Roadster & RX7

After numerous searches, I cannot find a straight answer on offset for 18x8 and 18x9 wheels for an FC.

So now I am asking, what offset would one run for the following:

Stock suspension (Unmodified fenders):
Front 18x8 w/ 225/40/18 tires Offset?
Rear 18x9 w/ 255/40/18 tires Offset?

Lowered (KR2D Coilover set, lowered to flush wheel with top of fender)(Unmodified fenders):
Front 18x8 w/ 225/40/18 tires Offset?
Rear 18x9 w/ 255/40/18 tires Offset?

Thank you,
Stephen

ARD T2

iTrader: (22)

I got your back. lol.

I believe these will work.

Tire Sizes, Watch my profiles carefully: 225/40/18 and 255/35/18, these are nearest to your stock tire diameters, while acquiring max section width. 255/40 series in the rear is tall and you will lose gearing.

18x8.0 +30 with height adjustable coilover, +35 with OE style spring.
18x9.0 can go down to probably a +25, but stick to the more common +35 or +40.

Rishie

ARD T2

iTrader: (22)

What wheels are you looking at?

What are your objectives for getting wheels? Looks, performance, etc...

Roadster & RX7

Thank you. I appreciate it! I really havent narrowed down a wheel, but I am trying to get some ideas on specs, before I select a wheel, so I have an idea of what I can and cannot look at. I still would like it as performance, but I also want looks too! I went all performance on the Miata, and I am not as pleased with it's appearance (I would have went with a 16, and a wider offset, had I known). So I don't want to "screw it up" this time.

Ideally, I would like:
Weight: Under 25lbs, probably like 20 lbs.
Design: 5 spoke
Color: All black, or silver with a mirror lip, or chrome
Price: Hopefully $500 or less a wheel ($2000 or less, total for wheels)

Thanks again for your help

YearsOfDecay

I just went through this delemma... I ended up going with 17 inch wheels because of the pothole situation in Pennsylvania.... .. however..

I got shuk BS1's from Tire rack, they are six spoke.. but damn i like 'em!!!

They have an 18X7.5 +38 (21lbs) that will fit perfectly on the front with a 215/35/18 tire..

In the rear.. the have the same rims in 18X8.5 in 40, 39, 33 32 and 30 offsets.. I got them in +40 with a 245/45/17 and its BEAUTIFUL..

If you were getting 18's, though .. I'd go with a 245/40/18... thats a 9.9 section width for a kuhmo MX measued on an 8.5 inch rim, so its going to be 9.9 inch.. My tire are 9.7 section width.. with a 40mm offset on the rear, I have about 10mm to clear the suspension and the fender lip..

I'd go with the +33 or 32 with an 18 iinch wheel and a 245/40/18 tire or the rear.. it will clear the inner fender lip (barely) and you can then run a wider tire later if you get the inner lips rolled since you'll have an extra 7mm or so to the inside than what i have.


whatever wheels you end up with, remeber its the tires section with that you really have to watch out for.. Here's a pic of my wheels.. the rims are 8.5"+40mm but the tires have a 9.7 inch section width... theres about 10-12mm of room there... goint to a 9 inch rim wont make much difference, being that the tires sill stick out .5 inch from the rim on either side.. (tires swell by about .1-.2 inch in total width for each 0.5 inch of wheel diameter above the wheel they were measured on)

SO... you can see that if you are running a tire with a 10 inch section width, you want to stay with a lower offset to push the wheels away from the suspension. +32 should work great without pushing the tire past the outer fender.

Roadster & RX7

We don't have too many potholes around here, and the roads are fairly wide enough, that I can dodge most of what is bad. Man that looks great. Thanks for the ideas. a 245 sounds good, I just assumed 255, because that is most of what I read around here. 245s are cheaper too Thanks for the replies. I'll keep an eye out for a 18x8.5 w/ around 30-32 offset

YearsOfDecay

you could run 255's with a 30-32 offset.. BUT.. i would find wheels in the size and offset you want... and get your first set of tires as 245's (leaves room for error.. dontcha know!!!) And your right... there's a big jump in price from 245 to 255!!!!

ARD T2

iTrader: (22)

Keep your tire diameters near stock. 245/40/18 is Corvette diameters, we running shorter diameters.

I would suggest 17" front and 18" rear the way the FC is. I can make many suggestions and have several several FC's of my own with many many different combinations. I am recommending you the standard and what might be easy to find in wheel brands.

Rishie

sales@autornd.com

YearsOfDecay

What rishie is getting at is that the Tire "diameter" for a 245/40/18 is about 25.5 to 25.7 inches depending on tire manufacturer..

Stock TII 205/55/16's are from 24.7 to 25.2 depending on manufacturer...

SO... no matter what brand tire you get.. a 245/40/18 is going to be one inch larger, rotate less times per mile, and your speedo is going to be showing slower that you are running.... about 5%

A 235/40/18 has an average diameter right around 25 inches, so the speedo will be on.. , but, they aren't as wide either!!!!

THis is another reason i went with 17's

the easiest tire to fit on the front on an 18 inch wheel is a 215/35/18... with diameters in the 23.7 to 23.9 range.. a full inch shorter that stock and leaving a sidewall height of less than three inches.. which should be no big deal on the fronts, but thats too thin for my taste!!!!!!! (back to the potholes again)

Rishie has set up several cars that i've seen posted on other sites, so, get him to link you to the pics and pick out what you like!!!! That one dude has gonzo meatball rears on his car... i have no idea how they clear the suspension and tuck under the fenders!!

Roadster & RX7

I have some time to think. I would like to see some pictures of 17s, and 18s, I'll be searching through some posts again Thanks guys, very helpful!!