FearNoPiston

iTrader: (17)

this guy on ebay is selling eibachs cheap!

http://cgi.ebay.com/ebaymotors/Mazda...3A1|240%3A1318

silverTRD

iTrader: (37)

so here is another quick question then...would 315's on the back(obviously the back) be too much rear tire for the 500hp level? i dont want to much weight in the back but that is a lot of traction i want to run 17's personally, and 295's are extremely difficult to source.

Type_P10

I was wondering if someone could help me a little here!? I'm going to try howards set up on my FD, but I am having some small problems..

This is what he wrote in the first thread:

Toe in front between a 1/16 and 1/8th inch
Toe in rear zero
Camber front and rear 1.2 degrees negative
Caster equal minimal
Zero rear thrust angle.

In the line marked bold the adjustment is in inches, but I need it in degrees to use the hardware we use to adjust the set up. if someone knows it would really help.
thanks..

habu2

angle = inverse tangent of (toe/2) divided by the tire radius

helghast7

iTrader: (6)

you know it would have been alot quicker to just do the math then write all that down

gracer7-rx7

iTrader: (16)

teach a man to fish and he'll never go hungry....

helghast7

iTrader: (6)

all to true

habu2

If I had simply replied with "0.25 degrees" the inevitable question would have been "how did you come up with that?"

gracer7-rx7

iTrader: (16)

And then someone would come along and tell the alignment people to do .25 toe and really get it wrong.

FWIW, I think 1/16 or 1/8 comes out to .04 or .06 which I think is the value you'd be looking for - depending on the alignment machine or equipment being used. Some alignment guys understand and can do math. Others don't. I've had better results with the ones that can do math.

habu2

for a 25" tall tire & 1/8" toe-in (or out) the leading (or trailing) edge of each tire is 1/16" displaced from "straight".

deviation in degrees would then be the inverse tangent of (1/16)/(25/2) = 2/(16*25) = 1/200 = 0.2865 degrees. (not .04 or .06, not even in radians)

The real question is how you would measure this. For camber and castor you can measure against a vertical reference. What reference do you measure toe against? If your rear wheels can have toe adjusted you can't reference them. What alighnment equipment measures the true fore/aft centerline of the suspension for alignment? That's why you measure the difference in the front and rear of the opposite tires, aka Toe. They are "referenced" to each other.

It's really not all that hard, and you don't need lasers or protractors or trigonometry to do it. You just have to understand the geometry of alignment.

helghast7

iTrader: (6)

having a hunter rack also helps

helghast7

iTrader: (6)

does anybody have a site that sells the tien SS coil overs for a good deal?

helghast7

iTrader: (6)

does anyone know the spring rates for the Apexi N1 EXV Coilovers?

silverTRD

iTrader: (37)

12/10

helghast7

iTrader: (6)

oh ok i wasnt sure...there site didnt list any rates at all...and the n1 circuits said 16 all around

thanks

M104-AMG

iTrader: (8)

Well, my concern has just reared its head with two loose T-nuts:

https://www.rx7club.com/showpost.php...3&postcount=33

If you have a recommendation on how to fix, please post to the link above.

:-( neil

allenhah

iTrader: (4)

Wow - I just spent about 3 hours reading through all the pages of this thread.

1) Not to beat a dead horse, but thank you so much Howard for taking the time to share.

2) Thanks to all those that contributed and shared your own experiences/opinions!

2) I've been going to track events for years now, and although I knew some of the basics of chassis setup, this thread has completely revamped what I know, and I really do feel like I did just take an extremely helpful class. I'm planning on taking some measurements tomorrow to check my starting point, and I'm going to check the shock travel at the next track event I go to, probably in the summer sometime when I have a little more free time.

3) I'm thinking of starting a thread once I get into it detailing the starting point and progress with the chassis setup, which I hope will help others going down this path.

Thanks again...you guys have totally re-energized my passion for driving the FD at the track!

Allen

adam-trd

i am bottoming out my rear shocks, running 450Pound springs on the rear, 25" High as stated, also the tyre is bottoming out on the inside of the guard.

I think my only option at the moment is to get my rear upper arm modified, or get some new custom ones made.

Svelte_7

iTrader: (4)

Master Coleman,

After reading through this thread, I decided to lower my usual starting cold tire pressures from 34/34 to the 30/27 you recommended. WOW - I took 3 seconds off my fastest time at Infineon Raceway and estimate I'm left another 2-3 seconds on the table since the tires weren't screaming nearly as loudly as usual.

I took pyrometer readings for 4 out of 5 sessions and will be doing the analysis shortly. Thank you for sharing your experience and knowledge.

Daniel

gracer7-rx7

iTrader: (16)

You might want to start a separate thread with your issues and state your suspension and wheel tire setup.

From your description I can't tell if you are trying to say your rear shocks are bottoming or that your tire is rubbing something.

Howard Coleman

iTrader: (6)

a picture can produce a thousand words... no i am not going to lay that many on you but...

here is boardmember James Pearson's (wjp005) FD on the way to placing 11th of 60 during a hillclimb event. (only 3 tintops beat him) does that look fun or what.

this picture shows the genius of the FD chassis. the car is rolling 3 degrees or thereabouts and look at the all important outside tires camber. the front tire is just about perfect.

w 2 inches of bump the FD chassis pulls the front tire in at the top about 3 degrees thus maintaining the necessary camber thru body roll.

the rear looks like it needs about a degree or so more negative camber set static.

i recently spec'd the suspension on a Hyundai Genesis Coupe. since it has a strut front suspension (and the front is the most important) it has virtually no camber gain in bump. so if you put it in this picture you would see 3+degrees of body roll and the front outside tire would be positive camber 3+ degrees and the car would be plowing like a John Deer tractor.

love the FD.

really nice car James.

hc

wjp005

iTrader: (3)

Cheers Howard.

Just for people's information, my current suspension setup / brands is:

Shocks: Bilstein (all round)
Springs: Tein (all round)

I run using the standard Mazda swaybars and bushes.

Alignment settings are:

Front:

Toe: -0.3mm each side (Total toe = -0.6mm)
Camber: -1.5deg (L&R)
Caster: +5.5deg (L&R)
King Pin Angle: +15.2deg (L&R)
Included Angle: +14deg

Rear:

Toe: +0.5mm each side (Total toe = +1.0mm)
Camber: -0.5deg (L&R)

I find that with these settings on full slicks at the right pressures, the car is nice and neutral and turns in well without much oversteer at high speed.

Cheers!

matty

howard is recommending -1.2 camber however if i am using a 17 inch rim should i reduce the camber? pettit offers 3 different recommendations based on rim size and i am just not sure if howards settings are for the 16 inch rim alone???

helghast7

iTrader: (6)

i think there for his rims, which i believe are 18's

aoc007

iTrader: (5)

what should be my alignment with 12/10kg coilovers and 265 / 18in bfg-r1 slicks all around?