF g/s min: 6,21 medel: 112,86 max: 229,91
Acceleration G Max 0,42g
Deacceleration G Max -1,415g

Logg 3:

Blandad förbrukning 34,9L/100km
Blandad förbrukning 30,5l/h
ECT Min: 96grader medel: 99,14grader max: 102grader
IAT min: 15grader medel: 16,96grader max: 32grader
fart min: 55km/h medel: 109km/h max: 167km/h
rpm min: 3188rpm medel: 6095rpm max: 8857rpm
MAF g/s min: 6,83 medel: 101,8 max: 227,15
Acceleration G Max 0,66g
Deacceleration G Max -2,583g


Comments (these where written in english):
"Me too, I found a quite good setup this time. hawk DTC60 is the ****. almost too good (not kidding, be carefull they are not as Carbotech. Too mutch and you can spinn out.) my last tune did wonders there was good power in the top.

Now my weak points is springs and dampers, KW V3 don't cut it anymore too soft! and grip, I need to test out atleast 255, im sliding out of corners to easy."

"Actually I loved how my car handled with front and rear grip relationship. No understeer what so ever, Little oversteer but not that mutch. I was going with four wheel slides in almost all corners and I could get more oversteer by the gaspedal input. It was incredible fun! So I don't want to mess that up I only need more grip all around (higher level of total grip).

Im not saying I had bad grip here it just that I have come to the point where I need to get the car to next level.

im afraid I need to look into something else then "on the shelf" coilovers, KW V3 springs are quite stiff compared to the competitions coilovers but still to soft."

Videos:
http://vimeo.com/14710996 <--First out me, next heat is Instructor (Also Miata Cup driver) Henrik Phil testing my car.
http://vimeo.com/14713740 <--Instructor (also driver in Endurance Racing Cup) Matz Olli tests my car.

I do of course write down/record more but im at work so this what I can post up easy.

alnielsen

iTrader: (4)

Many teams use nitrogen in their tires because they use it to run their air tools. The nitrogen in the cylinders is compressed at a very high pressure and last quite a while. The low moisture and larger molecule size is a additional benefit.

Highway8

iTrader: (11)

Custom spring rates and and revalving might be a good option.

fastlaneracing

Yepp thats a possibility =)

But I do really fancy Öhlin dampers, but my wallet don't =(

04Green

iTrader: (1)

Track Data:

2004 RX-8 MT
Tein H-Tech Springs, D-Spec Shocks (set on 2), Stock Sway Bars
Hankook V-12 Tires
Freaking Cold, lower 30’s to upper 60’s
Camber: -1.8 in Front, -1.3 in Rear (that is the most the front will take, rear can go another degree)
Roebling Road Raceway, November 2010

Observations:
1. When they say do not use Summer Performance Tires at near freezing, they freaking mean it.
2. See Observation 1, car also makes more power in the cold than at 80 degrees in FL. First run will not be spoken of again.
3. Car was best with a 4 psi stagger front to back, higher in front.
4. Best runs were with hot pressures, after cool down lap, of 44 front, 40 rear. Wear was just above the tip of the little triangle on the sidewall front and back.
5. Temps were even across left side, progressive across right (hot inside, cooler outside), that is just this track.
6. If you listen, V-12 will tell you when sliding, even with full face helmet. They just do not howl like old tires did.
7. These were relatively new tires, with full tread. Got tread squirm in several places. Odd until I figured out what it was.
8. Swapping front to rear on left side after one track day was a good idea. Gave the right front a break and helped with tire wear.

If I had it to do over, and the plan for next time:
1. More negative camber in the rear. Maybe as much as -2.0. I learned I can adjust under/over steer with rear air pressure fairly easily (+2 psi is a big difference).
2. Front and rear sway bars, lots of research to do here.
3. Apex even earlier (thanks TrackAddict)

REDRX3RX8

04Green,

Hey great, you beat me to the full Hankook V12 review.

I was cleaning my wheels up, so I put in 36 psi all around on a 70 deg afternoon, per our discussion.

So when I turned left kinda quick, the traction control went nuts, and the tires felt too firm even before warmed up.

I lowered to 35 psi all around, and will test next weekend at H2R San Marcos.

Last month at MSR Cresson, I had the fronts at 36 psi about the same ambient temp, and it heated up to 42 psi, so I seem close to yours, and I can reduce rear if needed after first run. With my rear bar working, I don't think I'll need to run more than 2 psi more in fronts: 35f cold - 33r cold.

Yeah, you know after my last track day, I was thinking those apex cones are a little too late apex. I'm thinking to just aim for earlier apex myself.

Good info on your track day!

REDRX3RX8

Just had a track day at H2R with my new Hankook Ventus V12's and the pressures were too low at 39 front 37 rear medium warm after run.

04Green is right! 44psi front hot and 40psi rear hot is perfect for this tire.

For street, I think I'll run 38 psi front and 35 psi rear cold.

REDRX3RX8

Ok, so we discussed about other people recommending .5 deg less camber on the rear, but you got it there, and don't like it. Right?

I agree with hot pressure of 44 front and 40 rear, but with the -1.6 f and -1.9 rear, it still feels like too much understeer.

Is the -1.3 rear giving too much over steer, so you need more neg camber in back?

04Green

iTrader: (1)

Good question..

The plan is to get to where I can add a little more power without oversteer. There are a few corners I have to tiptoe out of. My thought is to get a little more rear grip, and if I have screwed it up, add 2 psi to the rear tires to make it go away. Towards the end of my last weekend, I was wishing that the rear would be a little more planted, not much, but a little, especially coming out of corners with power on.

If I remember the discussion, we were talking about people who actually knew how to drive running that setup, as opposed to me . I am kind of progressing through this, trying to change one thing at a time. Added to the mix will be the set of sway bars the Mrs. 04Green is looking at as a Christmas present. All in all, I think having the extra rear grip, now that I know how easy it is to adjust away with air pressure, is not a bad thing for my current skill level.

A deeper question is if I want the car to break to understeer or oversteer or keep it pretty neutral. The current set of line suggestions is to try to grow to the point where I am rolling through the corners coupled with a little bit earlier apex. The approach above will let me try a little more rear grip, and if it does not go well, I can add a little air pressure to make it go away.

A lot could also change between now and the next event. I want to wait until it warms up a bit. I also want to read over the Trackaddict and Eric Meyer threads again as well.

REDRX3RX8

I notice OD was trying all kinds of camber settings, but lately he said he's at -1.5 front and back, and that's about as good as he can get.

My front -1.6 was all the guy could get with the caster left alone, but I think I'll go for -1.5 in the rear in stead of the -1.9.

I've got traction in the rear at full throttle coming out of turns, close to neutral, but I don't have much traction starting up and turning at slow speed on the street.

REDRX3RX8

04Green,

Don't you have a 07 6spd auto like I do?

How many miles, and have you had any trouble.

I bought mine "new" with 650 miles on it, and about 2 wks into it, it was slipping one morning driving gently to warm up for a good sunday run.

So I tiptoe back gently, park, and it works fine to drive to dealer for a check.

I seemed to be 2 quarts over, which they drained from the special overflow check fill under car (no dipstick you know).

My tranny has 22k miles on it, and it imploded last weekend.

It's gonna be fixed under warranty, but I just now figured out what might have happened.

The torque converter quit pumping up at 2k miles, so when they checked fluid, it was 2 quarts over.

So for 20k more miles and 3 1/2 years somehow the tranny was seeming ok, but running 2 quarts low some of the time. Anyway, defective.

04Green

iTrader: (1)

Ouch,

Love that warranty thing.

I have an 04, Nordic Green, 6 speed. It is a 2003, September I think, build.