ive been reading old posts about fitment and tire sizing. but they all say either stock height or with coilovers. (i would assume adjustable?) i have koni yellow shocks and eibach springs (lowering, not sure how much lower, i bought the car as it sits)

either way, i need wider tires. only can fit 225's on my current rims. need to get to 275 or higher. (at least in the rear) im looking into 17" rims. just with all the different combo's, not sure what will work. i dont mind rolling the fender but do not want to flare them out. most people say to use 43 and higher offset. does that apply to lowered cars as well?

 

no one?

 

dont even bother looking at offset untill you know what width you want. For 275's I would hope you are going with 10" or 10.5"

 

not a pro by anymeans but i was on nitto's website. and from what i understand they recomend a wheel to be 9-11" wide to run a 275 tire. i want to run at least a 275 in the rear. i do not want to cut or"flare" my fenders. i dont mind rolling the fenders though. so whatever i can fit back there being that the car is lowered.

the car was lowered before i bought it. the eibach website says the only kit they make lowers the car 1" in the front and rear.

 

Eibach springs lowers the front quite a bit, but the rear not much. Here's a thread with some comparisons:

https://www.rx7club.com/showthread.p...ghlight=eibach

Having said that, while 275's will go on a 9" wheel; but it's less than ideal. However, it also depends on what you do with the car. Fitting a wider tire on a smaller wheel causes the sidewalls to bulge. That will decrease the sidewall stiffness and hurt your cornering capabilities. However, if you are only looking to go fast in a straight line, then it's not a problem.

 

i truely want better traction over all.; i did a ls1 swap and drove it for the first time 2 days ago. i thought it was broken cuz it was reving up but not going ne faster. then i realized it was not broken. i was just spinning the tires 1st/2nd/3rd gear. i currently have 225's on the car now and i think thats alli can fit with a 7" wide wheel. i will be doing some 1/4 racing but also live in an area with lots of back roads with twists and turns. plus once the car is all sorted out i want to try auto cross. so like i said, even if i just replace the rear wheels for now i want to put as much rubber to the ground as i can.

 

Getting more traction has as much to do with the tire type as it does the size. i.e. you can get more grip with the same size tire but a sticker compound. I would recommend looking at something in the 17x9" (+38 to +43) all around with 255's, then roll the front fenders. Grab a decent tire like:

Dunlop Direzza Sport Z1 Star Spec
Falken Azenis RT615
Sumitomo HTR Z III
Kumho XS
or the upcoming Nitto NT05

you'll have enough traction to have fun.

 

well never had too big of an issue with the 13b in it. 1st i didnt have alot but the rest was ok unless it was wet out. although then i was in south fl and it was always hot out. and now i live in pa and it was 20*f out when i drove the car. so maybe the fact that it was much colder played a big factor. is a 255 the largest tire that will functionally fit on a 9" wheel?

 

It's not the largest, but it's a perfect fit. Yes, colder weather has an effect on tires.

 

would i be able to run 9.5's in the back? and run a staggard setup in the front? that way i can get the wider wheel and the better tires as you suggested....

maybe run 8.5 up front and 9.5 in the back.

 

rimtuck.com has pics and specs of FD's with alot of different wheels. even if its not the size and offset your going with it'll give you an idea of what works

 

Sure, but keep in mind that running more rubber in the rear than in the front, increases understeer. IMO, I don't think you really have a need for anything larger than a 17x9" wheel. If you run 17x9 all around, you can rotate tires.

 

In my experience (I've run virtually everything), a 255 front, 275 rear is a nice street combo in either 17" or 18". Ideally on 9" front, 10" rear wheels.

9"/255 all around is nice as well for rotation ability, if you don't mind giving up a little at the back. Even 245/40/17 all around on 8-8.5's will work if you're wheel width challenged.

Going up to a 275/40/17 or 35/18 front to match a similar rear will give you some additional trouble. If you're not doing it on a track wheel set up, I don't think the fitment hassle is worth the rotation ability. The front FD wheel wells are TIGHT.

You'll actually fare a little better with a 285/30/18 all around instead, if you go that route. The 285/30 is shorter, and thus with the right offset (+50 all around) can be workable up front and allow rotation. Again though, I don't think a 285 up front is necessary on the street... you'd do this if you only have one set of wheels and plan to track it.

 

well i def will be going to the 1/4 track. i do my fair share of street runs and would like to get into some road course stuff. so being able to mash the gas in 2nd and be able to grip and go is important. i know first doesnt get alot of traction with tons of torque.

my car has a stock ls1, with eventually going to do heads, cam, and a 100-150 N02 shot. so being able to somewhat hook with 450-550 rwhp is what im looking foward to.

the 255f/275r sounds like a good combo. im not conserned about being able to rotate the tires so much so running staggard is not a big concern.

 

You're looking at quite a bit of power, and quite a wide range of use for one set of wheels/tires.

Without modding your fenders to much, I'd go with the 255/275 combo at the minimum. 285/30 all around will be nice on the road course, but the steamrollers up front might cost you some rolling resistance, and the super short rear sidewalls might not offer the best drag launch.

 

so you think a set of 275/40/17's will be ok in the rear. assuming i get a decent tire...the new nitto nt05 looks appealing.

and then 255/40/17 up front.

so maybe a 9" front and 9.5" rear wheel?

 

None of those tires or sizes are going to "hook up" a modded LS1 with a nitrous shot (or a rotary powered vehicle at the same power levels). If you want to do dragging, then you need drag tires to "hook up". Any other tires is going to give "some" wheel spin as they aren't designed for that purpose.

You either need to have a different set of wheels (at least rear wheels) for dragging and road courses, or you have to pick a tire that will do neither great; but both "ok".

 

i understand diff tires for diff applications. but for now i just want better traction on the street. thus my search for a wider wheel/tire combo. getting another set of back wheels/tires for dragging is not a problem. im just trying to find a wheel tire size that i can fit back there.

 

I agree with ptrhahn.

Use the 275s in the rear and look for some 8.5" or 9" wide wheels for the front and run 245 or 255. Search on some posts from Goodfellafd3s as he used that fitment on Fikse wheels. I think he might be selling a set actually...

 

Thanks Alberto

For about 6 years I ran Fikse FM5 Classics in 17x8.5,10 with 245/40 and 275/40 tires. Offset front and rear was +44. Fitment was perfect, and it looked great. I run Tanabe Sustec Pro S/S coilovers, I'm on my second set actually. I can dig up some pics, but I used to receive frequent PM's from member wanting to duplicate my setup.

I'm now running the newer iteration of the FM5 Classics, the Profil 5, in 17x9, 10 and 255/40 and 275/40 Toyo RA1 road race rubber.

http://www.fikse.com/technipol.html

The setup has maybe 200 miles on it and I am selling it, PM me if you're interested.

 

I don't know if this helps but I'm running 8.5" front (245/35R18) and 9.5" rear (285/30R18). Fitment is perfect. With Pirelli Pzero Rosso I no longer need spacers in the rear since the tires are 11.4" wide. compared to 11.2

 

just my .02. hope it helps

I am currently running a similar spring/shock set-up.
my koni's are perched front-top rear-middle.

9" 255/40/17 +38 sumitomo htr zIII front
9.5" 275/40/17 +45 " " rear

it looks and fits fine. perching could be moved from front->mid rear->bottom.. i didnt do it however because I fear rubbing up front (fear, not sure if it will).

 

17x9.5 +35
255/40/17 all around
rolled front fenders

 

Maybe I missed the offset and body modifications, if any?
I just bought 18x8.5 +45 and 18x9.5 +40 and looking for tires. I would prefer not rolling fenders but will if I have to. I'd like to run same tires as yours. Thoughts?