I'm currently dropped on eibach sportlines and been scraping lately with my recently added chargespeed bumper and sideskirts. My tire setup is 245/35/19 and 275/35/19 and wheels are 19x8.5 +10 and 19x9.5 +15. If i run bigger tires such as 255 fr and 285 r, will it raise the car? and if it does, by how much and is it a good idea? Or should I just buy coilovers? I really like my sportlines setup and the drop but I just need to raise it a tad bit to avoid the bumpers i go through everyday. I need some suggestions
Thanks.

 

you can compare tire sizes here:

http://www.miata.net/garage/tirecalc.html

 

275(tire width)/35(thickens)/19(u show know that)
so increase the thickness of the tire will raise ur car but the issue is ur tire will rube ur fender so get em rolled.
good luck

 

275 to 285 mm will increase rear axle ground clearance by half of overall height or 3.5 mm.

 

First of all,the Z stock sits pretty low if the front for everyday driving.I cannot believe the number of guys add spoilers/skirts etc,and do coil overs and then start complaining.
Setting your Z up to be a show car is one thing.Being an everyday driver is another.
The current wheel/tire setup you have is good.I run similar sizes on my Z.Going to the larger tire sizes you mentioned will not work.Your tire diameters will be out of wack.Also,
more than likely be rubbing the wheel wells.Even if you rolled out the fenders,the rolling
diameters will screw up your traction control...get slip messages.
Bottom line,got to plan all the steps before you do these mods.My Z 19's,245/275...
similar offset to yours.Only body mod is a Mine's front lip...and its about 4" from the ground at the sides.
Your car must look good ,but nothing looks worse than scrapped/cracked
lower body parts.

 

The simple answer is "only if the OD of the tires is larger will it raise the car. if the OD is smaller, then it lowers the car.".

Use one fo the calculators referenced above to calculate the OD of your new tires vs the old ones to tell for sure.

 

TCS is based on a %; not the size of the tire. Perhaps he's one of the lucky ones with a base model and he doesn't have to worry about things like that.

I beg to differ; I'm proud that my car is missing most of the paint from the underside of the front bumper cover. It's also why I will never use fiberglass/cf parts on my front lip. I don't like cars that are too pretty; means that they're most likely not driven how they should be

As for OP, I don't think you're going to notice a 3.5mm difference, though I could be entirely wrong; depends on how hard you're scraping. Why not just change the sidewall height? That will make a much larger difference.

 

you should just get coilovers. If you get bigger (as in higher profile with a taller sidewall) you will just run into other problems such as

1. VDC being thrown off due to incorrect sizing
2. really fat tires making your car look like a SUV
3. fatter tires hitting your fenders

 

Or the tires the OP mentioned are VDC/TCS/ABS compliant, not really fat and SUV like and if the extra 5mm causes a rub its only a slight roll away.

3.5mm is not worth buying new tires, wait till they wear out.

 

IMO your tires are pretty maxed out for the wheels sizes you provided, A 285 on a 9" wheel gunna look a monster truck status. Stick with your current tire setup, get new WIDER wheels if you want wider tires. I dont really know the reason you want wider tires, but that plays part in you goals too. If your just driving your car around, leave it the way it is. besides 275 tires is plenty tire for the whopping 280hp we have... You'll probrably lose a little acceleration doing that too.

 

I run 285s up front and 315s in the rear...no one has told me that my tires look like they're off an SUV yet, though I suppose anything is possible.

I agree with you on the 285 being too wide for a 9" rim, but it depends on the manufacturer's specs. I haven't seen a 9" rim recommended for a 285 yet, but it's possible.

Also, WTB your horsepower secrets to having 280hp stock

 

I think you're confused on how tire sizes work. Let's start with sizing, then I can try to answer your questions.

Let's say you have a 245/35R19 tire. The 1st part of the size is tire width in millimeters (245mm), the 2nd part is sidewall height, shown as a percentage of the 1st number, (35% of 245mm). The 'R' designates it as a Radial tire. Some people use a "/" instead of an R, and as far as sizing, it doesn't matter what you use. The last part, the 19, is the inner diameter. This is of course the size wheel it will fit.

Now, you could go to a 255/35/19 in the front, and it would be about 1/4" taller. Not worth it imo. Going to a 245/40/19 would get you almost an inch, but still not worth it imo.

My suggestion would be coilovers. With coilovers, you can achieve the same drop you've got with your Sportlines, but stiffen them up to avoid scraping.

 

I agree with VividRacing. Buy coilovers with height and damping adjustability. The combination of raising the car just a bit along with setting the dampers stiffer should help to keep your nose a little more off the ground than it is now.