legatia

Ok guys, so ive been doing alot of reading on the subject lately but i cant really figure out how to go about this.

Ive got a FD, and it will be street driven but built to go fast around tracks. Nurburgring is my goal.

Ive just ordered a feed widebody kit from auto-shine. Its building 25mm both front and rear fenders.

First i thought of cramming some really big wheels in the rear and whatever i could fit in the front. But might it be necessary use the same tire with both front and rear in order to keep it from understeering?

Has anyone done big wheel fitments with this bodykit? How big wheels could i stuff under there? I dont mind doing bodywork to make it fit. As far as tires go, are toyo r88 the right way to go about it? They need to be streetable. Ive looked into some BF Goodrich ones aswell, but i havent found much feedback on them. They look quite sharp.

I need some solid advice as far as wheels go aswell, ive been looking into ccw custom wheels but if there are other possibilities that are lighter and that might fit my fd id really appreciate the input.

Suspension - Ive got mazdaspeed coilovers from the previous owner. My research tells me they are 12kg front and 10kg rear. And after looking at howards posts in here thats just too much. Is there anywhere to buy coilover springs with different rates? Howard says 8kg front and 6kg rear, but Ive also read someone stating that bigger wheels might need stiffer springs, i.e. 10kg and 8kg. Is there any truth too that? Or might i just aswel go with brand new coiolvers? The ones i have only got 4 settings on damper stiffness.

anees

iTrader: (6)

I am running 235 front 255 rear
17 inch MS 01 rims
Coilovers 10 k front 8 k rear
Perfect combo for street as well as some track use
However the ride mite get a lil harsh on potholes n other obstacles
But in germany you should be good with this kinda of setup

zman600

iTrader: (5)

^could you be a little more specific please. wheel width, offset, actually tire size.
are you running the same body kit?
op said something about stuffing BIG wheels in there. 255 seams small for a widebody kit.

p.s. - i have the feed fenders also but have yet to buy rims

legatia

I was leaning towards 18x11 315 rear and 18x10 285 front. But Im not so sure that the different tire size is good for track use. So i was hoping someone could chime in on this.

I need big as possible really. So if I can somehow fit 315 front thats what Im doing.

HadaVette

iTrader: (3)

The understeer / oversteer balance is more than just tire sizes. It is a balance between tires, springs, sway bars, alignment, etc. Shocks effect the balance (there's that word again) on transitions as well.

I'm running 255-17 in the front, and 275-17 in the rear (with a stock body), and it feels nicley balanced to me at the autocross. Balance for a high speed track, such as the Ring, will be different: you'll want to favor stability (more understeer / less oversteer) more that quick transitions.

Start with the wheels and tire sizes you want, then tune the suspension to match!

gracer7-rx7

iTrader: (16)

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gracer7-rx7

iTrader: (16)

Agreed.

I run 255/40/17 on 17x9 wheels with a +45 offset. That is well known to be a good "square" setup where front and rear tires are the same size and it fits w/o rubbing the body work. I have ~300 rwhp at 10 PSI and that is enough to fit my needs as a dual purpose street and track day car. I run 450lb front springs and 350lb rear springs on a Ground Control coil over setup over Koni adjustable shocks. It is a good compromise setup for a car that sees lots of street usage on various road surfaces (crappy to good).

If you stick with that kind of rate split % and the same size tire front/rear, you should be able to adjust attitude with sway bars.

The 12k/10k might be a bit much for a car that sees both street and track usage on varying road surfaces. Especially in the wet. Also, if you are not an experienced track driver, the high rate will make it more difficult to feel when you run out of traction and will offer less ride comfort on the street.

I wonder if you can get some generic 2.5" diameter racing springs (such as Eibach) in the same length to replace what is in your existing coilovers. 8k/6k works so does 10k/8k for a more aggressive setup w/ less street comfort. Depends what your goals are.


Personally, I like to match spring rate with the type of tire I am running. A sticky tire like the Toyo R888 can take advantage of 500-550lb front springs with the appropriately matching rear spring rate (400-450ish). When you use soft spring rates with sticky tires, you wind up getting more body movement than you may like. The car will dive a lot under hard, at the limit braking on track and roll more b/c the tires offer more traction. If you run a less track oriented tire / more dual duty street/track tire like the Dunlop Star Spec or Bridgestone RE11 or perhaps some of the high end Michelins, it may be better paired with the softer 450 lb / ~8k or 9k front spring.


If you haven't already, Read the sticky in this forum that howard coleman wrote on his thoughts about the FD suspension. That really is the single best thread for you to learn about your possible options as there are tons of opinions in there.



On a side note.
You really don't need the Shine wide kit as 285/30/18 can fit under rolled fenders on the proper offset wheels (18" x 10" +50 I think). With the wide body kit, you will want to take some measurements to see what offset will visually fit the wider wheel wells better. The kit may work better with different offsets front and rear so you can put a 285 on the rear and use a 265 up front. Depending on your skill and power levels a 285 up front may not be worthwhile enough for the extra weight that comes along with it.

Stay away from the poser-ish, idiotic "hella flush" / aggressive fitments unless you want to rub body work and fenders on track. I think you know this already.

legatia

Indeed the balance of the car consists of many parameters. And there are many ways to skin a cat. But it starts on the wheels. Anything from there can be modified - but i dont want to change wheels after i pay $$$$ for whatever wheelsetup i find suitable.

I think I'll just have to wait till my widebody arrives and then start measuring what i can fit in there. I might go a little bigger in the rear anyhow, but try to stay within reason.

It actually looks like the springs on my coilovers might not be the "stock" ones. The coilovers are mazdaspeed as stated, but the springs are eibach. Dont know what the rates are though. I think 10kg front and 8kg rear would be good for me, as Im going to fit semi slicks on there. Its not excactly going to be my daily driver anyway.

I got pretty much your power leves atm. 290whp, so for now the big wheels might not be ideal, but within next summer its going to be somewhere around 500whp.
Im not going for a "hella flush" poser look. In fact, the posers are most likely going to enjoy the view of my tail lights.

And yes, I already read howards writeup on this - and its fantastic.

gracer7-rx7

iTrader: (16)

Yep, you are taking a good approach. I'd be tempted to leave the 12/10 for semi slick tires and try them before making changes.

You may want to consider finding a good local wheel source that will work with you on fitting some wheels once the shine parts are installed.

I look forward to seeing your progress.