sixshooter

Why wouldn't you run the 2.5? Any reason?

sixshooter

And after playing with the FCM suspension calculator I think your front roll couple percentage will be low with those spring rates. Even with no rear sway it will likely be a little tail happy. Dropping back to a 400 rear spring rate gets you about right with no rear bar and 375 gets you right if you keep the stock 11mm rear bar.

Hours of tinkering in here: http://www.fatcatmotorsports.com/FRC...MSDS_1_8NB.htm

But if you haven't already used it go through the tutorial first and scroll over the comments section (it says red lettered section but it is wrong). Here is the tutorial :http://www.fatcatmotorsports.com/FRC...S_TUTORIAL.htm

Track

I want to run 2.25" for less weight. not much, but it all counts here and there. I blame Ryan (ThePass).

I think you aren't accounting for the incorrect front sway thickness thats stored in the FCM calculator's testers. the wall thickness is actually 4.78 and not 3.18. otherwise you are totally right.

my FRC is 60.8% without the rear sway, so I am about equivalent of sport package FRC.

what sway bar values are you putting in for 375 rear springs?

sixshooter

I didn't think you were going with the thicker bar for some reason. I think it was the weight comment.

400 springs will be thinner steel than 450 springs and therefore weigh less, haha.

I thought 61% was magic for some reason.

Track

well the hollow RB is always .188" wall thickness, its either 1.125" diameter or 1.25" diameter.

I am going with the 1.125" and .188" wall thickness (.188=4.78mm, not sure why he has 3.14 in there).

I think 61% is a pretty good number to start at. since i have the stock rear sway and an msm, I can drop all the way down to 57.x% in two steps of about ~1.5%

I think I am going to get the ISC stuff, it seems the only reasonable prices they have is on the bilsteins, adjustable sleeves, and springs. plus I can save a bit on those SSS springs over hypercoil.

It would have been nice to stay on 2.25" springs so I could move them over to the Xidas if I decide to go that route in the future. But I think the Bilsteins will be better than the konis.

Dntlift

Are you driving a msm, or normal miata, its late and im too lazy to look it up. only reason I ask is because my car is at 55.9% FRC

What I dont understand is that my car doesnt feel oversteery at all. At CMP Ive got my foot buried in the floor well before the apex, no issues with oversteer whatsoever. I would post more about my setup, but im not really sure if this was a post what youve got thread, or more of a personal thread joe.

Track

Go ahead and post it. This is my first time actually put any thought into a suspension build. so I don't really know what FRC is neutral and what is oversteery. If I switch over to a FM 1" bar, I can drop down to 55%, the setup is great, because I can really change everything depending on what front bar I have. unlike the 700/325 setup where you really reallly need to keep the front and rear that it was designed with.

Shaikh says he doesn't like oversteer, so he tends to stick in 60%+. I like my car neutral, I already get enough oversteer while trail braking (I just need to work on my trail braking more).

but lets see it collin!

sixshooter

Meh, the thread is what you make it, imo. We can have suspension discussions wherever you like.

Back to your FRC, a low FRC will be more likely to be trouble when braking, especially trail braking, because you are unloading the rear suspension. Adding throttle in the corner will put weight back on the rear giving it a stabilizing effect if your FRC is low. I would just be aware of this if you ever need to add brake mid-corner. You might need to countersteer suddenly. 56% isn't really bad or dangerous, though. Stock is ~57-58% iirc.

Track

^depends on the year. 55.5% for the NA6, 58.9% for the NA8, 63% for the NB.

Dntlift

I figured it wouldnt be too much of an issue. At cmp the only excitement I got was a twitch of tailhappyness coming out of three once. I really dont trailbrake too too much to notice issues while doing so. At CMP at least, I get all of my braking done before the turn, except at... turn 4 and 12.

Suspension: (to my knowledge, as bad as that sounds, I dont know if someone changed the front or rear bar, havent measured it to find out.)

KYB AGX with 375lb/in FR and 250 lb/in R
Stock 93 bars (again to my knowledge) so, 19mm front, 12 mm rear
This gives me a 55.9% FRC

alignment: Im not really happy with my alignment, but this is what I have. Reason being is cause there is something wrong, either with the machine I go to and their calibration, or the car itself. The only way we could balance everything left to right was to get a retarded alignment. lol


Camber -3 deg FR -2.5 deg R
Caster I cant remember off the top of my head, but it was somwhere around 3-5 deg (no ps, depowered rack)
Toe factory in so like 1/16 in? in the front
and I believe zero toe in rear. maybe a touch in in the rear.

Managed a 2:08 at cmp though. not too bad considering my newness to track events.